63 research outputs found

    TissUExM protocol for ultrastructure expansion microscopy of zebrafish larvae and mouse embryos

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    Expansion microscopy of millimeter-large mechanically heterogeneous tissues, such as whole vertebrate embryos, has been limited, particularly when combined with post-expansion immunofluorescence. Here, we present a protocol to perform ultrastructure expansion microscopy of whole vertebrate embryos, optimized to perform post-expansion labeling. We describe steps for embedding and denaturing zebrafish larvae or mouse embryos. We then detail procedures for hydrogel handling and mounting. This protocol is particularly well suited for super-resolution imaging of macromolecular protein complexes in situ but does not preserve lipids. For complete details on the use and execution of this protocol, please refer to Steib et al.1

    Host and microbiome features of secondary infections in lethal covid-19

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    Secondary infections contribute significantly to covid-19 mortality but driving factors remain poorly understood. Autopsies of 20 covid-19 cases and 14 controls from the first pandemic wave complemented with microbial cultivation and RNA-seq from lung tissues enabled description of major organ pathologies and specification of secondary infections. Lethal covid-19 segregated into two main death causes with either dominant diffuse alveolar damage (DAD) or secondary pneumonias. The lung microbiome in covid-19 showed a reduced biodiversity and increased prototypical bacterial and fungal pathogens in cases of secondary pneumonias. RNA-seq distinctly mirrored death causes and stratified DAD cases into subgroups with differing cellular compositions identifying myeloid cells, macrophages and complement C1q as strong separating factors suggesting a pathophysiological link. Together with a prominent induction of inhibitory immune-checkpoints our study highlights profound alterations of the lung immunity in covid-19 wherein a reduced antimicrobial defense likely drives development of secondary infections on top of SARS-CoV-2 infection

    Pushing the high count rate limits of scintillation detectors for challenging neutron-capture experiments

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    One of the critical aspects for the accurate determination of neutron capture cross sections when combining time-of-flight and total energy detector techniques is the characterization and control of systematic uncertainties associated to the measuring devices. In this work we explore the most conspicuous effects associated to harsh count rate conditions: dead-time and pile-up effects. Both effects, when not properly treated, can lead to large systematic uncertainties and bias in the determination of neutron cross sections. In the majority of neutron capture measurements carried out at the CERN n\_TOF facility, the detectors of choice are the C6_{6}D6_{6} liquid-based either in form of large-volume cells or recently commissioned sTED detector array, consisting of much smaller-volume modules. To account for the aforementioned effects, we introduce a Monte Carlo model for these detectors mimicking harsh count rate conditions similar to those happening at the CERN n\_TOF 20~m fligth path vertical measuring station. The model parameters are extracted by comparison with the experimental data taken at the same facility during 2022 experimental campaign. We propose a novel methodology to consider both, dead-time and pile-up effects simultaneously for these fast detectors and check the applicability to experimental data from 197^{197}Au(nn,ő≥\gamma), including the saturated 4.9~eV resonance which is an important component of normalization for neutron cross section measurements

    Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

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    This article presents a few selected developments and future ideas related to the measurement of (n,ő≥) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with ő≥-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area

    Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

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    This article presents a few selected developments and future ideas related to the measurement of (n,ő≥) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with ő≥-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low‚Äďmiddle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‚Äėsingle-use‚Äô consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low‚Äďmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high‚Äď and low‚Äďmiddle‚Äďincome countries

    Ytterbium (

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    The thick foils activation technique has been applied to estimate the average cross-sections of 168,170,176Yb (ő≥,n)(\gamma, \mathrm{n}) reaction near to photodisintegration threshold. The (ő≥,n)(\gamma, \mathrm{n}) cross-sections are derived using the integrated photon flux at any energy range from the reaction threshold to the bremsstrahlung end-point energy. The photon flux is estimated using a calibration photodisintegration set of foils and taking in advance the spectrum linearity at high energies. The p-nuclei 168Yb average cross-section is 106¬Ī21 106 \pm 21 mb corresponding to Emean=10E_{\mathrm{mean}} = 10 MeV. The 170Yb average cross section is 117¬Ī31 117 \pm 31 mb matching Emean=9 E_{\mathrm{mean}} = 9 MeV while the 176Yb one is 123¬Ī36 123 \pm 36 mb corresponding to Emean=8 E_{\mathrm{mean}} = 8 MeV. The experimental results associate to statistical model simulations performed by the TALYS code. The simulated data of 168Yb ranges 83‚Äď139 mb, while 170Yb and 176Yb vary between 89‚Äď152 and 84‚Äď170mb; which agree with the measurements within uncertainties. The simulated average cross-section of natYb (ő≥,n)(\gamma, \mathrm{n}) reaction is 127¬Ī25 127 \pm 25 mb corresponding to energy ranges 6.6-14 MeV. The simulation results based on Lorentzian ő≥ \gamma-strength considerations with the density level of Fermi gas plus the constant temperature model are closest to the average cross-sections measured
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