484 research outputs found

    Diagonal compression testing of masonry panels with irregular texture strengthened with inorganic composites

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    AbstractInorganic composites for enhancing the in-plane shear capacity of masonry walls with irregular texture were investigated on twenty-one panels under diagonal compression tests. Three specimens were used as control and twelve specimens were strengthened with two Fibre Reinforced Mortars (FRM-A and FRM-B), characterized by a different content of fibres embedded in the lime-based matrix. The remaining six specimens were strengthened with Fabric Reinforced Cementitious Mortars (FRCM), consisting in a GFRP grid embedded in a fibre reinforced matrix (the same used for FRM-A). The influence of single-side and double-side strengthening configurations on the capacity of strengthened panels was also investigated, to point out the reduction in strengthening effectiveness in case of single-sided applications. The results showed that all the inorganic composites adopted for the strengthening techniques provided a substantial increase of shear capacity. The grid in FRCM strengthened panels played an important role in both strength and deformation capacity at peak. The different fibres content (lower than 50% in weight) in FRM systems slightly affected the overall performance of panels. Finally, analytical predictions of experimental results were reported and discussed and a preliminary analytical model for estimating the FRM shear contribution was proposed, obtaining a good agreement with test results

    Effect of buoyancy loads on the tsunami fragility of existing reinforced concrete frames including consideration of blow-out slabs

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    Currently available performance-based methodologies for assessing the fragility of structures subjected to tsunami neglect the effects of tsunami-induced vertical loads due to internal buoyancy. This paper adopts a generalized methodology for the performance assessment of structures that integrates the effects of buoyancy loads on interior slabs during a tsunami inundation. The methodology is applied in the fragility assessment of three case-study frames (low, mid and high-rise), representative of existing masonry-infilled reinforced concrete (RC) buildings typical of Mediterranean region. The paper shows the effect of modelling buoyancy loads on damage evolution and fragility curves associated with different structural damage mechanisms for existing RC frames with breakaway infill walls including consideration of blow-out slabs. The outcomes attest that buoyancy loads affect the damage assessment of buildings during a tsunami, especially in the case of mid and high-rise structures with blow-out slabs. The rate of occurrence of slabs uplift failure increases with the number of stories of the building, indicating the need to account for such damage mechanism when assessing the performance of structures. It is also found that buoyancy loads slightly affect the fragility curves associated to other structural damage mechanisms for existing RC buildings commonly monitored for fragility assessment

    Simplified assessment of seismic performance for RC building classes towards preliminary applications of SISMABONUS incentive at the community scale

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    This paper applies a simplified approach for the attribution of seismic risk classes SRC to infilled reinforced concrete RC archetype buildings representative of existing gravity load designed GLD building typologies in Italy and investigates on the effect of possible local retrofit interventions to reduce SRC. The evaluation is based on simplified modeling of lateral seismic behavior and on the estimate of the peak ground acceleration PGA corresponding to attainment of building capacity at increasing damage limit states. The SRC is attributed as the minimum between two classes, depending on safety level (percentage of new building standard %NBS) and on expected annual loss EAL. It is shown that, due to brittle failures induced by local infill-frame interaction and consequent low seismic capacity at life safety limit state, the lower (worst) SRC is generally attained for the considered building typologies, independently from the seismic hazard at the site. The application of local retrofit interventions allows ameliorating the SRC and it is found that the most probable SRC for retrofitted building typology depends on the seismic hazard at the sitelower SRC are obtained for zones of higher hazard. Application to RC building typologies in the town of Pompei, near Naples, and cost benefit analysis CBA is performed to investigate on the convenience of alternative retrofit strategies towards risk reduction at the community level

    Experimental analysis of lime putty and pozzolan-based mortar for interventions in archaeological sites

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    The study aims at defining and characterizing a specific restoration mortar for archaeological masonry structures made with traditional materials and to assess the suitability of the mixture compared to other mortars; such a goal is crucial to develop and define interventions in the archaeological sites. The mixture was defined to ensure compatibility with ancient materials and following frequently adopted recommendations at the site, specifically by using: (1) raw materials as similar as possible to the ancient ones; (2) traditional mix design. Therefore, the mixture was made with commercial lime putty CL 90-S type and natural Phlegrean pozzolan, i.e. volcanoclastic material collected from the volcanic area located in the West of Naples in Italy. The precious and limitedly available natural pozzolan used in the experiments resulted in an exclusive mortar which is very similar to the archaeological ones. The mortar has a binder to aggregate ratio 1:3 by volume, according to traditional techniques typically encountered in the ancient Roman city of Pompeii and Vesuvius surrounding area. The evolution of the flexural and compressive strength, elastic modulus, bulk density, open porosity and ultrasonic pulse velocity has been monitored for up to 200 days, based on standard procedures. Moreover, the hardening process was monitored with Differential Thermal Analysis up to 90 days, through the evaluation of phase transitions associated with dehydroxylation and decarboxylation, considering different depths from the external surface of the mortar. The achieved mechanical properties were compatible with those of lime-based mixtures for repair interventions of ancient masonry structures. Moreover, the mortar was found to be well-suited to mitigate cracking, showing a low ratio between its stiffness and load capacity compared to other typologies of mortars used for masonry restoration. Ultrasonic pulse velocity test proved to be a reasonable complementary method to monitor the evolution of the hardened properties of the mortar. Carbonation was found to be still progressing at 90 days. The data presented provide useful and reliable information to approach the complex process of restoration in archeological sites.Open access funding provided by Universita degli Studi di Napoli Federico II within the CRUI-CARE Agreement. This study was supported by the PhD research program in Industrial Product and Process Engineering, at the University of Naples Federico II attributed to the first author. Grants were also provided by the Portuguese Foundation for Science and Technology FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020 and by national funds through FCT-Foundation for Science and Technology, under grant agreement (SFRH/BD/137358/2018) attributed to the second author

    The new HFA/ICOS risk assessment tool to identify patients with chronic myeloid leukaemia at high risk of cardiotoxicity

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    AimsTyrosine kinase inhibitors (TKIs) used to treat chronic myeloid leukaemia (CML) can cause cardiovascular adverseevents. So far, the Systematic Coronary Risk Evaluation (SCORE) charts of the European Society of Cardiology (ESC) have beenused to identify cancer patients at increased cardiovascular risk. The primary aim of our study was to evaluate the usefulnessof the new cardiovascular risk assessment model proposed by the Cardio-Oncology Study Group of the Heart Failure Associ-ation (HFA) of the ESC in collaboration with the International Cardio-Oncology Society (ICOS) to stratify the cardiovascular riskin CML patients, compared with SCORE risk charts. The secondary aim was to establish the incidence of adverse arterial events(AEs) in patients with CML treated with TKIs and the influence of preventive treatment with aspirin.Methods and resultsA retrospective single-centre observational study was carried out on 58 patients (32 men and 26women; mean age ± SD: 59 ± 15 years) with CML treated with TKIs for a median period of 43 ± 31 months. Cardiological eval-uation was performed and cardiovascular risk was estimated with SCORE risk charts and with the new risk assessment toolproposed by HFA/ICOS. AEs were recorded. According to SCORE charts and the new HFA/ICOS risk stratification tool, respec-tively, 46% (Group A1) and 60% (Group A2) of patients were at high–very high risk, and 54% (Group B1) and 40% (Group B2) atlow–moderate risk. AEs were significantly more frequent in Group A1 than Group B1 (Pvalue<0.01) when considered overall;they were significantly more frequent in Group A2 than Group B2 either overall or considered individually. HFA/ICOS risk strat-ification tool was significantly more sensitive than SCORE (P<0.01) in identifying patients at higher risk of cardiovascular tox-icity. In addition, we did notfind AEs in patients pretreated with aspirin.ConclusionsThe new HFA/ICOS risk stratification model allows a more tailored cardiovascular risk stratification in patientswith CML and it is more sensitive than SCORE chart

    PARP inhibition: a promising therapeutic target in ovarian cancer

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    Ovarian cancer is burdened by the highest mortality rate among gynecological cancers. Gold standard is represented by the association of platinum-taxane -based chemotherapy and radical surgery. Despite several adjustments occurred in cytotoxic drug in last decades, most patients continue to relapse, and no significant enhancement has been reached in the overall survival. The development of drug resistance and the recurrence of disease have prompted the investigations of other targets that can be used in the treatment of ovarian cancers. Among such targets, polyadenosine diphosphate-ribose polymerase (PARP) represents a novel way to target specific patways involved in tumor growth. PARP accelerates the reaction of the polyADP-ribosylation of proteins implicated in DNA repair. PARP inhibitors have shown activity in cancers with BRCA mutations, with other deficient DNA repair genes or signaling pathways that modulate DNA repair, or in association with DNA damaging agents not involved in DNA repair dysfunction. A number of inhibitors for PARP has been developed, and such drugs are under investigation in clinical trials to identify their impact in the treatment of ovarian cancers. This review aims to summarize the recent researches and clinical progress on PARP inhibitors as novel target agents in ovarian cancer

    Hemodynamic Surveillance of Ventricular Pacing Effectiveness with the Transvalvular Impedance Sensor

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    The Transvalvular Impedance (TVI) is derived between atrial and ventricular pacing electrodes. A sharp TVI increase in systole is an ejection marker, allowing the hemodynamic surveillance of ventricular stimulation effectiveness in pacemaker patients. At routine follow-up checks, the ventricular threshold test was managed by the stimulator with the supervision of a physician, who monitored the surface ECG. When the energy scan resulted in capture loss, the TVI system must detect the failure and increase the output voltage. A TVI signal suitable to this purpose was present in 85% of the tested patients. A total of 230 capture failures, induced in 115 patients in both supine and sitting upright positions, were all promptly recognized by real-time TVI analysis (100% sensitivity). The procedure was never interrupted by the physician, as the automatic energy regulation ensured full patient’s safety. The pulse energy was then set at 4 times the threshold to test the alarm specificity during daily activity (sitting, standing up, and walking). The median prevalence of false alarms was 0.336%. The study shows that TVI-based ejection assessment is a valuable approach to the verification of pacing reliability and the autoregulation of ventricular stimulation energy

    Plasma cholesterol and lipoprotein levels in relation to tumor aggressiveness and survival in HCC patients

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    open13Hepatocellular carcinoma is associated with several chronic liver diseases, especially chronic hepatitis B virus, hepatitis C virus, and alcoholism. It is increasingly appreciated that obesity/metabolic syndrome is also associated with chronic liver disease and subsequent hepatocellular carcinoma.openCarr, Brian I; Giannelli, Gianluigi; Guerra, Vito; Giannini, Edoardo G; Farinati, Fabio; Rapaccini, Gian Ludovico; Marco, Maria Di; Zoli, Marco; Caturelli, Eugenio; Masotto, Alberto; Virdone, Roberto; Sacco, Rodolfo; Trevisani, FrancoCarr, Brian I; Giannelli, Gianluigi; Guerra, Vito; Giannini, Edoardo G; Farinati, Fabio; Rapaccini, Gian Ludovico; Marco, Maria Di; Zoli, Marco; Caturelli, Eugenio; Masotto, Alberto; Virdone, Roberto; Sacco, Rodolfo; Trevisani, Franc

    Adjuvant HPV Vaccination to Prevent Recurrent Cervical Dysplasia after Surgical Treatment:A Meta-Analysis

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    Objective: The aim of this meta-analysis was to discuss evidence supporting the efficacy of adjuvant human papillomavirus (HPV) vaccination in reducing the risk of recurrent cervical intraepithelial neoplasia (CIN) 2 or greater after surgical treatment. Methods: A systematic literature search was performed for studies reporting the impact of HPV vaccination on reducing the risk of recurrence of CIN 2+ after surgical excision. Results were reported as mean differences or pooled odds ratios (OR) with 95% confidence intervals (95% CI). Results: Eleven studies met the inclusion criteria and were selected for analysis. In total, 21,310 patients were included: 4039 (19%) received peri-operational adjuvant HPV vaccination while 17,271 (81%) received surgery alone. The recurrence of CIN 2+ after treatment was significantly lower in the vaccinated compared with the unvaccinated group (OR 0.35; 95% CI 0.21–0.56; p < 0.0001). The recurrence of CIN 1+ after treatment was significantly lower in the vaccinated compared with the unvaccinated group (OR 0.51; 95% CI 0.31–0.83; p = 0.006). A non-significant trend of reduction rate of HPV persistence was observed in the vaccinated compared with the unvaccinated cohorts (OR was 0.84; 95% CI 0.61–1.15; p = 0.28). Conclusions: HPV vaccination, in adjuvant setting, is associated with a reduced risk of recurrent CIN 1+ and CIN 2+ after surgical treatment
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