970 research outputs found

    An extremely low-noise heralded single-photon source: a breakthrough for quantum technologies

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    Low noise single-photon sources are a critical element for quantum technologies. We present a heralded single-photon source with an extremely low level of residual background photons, by implementing low-jitter detectors and electronics and a fast custom-made pulse generator controlling an optical shutter (a LiNbO3 waveguide optical switch) on the output of the source. This source has a second-order autocorrelation g^{(2)}(0)=0.005(7), and an "Output Noise Factor" (defined as the ratio of the number of noise photons to total photons at the source output channel) of 0.25(1)%. These are the best performance characteristics reported to date

    Greenlight laser™ photovaporization versus transurethral resection of the prostate: A systematic review and meta-analysis

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    none9GreenLight laser™ photovaporization of the prostate (GLL-PVP) has become a valid alternative to traditional transurethral resection of the prostate (TURP) in men requiring surgery for benign prostatic hyperplasia. We aimed to review systematically the safety and efficacy of studies comparing GLL PVP and TURP in the medium-term. A comprehensive literature search was performed. Twelve studies were identified for meta-analysis. Meta-analyses showed a longer postoperative catheterization time (risk ratio (RR): 1.12, 95% CI:1.09–1.14, p<0.00001) and length of stay (RR: 1.16, 95% CI:1.12–1.19, p<0.00001) in the TURP group; higher risk of transfusion in the TURP group (RR: 6.51, 95% CI: 2,90–14,64 p<0.00001); no difference in the risk of urinary tract infections (RR: 0.83, 95% CI: 0.58–1.18, p=0.30) and transient re-catheterization (RR: 1.11, 95% CI: 0.76–1.60, p=0.60). Regarding reoperation rate, no difference was found in term of postoperative urethral stricture (RR: 1.13, 95% CI: 0.73–1.75, p=0.59) and bladder neck contracture (RR: 0.66, 95% CI: 0.31–1.40, p=0.28). A significantly higher incidence in reoperation for persistent/regrowth adenoma was present in the GLLL-PVP (RR: 0.64, 95% CI: 0.41–0.99, p=0.05). Data at 2-year follow-up showed significant better post-voiding residual (PVR) (MD:-1.42, 95% CI:-2.01,-0.82, p<0.00001) and International Prostate Symptom Score (IPSS) (MD:-0.35, 95% CI:-0.50,-0.20, p<0.00001) after TURP. No difference was found in the mean PVR at 2 years after TURP, in the mean maximum flow rate (Qmax) (MD: 0.30, 95% CI:-0.02–0.61, p=0.06) and quality of life QoL score (MD: 0.05, 95% CI:-0.02–0.42, p=0.13). At 5-year follow-up, data showed better IPSS (MD:-1.70, 95% CI:-2.45,-0.95, p<0.00001), QoL scores (MD:-0.35, 95% CI:-0.69,-0.02, p=0.04) and Qmax (MD: 3.29, 95% CI: 0.19–6.38, p=0.04) after TURP. Data of PVR showed no significant difference (MD:-11.54, 95% CI:-29.55–6.46, p=0.21). In conclusion, our analysis shows that GLL-PVP is a safer and more efficacious procedure than standard TURP in the early and medium-term. However, in the long term period GLL-PVP showed a higher incidence of reoperation rate due to incomplete vaporization/regrowth of prostatic adenoma.openCastellani D.; Pirola G.M.; Rubilotta E.; Gubbiotti M.; Scarcella S.; Maggi M.; Gauhar V.; Teoh J.Y.-C.; Galosi A.B.Castellani, D.; Pirola, G. M.; Rubilotta, E.; Gubbiotti, M.; Scarcella, S.; Maggi, M.; Gauhar, V.; Teoh, J. Y. -C.; Galosi, A. B

    Understanding the Dynamics of Ancillary Pelagic Species in the Adriatic Sea

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    The status of fishery resources in the Mediterranean Sea is critical: most of the fish and shellfish stocks are in overexploitation and only half of them are routinely assessed. This manuscript presents the use of Surplus Production Models (SPMs) as a valid option to increase the number of assessed stocks, with specific attention to the Adriatic basin. Particularly, the stock of European sprat (Sprattus sprattus), Mediterranean horse mackerel (Trachurus mediterraneus), and Atlantic horse mackerel (Trachurus trachurus) living in the Adriatic Sea have been evaluated comparing three SPMs: Catch Maximum Sustainable Yields (CMSY), Stochastic surplus Production model in Continuous Time (SPiCT), and Abundance Maximum Sustainable Yields (AMSY). The different approaches present some variations; however, they generally agree on describing all the stocks close to the reference values for both biomass and fishing mortality in the most recent year. For the European sprat, AMSY results are the most robust model for this species’ survey data allow depicting a clearer picture of the history of this stock. Indeed, for the horse mackerel species, CMSY or SPiCT results are the preferred models, since for these species landings are not negligible. Notwithstanding, age-structured assessments remain the most powerful approach for evaluating the status of resources, but SPMs have proved to be a powerful tool in a data-limited context

    Formalin-fixed and paraffin-embedded samples for next generation sequencing: Problems and solutions

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    Over the years, increasing information has been asked of the pathologist: we have moved from a purely morphological diagnosis to biomolecular and genetic studies, which have made it possible to implement the use of molecular targeted therapies, such as anti-epidermal growth factor receptor (EGFR) molecules in EGFR-mutated lung cancer, for example. Today, next generation sequencing (NGS) has changed the approach to neoplasms, to the extent that, in a short time, it has gained a place of absolute importance and diagnostic, prognostic and therapeutic utility. In this scenario, formaldehyde-fixed and paraffin-embedded (FFPE) biological tissue samples are a source of clinical and molecular information. However, problems can arise in the genetic material (DNA and RNA) for use in NGS due to fixation, and work is being devoted to possible strategies to reduce its effects. In this paper, we discuss the applications of FFPE tissue samples in the execution of NGS, we focus on the problems arising with the use of this type of material for nucleic acid extraction and, finally, we consider the most useful strategies to prevent and reduce single nucleotide polymorphisms (SNV) and other fixation artifacts

    Risk factors for bronchiolitis hospitalization during the first year of life in a multicenter Italian birth cohort

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    BACKGROUND: Respiratory Syncytial Virus (RSV) is one of the main causes of respiratory infections during the first year of life. Very premature infants may contract more severe diseases and 'late preterm infants' may also be more susceptible to the infection. The aim of this study is to evaluate the risk factors for hospitalization during the first year of life in children born at different gestational ages in Italy. METHODS: A cohort of 33-34 weeks gestational age (wGA) newborns matched by sex and age with two cohort of newborns born at 35-37 wGA and &gt; 37 wGA were enrolled in this study for a three-year period (2009-2012). Hospitalization for bronchiolitis (ICD-9 code 466.1) during the first year of life was assessed through phone interview at the end of the RSV season (November-March) and at the completion of the first year of life. RESULTS: The study enrolled 2314 newborns, of which 2210 (95.5 %) had a one year follow-up and were included in the analysis; 120 (5.4 %) were hospitalized during the first year of life for bronchiolitis. Children born at 33-34 wGA had a higher hospitalization rate compared to the two other groups. The multivariate analysis carried out on the entire population associated the following factors with higher rates for bronchiolitis hospitalization: male gender; prenatal treatment with corticosteroids; prenatal exposure to maternal smoking; singleton delivery; respiratory diseases in neonatal period; surfactant therapy; lack of breastfeeding; siblings &lt;10 years old; living in crowded conditions and/or in unhealthy households and early exposure to the epidemic RSV season. When analysis was restricted to preterms born at 33-34 wGA the following variables were associated to higher rates of bronchiolitis hospitalization: male gender, prenatal exposure to maternal smoking, neonatal surfactant therapy, having siblings &lt;10 years old, living in crowded conditions and being exposed to epidemic season during the first three months of life. CONCLUSION: Our study identified some prenatal, perinatal and postnatal conditions proving to be relevant and independent risk factors for hospitalization for bronchiolitis during the first year of life. The combination of these factors may lead to consider palivizumab prophylaxis in Italy

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations
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