64 research outputs found

    X-point and divertor filament dynamics from Gas Puff Imaging on TCV

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    A new Gas Puff Imaging (GPI) diagnostic has been installed on the TCV tokamak, providing two-dimensional insights into Scrape-Off-Layer (SOL) turbulence dynamics above, at and below the magnetic X-point. A detailed study in L-mode, attached, lower single-null discharges shows that statistical properties have little poloidal variations, while vast differences are present in the 2D behaviour of intermittent filaments. Strongly elongated filaments, just above the X-point and in the divertor far-SOL, show a good consistency in shape and dynamics with field-line tracing from filaments at the outboard midplane, highlighting their connection. In the near-SOL of the outer divertor leg, shortlived, high frequency and more circular (diameter \sim15 sound Larmour radii) filaments are observed. These divertor-localised filaments appear born radially at the position of maximum density and display a radially outward motion with velocity \approx400\,m/s that is comparable to radial velocities of upstream-connected filaments. Conversely, in these discharges (B×BB\times\nabla B pointing away from the divertor), these divertor filaments' poloidal velocities differ strongly from those of upstream-connected filaments. The importance of divertor-localised filaments upon radial transport and profile broadening is explored using filament statistics and in-situ kinetic profile measurements along the divertor leg. This provides evidence that these filaments contribute significantly to electron density profile broadening in the divertor.Comment: This is the version of the article before peer review or editing, as submitted by an author to IOPScience Nuclear Fusion. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. 15 pages, 15 figure

    Clinical and molecular epidemiological features of critically ill patients with invasive group A Streptococcus infections: a Belgian multicenter case-series.

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    peer reviewed[en] BACKGROUND: Recent alerts have highlighted an increase in group A streptococcal (GAS) infections since 2022 in Europe and the United States. Streptococcus pyogenes can cause limited skin or mucosal disease, but can also present as severe invasive disease necessitating critical care. We performed a multicenter retrospective study of patients with GAS infections recently admitted to Belgian intensive care units (ICUs) since January 2022. We describe patient characteristics and investigate the molecular epidemiology of the S. pyogenes strains involved. RESULTS: Between January 2022 and May 2023, a total of 86 cases (56 adults, 30 children) with GAS disease were admitted to critical care in the university hospitals of Leuven, Antwerp and Liège. We noted a strikingly high incidence of severe community-acquired pneumonia (sCAP) (45% of adults, 77% of children) complicated with empyema in 45% and 83% of adult and pediatric cases, respectively. Two-thirds of patients with S. pyogenes pneumonia had viral co-infection, with influenza (13 adults, 5 children) predominating. Other disease presentations included necrotizing fasciitis (23% of adults), other severe skin/soft tissue infections (16% of adults, 13% of children) and ear/nose/throat infections (13% of adults, 13% of children). Cardiogenic shock was frequent (36% of adults, 20% of children). Fifty-six patients (65%) had toxic shock syndrome. Organ support requirements were high and included invasive mechanical ventilation (77% of adults, 50% of children), renal replacement therapy (29% of adults, 3% of children) and extracorporeal membrane oxygenation (20% of adults, 7% of children). Mortality was 21% in adults and 3% in children. Genomic analysis of S. pyogenes strains from 55 out of 86 patients showed a predominance of emm1 strains (73%), with a replacement of the M1global lineage by the toxigenic M1UK lineage (83% of emm1 strains were M1UK). CONCLUSIONS: The recent rise of severe GAS infections (2022-23) is associated with introduction of the M1UK lineage in Belgium, but other factors may be at play-including intense circulation of respiratory viruses and potentially an immune debt after the COVID pandemic. Importantly, critical care physicians should include S. pyogenes as causative pathogen in the differential diagnosis of sCAP

    Autoantibodies neutralizing type I IFNs are present in ~4% of uninfected individuals over 70 years old and account for ~20% of COVID-19 deaths

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    Publisher Copyright: © 2021 The Authors, some rights reserved.Circulating autoantibodies (auto-Abs) neutralizing high concentrations (10 ng/ml; in plasma diluted 1:10) of IFN-alpha and/or IFN-omega are found in about 10% of patients with critical COVID-19 (coronavirus disease 2019) pneumonia but not in individuals with asymptomatic infections. We detect auto-Abs neutralizing 100-fold lower, more physiological, concentrations of IFN-alpha and/or IFN-omega (100 pg/ml; in 1:10 dilutions of plasma) in 13.6% of 3595 patients with critical COVID-19, including 21% of 374 patients >80 years, and 6.5% of 522 patients with severe COVID-19. These antibodies are also detected in 18% of the 1124 deceased patients (aged 20 days to 99 years; mean: 70 years). Moreover, another 1.3% of patients with critical COVID-19 and 0.9% of the deceased patients have auto-Abs neutralizing high concentrations of IFN-beta. We also show, in a sample of 34,159 uninfected individuals from the general population, that auto-Abs neutralizing high concentrations of IFN-alpha and/or IFN-omega are present in 0.18% of individuals between 18 and 69 years, 1.1% between 70 and 79 years, and 3.4% >80 years. Moreover, the proportion of individuals carrying auto-Abs neutralizing lower concentrations is greater in a subsample of 10,778 uninfected individuals: 1% of individuals 80 years. By contrast, auto-Abs neutralizing IFN-beta do not become more frequent with age. Auto-Abs neutralizing type I IFNs predate SARS-CoV-2 infection and sharply increase in prevalence after the age of 70 years. They account for about 20% of both critical COVID-19 cases in the over 80s and total fatal COVID-19 cases.Peer reviewe

    A Novel Multiscale Cross-Entropy Method Applied to Navigation Data Acquired with a Bike Simulator

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    Vitamin D Fortification of Consumption Cow’s Milk: Health, Nutritional and Technological Aspects. A Multidisciplinary Lecture of the Recent Scientific Evidence

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    Vitamin D is essential in assuring bone health at all stages of life, but its non-skeletal effects are also essential: This vitamin impacts the physiology of the immune system, skeletal muscles and adipose tissue, glucose metabolism, skin, cardiovascular and reproductive systems, neuro-cognitive functions and cell division. The incidence of vitamin D deficiency is widespread worldwide, at any age, in young and healthy subjects, as well as in pregnant women and the elderly population, due to several factors, including inadequate sunlight exposure, skin pigmentation and coverage, adiposity, lifestyle and low dietary intakes. To overcome this problem, the fortification of foods that are consumed on a daily basis, such as milk, is strongly advisable. This opinion paper aims to discuss, in a multidisciplinary way, the current evidence supporting the importance of vitamin D in health and disease and the role of milk as an optimal carrier of this vitamin, to promote adequate intakes, highlighting its unique physico-chemical characteristics linked to both fat globule membrane and casein micelle structure. Moreover, it addresses the impact of industrial processing and storage of consumption milk on the stability of these structures, thus in determining vitamin D bioavailability and the achievement of adequate intakes

    Orthostatic hypotension and neurocognitive disorders in older women: Results from the EPIDOS cohort study

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    International audienceBackground : Although it is well-admitted that cardiovascular health affects cognition, the association between orthostatic hypotension (OH) and cognition remains unclear. The objectives of the present study were i) to determine among the EPIDOS cohort (EPIdémiologie de l’OStéoporose) whether OH was cross-sectionally associated with cognitive impairment at baseline, and ii) whether baseline OH could predict incident cognitive decline after 7 years of follow-up.Methods : Systolic and Diastolic Blood Pressure (SBP and DBP) changes while standing (ie, ΔSBP and ΔDBP, in %) were measured at baseline among 2,715 community-dwelling older women aged 75 years and older using no antihypertensive drugs from the French EPIDOS cohort. OH was defined as a decrease in SBP ≥20 mmHg and/or a decrease in DBP ≥10 mmHg within 3 min after standing. Cognitive impairment was defined as a Short Portable Mental Status Questionnaire (SPMSQ) score <8 (/10). Among those without cognitive impairment at baseline, a possible incident onset of cognitive decline was then sought after 7 years of follow-up among 257 participants.Results : Baseline ΔSBP was associated with baseline cognitive impairment (adjusted OR = 1.01, p = 0.047), but not with incident onset of cognitive decline after 7 years (adjusted OR = 0.98, p = 0.371). Neither baseline OH nor baseline ΔDBP were associated with cognitive impairment neither at baseline (p = 0.426 and p = 0.325 respectively) nor after 7 years (p = 0.180 and p = 0.345 respectively).Conclusions : SBP drop while standing, but neither OH per se nor DBP drop while standing, was associated with baseline cognitive impairment in older women. The relationship between OH and cognitive impairment appears more complex than previously expected

    Anatomic correlation of the mini-mental state examination: A voxel-based morphometric study in older adults

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    The clinical utility of the Mini-Mental State Examination (MMSE) and its shorter version (SMMSE) is still debated. There is a need to better understand the neuroanatomical correlates of these cognitive tests. The objective of this cross-sectional study was to determine whether lower MMSE and SMMSE scores correlated with focal brain volume reduction in older adults. Participants from the GAIT study (n = 207; mean, 70.9±5.9 years; 57% female; mean MMSE 26.2±3.9; mean SMMSE 5.1±1.1) were evaluated using the MMSE and SMMSE and received a 1.5-Tesla MRI scan of the brain. Cortical gray and white matter subvolumes were automatically segmented using Statistical Parametric Mapping. Age, gender, education level, and total intracranial volume were included as potential confounders. We found correlations between the MMSE score and specific cortical regions of the limbic system including the hippocampus, amygdala, cingulate gyrus, and parahippocampal gyrus, independently of the diagnostic category (i.e., mild cognitive impairment or Alzheimer disease or controls). Regarding correlations with the SMMSE score, only one cluster in the left hippocampus was identified, which overlapped with the cluster that was positively correlated with the MMSE score. There were no correlations with the volume of white matter. In conclusion, worse MMSE and SMMSE scores were associated with gray matter atrophy mainly in the limbic system. This finding highlights that atrophy of specific brain regions are related to performance on the MMSE and the SMMSE tests, and provides new insights into the cognitive function probed by these tests
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