2,845 research outputs found

    Uphill walking at iso-efficiency speeds

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    Uphill walking gait has been extensively studied, but the optimal uphill speed able to enhance the metabolic demand without increasing fatigability has so far received little attention. Therefore, the aim of this study was to assess the metabolic/kinematic demand at constant speed (6 km\ub7h 121 G0 level, G2 2% uphill, G7 7% uphill) and at iso-efficiency speeds (G2IES 5.2 km\ub7h 121 2% uphill and G7IES 3.9 km\ub7h 121 7% uphill). For this aim, physically active women (n:24, Age 33.40 \ub1 4.97 years, BMI 21.62 \ub1 2.06 kg/m-2) after an 8-min warm-up were studied on a treadmill for 10\u2b9 for every walking condition with a 5\u2b9 rest in between. Average heart rate (AVG-HR), rating of perceived exertion (RPE) and kinematic variables (stance time, swing time, stride length, stride cycle, stride-length variability, stride-cycle variability and internal work) were studied. Modif\ufeffications in stance time, stride length and stride cycle (p<0.005), and lower internal-work values (p<0.001) occurred in G7IES in comparison to the other conditions. Swing time was significantly modified only in G7IES compared to G0 and G7 (p<0.001 and p<0.005, respectively). Stride-length variability and stride-cycle variability were higher in G7IES compared to the other conditions (p<0.001). G7 induced the highest AVG-HR (p<0.005) and RPE (p<0.001) compared to the other conditions. This study demonstrates that by applying the equation for uphill walking gait, it is possible to maintain a similar metabolic demand and RPE at iso-efficiency speeds during uphill compared to level walking, inducing at the same time a modification of the kinematic parameters of walking gait performed at the same slope condition

    Effect of inhaled bronchodilators on inspiratory capacity and dyspnoea at rest in COPD

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    It has been shown that patients with chronic obstructive pulmonary disease (COPD) develop dynamic hyperinflation (DH), which contributes to dyspnoea and exercise intolerance. Formoterol, salmeterol and oxitropium have been recommended for maintenance therapy in COPD patients, but their effect on DH has only been assessed for salmeterol. The aim of the present study was to compare the acute effect of four inhaled bronchodilators (salbutamol, formoterol, salmeterol and oxitropium) and placebo on forced expiratory volume in one second, inspiratory capacity, forced vital capacity and dyspnoea in COPD patients. A cross-over, randomised, double-blind, placebo-controlled study was carried out on 20 COPD patients. Patients underwent pulmonary function testing and dyspnoea evaluation, in basal condition and 5, 15, 30, 60 and 120 min after bronchodilator or placebo administration. The results indicate that in chronic obstructive pulmonary disease patients with decreased baseline inspiratory capacity, there was a much greater increase of inspiratory capacity after bronchodilator administration, which correlated closely with the improvement of dyspnoea sensation at rest. For all bronchodilators used, inspiratory capacity reversibility should be tested at 30 min following the bronchodilator. On average, formoterol elicited the greatest increase in inspiratory capacity than the other bronchodilators used, though the difference was significant only with salmeterol and oxitropium. The potential advantage of formoterol needs to be tested in a larger patient population

    Monocyte Distribution Width (MDW) as novel inflammatory marker with prognostic significance in COVID-19 patients

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    Monocyte Distribution Width (MDW), a new cytometric parameter correlating with cytomorphologic changes occurring upon massive monocyte activation, has recently emerged as promising early biomarker of sepsis. Similar to sepsis, monocyte/macrophage subsets are considered key mediators of the life-threatening hyper-inflammatory disorder characterizing severe COVID-19. In this study, we longitudinally analyzed MDW values in a cohort of 87 COVID-19 patients consecutively admitted to our hospital, showing significant correlations between MDW and common inflammatory markers, namely CRP (p < 0.001), fibrinogen (p < 0.001) and ferritin (p < 0.01). Moreover, high MDW values resulted to be prognostically associated with fatal outcome in COVID-19 patients (AUC = 0.76, 95% CI: 0.66\u20130.87, sensitivity 0.75, specificity 0.70, MDW threshold 26.4; RR = 4.91, 95% CI: 1.73\u201313.96; OR = 7.14, 95% CI: 2.06\u201324.71). This pilot study shows that MDW can be useful in the monitoring of COVID-19 patients, as this innovative hematologic biomarker is: (1) easy to obtain, (2) directly related to the activation state of a fundamental inflammatory cell subset (i.e. monocytes, pivotal in both cytokine storm and sepsis immunopathogenesis), (3) well correlated with clinical severity of COVID-19-associated inflammatory disorder, and, in turn, (4) endowed with relevant prognostic significance. Additional studies are needed to define further the clinical impact of MDW testing in the management of COVID-19 patients

    Expansion of plasmablasts and loss of memory B cells in peripheral blood from COVID-19 patients with pneumonia

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    Studies on the interactions between SARS-CoV-2 and humoral immunity are fundamental to elaborate effective therapies including vaccines. We used polychromatic flow cytometry, coupled with unsupervised data analysis and principal component analysis (PCA), to interrogate B cells in untreated patients with COVID-19 pneumonia. COVID-19 patients displayed normal plasma levels of the main immunoglobulin classes, of antibodies against common antigens or against antigens present in common vaccines. However, we found a decreased number of total and na\uefve B cells, along with decreased percentages and numbers of memory switched and unswitched B cells. On the contrary, IgM+ and IgM 12 plasmablasts were significantly increased. In vitro cell activation revealed that B lymphocytes showed a normal proliferation index and number of dividing cells per cycle. PCA indicated that B-cell number, naive and memory B cells but not plasmablasts clustered with patients who were discharged, while plasma IgM level, C-reactive protein, D-dimer, and SOFA score with those who died. In patients with pneumonia, the derangement of the B-cell compartment could be one of the causes of the immunological failure to control SARS-Cov2, have a relevant influence on several pathways, organs and systems, and must be considered to develop vaccine strategies

    Visualisation of the Interaction Between Acidithiobacillus Ferrooxidans and Oil Shale by Atomic Force Microscopy

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    This study visually documents the mechanical contact and interaction between the bacterial cells of two biogeocenotically different strains of Acidithiobacillus ferrooxidans (At. ferrooxidans) and oil shale containing pyrite. Atomic force microscopy (AFM) imaging was used to visualise initial interaction between the microorganisms and the surface minerals of an oil shale and to evaluate bacterial effects in the first hours of the bioleaching process. Acidithiobacillus ferrooxidans was attached to the shale surface already after 2 h, and after 48 h, numerous cells covered the surface with a biofilm. After 5 day incubation with At. ferrooxidans, AFM imaging revealed ellipsoid etched pits that represent footprints left by detached cells. Combining AFM surface imaging and leaching analysis following bacterial colonisation of oil shale layers demonstrates that an initial attachment to the surface is necessary for the leaching and that later on, once a sufficient concentration of Fe2+ ions in the solution is achieved, cells detach to become free cells, and leaching occurs primarily by the Fe3+. This experiment confirmed that microorganisms isolated from sites in which a particular substrate is found will demonstrate stronger binding to that substrate

    New drugs for non-alcoholic steatohepatitis and HIV infection: great expectations with a great absent?

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    In recent years, there has been an increasing number of clinical trials for the treatment of non‐alcoholic steatohepatitis (NASH). People living with HIV (PLWH) are commonly excluded from these studies, usually due to concerns over drug‐drug interactions (DDI) associated with antiretroviral therapy (ART). The Steatohepatitis in HIV Emerging Research (SHIVER) Network, a group of international experts in hepatology and infectious diseases, discusses our current understanding on the interaction between HIV and NASH, and the issues related to the inclusion of PLWH in NASH clinical trials. Recent trials addressing NASH treatment in PLWH are discussed. The risk of DDI between ART and aramchol, cenicriviroc, elafibranor, obeticholic acid and resmetirom (MGL‐3196), which are currently in phase III trials for the treatment of NASH, are reviewed. Finally, a model for trial design to include PLWH is proposed, strongly advocating for the scientific community to include this group as a sub‐population within studies

    CHANNEL CAPACITY OF THE MACRO-DIVERSITY SC SYSTEM IN THE PRESENCE OF KAPPA-MU FADING AND CORRELATED SLOW GAMMA FADING

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    In this paper macrodiversity system consisting of two microdiversity SC (Selection Combiner) receivers and one macrodiversity SC receiver are analyzed. Independent κ-μ fading and correlated slow Gamma fading are present at the inputs to the microdiversity SC receivers. For this system model, analytical expression for the probability density of the signal at the output of the macrodiversity receiver SC, and the output capacity of the macrodiversity SC receiver are calculated. The obtained results are graphically presented to show the impact of Rician κ factor, the shading severity of the channel c, the number of clusters µ and correlation coefficient ρ on the probability density of the signal at the output of the macrodiversity system and channel capacity at the output of the macrodiversity system. Based on the obtained results it is possible to analyze the real behavior of the macrodiversity system in the presence of  κ-μ fading

    Mastiha has efficacy in immune-mediated inflammatory diseases through a microRNA-155 Th17 dependent action

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    Mastiha is a natural nutritional supplement with known anti-inflammatory properties. Non-alcoholic fatty liver disease (NAFLD) and Inflammatory bowel disease (IBD) are immune mediated inflammatory diseases that share common pathophysiological features. Mastiha has shown beneficial effects in both diseases. MicroRNAs have emerged as key regulators of inflammation and their modulation by phytochemicals have been extensively studied over the last years. Therefore, the aim of this study was to investigate whether a common route exists in the anti-inflammatory activity of Mastiha, specifically through the regulation of miRNA levels. Plasma miR-16, miR-21 and miR-155 were measured by Real-Time PCR before and after two double blinded and placebo-controlled randomized clinical trials with Mastiha. In IBD and particularly in ulcerative colitis patients in relapse, miR-155 increased in the placebo group (p = 0.054) whereas this increase was prevented by Mastiha. The mean changes were different in the two groups even after adjusting for age, sex and BMI (p = 0.024 for IBD and p = 0.042). Although the results were not so prominent in NAFLD, miR-155 displayed a downward trend in the placebo group (p = 0.054) whereas the levels did not changed significantly in the Mastiha group in patients with less advanced fibrosis. Our results propose a regulatory role for Mastiha in circulating levels of miR-155, a critical player in T helper-17 (Th17) differentiation and function

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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