11 research outputs found

    Seismic amplification effects and soil, to, structure interaction study nearby a fault zone: the Tremestieri fault and Madre Teresa di Calcutta School (Catania)

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    Results of passive seismic surveys, in terms of both amplification and polarization effects in a section of the Tremestieri Etneo Fault (Sicily Eastern center - Catania) are discussed. For the purpose, velocimetric and accelerometric records of seismic ambient noise were analyzed. The polarization analysis of particle motion was performed and azimuthally dependent resonant frequencies were estimated. Ambient noise data were also used to assess the dynamic properties of a reinforced concrete building, located on the fault zone. The fundamental modes have been estimated through ambient noise recordings acquired by three-directional accelerometers, installed at the highest accessible floor and outside the building. The study revealed a clear oriented seismic amplification in the fault zone. This effect was observed in intensely jointed rock masses, located inside the fault area, as the result of specific geometries and significant directional impedance contrasts characterizing the area under study. The analyses show that the direction of the largest resonance motions has transversal relationship with the dominant fracture orientation. The directional amplification is inferred to be produced by stiffness anisotropy of the fault damage zone, with larger seismic motions high angle to the fractures. The results obtained are in complete agreement with those obtained by a previous study which analyzed the fault section located to the north-west.Finally, comparing the dynamic properties of the school building and the vibrational characteristics of the soil in the direction of maximum amplification, no clear resonant effect in the soil-structure interaction has been observed.This paper has been funded by the following research projects: “Attività di sviluppo sperimentale finalizzata alla riduzione del rischio sismico nella Sicilia Orientale” inside the PO-FESR 2007-2013 Sicilia; MED-SUV funded from the European Union Seventh Framework Programme (FP7) under Grant agreement n°308665. This work is sponsored by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n° 798480

    Structural health monitoring and earthquake early warning: preliminary studies for application in eastern Sicily

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    In this work, the reduction of seismic hazard in eastern Sicily is addressed by both studying the fundamental resonant frequency of strategic buildings through low cost geophysical investigation techniques, and exploring a practical approach to earthquake early warning EEW) system. The fundamental period and the corresponding amplification of some selected strategic buildings has been estimated using ambient vibration and earthquake data. We analyzed the basic dynamic parameters of buildings chosen as target, by using continuous vibration measurements at different floors. The dynamic behavior of structures was evaluated considering both small strains induced by ambient vibrations and larger excitation levels due to the earthquakes occurrence. A practical approach to earthquake early warning in the investigated area was dealt with by using empirical relationships between parameters measured on the initial portion of seismic recordings and related to the earthquake magnitude and peak ground motion. In particular, we performed the first preliminary tests by using empirical relationships calibrated for the considered area and taking into account the geometry of the existing permanent seismic network deployed in the eastern Sicily. The estimated relationships have been used to provide onsite warning around a given seismic station and evaluate the potential damaging effects. The joint of EEW system and geophysical investigation shown in this work may be deemed a useful guide for the future implementation of the in real time seismic monitoring in the region.This work has been supported by the following project: “Attività di sviluppo sperimentale finalizzata alla riduzione del rischio sismico nella Sicilia Orientale” inside the PO-FESR 2007-2013 Sicilia; MED-SUV funded from the European Union Seventh Framework Programme (FP7) under Grant agreement n°308665. This work is sponsored by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n° 798480. We are thankful to Salvatore Rapisarda and Danilo Contrafatto to support us in the field work

    The Borehole Experiment: Investigation of Cortical Structures Through 3D Array Techniques

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    Over the last few years it is growing the need to monitor the volcanic activity with modern technology in order to mitigate volcanic hazard through the detection of any possible precursor phenomena. The use of high performance seismic stations, such as borehole instruments, may increase the signal to noise ratio (SNR), improving the capability to detect very small signals. Over the past 40 years much attention has been given to the use of seismic arrays to measure the slowness vector of coherent signals. The main advantage of seismic arrays consists in their ability to detect weak or emergent signals, and to allow for an effective noise reduction through multichannel waveform stacking. A reliable prediction of the ray-path back-propagated from the recording site to the source is strongly limited by the poor knowledge of the local shallow velocity structure. Usually in volcanic environments the propagation of seismic signals through the shallow layers is strongly affected by lateral heterogeneity, attenuation, scattering, and interaction with the free surface. Driven by these motivations, on May 2014, in collaboration with the colleagues of Osservatorio Vesuviano (INGV), we deployed a 3D seismic array in the area where the borehole seismic station called Pozzo Pitarrone is installed at a depth of about 130 meters. This will improve our knowledge about: • the structure of the top layer and its relationship with geology; • analysis of the signal to noise ratio (SNR) of volcanic signals as a function of frequency; • study of seismic ray-path deformation caused by the interaction of the seismic waves with the free surface; • evaluation of the attenuation of the seismic signals correlated with the volcanic activity. The results of these analyses will improve the general knowledge of wave propagation in the shallow layers and will give a new contribution to the seismic monitoring of Etna volcano.PublishedNicolosi (Catania), Italy1T. Struttura della Terr

    Colorectal neoplastic emergencies in immunocompromised patients: preliminary result from the Web-based International Register of Emergency Surgery and Trauma (WIRES-T trial)

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    Association of advanced age, neoplastic disease and immunocompromission (IC) may lead to surgical emergencies. Few data exist about this topic. Present study reports the preliminary data from the WIRES-T trial about patients managed for colorectal neoplastic emergencies in immunocompromised patients. The required data were taken from a prospective observational international register. The study was approved by the Ethical Committee with approval n. 17575; ClinicalTrials.gov Identifier: NCT03643718. 839 patients were collected; 753 (80.7%) with mild-moderate IC and 86 (10.3%) with severe. Median age was 71.9 years and 73 years, respectively, in the two groups. The causes of mild-moderate IC were reported such malignancy (753-100%), diabetes (103-13.7%), malnutrition (26-3.5%) and uremia (1-0.1%), while severe IC causes were steroids treatment (14-16.3%); neutropenia (7-8.1%), malignancy on chemotherapy (71-82.6%). Preoperative risk classification were reported as follow: mild-moderate: ASA 1-14 (1.9%); ASA 2-202 (26.8%); ASA 3-341 (45.3%); ASA 4-84 (11.2%); ASA 5-7 (0.9%); severe group: ASA 1-1 patient (1.2%); ASA 2-16 patients (18.6%); ASA 3-41 patients (47.7%); ASA 4-19 patients (22.1%); ASA 5-3 patients (3.5%); lastly, ASA score was unavailable for 105 cases (13.9%) in mild-moderate group and in 6 cases (6.9%) in severe group. All the patients enrolled underwent urgent/emergency surgery Damage control approach with open abdomen was adopted in 18 patients. Mortality was 5.1% and 12.8%, respectively, in mild-moderate and severe groups. Long-term survival data: in mild-moderate disease-free survival (median, IQR) is 28 (10-91) and in severe IC, it is 21 (10-94). Overall survival (median, IQR) is 44 (18-99) and 26 (20-90) in mild-moderate and severe, respectively; the same is for post-progression survival (median, IQR) 29 (16-81) and 28, respectively. Univariate and multivariate analyses showed as the only factor influencing mortality in mild-moderate and severe IC is the ASA score. Colorectal neoplastic emergencies in immunocompromised patients are more frequent in elderly. Sigmoid and right colon are the most involved. Emergency surgery is at higher risk of complication and mortality; however, management in dedicated emergency surgery units is necessary to reduce disease burden and to optimize results by combining oncological and acute care principles. This approach may improve outcomes to obtain clinical advantages for patients like those observed in elective scenario. Lastly, damage control approach seems feasible and safe in selected patients

    How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

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    COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

    Attività sperimentali per l’implementazione del monitoraggio sismico di edifici pubblici nella Regione Marche

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    This paper describes a pilot project for the seismic monitoring of public buildings proposed by the Functional Centre of the Security Integrated Policies and Civil Protection Department - Marche Region (DPISPC) and the Ancona branch of National Institute of Geophysics and Volcanology (INGV). The aim of the pilot project is to associate to vulnerability profile more information about vibrational characteristics of the building and subsoil, in addition to the seismic instrumental history that describe the seismic shaking at the base of the structure. To start the pilot project with the available resources, 11 sites in the Regione Marche were identified where there are already permanent accelerometers at the base of public buildings and temporary measurements of ambient seismic noise were carried out, both inside and outside the structures. Frequencies and directions of the main spectral peaks of vibration of buildings were estimated, using spectral analysis techniques. The directional analysis was useful for interpreting the irregular morphology of some spectral peaks resulting from the standard analysis obtained with the composition of the horizontal components of motion. The collected information, combined with the geological and morphological classification of the sites, provide knowledge about seismic response of structures. Moreover, this approach will be compared to other case studies in which the seismic monitoring of individual structures is carried out with large instrumental and computational resources that allow precise and detailed results but difficult to largely apply on the territory.Published1SR. TERREMOTI - Servizi e ricerca per la SocietĂ N/A or not JC

    Microseismic assessment and fault characterization at the Sulcis (South-Western Sardinia) field laboratory

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    The general acceptance of the CO 2 geological storage by stakeholders passes through the assessment and mi- tigation of risks, potentially induced or increased by the disposal activity. Injection of moderate to large quantities of CO 2 in the sub-surface may unbalance local stress and trigger earthquakes if faults are critically stressed, condition that is not easily verifiable. Pilot sites are therefore the best way to proceed further in order to address such challenging issues. In such cases, the reconnaissance of faults and seismicity in the sub-surface, before the onset of activity, is mandatory. In this paper, we present studies carried out in the site where the Sotacarbo Fault Lab is going to be installed. This facility will be located in a very low seismic hazard region of central Mediterranean, where reports on historical large earthquakes are poor. We show results from a series of experiments aimed to monitor the background seismicity around the pilot site. As expected, seismicity is almost absent down to small magnitude close to the future injection-test well. Further seismic imaging of the sub- surface layers obtained by ambient noise tomography offers the ability to resolve the presence of a seismicity- free fault located in the first 200 m below the surface, of which the last episode of activity is difficult to assess. Our results encourage the use of this site to follow the response of the system to injection of small quantity of CO2.Published1029744T. SismicitĂ  dell'ItaliaJCR Journa

    Shallow velocity model in the area of Pozzo Pitarrone, Mt. Etna, from single station, array methods and borehole data.

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    Seismic noise recorded by a temporary array installed around Pozzo Pitarrone, NE flank of Mt. Etna, have been analysed with several techniques. Single station HVSR method and SPAC array method have been applied to stationary seismic noise to investigate the local shallow structure. The inversion of dispersion curves produced a shear wave velocity model of the area reliable down to depth of about 130 m. A comparison of such model with the stratigraphic information available for the investigated area shows a good qualitative agreement. Taking advantage of a borehole station installed at 130 m depth, we could estimate also the Pwave velocity by comparing the borehole recordings of local earthquakes with the same event recorded at surface. Further insight on the P-wave velocity in the upper 130 m layer comes from the surface reflected wave observable in some cases at the borehole station. From this analysis we obtained an average P-wave velocity of about 1.2 km/s, compatible with the shear wave velocity found from the analysis of seismic noise.PublishedS04331V. Storia e struttura dei sistemi vulcaniciJCR Journalope

    Second-line therapy in pancreatic ductal adenocarcinoma (PDAC) patients with germline BRCA1-2 pathogenic variants (gBRCA1-2pv)

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    BackgroundPancreatic ductal adenocarcinoma (PDAC) harbouring germline BRCA1-2 pathogenic variants (gBRCA1-2pv) is a distinct nosological entity. Information on second-line therapy (2LT) outcome in this setting is lacking. MethodsData of gBRCA1-2pv metastatic PDAC patients treated with chemotherapy were collected. A primary analysis of 2LT RECIST response, median progression-free survival (mPFS(2)) and overall survival (mOS(2)), was performed. A secondary analysis addressed the impact of timing of platinum introduction on the outcome of patients receiving at least a first-line combination chemotherapy (1LT). ResultsEighty-four gBRCA1-2pv metastatic PDAC patients were enrolled. The primary analysis, including 43 patients, highlighted a significant improvement of mPFS(2) and a doubled response rate, in the platinum-based 2LT subgroup as compared to the platinum-free (8.8 versus 3.7 months, p = 0.013). Seventy-seven patients were included in the secondary analysis. Median PFS1 of 3- and 4-drug platinum-based 1LT significantly outperformed both platinum-free combinations and platinum-based doublets (11.4 versus 6.4 versus 7.9 months, p = 0.01). Albeit still immature, data on mOS paralleled those on mPFS. ConclusionsThis study highlighted the beneficial role of platinum agents in gBRCA1-2pv PDAC patients also in second-line treatment setting. However, our data suggest that early use of 3- and 4-drug platinum-based chemotherapy combinations provides a survival outcome advantage

    Asthma in patients admitted to emergency department for COVID-19: prevalence and risk of hospitalization

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