| 1. |
- Espen Yttri, Karl, et al.
(author)
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Trends, composition, and sources of carbonaceous aerosol at the Birkenes Observatory, northern Europe, 2001-2018
- 2021
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In: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 21:9, s. 7149-7170
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Journal article (peer-reviewed)abstract
- We present 18 years (2001-2018) of aerosol measurements, including organic and elemental carbon (OC and EC), organic tracers (levoglucosan, arabitol, mannitol, trehalose, glucose, and 2-methyltetrols), trace elements, and ions, at the Birkenes Observatory (southern Norway) - a site representative of the northern European region. The OC=EC (2001-2018) and the levoglucosan (2008-2018) time series are the longest in Europe, with OC=EC available for the PM10, PM2:5 (fine), and PM10-2:5 (coarse) size fractions, providing the opportunity for a nearly 2-decade-long assessment. Using positive matrix factorization (PMF), we identify seven carbonaceous aerosol sources at Birkenes: mineraldust- dominated aerosol (MIN), traffic/industry-like aerosol (TRA/IND), short-range-transported biogenic secondary organic aerosol (BSOASRT), primary biological aerosol particles (PBAP), biomass burning aerosol (BB), ammoniumnitrate- dominated aerosol (NH4NO3), and (one low carbon fraction) sea salt aerosol (SS). We observed significant (p < 0:05), large decreases in EC in PM10 (-3:9%yr-1) and PM2:5 (-4:2%yr-1) and a smaller decline in levoglucosan (-2:8%yr-1), suggesting that OC=EC from traffic and industry is decreasing, whereas the abatement of OC=EC from biomass burning has been slightly less successful. EC abatement with respect to anthropogenic sources is further supported by decreasing EC fractions in PM2:5 (-3:9%yr-1) and PM10 (-4:5%yr-1). PMF apportioned 72% of EC to fossil fuel sources; this was further supported by PMF applied to absorption photometer data, which yielded a two-factor solution with a low aerosol ngstr m exponent (AAED0.93) fraction, assumed to be equivalent black carbon from fossil fuel combustion (eBCFF), contributing 78% to eBC mass. The higher AAE fraction (AAED2.04) is likely eBC from BB (eBCBB). Source-receptor model calculations (FLEXPART) showed that continental Europe and western Russia were the main source regions of both elevated eBCBB and eBCFF. Dominating biogenic sources explain why there was no downward trend for OC. A relative increase in the OC fraction in PM2:5 (C3:2%yr-1) and PM10 (C2:4%yr-1) underscores the importance of biogenic sources at Birkenes (BSOA and PBAP), which were higher in the vegetative season and dominated both fine (53 %) and coarse (78 %) OC. Furthermore, 77 %-91% of OC in PM2:5, PM10-2:5, and PM10 was attributed to biogenic sources in summer vs. 22 %- 37% in winter. The coarse fraction had the highest share of biogenic sources regardless of season and was dominated by PBAP, except in winter. Our results show a shift in the aerosol composition at Birkenes and, thus, also in the relative source contributions. The need for diverse offline and online carbonaceous aerosol speciation to understand carbonaceous aerosol sources, including their seasonal, annual, and long-term variability, has been demonstrated.
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| 2. |
- Sjöberg, Karin, et al.
(author)
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Multi-decadal surface ozone trends at globally distributed remote locations.
- 2020
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In: Elementa. - : University of California Press. - 2325-1026. ; 8:23
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Journal article (peer-reviewed)abstract
- Extracting globally representative trend information from lower tropospheric ozone observations is extremely difficult due to the highly variable distribution and interannual variability of ozone, and the ongoing shift of ozone precursor emissions from high latitudes to low latitudes. Here we report surface ozone trends at 27 globally distributed remote locations (20 in the Northern Hemisphere, 7 in the Southern Hemisphere), focusing on continuous time series that extend from the present back to at least 1995. While these sites are only representative of less than 25% of the global surface area, this analysis provides a range of regional long-term ozone trends for the evaluation of global chemistry-climate models. Trends are based on monthly mean ozone anomalies, and all sites have at least 20 years of data, which improves the likelihood that a robust trend value is due to changes in ozone precursor emissions and/or forced climate change rather than naturally occurring climate variability. Since 1995, the Northern Hemisphere sites are nearly evenly split between positive and negative ozone trends, while 5 of 7 Southern Hemisphere sites have positive trends. Positive trends are in the range of 0.5–2 ppbv decade–1, with ozone increasing at Mauna Loa by roughly 50% since the late 1950s. Two high elevation Alpine sites, discussed by previous assessments, exhibit decreasing ozone trends in contrast to the positive trend observed by IAGOS commercial aircraft in the European lower free-troposphere. The Alpine sites frequently sample polluted European boundary layer air, especially in summer, and can only be representative of lower free tropospheric ozone if the data are carefully filtered to avoid boundary layer air. The highly variable ozone trends at these 27 surface sites are not necessarily indicative of free tropospheric trends, which have been overwhelmingly positive since the mid-1990s, as shown by recent studies of ozonesonde and aircraft observations.
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| 3. |
- Aas, Wenche, et al.
(author)
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Trends in Air Pollution in Europe, 2000–2019
- 2024
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In: Aerosol and Air Quality Research. - 2071-1409 .- 1680-8584. ; 24:4
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Journal article (peer-reviewed)abstract
- This paper encompasses an assessment of air pollution trends in rural environments in Europe over the 2000–2019 period, benefiting from extensive long-term observational data from the EMEP monitoring network and EMEP MSC-W model computations. The trends in pollutant concentrations align with the decreasing emission patterns observed throughout Europe. Annual average concentrations of sulfur dioxide, particulate sulfate, and sulfur wet deposition have shown consistent declines of 3–4% annually since 2000. Similarly, oxidized nitrogen species have markedly decreased across Europe, with an annual reduction of 1.5–2% in nitrogen dioxide concentrations, total nitrate in the air, and oxidized nitrogen deposition. Notably, emission reductions and model predictions appear to slightly surpass the observed declines in sulfur and oxidized nitrogen, indicating a potential overestimation of reported emission reductions. Ammonia emissions have decreased less compared to other pollutants since 2000. Significant reductions in particulate ammonium have however, been achieved due to the impact of reductions in SOx and NOx emissions. For ground level ozone, both the observed and modelled peak levels in summer show declining trends, although the observed decline is smaller than modelled. There have been substantial annual reductions of 1.8% and 2.4% in the concentrations of PM10 and PM2.5, respectively. Elemental carbon has seen a reduction of approximately 4.5% per year since 2000. A similar reduction for organic carbon is only seen in winter when primary anthropogenic sources dominate. The observed improvements in European air quality emphasize the importance of comprehensive legislations to mitigate emissions.
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| 4. |
- Ahn, J. M., et al.
(author)
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Microcirculatory Resistance Predicts Allograft Rejection and Cardiac Events After Heart Transplantation
- 2021
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In: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097. ; 78:24, s. 2425-2435
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Journal article (peer-reviewed)abstract
- BACKGROUND: Single-center data suggest that the index of microcirculatory resistance (IMR) measured early after heart transplantation predicts subsequent acute rejection. OBJECTIVES: The goal of this study was to validate whether IMR measured early after transplantation can predict subsequent acute rejection and long-term outcome in a large multicenter cohort. METHODS: From 5 international cohorts, 237 patients who underwent IMR measurement early after transplantation were enrolled. The primary outcome was acute allograft rejection (AAR) within 1 year after transplantation. A key secondary outcome was major adverse cardiac events (MACE) (the composite of death, re-transplantation, myocardial infarction, stroke, graft dysfunction, and readmission) at 10 years. RESULTS: IMR was measured at a median of 7 weeks (interquartile range: 3-10 weeks) post-transplantation. At 1 year, the incidence of AAR was 14.4%. IMR was associated proportionally with the risk of AAR (per increase of 1-U IMR; adjusted hazard ratio [aHR]: 1.04; 95% confidence interval [CI]: 1.02-1.06; p < 0.001). The incidence of AAR in patients with an IMR >= 18 was 23.8%, whereas the incidence of AAR in those with an IMR <18 was 6.3% (aHR: 3.93; 95% CI: 1.77-8.73; P = 0.001). At 10 years, MACE occurred in 86 (36.3%) patients. IMR was significantly associated with the risk of MACE (per increase of 1-U IMR; aHR: 1.02; 95% CI: 1.01-1.04; P = 0.005). CONCLUSIONS: IMR measured early after heart transplantation is associated with subsequent AAR at 1 year and clinical events at 10 years. Early IMR measurement after transplantation identifies patients at higher risk and may guide personalized posttransplantation management. Published by Elsevier on behalf of the American College of Cardiology Foundation.
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| 5. |
- Börjesson, Mats, 1965, et al.
(author)
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Brief recommendations for participation in leisure time or competitive sports in athletes-patients with coronary artery disease: Summary of a Position Statement from the Sports Cardiology Section of the European Association of Preventive Cardiology (EAPC)
- 2020
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In: European Journal of Preventive Cardiology. - : Oxford University Press (OUP). - 2047-4873 .- 2047-4881. ; 27:7, s. 770-776
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Journal article (peer-reviewed)abstract
- This paper presents a brief summary of the recommendations from the Sports Cardiology section of the European Association of Preventive Cardiology (EAPC) on sports-participation in patients with coronary artery disease, coronary artery anomalies or spontaneous dissection of the coronary arteries, all entities being associated with myocardial ischaemia.1 Given the wealth of evidence supporting the benefits of exercise for primary and secondary prevention of coronary artery disease, individuals should be restricted from competitive sport only when a substantial risk of adverse event or disease progression is present. These recommendations aim to encourage regular physical activity including participation in sports and, with reasonable precaution, ensure a high level of safety for all individuals with coronary artery disease. The present document is based on available current evidence, but in most instances because of lack of evidence, also on clinical experience and expert opinion.
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| 6. |
- Ge, Yao, et al.
(author)
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Evaluation of modelled versus observed non-methane volatile organic compounds at European Monitoring and Evaluation Programme sites in Europe
- 2024
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In: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 24:13, s. 7699-7729
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Journal article (peer-reviewed)abstract
- Atmospheric volatile organic compounds (VOCs) constitute a wide range of species, acting as precursors to ozone and aerosol formation. Atmospheric chemistry and transport models (CTMs) are crucial to understanding the emissions, distribution, and impacts of VOCs. Given the uncertainties in VOC emissions, lack of evaluation studies, and recent changes in emissions, this work adapts the European Monitoring and Evaluation Programme Meteorological Synthesizing Centre-West (EMEP MSC-W) CTM to evaluate emission inventories in Europe. Here we undertake the first intensive model-measurement comparison of VOCs in 2 decades. The modelled surface concentrations are evaluated both spatially and temporally, using measurements from the regular EMEP monitoring network in 2018 and 2019, as well as a 2022 campaign. To achieve this, we utilised the UK National Atmospheric Emissions Inventory to derive explicit emission profiles for individual species and employed a tracer method to produce pure concentrations that are directly comparable to observations. The degree to which the modelled and measured VOCs agree varies depending on the specific species. The model successfully captures the overall spatial and temporal variations of major alkanes (e.g. ethane, n-butane) and unsaturated species (e.g. ethene, benzene) but less so for propane, i-butane, and ethyne. This discrepancy underscores potential issues in the boundary conditions for the latter species and in their primary emissions from, in particular, the solvent and road transport sectors. Specifically, potential missing propane emissions and issues with its boundary conditions are highlighted by large model underestimations and smaller propane-To-ethane ratios compared to the measurement. Meanwhile, both the model and measurements show strong linear correlations among butane isomers and among pentane isomers, indicating common sources for these pairs of isomers. However, modelled ratios of i-butane to n-butane and i-pentane to n-pentane are approximately one-Third of the measured ratios, which is largely driven by significant emissions of n-butane and n-pentane from the solvent sector. This suggests issues with the speciation profile of the solvent sector, underrepresented contributions from transport and fuel evaporation sectors in current inventories, or both. Furthermore, the modelled ethene-To-ethyne and benzene-To-ethyne ratios differ significantly from measured ratios. The different model performance strongly points to shortcomings in the spatial and temporal patterns and magnitudes of ethyne emissions, especially during winter. For OVOCs, the modelled and measured concentrations of methanal and methylglyoxal show a good agreement, despite a moderate underestimation by the model in summer. This discrepancy could be attributed to an underestimation of contributions from biogenic sources or possibly a model overestimation of their photolytic loss in summer. However, the insufficiency of suitable measurements limits the evaluation of other OVOCs. Finally, model simulations employing the CAMS inventory show slightly better agreements with measurements than those using the Centre on Emission Inventories and Projections (CEIP) inventory. This enhancement is likely due to the CAMS inventory's detailed segmentation of the road transport sector, including its associated sub-sector-specific emission profiles. Given this improvement, alongside the previously mentioned concerns about the model's biased estimations of various VOC ratios, future efforts should focus on a more detailed breakdown of dominant emission sectors (e.g. solvents) and the refinement of their speciation profiles to improve model accuracy.
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| 7. |
- Ciccozzi, Federico, 1983-, et al.
(author)
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Preface of MeSS 2022
- 2022
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In: CEUR Workshop Proceedings. - : CEUR-WS. - 1613-0073. ; 3250
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Journal article (peer-reviewed)
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| 8. |
- Dangmann, C., et al.
(author)
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Resilience in Syrian refugee youth
- 2022
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In: European Journal of Public Health. - : Oxford University Press. - 1101-1262 .- 1464-360X. ; 32:Suppl. 3
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Journal article (peer-reviewed)abstract
- Background: The importance of resilience factors in the positive adaptation of refugee youth is widely recognised. However, their actual mechanism of impact remains under-researched. The aim of this study was therefore to explore protective and promotive resilience mechanisms on both negative and positive mental health outcomes. Promotive resilience is seen as a direct main effect and protective resilience as a moderating effect.Methods: Cross-sectional study with 160 Syrian youth aged 13-24 years, who recently resettled in Norway. A multi-dimensional measure for resilience was used to explore the potential impact of resilience factors on pathways between potentially traumatic events from war and flight (PTE), post-migration stress, mental distress and health-related quality of life (HRQoL). Analyses included regression, moderation and moderated mediation using the PROCESS macro for SPSS.Results: A direct main effect of resilience factors (promotive resilience mechanism) was found for HRQoL and general mental distress, but not for post-traumatic stress disorder (PTSD). No moderating effects of resilience factors (protective resilience mechanism) were found. Post-migration stressors mediated the effects of PTE, and this indirect effect was present at all levels of resilience. Relational and environmental level resilience factors and combined amounts had more impact than individual level factors.Conclusions: Despite high risk exposure and mental distress, resilience was also high. The direct main effect of resilience factors and less impact on PTSD, suggests universal resilience building interventions may be beneficial, compared to exclusively targeting groups with high symptom levels. These interventions should target relational and environmental resilience factors as well as individual coping techniques. Additionally, reducing current stress and symptoms could increase the efficacy of resilience factors already present.
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| 9. |
- Hui, I. S. B., et al.
(author)
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Biocomposites containing poly(lactic acid) and chitosan for 3D printing - Assessment of mechanical, antibacterial and in vitro biodegradability properties
- 2023
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In: Journal of the Mechanical Behavior of Biomedical Materials. - : Elsevier Ltd. - 1751-6161 .- 1878-0180. ; 147
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Journal article (peer-reviewed)abstract
- New bone repair materials are needed for treatment of trauma-and disease-related skeletal defects as they still represent a major challenge in clinical practice. Additionally, new strategies are required to combat orthopedic device-related infections (ODRI), given the rising incidence of total joint replacement and fracture fixation surgeries in increasingly elderly populations. Recently, the convergence of additive manufacturing (AM) and bone tissue engineering (BTE) has facilitated the development of bone healthcare to achieve personalized three-dimensional (3D) scaffolds. This study focused on the development of a 3D printable bone repair material, based on the biopolymers poly(lactic acid) (PLA) and chitosan. Two different types of PLA and chitosan differing in their molecular weight (MW) were explored. The novel feature of this research was the successful 3D printing using biocomposite filaments composed of PLA and 10 wt% chitosan, with clear chitosan entrapment within the PLA matrix confirmed by Scanning Electron Microscopy (SEM) images. Tensile testing of injection molded samples indicated an increase in stiffness, compared to pure PLA scaffolds, suggesting potential for improved load-bearing characteristics in bone scaffolds. However, the potential benefit of chitosan on the biocomposite stiffness could not be reproduced in compression testing of 3D printed cylinders. The antibacterial assays confirmed antibacterial activity of chitosan when dissolved in acetic acid. The study also verified the biodegradability of the scaffolds, with a process producing an acidic environment that could potentially be neutralized by chitosan. In conclusion, the study indicated the feasibility of the proposed PLA/chitosan biocomposite for 3D printing, demonstrating adequate mechanical strength, antibacterial properties and biodegradability, which could serve as a new material for bone repair.
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| 10. |
- Mousavi, Hesam, et al.
(author)
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Nitrogen Enriched Organic Fertilizer (NEO) and Its Effect on Ryegrass Yield and Soil Fauna Feeding Activity under Controlled Conditions
- 2022
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In: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 14:4
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Journal article (peer-reviewed)abstract
- This study aimed to investigate the effects of a new nitrogen-enriched organic-based fertilizer (NEO) on Italian ryegrass (Lolium multiflorum Lam.) yield and soil fauna feeding activity. Nitrogen is transformed from the air to manure by a plasma process. At the farm level, NEO could improve self-sufficiency and sustainability. The work was carried out under controlled conditions in two pot trials. Five fertilization regimes were used: no fertilizer, different amounts of mineral fertilizer, three NEO types, organic fertilizer (untreated manure), and organic fertilizer + different amounts of N in mineral fertilizer, including 14 treatments in trial one and 11 treatments in trial two. Besides evaluating dry matter yields, we utilized the Bait-lamina test system to assess the feeding activity of soil fauna. The results indicated a clear positive impact of nitrogen (N) on ryegrass yield where all fertilizers increased the yield in correspondence with their N availability regardless of the fertilizer type; whereas the yield was highest with mineral fertilizer up to our maximum level of 235 kg N ha−1 in trial one and 175 kg N ha−1 in trial two. The NEO fertilizers yielded in the same range as mineral fertilizers. The same clear pattern was not observed for soil fauna feeding activity. Instead, a tendency was observed where no fertilization tends to give the highest feeding activity. We saw no correlation between the yield and the soil fauna feeding activity. The feeding activity was highest in depth below 5 cm from the soil surface. Feeding activity also increased over time after fertilization. The NEO fertilizers had no more adverse effects on soil fauna feeding activity than other fertilizers. Other factors than fertilization alone are determining the soil fauna feeding activity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
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