98 research outputs found

    Observation of a nuclear recoil peak at the 100 eV scale induced by neutron capture

    Full text link
    Coherent elastic neutrino-nucleus scattering and low-mass Dark Matter detectors rely crucially on the understanding of their response to nuclear recoils. We report the first observation of a nuclear recoil peak at around 112 eV induced by neutron capture. The measurement was performed with a CaWO4_4 cryogenic detector from the NUCLEUS experiment exposed to a 252^{252}Cf source placed in a compact moderator. The measured spectrum is found in agreement with simulations and the expected peak structure from the single-Îł\gamma de-excitation of 183^{183}W is identified with 3 σ\sigma significance. This result demonstrates a new method for precise, in-situ, and non-intrusive calibration of low-threshold experiments

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

    Get PDF
    Coherent elastic neutrino-nucleus scattering (CEÎœ\nuNS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is large by neutrino standards, CEÎœ\nuNS has long proven difficult to detect, since the deposited energy into the nucleus is ∌\sim keV. In 2017, the COHERENT collaboration announced the detection of CEÎœ\nuNS using a stopped-pion source with CsI detectors, followed up the detection of CEÎœ\nuNS using an Ar target. The detection of CEÎœ\nuNS has spawned a flurry of activities in high-energy physics, inspiring new constraints on beyond the Standard Model (BSM) physics, and new experimental methods. The CEÎœ\nuNS process has important implications for not only high-energy physics, but also astrophysics, nuclear physics, and beyond. This whitepaper discusses the scientific importance of CEÎœ\nuNS, highlighting how present experiments such as COHERENT are informing theory, and also how future experiments will provide a wealth of information across the aforementioned fields of physics

    Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

    Get PDF
    Coherent elastic neutrino-nucleus scattering (CEÎœ\nuNS) is a process inwhich neutrinos scatter on a nucleus which acts as a single particle. Thoughthe total cross section is large by neutrino standards, CEÎœ\nuNS has longproven difficult to detect, since the deposited energy into the nucleus is∌\sim keV. In 2017, the COHERENT collaboration announced the detection ofCEÎœ\nuNS using a stopped-pion source with CsI detectors, followed up thedetection of CEÎœ\nuNS using an Ar target. The detection of CEÎœ\nuNS hasspawned a flurry of activities in high-energy physics, inspiring newconstraints on beyond the Standard Model (BSM) physics, and new experimentalmethods. The CEÎœ\nuNS process has important implications for not onlyhigh-energy physics, but also astrophysics, nuclear physics, and beyond. Thiswhitepaper discusses the scientific importance of CEÎœ\nuNS, highlighting howpresent experiments such as COHERENT are informing theory, and also how futureexperiments will provide a wealth of information across the aforementionedfields of physics.<br

    Pregnancy and neonatal outcomes of COVID-19: The PAN-COVID study

    Get PDF
    Objective To assess perinatal outcomes for pregnancies affected by suspected or confirmed SARS-CoV-2 infection. Methods Prospective, web-based registry. Pregnant women were invited to participate if they had suspected or confirmed SARS-CoV-2 infection between 1st January 2020 and 31st March 2021 to assess the impact of infection on maternal and perinatal outcomes including miscarriage, stillbirth, fetal growth restriction, pre-term birth and transmission to the infant. Results Between April 2020 and March 2021, the study recruited 8239 participants who had suspected or confirmed SARs-CoV-2 infection episodes in pregnancy between January 2020 and March 2021. Maternal death affected 14/8197 (0.2%) participants, 176/8187 (2.2%) of participants required ventilatory support. Pre-eclampsia affected 389/8189 (4.8%) participants, eclampsia was reported in 40/ 8024 (0.5%) of all participants. Stillbirth affected 35/8187 (0.4 %) participants. In participants delivering within 2 weeks of delivery 21/2686 (0.8 %) were affected by stillbirth compared with 8/4596 (0.2 %) delivering ≄ 2 weeks after infection (95 % CI 0.3–1.0). SGA affected 744/7696 (9.3 %) of livebirths, FGR affected 360/8175 (4.4 %) of all pregnancies. Pre-term birth occurred in 922/8066 (11.5%), the majority of these were indicated pre-term births, 220/7987 (2.8%) participants experienced spontaneous pre-term births. Early neonatal deaths affected 11/8050 livebirths. Of all neonates, 80/7993 (1.0%) tested positive for SARS-CoV-2. Conclusions Infection was associated with indicated pre-term birth, most commonly for fetal compromise. The overall proportions of women affected by SGA and FGR were not higher than expected, however there was the proportion affected by stillbirth in participants delivering within 2 weeks of infection was significantly higher than those delivering ≄ 2 weeks after infection. We suggest that clinicians’ threshold for delivery should be low if there are concerns with fetal movements or fetal heart rate monitoring in the time around infection

    W/W−SiCH/TaOxNy Multinanolayers for Concentrated Solar Power

    No full text
    International audienceAbsorbers for concentrating solar power plants require materials that are resistant to high temperatures and spectrally selective, i.e., highly absorbent in the visible and near infrared range and low-emissive in the infrared range. To improve the absorbing power of the receivers in concentrating solar power plants, an optical end coating based on tantalum oxynitride can be deposited on an absorbing bilayer based on metal and ceramic materials. Antireflective Ta O x N y coating can maximize the transmission of solar radiation to the W/W-SiCH bilayer absorber material which has been previously studied and ensure a good thermomechanical resistance of the whole coating. For this study, Ta O x N y are deposited by reactive sputtering technique. Their chemical composition is investigated by Ion Beam Analysis which shows compositions ranging from tantalum oxide to tantalum nitride depending of the gas flow rate. Optical properties are determined by ellipsometry and UV-Visible spectroscopy. The microstructure determined by the Pair Distribution Function (PDF) reveals a mixture of TaN, TaON and Ta 2 O 5 phases

    The anti-biofilm activity secreted by a marine Pseudoalteromonas strain.

    No full text
    International audienceBacterial biofilms occur on all submerged structures in marine environments. The authors previously reported that the marine bacterium Pseudoalteromonas sp. 3J6 secretes antibiofilm activity. Here, it was discovered that another Pseudoalteromonas sp. strain, D41, inhibited the development of strain 3J6 in mixed biofilms. Confocal laser scanning microscope observations revealed that the culture supernatant of strain D41 impaired biofilm formation of strain 3J6 and another marine bacterium. A microtiter plate assay of the antibiofilm activity was set up and validated with culture supernatants of Pseudoalteromonas sp. 3J6. This assay was used to determine the spectra of action of strains D41 and 3J6. Each culture supernatant impaired the biofilm development of 13 marine bacteria out of 18. However, differences in the spectra of action and the physical behaviours of the antibiofilm molecules suggest that the latter are not identical. They nevertheless share the originality of being devoid of antibacterial activity against planktonic bacteria

    Comprehensive analysis of post‐diagnostic prostate‐specific antigen kinetics as predictor of a prostate cancer progression in active surveillance patients

    No full text
    What's known on the subject? and What does the study add? A significant proportion of patients diagnosed with prostate cancer do not require immediate treatment and could be managed by active surveillance, which usually includes serial measurements of prostate‐specific antigen (PSA) levels and regular biopsies. The rate of rise in PSA levels, which could be calculated as PSA velocity or PSA doubling time, was previously suggested to be associated with the biological aggressiveness of prostate cancer. Although these parameters are obvious candidates for predicting tumour progression in active surveillance patients, earlier studies that examined this topic provided conflicting results. Our analysis showed that PSA velocity and PSA doubling time calculated at different time‐points, by different methods, over different intervals, and in different sub‐groups of active surveillance patients provide little if any prognostic information. Although we found some significant associations between PSA velocity and the risk of progression as determined by biopsy, the actual clinical significance of this association was small. Furthermore, PSA velocity did not add to the predictive accuracy of total PSA. Objective To study whether prostate‐specific antigen (PSA) velocity (PSAV) and PSA doubling time (PSADT) are associated with biopsy progression in patients managed by active surveillance. Patients and Methods Our inclusion criteria for active surveillance are biopsy Gleason sum <7, two or fewer positive biopsy cores, ≀20% tumour present in any core, and clinical stage T1–T2a. Changes in any of these parameters during the follow‐up that went beyond these limits are considered to be progression. This study included 250 patients who had at least one surveillance biopsy, an available PSA measured no earlier than 3 months before diagnosis, and at least one PSA measurement before each surveillance biopsy. We evaluated the association between PSA kinetics and progression at successive surveillance biopsies in different sub‐groups of patients by calculating the area under the curve (AUC) as well as sensitivity and specificity of different thresholds. Results Over a median follow‐up of 3.0 years, the disease of 64 (26%) patients progressed. PSADT was not associated with biopsy progression, whereas PSAV was only weakly associated with progression in certain sub‐groups. However, incorporation of PSAV in models including total PSA resulted in a moderate increase in AUC only when the entire cohort was analysed. In other sub‐groups the predictive accuracy of total PSA was not significantly improved by adding PSAV. Conclusions Our findings confirm that PSA kinetics should not be used in decision‐making in patients with low‐risk prostate cancer managed by active surveillance. Regular surveillance biopsies should remain as the principal method of monitoring cancer progression in these men
    • 

    corecore