1,342 research outputs found

    The deep and magmatic degassing source of unrest episodes at Campi Flegrei caldera (southern Italy)

    Get PDF
    Volcanic calderas are affected by unrest episodes usually dominated by hybrid magmatic-hydrothermal system dynamics. Unrest episodes can evolve to eruptions of variable intensity, up to Plinian. Campi Flegrei caldera (CFc) is a type-location for this kind of activity escalation. CFc provides unique opportunity to build-up a volcanological model in which geochemical, geological and geophysical data are interpreted together to understand how degassing following magma emplacement drives the caldera resurgence. Uneruptive unrest episodes reflect i) a sudden increase of the CO2 magmatic fraction following the shallow emplacement of one single volatile-rich magma batch, ii) voluminous gas separation in a nearly single-step process, and iii), on longer times scales of 10-20 years, degassing driven by crystallization and deep gas fluxing. Our volcanological model matches three decades of geochemical constraints from fumarole discharges, as well as data from melt inclusions of past CFc eruptions. Besides, magma physical properties demanded for modeled degassing conditions are in good agreement with existing geophysical data. Our results open new perspectives to the definition of unrest scenarios at highly-populated CFc

    A method to localize gamma-ray bursts using POLAR

    Full text link
    The hard X-ray polarimeter POLAR aims to measure the linear polarization of the 50-500 keV photons arriving from the prompt emission of gamma-ray bursts (GRBs). The position in the sky of the detected GRBs is needed to determine their level of polarization. We present here a method by which, despite of the polarimeter incapability of taking images, GRBs can be roughly localized using POLAR alone. For this purpose scalers are attached to the output of the 25 multi-anode photomultipliers (MAPMs) that collect the light from the POLAR scintillator target. Each scaler measures how many GRB photons produce at least one energy deposition above 50 keV in the corresponding MAPM. Simulations show that the relative outputs of the 25 scalers depend on the GRB position. A database of very strong GRBs simulated at 10201 positions has been produced. When a GRB is detected, its location is calculated searching the minimum of the chi2 obtained in the comparison between the measured scaler pattern and the database. This GRB localization technique brings enough accuracy so that the error transmitted to the 100% modulation factor is kept below 10% for GRBs with fluence Ftot \geq 10^(-5) erg cm^(-2) . The POLAR localization capability will be useful for those cases where no other instruments are simultaneously observing the same field of view.Comment: 13 pages, 10 figure

    Epidemiology of intensive care unit-acquired sepsis in Italy: results of the SPIN-UTI network

    Get PDF
    BACKGROUND: Sepsis is the major cause of mortality from any infectious disease worldwide. Sepsis may be the result of a healthcare associated infection (HAI): the most frequent adverse events during care delivery especially in Intensive Care Units (ICUs). The main aim of the present study was to describe the epidemiology of ICU-acquired sepsis and related outcomes among patients enrolled in the framework of the Italian Nosocomial Infections Surveillance in ICUs - SPIN-UTI project. STUDY DESIGN: Prospective multicenter study. METHODS: The SPIN-UTI network adopted the European protocols for patient-based HAI surveillance. RESULTS: During the five editions of the SPIN-UTI project, from 2008 to 2017, 47.0% of HAIs has led to sepsis in 832 patients. Overall, 57.0% episodes were classified as sepsis, 20.5% as severe sepsis and 22.5% as septic shock. The most common isolated microorganisms from sepsis episodes were Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. The case fatality rate increased with the severity of sepsis and the mean length of ICU-stay was significantly higher in patients with ICU-acquired sepsis than in patients without. CONCLUSION: Our study provides evidence that ICU-acquired sepsis occurs frequently in Italian ICU patients and is associated with a high case fatality rate and increased length of stay. However, in order to explain these findings further analyses are needed in this population of ICU patient

    Emergency department syndromic surveillance system for early detection of 5 syndromes: a pilot project in a reference teaching hospital in Genoa, Italy

    Get PDF
    Early detection is fundamental for achieving effective control of infectious disease outbreaks. We described the development of a local chief complaint emergency department (ED)-based syn- dromic surveillance system to improve public health response in Genoa, Italy. The five syndromes under investigation by the syn- dromic surveillance system were influenza-like illness (ILI), low- respiratory tract illness (LRTI), not-haemorrhagic gastroenteritis, acute hepatitis, fever-with-rash (maculo-papular or vescicular) syndrome. Syndrome coding, data capture, transmission and processing, statistical analysis to assess indicators of disease activity and alert thresholds, and signal response were operatively described. Preliminary results on ILI syndromic surveillance showed that new system allowed the activation of the alert state with a specificity of 90.3% and a sensitivity of 72.9% in predicting epidemiological relevant events, such as ? 10 accesses to ED for ILI in 3 days. The new syndromic surveillance system allowed to alert the public health institutions 2.5 days before than the local surveillance system based on sentinel physicians and paediatri- cians, permitting the early activation of the necessary measures for the containment and for burden reduction of the epidemic event. It is noteworthy that the syndromic surveillance epidemic cut-off was overcome once before and 4 times after influenza outbreak detected by sentinel-based surveillance system: all episodes were contemporary with Respiratory Syncytial Virus and Parainfluenza Virus circulation, as detected by regional reference laboratory

    Ultrasound and cone beam CT fusion for liver ablation : technical note

    Get PDF
    Purpose: To assess the feasibility of fusion imaging between intraprocedural ultrasound (US) and contrast-enhanced cone-beam CT (CBCT) for small (< 2 cm) hepatocellular carcinoma (HCC). Materials and methods: Six patients (five males, one female, age range 58\u201380, mean 69 years), with small (mean diameter 16.8 mm) HCC poorly visible at US underwent percutaneous microwave ablation under US/CBCT fusion guidance. During general anesthesia with apnea control, a contrast- enhanced CBCT was acquired with an active tracker. Subsequently, real time US images were fused with CBCT images, and treatment performed under fusion imaging guidance. Feasibility of fusion imaging and percutaneous ablation were assessed, correct targeting (distance from center of tumor and center of ablation area <5 mm) and one-month primary technical efficacy were evaluated. Major and minor complications as well as overall procedural time were recorded. Results: US/CBCT fusion was feasible in all cases, allowing for completion of the treatment as previously planned (technical success 100%). Correct targeting was achieved in 4/6 cases (66%), while in two cases, center of tumor and center of ablated area were respectively 7 and 8 mm distant. At 1 month CT scan, all tumors were completely ablated (primary technical efficacy 100%). No major or minor complications occurred. Mean overall procedure time was 127 min. Conclusions: US/CBCT fusion is a feasible technique for liver ablation, and might represent a useful tool to increase the correct targeting of poorly US-visible HCC nodules in the angio suite

    Molecular epidemiology and case-control approaches for management of an outbreak of hepatitis A in Liguria, Italy

    Get PDF
    Introduction and methods. Hepatitis A remains an important public health problem in low endemicity areas, because of the social and economic high burden of cyclical outbreaks. In this study we described an outbreak of HAV infection occurred in the city of Genoa and in its proximity and the viral circulation in the post-epidemic period. In order to identify risk factors associated to the illness and to determine the source of infection and the dynamics of virus evolution, we conducted an epidemiological and molecular investigation by a case-control study and by sequence analysis of high variable regions of the genome. Results. From May to October 2005, 58 HAV hepatitis cases were notified. The case-control study showed that beach establishment attending is strongly associated with HAV hepatitis (OR = 24.5, p-value inf. 0.01), at multivariate analysis. The profile of epidemic curve, the clinical onset of primary cases who occurred in few weeks and the geographic distribution of cases clearly indicated a common exposure to a point source: the outbreak can be probably associated with a contaminated food product dispensed in the affected area. The outbreak has been mainly caused by a single variant, confirming the common exposure to a point source; this variant previously circulated within homosexual man (MSM) network in Northern Europe. During the outbreak and in the following months, different variants originating from Southeast Asia, Southern America and Northern Africa, have co-circulated: all these cases were related to international travel and none of these had determined secondary cases. Discussion. The epidemiological picture of hepatitis A in Liguria is characterized by a wide heterogeneity of circulating HAV strains. This pattern could be associated with the increase of imported cases and transmission within network of persons with similar risk factors. Molecular approach coupled to descriptive and analytical epidemiological studies appeared un-replaceable tools for management and control of HAV outbreaks, because of their capacity to recognize infection origin, transmission patterns and dynamics of virus evolution

    No evidence of sars-cov-2 circulation in rome (Italy) during the pre-pandemic period. Results of a retrospective surveillance

    Get PDF
    In March 2020, the World Health Organization (WHO) declared that the COVID-19 outbreak recorded over the previous months could be characterized as a pandemic. The first known Italian SARS-CoV-2 positive case was reported on 21 February. In some countries, cases of suspected “COVID-19-like pneumonia” had been reported earlier than those officially accepted by health authorities. This has led many investigators to check preserved biological or environmental samples to see whether the virus was detectable on dates prior to those officially stated. With regard to Italy, the results of a microbiological screening in sewage samples collected between the end of February and the beginning of April 2020 from wastewaters in Milan (Northern Italy) and Rome (Central Italy) showed presence of SARS-CoV-2. In the present study, we evaluated, by means of a standardized diagnostic method, the SARS-CoV-2 infection prevalence amongst patients affected by severe acute respiratory syndrome (SARI) in an academic hospital located in Central Italy during the period of 1 November 2019–1 March 2020. Overall, the number of emergency room (ER) visits during the investigated period was 13,843. Of these, 1208 had an influenza-like syndrome, but only 166 matched the definition of SARI as stated in the study protocol. A total of 52 SARI cases were laboratory confirmed as influenza: 26 as a type B virus, 25 as a type A, and 1 as both viruses. Although about 17% of the total sample had laboratory or radiological data compatible with COVID-19, all the nasopharyngeal swabs stored underwent SARS-CoV-2 RT-PCR and tested negative. Based on our result, it is confirmed that the COVID-19 pandemic spread did not start prior to the “official” onset in central Italy. Routine monitoring of SARI causative agents at the local level is critical for reporting epidemiologic and etiologic trends that may differ from one country to another and also among different influenza seasons. This has a practical impact on prevention and control strategies

    Outbreak of sars-cov-2 lineage 20i/501y.V1 in a nursing home underlines the crucial role of vaccination in both residents and staff

    Get PDF
    Elderly residents in nursing homes are at very high risk of life-threatening COVID-19-related outcomes. In this report, an epidemiological and serological investigation of a SARS-CoV-2 outbreak in an Italian nursing home is described. Among the residents, all but one (19/20) were regularly vaccinated against SARS-CoV-2. In mid-February 2021, a non-vaccinated staff member of the nursing home was diagnosed with the SARS-CoV-2 infection. Following the outbreak investigation, a total of 70% (14/20) of residents aged 77–100 years were found positive. The phylogenetic analysis showed that the outbreak was caused by the SARS-CoV-2 variant of concern 202012/01 (the so-called “UK variant”). However, all but one positive subjects (13/14) were fully asymptomatic. The only symptomatic patient was a vaccinated 86-year-old female with a highly compromised health background and deceased approximately two weeks later. The subsequent serological investigation showed that the deceased patient was the only vaccinated subject that did not develop the anti-spike protein antibody response, therefore being likely a vaccine non-responder. Although the available mRNA SARS-CoV-2 vaccine was not able to prevent several asymptomatic infections, it was able to avert most symptomatic disease cases caused by the SARS-CoV-2 variant of concern 202012/01 in nursing home residents
    • …
    corecore