98 research outputs found

    High power ultrasound treatments of red young wines: effect on anthocyanins and phenolic stability indices

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    6openInternationalItalian coauthor/editorPolyphenols, especially anthocyanins, play an important role on red wine sensory qualities and their evolution during storage. High Power Ultrasound (HPU) has been recognized as one of the most promising technologies which can be applied in winemaking processes for several purposes, and it is recently officially approved for crushed grapes treatments. The effect of ultrasound amplitude (41 and 81%) and treatment time (1, 3, and 5 min) has been studied on anthocyanins, flavan-3-ols, tannins, polymerized pigments, HCl index, and the color intensity of two finished red young wines. Anthocyanins and phenols compounds were not degraded with an increase in amplitude and sonication time, and the chromatic properties of the selected wines were preserved. Amplitude and ultrasound time were also evaluated considering their effect on evolution of anthocyanin content and phenolic stability indices during the first thirty days of storage. The higher level of amplitude (81%) induced a higher percentage decrease in tannins, 15% and 40% after 15 and 30 days of storage, respectively, compared to untreated wine which did not show a significant change during storage. HPU shows a possible chemical effect on the evolution of some analytical indices during bottling maturation, but their effectiveness could be strictly linked with the initial phenolic profile and ratios between polyphenol classesopenCelotti, E.; Stante, S.; Ferraretto, P.; Roman, T.; Nicolini, G.; Natolino, A.Celotti, E.; Stante, S.; Ferraretto, P.; Roman, T.; Nicolini, G.; Natolino, A

    Inter-comparison of Radio-Loudness Criteria for Type 1 AGNs in the XMM-COSMOS Survey

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    Limited studies have been performed on the radio-loud fraction in X-ray selected type 1 AGN samples. The consistency between various radio-loudness definitions also needs to be checked. We measure the radio-loudness of the 407 type 1 AGNs in the XMM-COSMOS quasar sample using nine criteria from the literature (six defined in the rest-frame and three defined in the observed frame): RL=log(L5GHz/LB)R_L=\log(L_{5GHz}/L_B), q24=log(L24μm/L1.4GHz)q_{24}=\log(L_{24\mu m}/L_{1.4GHz}), Ruv=log(L5GHz/L2500A˚)R_{uv}=\log(L_{5GHz}/L_{2500\AA}), Ri=log(L1.4GHz/Li)R_{i}=\log(L_{1.4GHz}/L_i), RX=log(νLν(5GHz)/LX)R_X=\log(\nu L_{\nu}(5GHz)/L_X), P5GHz=log(P5GHz(W/Hz/Sr))P_{5GHz}=\log(P_{5GHz}(W/Hz/Sr)), RL,obs=log(f1.4GHz/fB)R_{L,obs}=\log(f_{1.4GHz}/f_B) (observed frame), Ri,obs=log(f1.4GHz/fi)R_{i,obs}=\log(f_{1.4GHz}/f_i) (observed frame), and q24,obs=log(f24μm/f1.4GHz)q_{24, obs}=\log(f_{24\mu m}/f_{1.4GHz}) (observed frame). Using any single criterion defined in the rest-frame, we find a low radio-loud fraction of 5%\lesssim 5\% in the XMM-COSMOS type 1 AGN sample, except for RuvR_{uv}. Requiring that any two criteria agree reduces the radio-loud fraction to 2%\lesssim 2\% for about 3/4 of the cases. The low radio-loud fraction cannot be simply explained by the contribution of the host galaxy luminosity and reddening. The P5GHz=log(P5GHz(W/Hz/Sr))P_{5GHz}=\log(P_{5GHz}(W/Hz/Sr)) gives the smallest radio-loud fraction. Two of the three radio-loud fractions from the criteria defined in the observed frame without k-correction (RL,obsR_{L,obs} and Ri,obsR_{i,obs}) are much larger than the radio-loud fractions from other criteria.Comment: 12 pages, 7 figures, MNRAS submitte

    Trend of estimated glomerular flitration rate in a large cohort of HIV mother-to -child infected patients, an observational multicenter study from 2010 to 2018

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    Background: People vertically infected with HIV (PVI-HIV) are a special population, due to exposition since birth to HIV and antiretroviral therapy (ART). Among ART, Tenofovir disoproxil fumarate (TDF) was widely used in recent years, but there are few data on safety in these patients; in particular, data about estimated glomerular filtration rate (eGFR) trend in this population. Aim of our study is to evaluate eGFR trend in a multicentre cohort of PVI-HIV exposed to TDF

    Jet-disc coupling through a common energy reservoir in the black hole XTE J1118+480

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    We interpret the rapid correlated UV/optical/ X-ray variability of XTE J1118+480 as a signature of the coupling between the X-ray corona and a jet emitting synchrotron radiation in the optical band. We propose a scenario in which the jet and the X-ray corona are fed by the same energy reservoir where large amounts of accretion power are stored before being channelled into either the jet or the high energy radiation. This time dependent model reproduces the main features of the rapid multi-wavelength variability of XTE J1118+480. Assuming that the energy is stored in the form of magnetic field, we find that the required values of the model parameters are compatible with both a patchy corona atop a cold accretion disc and a hot thick inner disc geometry. The range of variability timescales for the X-ray emitting plasma are consistent with the dynamical times of an accretion flow between 10 and 100 Schwarzschild radii. On the other hand, the derived range of timescales associated with the dissipation in the jet extends to timescales more than 10 times larger, confirming the suggestion that the generation of a powerful outflow requires large scale coherent poloidal field structures. A strong requirement of the model is that the total jet power should be at least a few times larger than the observed X-ray luminosity. This would be consistent with the overall low radiative efficiency of the source. We present independent arguments showing that the jet probably dominates the energetic output of all accreting black holes in the low-hard state.Comment: 14 pages, 2 figures, to appear in MNRA

    A bright megaelectronvolt emission line in γ\gamma-ray burst GRB 221009A

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    The highly variable and energetic pulsed emission of a long gamma-ray burst (GRB) is thought to originate from local, rapid dissipation of kinetic or magnetic energy within an ultra-relativistic jet launched by a newborn compact object, formed during the collapse of a massive star. The spectra of GRB pulses are best modelled by power-law segments, indicating the dominance of non-thermal radiation processes. Spectral lines in the X-ray and soft γ\gamma-ray regime for the afterglow have been searched for intensively, but never confirmed. No line features ever been identified in the high energy prompt emission. Here we report the discovery of a highly significant (>6σ> 6 \sigma) narrow emission feature at around 1010 MeV in the brightest ever GRB 221009A. By modelling its profile with a Gaussian, we find a roughly constant width σ1\sigma \sim 1 MeV and temporal evolution both in energy (12\sim 12 MeV to 6\sim 6 MeV) and luminosity (1050\sim 10^{50} erg/s to 2×1049\sim 2 \times 10^{49} erg/s) over 80 seconds. We interpret this feature as a blue-shifted annihilation line of relatively cold (kBTmec2k_\mathrm{B}T\ll m_\mathrm{e}c^2) electron-positron pairs, which could have formed within the jet region where the brightest pulses of the GRB were produced. A detailed understanding of the conditions that can give rise to such a feature could shed light on the so far poorly understood GRB jet properties and energy dissipation mechanism.Comment: Submitte

    Novel Textbook Outcomes following emergency laparotomy:Delphi exercise

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    Background: Textbook outcomes are composite outcome measures that reflect the ideal overall experience for patients. There are many of these in the elective surgery literature but no textbook outcomes have been proposed for patients following emergency laparotomy. The aim was to achieve international consensus amongst experts and patients for the best Textbook Outcomes for non-trauma and trauma emergency laparotomy. Methods: A modified Delphi exercise was undertaken with three planned rounds to achieve consensus regarding the best Textbook Outcomes based on the category, number and importance (Likert scale of 1–5) of individual outcome measures. There were separate questions for non-trauma and trauma. A patient engagement exercise was undertaken after round 2 to inform the final round. Results: A total of 337 participants from 53 countries participated in all three rounds of the exercise. The final Textbook Outcomes were divided into ‘early’ and ‘longer-term’. For non-trauma patients the proposed early Textbook Outcome was ‘Discharged from hospital without serious postoperative complications (Clavien–Dindo ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation or death). For trauma patients it was ‘Discharged from hospital without unexpected transfusion after haemostasis, and no serious postoperative complications (adapted Clavien–Dindo for trauma ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation on or death)’. The longer-term Textbook Outcome for both non-trauma and trauma was ‘Achieved the early Textbook Outcome, and restoration of baseline quality of life at 1 year’. Conclusion: Early and longer-term Textbook Outcomes have been agreed by an international consensus of experts for non-trauma and trauma emergency laparotomy. These now require clinical validation with patient data.</p

    A mega-electron volt emission line in the spectrum of a gamma-ray burst

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    A long gamma–ray burst (GRB) is observed when the collapse of a massive star produces an ultrarelativistic outflow pointed toward Earth. Gamma-ray spectra of long GRBs are smooth, typically modeled by joint power-law segments describing a continuum, with no detected spectral lines. We report a significant (>6σ) narrow emission feature at ~10 mega–electron volts (MeV) in the spectrum of the bright GRB 221009A. Over 80 seconds, it evolves in energy (~12 to ~6 MeV) and in luminosity (~1.1 to <0.43 × 1050 erg second−1) but has a constant width of ~1 MeV. We interpret this feature as a blueshifted spectral line produced by the annihilation of electron-positron pairs, potentially in the same location responsible for emitting the brightest GRB pulses.M.E.R. acknowledges support from the research program Athena with project number 184.034.002, which is financed by the Dutch Research Council (NWO). O.S.S. acknowledges funding by the European Union-Next Generation EU, PRIN 2022 RFF M4C21.1 (202298J7KT- PEACE). S.A. is supported by the H2020 ERC Consolidator Grant “MAGNESIA” (grant no. 817661; principal investigator: Rea) and National Spanish grant PGC2018-095512-BI00. A.J.L. and D.B.M. are supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant no. 725246). D.B.M. thanks the Cosmic Dawn Center, supported by the Danish National Research Foundation (grant DNRF140), for kind hospitality. G.O. and M.B. acknowledge financial support from the European Union’s Horizon 2020 Programme under the AHEAD2020 project (grant no. 871158). B.B. and M.B. acknowledge financial support from the Italian Ministry of University and Research (MUR) for the PRIN grant METE under contract no. 2020KB33TPPeer reviewe

    A quasar-galaxy mixing diagram: quasar spectral energy distribution shapes in the optical to near-infrared

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    We define a quasar-galaxy mixing diagram using the slopes of their spectral energy distributions (SEDs) from 1 \u3bcm to 3000 \uc5 and from 1 to 3 \u3bcm in the rest frame. The mixing diagram can easily distinguish among quasar-dominated, galaxy-dominated and reddening-dominated SED shapes. By studying the position of the 413 XMM-selected type 1 AGN in the wide-field `Cosmic Evolution Survey' in the mixing diagram, we find that a combination of the Elvis et al. mean quasar SED with various contributions from galaxy emission and some dust reddening is remarkably effective in describing the SED shape from 0.3 to 3 \u3bcm for large ranges of redshift, luminosity, black hole mass and Eddington ratio of type 1 AGN. In particular, the location in the mixing diagram of the highest luminosity AGN is very close (within 1\u3c3) to that of the Elvis et al. SED template. The mixing diagram can also be used to estimate the host galaxy fraction and reddening in quasar. We also show examples of some outliers which might be AGN in different evolutionary stages compared to the majority of AGN in the quasar-host galaxy co-evolution cycle
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