77 research outputs found

    Effectiveness of the displacement-based seismic performance assessment for continuous RC bridges and proposed extensions

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    Seismic performance assessment of existing bridges, especially those designed without seismic criteria, is paramount in earthquake-prone countries. To perform this task, the Displacement-Based Assessment (DBA) represents a satisfactory trade-off between simplicity and accuracy. After describing the modal analysis-based DBA procedure, a static-based alternative is proposed in this paper, considering its strengths and limitations. Moreover, an extension of the procedure is proposed to derive the force-displacement curve of the bridge (pseudo-pushover capacity curve). The effectiveness of the DBA methodology, implemented via simplified mechanical models, is discussed through parametric analyses to address its practical applications. The DBA approach, both modal and static, is herein adopted for the transverse analysis of a set of 36 reinforced concrete continuous-deck bridges up to six spans, with pier height in the range 8–20 m and two different values of the deck transverse stiffness. Additional sensitivity analyses (24 case studies) are conducted to investigate the accuracy of the two approaches considering: 1) the length of the bridge, 2) the amount of longitudinal reinforcement in the piers; 3) different pier typologies. The results are compared to numerical pushover and time-history analyses using three suites of 10 scaled, natural ground motions respectively consistent with low-, medium- and high-seismicity sites. For the majority of the case studies, the resulting performance assessments fall within one standard deviation of the results of the time-history analyses. For this reason, the displacement-based modal or static approaches can represent a valid alternative to numerical non-linear static analyses for continuous bridges with six spans or less

    RPAS-Based Framework for Simplified Seismic Risk Assessment of Italian RC-Bridges

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    Existing reinforced concrete (RC) bridges that were designed in the decades between 1950 and 1990 exhibit inadequate structural safety with reference to both traffic loads and hazard conditions. Competent authorities are planning extensive inspections to collect data about these structures and to address retrofit interventions. In this context, Remotely Piloted Aircraft Systems (RPASs) represent a prospect to facilitate in-situ inspections, reducing time, cost and risk for the operators. A practice-oriented methodology to perform RPAS-based surveys is described. After that, a workflow to perform an in-situ RPAS inspection oriented to a photogrammetric data extraction is discussed. With the aim to connect the advantages of the RPAS technologies to the seismic risk assessment of bridges, a simplified mechanic-based procedure is described, oriented to map the structural risk in road networks and support prioritization strategies. A six-span RC bridge of the Basilicata road network, representing a typical Italian bridge typology is selected to practically describe the operating steps of the RPAS inspection and of the simplified seismic risk assessment approach

    On the use of MTInSAR data and UAV photogrammetry to monitor the behavior of existing bridge portfolios

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    Bridges play a vital role in road networks, and ensuring their safety and preservation is of utmost importance to both management companies and the scientific community. On the other hand, ensuring a continuous assessment of the bridge portfolios health state requires high costs (e.g.; sensor-based monitoring), which leads to employ different techniques to identify the most critical cases and implementing risk mitigation measures. With this goal in mind, this paper presents the application of two of the most actual and attractive cost-effective techniques for purpose of existing bridge portfolios health state monitoring: (a) multitemporal interferometry via synthetic aperture radar (MTInSAR) data; (b) unmanned aerial vehicle (UAV) photogrammetry. In detail, the paper deals with the use of the two above methodologies, where MTInSAR data can be employed to perform a qualitative assessment of the spatial displacements and velocities characterizing the focused bridges, while UAV flight surveys can be used to identify the occurrence of displacement phenomena (e.g.; landslides) in the area immediately close around the observed structures. After describing pros and cons of the two approaches, an application is provided on an existing bridge, for which MTInSAR temporal series are analyzed over 1 year of observation, while UAV surveys are performed at the start and at the end of the considered period. From the combination and the comparison of the techniques, some insights are provided, opening new scenarios in the field of the structural health monitoring of existing bridges portfoli

    Effects of diazepam on hippocampal blood flow in people at clinical high risk for psychosis

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    Elevated hippocampal perfusion has been observed in people at clinical high risk for psychosis (CHR-P). Preclinical evidence suggests that hippocampal hyperactivity is central to the pathophysiology of psychosis, and that peripubertal treatment with diazepam can prevent the development of psychosis-relevant phenotypes. The present experimental medicine study examined whether diazepam can normalize hippocampal perfusion in CHR-P individuals. Using a randomized, double-blind, placebo-controlled, crossover design, 24 CHR-P individuals were assessed with magnetic resonance imaging (MRI) on two occasions, once following a single oral dose of diazepam (5 mg) and once following placebo. Regional cerebral blood flow (rCBF) was measured using 3D pseudo-continuous arterial spin labeling and sampled in native space using participant-specific hippocampus and subfield masks (CA1, subiculum, CA4/dentate gyrus). Twenty-two healthy controls (HC) were scanned using the same MRI acquisition sequence, but without administration of diazepam or placebo. Mixed-design ANCOVAs and linear mixed-effects models were used to examine the effects of group (CHR-P placebo/diazepam vs. HC) and condition (CHR-P diazepam vs. placebo) on rCBF in the hippocampus as a whole and by subfield. Under the placebo condition, CHR-P individuals (mean [±SD] age: 24.1 [±4.8] years, 15 F) showed significantly elevated rCBF compared to HC (mean [±SD] age: 26.5 [±5.1] years, 11 F) in the hippocampus (F(1,41) = 24.7, pFDR < 0.001) and across its subfields (all pFDR < 0.001). Following diazepam, rCBF in the hippocampus (and subfields, all pFDR < 0.001) was significantly reduced (t(69) = −5.1, pFDR < 0.001) and normalized to HC levels (F(1,41) = 0.4, pFDR = 0.204). In conclusion, diazepam normalized hippocampal hyperperfusion in CHR-P individuals, consistent with evidence implicating medial temporal GABAergic dysfunction in increased vulnerability for psychosis

    Effects of diazepam on hippocampal blood flow in people at clinical high risk for psychosis

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    Elevated hippocampal perfusion has been observed in people at clinical high risk for psychosis (CHR-P). Preclinical evidence suggests that hippocampal hyperactivity is central to the pathophysiology of psychosis, and that peripubertal treatment with diazepam can prevent the development of psychosis-relevant phenotypes. The present experimental medicine study examined whether diazepam can normalize hippocampal perfusion in CHR-P individuals. Using a randomized, double-blind, placebo-controlled, crossover design, 24 CHR-P individuals were assessed with magnetic resonance imaging (MRI) on two occasions, once following a single oral dose of diazepam (5 mg) and once following placebo. Regional cerebral blood flow (rCBF) was measured using 3D pseudo-continuous arterial spin labeling and sampled in native space using participant-specific hippocampus and subfield masks (CA1, subiculum, CA4/dentate gyrus). Twenty-two healthy controls (HC) were scanned using the same MRI acquisition sequence, but without administration of diazepam or placebo. Mixed-design ANCOVAs and linear mixed-effects models were used to examine the effects of group (CHR-P placebo/diazepam vs. HC) and condition (CHR-P diazepam vs. placebo) on rCBF in the hippocampus as a whole and by subfield. Under the placebo condition, CHR-P individuals (mean [±SD] age: 24.1 [±4.8] years, 15 F) showed significantly elevated rCBF compared to HC (mean [±SD] age: 26.5 [±5.1] years, 11 F) in the hippocampus (F(1,41) = 24.7, pFDR < 0.001) and across its subfields (all pFDR < 0.001). Following diazepam, rCBF in the hippocampus (and subfields, all pFDR < 0.001) was significantly reduced (t(69) = −5.1, pFDR < 0.001) and normalized to HC levels (F(1,41) = 0.4, pFDR = 0.204). In conclusion, diazepam normalized hippocampal hyperperfusion in CHR-P individuals, consistent with evidence implicating medial temporal GABAergic dysfunction in increased vulnerability for psychosis

    Profiling severe asthma: Any relevance for age? An analysis from Severe Asthma Network Italy (SANI) cohort

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    Abstract Background Aging implies changes in terms of lung function, immune system, and respiratory and extra-respiratory comorbidities. Few studies have specifically addressed the relevance of age on severe asthma burden and control. We aimed to evaluate whether age acts as an independent determinant of asthma severity, in terms of clinical, functional, and inflammatory profile, and to explore potential cofactors that contribute to a more difficult disease control in different age groups. Methods Patients from Severe Asthma Network Italy (SANI) registry were retrospectively divided in subgroups according to their age. Cutoffs for age were established according to quartiles in order to obtain a comparable number of patients for each group, and then rounded for the sake of simplicity. Results Overall, 1805 severe asthma patients were analyzed. Lung function represented the most important age-related variable. On the opposite the level of asthma control was not differently distributed among age ranges. In young people the presence of atopy-related comorbidities (allergic rhinitis, atopic dermatitis) predominated, whilst systemic-metabolic and degenerative comorbidities such as diabetes, cardiovascular diseases, anxious-depressive syndrome, and osteoporosis prevailed in elderly. Bronchiectasis and sleep disturbances were significantly associated with age. Conclusions Despite that it cannot be considered a treatable trait, our study suggests that age should be evaluated within a personalized approach to severe asthma patients, in order to provide a better clinical profiling and a more tailored treatment strategy

    A practical guide to recognize allergic and immunologic skin diseases: diagnosis at first sight

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    Allergic and immunologic skin diseases are becoming increasingly common and this requires clinicians to be able to recognize and diagnose them. A joint meeting (GET TOGETHER 2022) of the Italian Society of Allergy, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) aimed to review the current knowledge on the differential diagnosis of contact dermatitis, atopic dermatitis, hereditary angioedema, urticaria, and cutaneous mastocytosis. The most important aspects to take into consideration when faced with a new cutaneous manifestation are the clinical features of the lesions, their distribution, age of onset, and comorbidities/aggravating factors. The document does not aim to provide an exhaustive and comprehensive description of all allergic and immunologic skin diseases. Instead, it should be a reference tool for the clinician who is faced with the onset of a new skin manifestation and its differential diagnosis

    Association between maternal dupilumab exposure and pregnancy outcomes in patients with moderate‐to‐severe atopic dermatitis: A nationwide retrospective cohort study

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    Background There is limited epidemiological evidence on outcomes associated with dupilumab exposure during pregnancy; monitoring pregnancy outcomes in large populations is required. Objective To investigate the potential association between exposure to dupilumab in pregnant women with atopic dermatitis and any adverse pregnancy, neonatal, congenital and post-partum outcomes. Methods We performed a multicentre retrospective cohort study across 19 Italian tertiary referral hospital. Childbearing women were eligible if aged 18–49 years and carried out the pregnancy between 1 October 2018 and 1 September 2022. Results We retrospectively screened records of 5062 patients receiving dupilumab regardless of age and gender, identifying 951 female atopic dermatitis patients of childbearing age, 29 of whom had been exposed to the drug during pregnancy (3%). The median duration of dupilumab treatment prior to conception was 22.5 weeks (range: 3–118). The median time of exposure to the drug during pregnancy was 6 weeks (range: 2–24). All the documented pregnancies were unplanned, and the drug was discontinued in all cases once pregnancy status was reported. The comparison of the study cohort and the control group found no significant drug-associated risk for adverse pregnancy, congenital, neonatal or post-partum outcomes. The absence of a statistically significant effect of exposure on the event was confirmed by bivariate analysis and multivariate analysis adjusted for other confounding factors. Conclusions This cohort of pregnant patients exposed to dupilumab adds to the existing evidence concerning the safety of biologic agents in pregnancy. No safety issues were identified regarding the primary outcome assessed. In clinical practice, these data provide reassurance in case of dupilumab exposure during the first trimester. However, the continuous use of dupilumab throughout pregnancy warrants further research

    Acquired angioedema

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    Acquired angioedema (AAE) is characterized by acquired deficiency of C1 inhibitor (C1-INH), hyperactivation of the classical pathway of human complement and angioedema symptoms mediated by bradykinin released by inappropriate activation of the contact-kinin system. Angioedema recurs at unpredictable intervals, lasts from two to five days and presents with edema of the skin (face, limbs, genitals), severe abdominal pain with edema of the gastrointestinal mucosa, life-threateing edema of the upper respiratory tract and edema of the oral mucosa and of the tongue. AAE recurs in association with various conditions and particularly with different forms of lymphoproliferative disorders. Neutralizing autoantibodies to C1-INH are present in the majority of patients. The therapeutic approach to a patient with AAE should first be aimed to avoid fatalities due to angioedema and then to avoid the disability caused be angioedema recurrences. Acute attacks can be treated with plasma-derived C1-INH, but some patients become non-responsive and in these patients the kallikrein inhibitor ecallantide and the bradykinin receptor antagonist icatibant can be effective. Angioedema prophylaxis is performed using antifibrinolytic agents and attenuated androgens with antifibrinolytic agents providing somewhat better results. Treatment of the associated disease can resolve AAE in some patients
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