89 research outputs found

    Mechanical Activation of Al-Oxyhydroxide Minerals – Physicochemical Changes, Reactivity and Relevance to Bayer Process

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    Overview of our research on ‘structure and reactivity’ of gibbsite and boehmite under varied conditions of mechanical activation, e.g. milling energy and presence of a second phase is presented. Bulk and surface changes induced in the solids by milling are characterized in terms of morphology, particle size distribution, specific surface area and nature of porosity, crystallite size and zeta potential. Results on enhanced amorphisation of gibbsite in presence of a second phase (quartz, hematite etc), changes in zeta potential of gibbsite due to loss of texture during milling and anomalous decrease in surface area of boehmite during milling are reported. Reactivity of the activated solids in sodium hydroxide and variation in thermal transformation temperatures is correlated with physicochemical characteristics of the samples and plausible explanation for the observed correlations presented. Significance of the results with specific reference to bauxite and alumina processing in Bayer process is highlighted

    Positive airway pressure (PAP) treatment reduces glycated hemoglobin (HbA1c) levels in obstructive sleep apnea patients with concomitant weight loss: Longitudinal data from the ESADA

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    Patients with obstructive sleep apnea (OSA) are at increased risk of developing metabolic disease such as diabetes. The effects of positive airway pressure on glycemic control are contradictory. We therefore evaluated the change in glycated hemoglobin (HbA1c) in a large cohort of OSA patients after long-term treatment with positive airway pressure. HbA1c levels were assessed in a subsample of the European Sleep Apnea Database [n=1608] at baseline and at long-term follow up with positive airway pressure therapy (mean 378.9±423.0 days). In a regression analysis, treatment response was controlled for important confounders. Overall, HbA1c decreased from 5.98±1.01% to 5.93±0.98% (p=0.001). Patient subgroups with a more pronounced HbA1c response included patients with diabetes (−0.15±1.02, p=0.019), those with severe OSA baseline (−0.10±0.68, p=0.005), those with morbid obesity (−0.20±0.81, p<0.001). The strongest HbA1c reduction was observed in patients with a concomitant weight reduction >5 kilos (−0.38±0.99, p<0.001). In robust regression analysis, severe OSA (p=0.038) and morbid obesity (p=0.005) at baseline, and weight reduction >5 kilos (p<0.001) during follow up were independently associated with a reduction of HbA1c following PAP treatment. In contrast, PAP treatment alone without weight reduction was not associated with significant Hb1Ac reduction. In conclusion, positive airway pressure therapy is associated with HbA1c reduction in patients with severe OSA, in morbidly obese patients. and most obviously in those with significant weight lost during the follow-up. Our study underlines the importance to combine positive airway pressure use with adjustments in lifestyle to substantially modify metabolic complications in OSA

    Sleep-disordered breathing-do we have to change gears in heart failure?

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    The majority of patients with heart failure have sleep-disordered breathing (SDB)-with central (rather than obstructive) sleep apnoea becoming the predominant form in those with more severe disease. Cyclical apnoeas and hypopnoeas are associated with sleep disturbance, hypoxaemia, haemodynamic changes, and sympathetic activation. Such patients have a worse prognosis than those without SDB. Mask-based therapies of positive airway pressure targeted at SDB can improve measures of sleep quality and partially normalise the sleep and respiratory physiology, but recent randomised trials of cardiovascular outcomes in central sleep apnoea have been neutral or suggested the possibility of harm, likely from increased sudden death. Further randomised outcome studies (with cardiovascular mortality and hospitalisation endpoints) are required to determine whether mask-based treatment for SDB is appropriate for patients with chronic systolic heart failure and obstructive sleep apnoea, for those with heart failure with preserved ejection fraction, and for those with decompensated heart failure. New therapies for sleep apnoea-such as implantable phrenic nerve stimulators-also require robust assessment. No longer can the surrogate endpoints of improvement in respiratory and sleep metrics be taken as adequate therapeutic outcome measures in patients with heart failure and sleep apnoea

    Thermal analysis of mechanochemically activated glass

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    POPE study: rationale and methodology of a study to phenotype patients with COPD in Central and Eastern Europe

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    Zuzana Zbozinkova,1 Adam Barczyk,2 Ruzena Tkacova,3 Arschang Valipour,4 Neven Tudoric,5 Kirill Zykov,6 Attila Somfay,7 Marc Miravitlles,8 Vladimir Koblizek91Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czech Republic; 2Department of Pneumology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland; 3Department of Respiratory Medicine, Faculty of Medicine, P.J. Safarik University, Kosice, Slovakia; 4Department of Respiratory and Critical Care Medicine, Ludwig-Boltzmann-Institute for COPD and Respiratory Epidemiology, Otto-Wagner-Spital, Wien, Austria; 5School of Medicine Zagreb, University Hospital Dubrava, Zagreb, Croatia; 6Laboratory of Pulmonology, Moscow State University of Medicine and Dentistry named after A.I. Evdokimov, Moscow, Russia; 7Department of Pulmonology, University of Szeged, Deszk, Hungary; 8Pneumology Department, Hospital Universitari Vall d’Hebron, CIBER de Enfermedades Respiratorias (CIBERES), Barcelona, Spain; 9Department of Pneumology, Faculty of Medicine in Hradec Kralove, University Hospital Hradec Kralove, Charles University in Prague, Hradec Kralove, Czech RepublicIntroduction: Chronic obstructive pulmonary disease (COPD) constitutes a major health challenge in Central and Eastern European (CEE) countries. However, clinical phenotypes, symptom load, and treatment habits of patients with COPD in CEE countries remain largely unknown. This paper provides a rationale for phenotyping COPD and describes the methodology of a large study in CEE.Methods/design: The POPE study is an international, multicenter, observational cross-sectional survey of patients with COPD in CEE. Participation in the study is offered to all consecutive outpatients with stable COPD in 84 centers across the CEE region if they fulfill the following criteria: age >40 years, smoking history ≥10 pack-years, a confirmed diagnosis of COPD with postbronchodilator FEV1/FVC ,0.7, and absence of COPD exacerbation ≥4 weeks. Medical history, risk factors for COPD, comorbidities, lung function parameters, symptoms, and pharmaceutical and nonpharmaceutical treatment are recorded. The POPE project is registered in ClinicalTrials.gov with the identifier NCT02119494.Outcomes: The primary aim of the POPE study was to phenotype patients with COPD in a real-life setting within CEE countries using predefined classifications. Secondary aims of the study included analysis of differences in symptoms, and diagnostic and therapeutic behavior in participating CEE countries.Conclusion: There is increasing acceptance toward a phenotype-driven therapeutic approach in COPD. The POPE study may contribute to reveal important information regarding phenotypes and therapy in real-life CEE.Keywords: COPD, phenotypes, Central Europe, Eastern Europe, study, GOLD, comorbidit
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