| 61. |
- Bersani, Marco, et al.
(författare)
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Combined EXAFS, XRD, DRIFTS, and DFT Study of Nano Copper Based Catalysts for CO2 Hydrogenation
- 2016
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 6:9, s. 5823-5833
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Tidskriftsartikel (refereegranskat)abstract
- Highly monodispersed CuO nanoparticles (NPs) were synthesized via continuous hydrothermal flow synthesis (CHFS) and then tested as catalysts for CO2 hydrogenation. The catalytic behavior of unsupported 11 nm sized nanoparticles from the same batch was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD), and catalytic testing, under CO2/H-2 in the temperature range 25-500 degrees C in consistent experimental conditions. This was done to highlight the relationship among structural evolution, surface products, and reaction yields; the experimental results were compared with modeling predictions based on density functional theory (DFT) simulations of the CuO system. In situ DRIFTS revealed the formation of surface formate species at temperatures as low as 70 degrees C. DFT calculations of CO2 hydrogenation on the CuO surface suggested that hydrogenation reduced the CuO surface to Cu2O, which facilitated the formation of formate. In situ EXAFS supported a strong correlation between the Cu2O phase fraction and the formate peak intensity, with the maxima corresponding to where Cu2O was the only detectable phase at 170 degrees C, before the onset of reduction to Cu at 190 degrees C. The concurrent phase and crystallite size evolution were monitored by in situ XRD, which suggested that the CuO NPs were stable in size before the onset of reduction, with smaller Cu2O crystallites being observed from 130 degrees C. Further reduction to Cu from 190 C was followed by a rapid decrease of surface formate and the detection of adsorbed CO from 250 degrees C; these results are in agreement with heterogeneous catalytic tests where surface CO was observed over the same temperature range. Furthermore, CH4 was detected in correspondence with the decomposition of formate and formation of the Cu phase, with a maximum conversion rate of 2.8% measured at 470 degrees C (on completely reduced copper), supporting the indication of independent reaction pathways for the conversion of CO2 to CH4 and CO that was suggested by catalytic tests. The resulting Cu NPs had a final crystallite size of ca. 44 nm at 500 degrees C and retained a significantly active surface.
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| 62. |
- Boudier, Anne, et al.
(författare)
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Ten-Year Follow-up of Cluster-based Asthma Phenotypes in Adults A Pooled Analysis of Three Cohorts
- 2013
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X .- 1535-4970. ; 188:5, s. 550-560
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: The temporal stability of adult asthma phenotypes identified using clustering methods has never been addressed. Longitudinal cluster-based methods may provide novel insights in the study of the natural history of asthma. Objectives: To compare the stability of cluster-based asthma phenotype structures a decade apart in adults and to address the individuals' phenotypic transition across these asthma phenotypes. Methods: The latent transition analysis was applied on longitudinal data (twice, 10 yr apart) from 3,320 adults with asthma who took part in the European Community Respiratory Health Survey, the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults, or the Epidemiological Study on Genetics and Environment of Asthma. Nine variables covering personal and phenotypic characteristics measured twice, 10 years apart, were simultaneously considered. Measurements and Main Results: Latent transition analysis identifies seven asthma phenotypes (prevalence range, 8.4-20.8%), mainly [GRAPHICS] characterized by the level of asthma symptoms ( low, moderate, high), the allergic status, and pulmonary function. Phenotypes observed 10 years apart showed strong similarities. The probability of membership in the same asthma phenotype at both times varied across phenotypes from 54 to 88%. Different transition patterns were observed across phenotypes. Transitions toward increased asthma symptoms were more frequently observed among nonallergic phenotypes as compared with allergic phenotypes. Results showed a strong stability of the allergic status over time. Conclusions: Adult asthma phenotypes identified by a clustering approach, 10 years apart, were highly consistent. This study is the first to model the probabilities of transitioning over time between comprehensive asthma phenotypes.
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| 63. |
- Bresin, Roberto, 1963-, et al.
(författare)
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Expressive sonification of footstep sounds
- 2010
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Ingår i: Proceedings of ISon 2010. - Stockholm, Sweden : KTH Royal Institute of Technology. ; , s. 51-54
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Konferensbidrag (refereegranskat)abstract
- In this study we present the evaluation of a model for the interactive sonification of footsteps. The sonification is achieved by means of specially designed sensored-shoes which control the expressive parameters of novel sound synthesis models capable of reproducing continuous auditory feedback for walking. In a previousstudy, sounds corresponding to different grounds were associated to different emotions and gender. In this study, we used an interactive sonification actuated by the sensored-shoes for providing auditory feedback to walkers. In an experiment we asked subjects to walk (using the sensored-shoes) with four different emotional intentions (happy, sad, aggressive, tender) and for each emotion we manipulated the ground texture sound four times (wood panels, linoleum, muddy ground, and iced snow). Preliminary results show that walkers used a more active walking style (faster pace) when the sound of the walking surface was characterized by an higher spectral centroid (e.g. iced snow), and a less active style (slower pace) when the spectral centroid was low (e.g. muddy ground). Harder texture sounds lead to more aggressive walking patters while softer ones to more tender and sad walking styles.
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| 64. |
- Bruno, Roberto, et al.
(författare)
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Comparative Study of the Kinetic Properties of Proton and Alpha Beams in the Alfvénic Wind Observed by SWA-PAS On Board Solar Orbiter
- 2024
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 969:2
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Tidskriftsartikel (refereegranskat)abstract
- The problems of heating and acceleration of solar wind particles are of significant and enduring interest in astrophysics. The interactions between waves and particles are crucial in determining the distributions of proton and alpha particles, resulting in non-Maxwellian characteristics, including temperature anisotropies and particle beams. These processes can be better understood as long as the beam can be separated from the core for the two major components of the solar wind. We utilized an alternative numerical approach that leverages the clustering technique employed in machine learning to differentiate the primary populations within the velocity distribution rather than employing the conventional bi-Maxwellian fitting method. Separation of the core and beam revealed new features for protons and alphas. We estimated that the total temperature of the two beams was slightly higher than that of their respective cores, and the temperature anisotropy for the cores and beams was larger than 1. We concluded that the temperature ratio between alphas and protons largely over 4 is due to the presence of a massive alpha beam, which is approximately 50% of the alpha core. We provided evidence that the alpha core and beam populations are sensitive to Alfvénic fluctuations and the surfing effect found in the literature can be recovered only when considering the core and beam as a single population. Several similarities between proton and alpha beams would suggest a common and local generation mechanism not shared with the alpha core, which may not have necessarily been accelerated and heated locally.
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| 65. |
- Cazzoletti, Lucia, et al.
(författare)
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Asthma control in Europe : a real-world evaluation based on an international population-based study
- 2007
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 120:6, s. 1360-1367
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Tidskriftsartikel (refereegranskat)abstract
- Background: Epidemiologic evidence related to asthma control in patients from the general population is scanty. Objectives: We sought to assess asthma control in several European centers according to the Global Initiative for Asthma (GINA) guidelines and to investigate its determinants. Methods: In the European Community Respiratory Health Survey 11 (1999-2002), 1241 adults with asthma were identified and classified into inhaled corticosteroid (ICS) users and non-ICS users in the last year. Control was assessed in both groups by using the GINA proposal (controlled, partly controlled, and uncontrolled asthma), and it was related to potential determinants. Results: Only 15% (95% CI, 12% to 19%) of subjects who had used ICSs in the last year and 45% (95% CI, 41% to 50%) of non-ICS users had their asthma under control; individuals with uncontrolled asthma accounted for 49% (95% CI, 44% to 53%) and 18% (95% CI, 15% to 21%), respectively. Among ICS users, the prevalence of uncontrolled asthma showed great variability across Europe, ranging from 20% (95% CI, 7% to 41%; Iceland) to 67% (95% CI, 35% to 90%; Italy). Overweight status, chronic cough and phlegm, and sensitization to Cladosporium species were associated with poor control in ICS users. About 65% and 87% of ICS users with uncontrolled and partly controlled asthma, respectively, were on a medication regimen that was less than recommended by the GINA guidelines. Conclusion: Six of 7 European asthmatic adults using ICSs in the last year did not achieve good disease control. The large majority of subjects with poorly controlled asthma were using antiasthma drugs in a suboptimal way. A wide variability in asthma control emerged across Europe. Clinical implications: Greater attention should be paid to asthma management and to the implementation of the GINA guidelines.
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| 66. |
- Cazzoletti, Lucia, et al.
(författare)
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Asthma Severity According to Global Initiative for Asthma and Its Determinants : An International Study
- 2010
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 151:1, s. 70-79
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Tidskriftsartikel (refereegranskat)abstract
- Background: The identification of the factors associated with severe asthma may shed some light on its etiology and on the mechanisms of its development. We aimed to describe asthma severity using the Global Initiative for Asthma (GINA) classification and to investigate its determinants in a cross-sectional, population-based sample in Europe. Methods: In the European Community Respiratory Health Survey II (1999-2002), 1,241 adults with asthma were identified. Severity was assessed using the 2002 GINA classification (intermittent, mild persistent, moderate persistent, severe persistent) and it was related to potential determinants by a multinomial logistic model, using the intermittent group as the reference category for relative risk ratios. Results: About 30% of asthmatic subjects were affected by moderate-to-severe asthma. Sensitization to Cladosporium was associated with a more than 5-fold greater risk of having (mild, moderate or severe) persistent asthma than intermittent asthma. Persistent asthma was positively associated with sensitization to house dust mite, nonseasonal asthma, an older age at asthma onset, and chronic cough and phlegm. Sensitization to cat increased the risk of severe asthma only. Smoking was more strongly associated with asthma severity in men, while rhinitis was more strongly associated with asthma severity in women. Conclusions: One third of the asthmatic population have moderate-to-severe asthma. Sensitization to perennial indoor allergens, particularly Cladosporium, is strongly associated with asthma severity. The role of smoking and rhinitis in determining asthma severity may differ between the sexes, and it should be further investigated. Copyright (C) 2009 S. Karger AG, Basel
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| 67. |
- Cerveri, Isa, et al.
(författare)
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The Impact of Cigarette Smoking on Asthma : A Population-Based International Cohort Study
- 2012
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Ingår i: International Archives of Allergy and Immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 158:2, s. 175-183
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Tidskriftsartikel (refereegranskat)abstract
- Background: The prevalence rates of smoking in subjects with asthma have frequently been reported as similar to those in the general population; however, available data are not up-to-date. There is only limited and somewhat conflicting information on the long-term effects of smoking on health outcomes among population-based cohorts of subjects with asthma. We aimed to investigate changes in smoking habits and their effects on forced expiratory volume in 1 s (FEV(1)) in subjects with asthma in comparison with the rest of the population, focusing on the healthy smoker effect. Methods: We studied 9,092 subjects without asthma and 1,045 with asthma at baseline who participated in both the European Community Respiratory Health Survey I (20-44 years old in 1991-1993) and II (1999-2002). Results: At follow-up, smoking was significantly less frequent among subjects with asthma than in the rest of the population (26 vs. 31%; p < 0.001). Subjects with asthma who were already ex-smokers at the beginning of the follow-up in the 1990s had the highest mean asthma score (number of reported asthma-like symptoms, range 0-5), probably as a result of the healthy smoker effect (2.80 vs. 2.44 in never smokers, 2.19 in quitters and 2.24 in smokers; p < 0.001). The influence of smoking on FEV(1) decline did not depend on asthma status. Smokers had the highest proportion of subjects with chronic cough/phlegm (p < 0.01). Conclusion: One out of 4 subjects with asthma continues smoking and reports significantly more chronic cough and phlegm than never smokers and ex-smokers. This stresses the importance of smoking cessation in all patients with asthma, even in those with less severe asthma.
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| 68. |
- Cerveri, Isa, et al.
(författare)
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Underestimation of airflow obstruction among young adults using FEV1/FVC<70% as a fixed cut-off : a longitudinal evaluation of clinical and functional outcomes
- 2008
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Ingår i: Thorax. - : BMJ. - 0040-6376 .- 1468-3296. ; 63:12, s. 1040-1045
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of airflow obstruction is particularly important among young adults because they are more likely to benefit from intervention. Using the forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) (FEV1/FVC) <70% fixed ratio, airflow obstruction may be underdiagnosed. The lower limit of normal (LLN), which is statistically defined by the lower fifth percentile of a reference population, is physiologically appropriate but it still needs a clinical validation.Methods: To evaluate the characteristics and longitudinal outcomes of subjects misidentified as normal by the fixed ratio with respect to the LLN, 6249 participants (aged 20-44 years) in the European Community Respiratory Health Survey were examined and divided into three groups (absence of airflow obstruction by the LLN and the fixed ratio; presence of airflow obstruction only by the LLN; presence of airflow obstruction by the two criteria) for 1991-1993. LLN equations were obtained from normal non-smoking participants. A set of clinical and functional outcomes was evaluated in 1999-2002.Results: The misidentified subjects were 318 (5.1%); only 45.6% of the subjects with airflow obstruction by the LLN were also identified by the fixed cut-off. At baseline, FEV1 (107%, 97%, 85%) progressively decreased and bronchial hyperresponsiveness (slope 7.84, 6.32, 5.57) progressively increased across the three groups. During follow-up, misidentified subjects had a significantly higher risk of developing chronic obstructive pulmonary disease and a significantly higher use of health resources (medicines, emergency department visits/hospital admissions) because of breathing problems than subjects without airflow obstruction (p<0.001).Conclusions: Our findings show the importance of using statistically derived spirometric criteria to identify airflow obstruction.
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| 69. |
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| 70. |
- Corsico, Angelo G, et al.
(författare)
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Factors affecting adherence to asthma treatment in an international cohort of young and middle-aged adults
- 2007
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 101:6, s. 1363-1367
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Tidskriftsartikel (refereegranskat)abstract
- Background A major reason of the poor control of asthma is that patients fail to adhere to their treatment. The aim of the study was to identify factors affecting changes in asthma treatment adherence in an international cohort. Methods A follow-up study was carried out by means of a structured clinical interview in 971 subjects with asthma from 12 countries who participated in both the European Community Respiratory Health Survey: ECRHS-I (1990–94) and ECRHS-II (1998–2002). Subjects were considered adherent if they reported they normally took all the prescribed drugs. A logistic model was used to study the adjusted effect of the determinants. Results The net change in adherence to anti-asthmatic treatment per 10 years of follow-up was −2% (95% CI: −9.5, 5.5), 7.5% (−2.6, 17.6), 15.0% (6.6, 23.5) and 19.8% (4.1, 35.5), respectively, in Nordic, Mediterranean, Continental and extra-European areas. Among the 428 non-adherent subjects in ECRHS-I, having regular consultations with health care professionals was the strongest predictor of increased adherence (OR 3.32; 95% CI: 1.08–10.17). Among the 543 adherent subjects in ECRHS-I, using inhaled corticosteroids significantly predicted a persistence of adherence (OR 2.04; 95% CI: 1.11–3.75). No effect of gender, age, duration of the disease, smoking habit and educational level was observed. Conclusions Our findings highlight the key role of doctors and nurses in educating and regularly reviewing the patients and support the efforts for an improvement of clinical communication.
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