43 research outputs found

    Opto-thermal dynamics of thin-film optical limiters based on the VO2 phase transition

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    Protection of human eyes or sensitive detectors from high-intensity laser radiation is an important challenge in modern light technologies. Metasurfaces have proved to be valuable tools for such light control, but the actual possibility of merging multiple materials in the nanofabrication process hinders their application. Here we propose and numerically investigate the opto-thermal properties of plane multilayered structures with phase-change materials for optical limiters. Our structure relies on thin-film VO2 phase change material on top of a gold film and a sapphire substrate. We show how such a multi-layer structure can act as a self-activating device that exploits light-to-heat conversion to induce a phase change in the VO2 layer. We implement a numerical model to describe the temporal evolution of the temperature and transmittivity across the device under both a continuous wave and pulsed illumination. Our results open new opportunities for multi-layer self-activating optical limiters and may be extended to devices based on other phase change materials or different spectral regions

    Cytomegalovirus blood reactivation in COVID-19 critically ill patients: risk factors and impact on mortality.

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    Purpose: Cytomegalovirus (CMV) reactivation in immunocompetent critically ill patients is common and relates to a worsening outcome. In this large observational study, we evaluated the incidence and the risk factors associated with CMV reactivation and its effects on mortality in a large cohort of COVID-19 patients admitted to the intensive care unit (ICU). Methods: Consecutive patients with confirmed SARS-CoV-2 infection and acute respiratory distress syndrome admitted to three ICUs from February 2020 to July 2021 were included. The patients were screened at ICU admission and once or twice per week for quantitative CMV-DNAemia in the blood. The risk factors associated with CMV blood reactivation and its association with mortality were estimated by adjusted Cox proportional hazards regression models. Results: CMV blood reactivation was observed in 88 patients (20,4%) of the 431 patients studied. SAPS II score (HR 1,031, 95% CI 1,010-1,053, p=0,006), platelet count (HR 0,0996, 95% CI 0,993-0,999, p=0,004), invasive mechanical ventilation (HR 2,611, 95% CI 1,223-5,571, p=0,013) and secondary bacterial infection (HR 5,041; 95% CI 2,852-8,911, p<0,0001) during ICU stay were related to CMV reactivation. Hospital mortality was higher in patients with (67,0%) than in patients without (24,5%) CMV reactivation but the adjusted analysis did not confirm this association (HR 1,141, 95% CI 0,757-1,721, p=0,528). Conclusion: The severity of illness and the occurrence of secondary bacterial infections were associated with an increased risk of CMV blood reactivation, which, however, does not seem to influence the outcome of COVID-19 ICU patients independently

    Digital PCR improves the quantitation of DMR and the selection of CML candidates to TKIs discontinuation

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    Treatment-free remission (TFR) by tyrosine kinase inhibitors (TKI) discontinuation in patients with deep molecular response (DMR) is a paramount goal in the current chronic myeloid leukemia (CML) therapeutic strategy. The best DMR level by real-time quantitative PCR (RT-qPCR) for TKI discontinuation is still a matter of debate. To compare the accuracy of digital PCR (dPCR) and RT-qPCR for BCR-ABL1 transcript levels detection, 142 CML patients were monitored for a median time of 24\ua0months. Digital PCR detected BCR-ABL1 transcripts in the RT-qPCR undetectable cases. The dPCR analysis of the samples, grouped by the MR classes, revealed a significant difference between MR4.0 and MR4.5 (P\ua0=\ua00.0104) or MR5.0 (P\ua0=\ua00.0032). The clinical and hematological characteristics of the patients grouped according to DMR classes (MR4.0 vs MR4.5-5.0 ) were superimposable. Conversely, patients with dPCR values <0.468 BCR-ABL1 copies/\ub5L (as we previously described) showed a longer DMR duration (P\ua0=\ua00.0220) and mainly belonged to MR4.5-5.0 (P\ua0=\ua00.0442) classes compared to patients with higher dPCR values. Among the 142 patients, 111 (78%) discontinued the TKI treatment; among the 111 patients, 24 (22%) lost the MR3.0 or MR4.0 . RT-qPCR was not able to discriminate patients with higher risk of MR loss after discontinuation (P\ua0=\ua00.8100). On the contrary, according to dPCR, 12/25 (48%) patients with BCR-ABL1 values 650.468 and 12/86 (14%) patients with BCR-ABL1 values <0.468 lost DMR in this cohort, respectively (P\ua0=\ua00.0003). Treatment-free remission of patients who discontinued TKI with a dPCR <0.468 was significantly higher compared to patients with dPCR\ua0 65\ua00.468 (TFR at 2\ua0years 83% vs 52% P\ua0=\ua00.0017, respectively). In conclusion, dPCR resulted in an improved recognition of stable DMR and of candidates to TKI discontinuation

    Towards a Muon Collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

    Erratum:Towards a muon collider

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    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

    Erratum: Towards a muon collider

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    The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected

    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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    Abstract 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–middle-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 ‘single-use’ 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–middle-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– and low–middle–income countries
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