73 research outputs found

    Engineered nanomaterials: from their properties and applications, to their toxicity towards marine bivalves in a changing environment

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    As a consequence of their unique characteristics, the use of Engineered Nanomaterials (ENMs) is rapidly increasing in industrial, agricultural products, as well as in environmental technology. However, this fast expansion and use make likely their release into the environment with particular concerns for the aquatic ecosystems, which tend to be the ultimate sink for this type of contaminants. Considering the settling behaviour of particulates, benthic organisms are more likely to be exposed to these compounds. In this way, the present review aims to summarise the most recent data available from the literature on ENMs behaviour and fate in aquatic ecosystems, focusing on their ecotoxicological impacts towards marine and estuarine bivalves. The selection of ENMs presented here was based on the OECD's Working Party on Manufactured Nanomaterials (WPMN), which involves the safety testing and risk assessment of ENMs. Physical-chemical characteristics and properties, applications, environmental relevant concentrations and behaviour in aquatic environment, as well as their toxic impacts towards marine bivalves are discussed. Moreover, it is also identified the impacts derived from the simultaneous exposure of marine organisms to ENMs and climate changes as an ecologically relevant scenario.publishe

    Investigation of the molecular mechanisms which contribute to the survival of the polychaete Platynereis spp. under ocean acidification conditions in the CO2 vent system of Ischia Island (Italy)

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    The continuous increase of CO2 emissions in the atmosphere due to anthropogenic activities is one of the most important factors that contribute to Climate Change and generates the phenomenon known as Ocean Acidification (OA). Research conducted at the CO2 vents of Castello Aragonese (Ischia, Italy), which represents a natural laboratory for the study of OA, demonstrated that some organisms, such as polychaetes, thrive under acidified conditions through different adaptation mechanisms. Some functional and ecological traits promoting tolerance to acidification in these organisms have been identified, while the molecular and physiological mechanisms underlying acclimatisation or genetic adaptation are still largely unknown. Therefore, in this study we investigated epigenetic traits, as histone acetylation and methylation, in Platynereis spp. individuals coming from the Castello vent, and from a nearby control site, in two different periods of the year (November-June). Untargeted metabolomics analysis was also carried out in specimens from the two sites. We found a different profile of acetylation of H2B histone in the control site compared to the vent as a function of the sampling period. Metabolomic analysis showed clear separation in the pattern of metabolites in polychaetes from the control site with respect to those from the Castello vent. Specifically, a significant reduction of lipid/sterols and nucleosides was measured in polychaetes from the vent. Overall results contribute to better understand the potential metabolic pathways involved in the tolerance to OA

    High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19

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    Background. This study’s primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods. This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray’s method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results. Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8–11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7–21.0) and 9.3 (95% CI, 7.9–11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018–3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions. In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurements of the charge asymmetry in top-quark pair production in the dilepton final state at s √ =8  TeV with the ATLAS detector

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    Measurements of the top-antitop quark pair production charge asymmetry in the dilepton channel, characterized by two high-pT leptons (electrons or muons), are presented using data corresponding to an integrated luminosity of 20.3  fb−1 from pp collisions at a center-of-mass energy s√=8  TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. Inclusive and differential measurements as a function of the invariant mass, transverse momentum, and longitudinal boost of the tt¯ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: AℓℓC based on the selected leptons and Att¯C based on the reconstructed tt¯ final state. The inclusive asymmetries are measured in the full phase space to be AℓℓC=0.008±0.006 and Att¯C=0.021±0.016, which are in agreement with the Standard Model predictions of AℓℓC=0.0064±0.0003 and Att¯C=0.0111±0.0004

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Transverse momentum, rapidity, and centrality dependence of inclusive charged-particle production in √snn = 5.02 TeV p + Pb collisions measured by the ATLAS experiment

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    Measurements of the per-event charged-particle yield as a function of the charged-particle transverse momentum and rapidity are performed using p + Pb collision data collected by the ATLAS experiment at the LHC at a centre-of-mass energy of √snn = 5.02 TeV. Charged particles are reconstructed over pseudorapidity | η | < 2.3 and transverse momentum between 0.1 GeV and 22 GeV in a dataset corresponding to an integrated luminosity of 1 μb − 1. The results are presented in the form of charged-particle nuclear modification factors, where the p + Pb charged-particle multiplicities are compared between central and peripheral p + Pb collisions as well as to charged-particle cross sections measured in pp collisions. The p + Pb collision centrality is characterized by the total transverse energy measured in − 4.9 < η < − 3.1, which is in the direction of the outgoing lead beam. Three different estimations of the number of nucleons participating in the p + Pb collision are carried out using the Glauber model and two Glauber–Gribov colour-fluctuation extensions to the Glauber model. The values of the nuclear modification factors are found to vary significantly as a function of rapidity and transverse momentum. A broad peak is observed for all centralities and rapidities in the nuclear modification factors for charged-particle transverse momentum values around 3 GeV. The magnitude of the peak increases for more central collisions as well as rapidity ranges closer to the direction of the outgoing lead nucleus

    Search for heavy lepton resonances decaying to a Z boson and a lepton in pp collisions at √s=8 TeV with the ATLAS detector

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    A search for heavy leptons decaying to a Z boson and an electron or a muon is presented. The search is based on pp collision data taken at s√=8 TeV by the ATLAS experiment at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 20.3 fb−1. Three high-transverse-momentum electrons or muons are selected, with two of them required to be consistent with originating from a Z boson decay. No significant excess above Standard Model background predictions is observed, and 95% confidence level limits on the production cross section of high-mass trilepton resonances are derived. The results are interpreted in the context of vector-like lepton and type-III seesaw models. For the vector-like lepton model, most heavy lepton mass values in the range 114–176 GeV are excluded. For the type-III seesaw model, most mass values in the range 100–468 GeV are excluded

    Study of the B-c(+) -> J/psi D-s(+) and Bc(+) -> J/psi D-s*(+) decays with the ATLAS detector

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    The decays B-c(+) -> J/psi D-s(+) and B-c(+) -> J/psi D-s*(+) are studied with the ATLAS detector at the LHC using a dataset corresponding to integrated luminosities of 4.9 and 20.6 fb(-1) of pp collisions collected at centre-of-mass energies root s = 7 TeV and 8 TeV, respectively. Signal candidates are identified through J/psi -> mu(+)mu(-) and D-s(()*()+) -> phi pi(+)(gamma/pi(0)) decays. With a two-dimensional likelihood fit involving the B-c(+) reconstructed invariant mass and an angle between the mu(+) and D-s(+) candidate momenta in the muon pair rest frame, the yields of B-c(+) -> J/psi D-s(+) and B-c(+) -> J/psi D-s*(+), and the transverse polarisation fraction in B-c(+) -> J/psi D-s*(+) decay are measured. The transverse polarisation fraction is determined to be Gamma +/-+/-(B-c(+) -> J/psi D-s*(+))/Gamma(B-c(+) -> J/psi D-s*(+)) = 0.38 +/- 0.23 +/- 0.07, and the derived ratio of the branching fractions of the two modes is B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi D-s(+) = 2.8(-0.8)(+1.2) +/- 0.3, where the first error is statistical and the second is systematic. Finally, a sample of B-c(+) -> J/psi pi(+) decays is used to derive the ratios of branching fractions B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi pi(+) = 3.8 +/- 1.1 +/- 0.4 +/- 0.2 and B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi pi(+) = 10.4 +/- 3.1 +/- 1.5 +/- 0.6, where the third error corresponds to the uncertainty of the branching fraction of D-s(+) -> phi(K+ K-)pi(+) decay. The available theoretical predictions are generally consistent with the measurement
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