Fatigue Characterization Of A High-Performance Steel Fiber Reinforced Concrete (HPFRC) By Means Of Compressive, Flexural, And Z-Type Shear Tests

The use of fiber-reinforced concretes (FRC) for infrastructures subject to fatigue loading can result into an extension of their service life by providing enhanced ductility and toughness. The cyclic actions might affect the fiber-matrix interface and it is necessary to assess to what extent the degradation hinders the mechanical properties of these materials. Currently, the only predictive models for fatigue life and performance reduction are empirical. Therefore, a mechanical characterization is required for any mix whose composition and performance might differ from the one pertinent to the database the models are based on. This work presents the effect of high-cycle fatigue on a high-performance fiber-reinforced concrete (HPFRC) with hybrid fiber reinforcement. The material was characterized under compressive, flexural, and shear loads at various stress ranges. The Palmgren-Miner rule was applied to predict the fatigue life of the material. The results showed the effects of fatigue loading on the strength of the material. The compressive strength remained constant in most cases, while the flexural and the shear performances were slightly reduced by the cycling process. The predictive capacity of the P-M model proved to be reliable only in limited scenarios

Experimental investigation of the flexural fatigue behaviour of a High-Performance Fibre Reinforced Concrete (HPFRC)

Several structures and infrastructures, including bridge decks, airport pavements, industrial floors, offshore platforms, and energy harvesting systems, experience, during their service life, significant cyclic loading due to traffic, machine vibrations, wind, waves, and thermal variations. In recent decades, High-Performance Fibre Reinforced Concrete (HPFRC) has gained traction as a suitable material for these applications, owing not only to its high strength but also to the enhanced properties provided by the fibres, including increased toughness and durability. Characterising the fatigue behaviour of HPFRC, especially under flexural stress (which is crucial for many of the aforesaid structures), is therefore of great relevance. To this end, this work presents a thorough investigation of the fatigue behaviour in flexure of a tailored HPFRC mix with hybrid fibres, through an extensive experimental campaign encompassing tests up to cycles and four different upper load levels. Subsequent tests focus also on the role played by pre-cracking of the specimens and by the loading frequency. The evolution of damage has thus been studied relying on the measured residual strengths after cycling as well as on the evolution of the Crack Mouth Opening Displacement (CMOD) and its derivative. Moreover, considering the requirements of designers, custom – curves for this material are presented and compared with existing models in current design codes

Green Nail Syndrome Treated with Ozenoxacin: Two Case Reports

Green nail syndrome (GNS) is a persistent greenish pigmentation of the nail plate, originally described in 1944 by Goldman and Fox, due to Pseudomonas aeruginosa infection. Recently, pulmonary co-infection of P. aeruginosa and Achromobacter spp. has been described in patients with cystic fibrosis. Achromobacter xylosoxidans is a multidrug-resistant (MDR) pathogen involved in lung and soft tissue skin infections. Both Achromobacter xylosoxidans and P. aeruginosa are mainly found in humid environments or in water. There are no recognized co-infections due to P. aeruginosa and A. xylosoxidans in the skin and appendages. We describe two cases of GNS, the first due to P. aeruginosa associated with Achromobacter xylosoxidans; the other due to MDR P. aeruginosa, both successfully treated with topical ozenoxacin 1% cream daily for 12 weeks. The clinical management of GNS can be confusing, especially when the bacterial culture result is inconsistent or when non-Pseudomonas bacteria are isolated. In our case, due to the co-infection of P. aeruginosa and Achromobacter spp., local treatment with ozenoxacin - the first nonfluorinated quinolone - could be a safe and effective treatment in case of MDR nail infections. Further studies are required to evaluate clinical isolation from nail infections and the co-presence of P. aeruginosa and A. xylosoxidans

Preparedness and response to the international poliovirus and diphtheria reintroduction alert: public health interventions and strategy review in the Veneto Region, Italy

BackgroundDiphtheria and polio continue to pose significant public health challenges globally, making sustained high vaccination coverage crucial. This study examines the strategies adopted in the Veneto Region to enhance vaccination rates for diphtheria and polio among priority target groups and improve poliovirus surveillance, following the WHO alert about the potential reintroduction and circulation of the two pathogens.AimThe main objective of this study is to assess the effectiveness of supplementary vaccination strategies implemented in the Veneto Region in response to international poliomyelitis and diphtheria alerts. Additionally, it aims to identify municipalities at higher risk of poliovirus AFP based on georeferenced vaccination coverage, enhancing environmental surveillance strategies. Ultimately, the study evaluates regional preparedness and response efforts, offering insights to mitigate the risk of reintroducing these diseases and providing a framework adaptable to similar contexts.MethodsThe Regional Directorate of Prevention, Food Safety, Veterinary Public Health analysed regional vaccination coverage and provided Local Health Authorities (LHAs) with a georeferenced representation of vaccination coverage across municipalities. Directives on targeted vaccination strategies were issued to address identified gaps and improve readiness. Ten months later, the Regional Directorate assessed the approaches implemented by LHAs to improve vaccine uptake and evaluated the resulting vaccination coverage. Based on this georeferenced analysis, the effectiveness of current environmental poliovirus surveillance was reviewed, and recommendations for optimising surveillance efforts were proposed.ResultsFollowing the implementation of the vaccination strategies recommended by the Regional Directorate, vaccination rates improved across all LHAs, especially among children aged 0–2 years who had not received any vaccine doses. The georeferenced analysis of vaccination coverage revealed critical gaps in environmental poliovirus surveillance and underscored the need for targeted interventions to reach unvaccinated populations.ConclusionThis study demonstrates that centralised governance, combined with georeferenced vaccination data, environmental poliovirus surveillance, and clinical AFP surveillance, enhances the ability to identify coverage gaps and respond to infectious disease threats. While improvements in vaccination rates were achieved, the findings underscore the need for targeted, community-specific interventions and continuous monitoring to address disparities. Strengthening data integration and adopting innovative surveillance methods will be crucial to sustaining high vaccination coverage and ensuring public health security

Effects of Fusion between Tactile and Proprioceptive Inputs on Tactile Perception

Tactile perception is typically considered the result of cortical interpretation of afferent signals from a network of mechanical sensors underneath the skin. Yet, tactile illusion studies suggest that tactile perception can be elicited without afferent signals from mechanoceptors. Therefore, the extent that tactile perception arises from isomorphic mapping of tactile afferents onto the somatosensory cortex remains controversial. We tested whether isomorphic mapping of tactile afferent fibers onto the cortex leads directly to tactile perception by examining whether it is independent from proprioceptive input by evaluating the impact of different hand postures on the perception of a tactile illusion across fingertips. Using the Cutaneous Rabbit Effect, a well studied illusion evoking the perception that a stimulus occurs at a location where none has been delivered, we found that hand posture has a significant effect on the perception of the illusion across the fingertips. This finding emphasizes that tactile perception arises from integration of perceived mechanical and proprioceptive input and not purely from tactile interaction with the external environment

The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool

Evaluation of Trends in Influenza A and B Viruses in Wastewater and Human Surveillance Data: Insights from the 2022–2023 Season in Italy

Wastewater-based epidemiology (WBE) is a recognized, dynamic approach to monitoring the transmission of pathogens in communities through urban wastewater. This study aimed to detect and quantify influenza A and B viruses in Italian wastewater during the 2022-2023 season (October 2022 to April 2023). A total of 298 wastewater samples were collected from 67 wastewater treatment plants (WTPs) across the country. These samples were analyzed for influenza A and B viruses (IAV, IBV) using primers originally developed by the Centers for Disease Control and Prevention (CDC) for real-time PCR and adapted for digital PCR. The overall detection rates of IAV and IBV across the entire study period were 19.1% and 16.8%, respectively. The prevalence of IAV in wastewater showed a gradual increase from October to December 2022, peaking at 61% in December. In contrast, IBV peaked at 36% in February 2023. This temporal discrepancy in peak concentrations suggests different seasonal patterns for the two influenza types. These trends mirrored human surveillance data, which showed influenza A cases peaking at 46% in late December and declining to around 2% by April 2023, and influenza B cases starting to increase significantly in January 2023 and peaking at about 14% in March. IAV concentrations ranged from 9.80 x 102 to 1.94 x 105 g.c./L, while IBV concentrations ranged from 1.07 x 103 to 1.43 x 104 g.c./L. Overall, the environmental data were consistent with the human surveillance trends observed during the study period in the country. These results demonstrate the value of WBE in tracking epidemiological patterns and highlight its potential as a complementary tool to infectious diseases surveillance systems

The rapid spread of SARS-COV-2 Omicron variant in Italy reflected early through wastewater surveillance

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5–11 December, to 17.5% (25/143 samples) in the week 12–18, to 65.9% (89/135 samples) in the week 19–25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased fromone in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Development of spoiled gradient echo sequences for MRI relaxometry

Abstract: Magnetic Resonance Imaging (MRI) is a noninvasive, non-ionizing technique that allows both anatomical and functional imaging with tunable contrast among soft tissues. Although MRI is a significant source of images with differences in signal intensity defined by differences in specific physical parameters; for the vast majority of applications, images are being interpreted qualitatively in the clinical practice. Quantitative MRI (qMRI) is an umbrella term that encompasses the quantification of the parameters specifying signal intensity. Among others, the relaxation parameters T1 and T2 remain a main research topic in qMRI as the relaxation times have been used as biomarkers for tissue characterization and differentiation, and can be of great radiological support. Several methods for fast relaxometry have been proposed, however there is yet no general consensus on fast relaxometry mapping techniques that allow good image quality within clinically acceptable time and with good reproducibility and repeatability, also due to the dependency of these parameters on confounding factors, including the RF excitation field B1. This PhD thesis starts with a short history of the concept of Nuclear Magnetic Resonance and the development of the Magnetic Resonance Imaging technique, after which the main qMRI techniques dedicated to relaxometry mapping are reported. The contributions of this thesis focus on improvements for T1 mapping. As for most T1 mapping methodologies, an accurate estimation of the flip angle is necessary, we start with the development of a preparation module for a faster steady state approach and sampling of Actual Flip angle Imaging (AFI), a B1 mapping technique. Next, we extended B1-mapping with T1-mapping using Variable flip angle with AFI (VAFI) approach in which we introduce a slice profile correction as well as a 2D multislice stacking approach for AFI, which respectively provide a more accurate and faster way to acquire parametric maps. Then, a newly developed sequence, Relaxation Alternate Mapping of Spoiled Echo Signals (RAMSES) for multiparametric mapping including T1, B1, and T2* is introduced. This was achieved by adding a bipolar multi-gradient-echo readout to AFI, with no additional scanning time required. Lastly, another newly developed sequence, Echo Planar Imaging Fast Actual Nutation Imaging (EPIFANI) for ultrafast B1-corrected T1 mapping is introduced. This sequence is an echo planar imaging (EPI) version of AFI, which can be used to provide high time efficiency to a multiparametric acquisition, and represents one of the very few attempts to acquire multiparametric maps with EPI