| 1. |
- Kulmala, M., et al.
(författare)
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General overview: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) - integrating aerosol research from nano to global scales
- 2011
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:24, s. 13061-13143
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we describe and summarize the main achievements of the European Aerosol Cloud Climate and Air Quality Interactions project (EUCAARI). EUCAARI started on 1 January 2007 and ended on 31 December 2010 leaving a rich legacy including: (a) a comprehensive database with a year of observations of the physical, chemical and optical properties of aerosol particles over Europe, (b) comprehensive aerosol measurements in four developing countries, (c) a database of airborne measurements of aerosols and clouds over Europe during May 2008, (d) comprehensive modeling tools to study aerosol processes fron nano to global scale and their effects on climate and air quality. In addition a new Pan-European aerosol emissions inventory was developed and evaluated, a new cluster spectrometer was built and tested in the field and several new aerosol parameterizations and computations modules for chemical transport and global climate models were developed and evaluated. These achievements and related studies have substantially improved our understanding and reduced the uncertainties of aerosol radiative forcing and air quality-climate interactions. The EUCAARI results can be utilized in European and global environmental policy to assess the aerosol impacts and the corresponding abatement strategies.
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| 2. |
- Tan, W., et al.
(författare)
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Atmospheric Chemistry of 2-Amino-2-methyl-1-propanol: A Theoretical and Experimental Study of the OH-Initiated Degradation under Simulated Atmospheric Conditions
- 2021
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 125:34, s. 7502-7519
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Tidskriftsartikel (refereegranskat)abstract
- The OH-initiated degradation of 2-amino-2-methyl-1-propanol [CH3C(NH2)(CH3)CH2OH, AMP] was investigated in a large atmospheric simulation chamber, employing time-resolved online high-resolution proton-transfer reaction-time-of-flight mass spectrometry (PTR-ToF-MS) and chemical analysis of aerosol online PTR-ToF-MS (CHARON-PTR-ToF-MS) instrumentation, and by theoretical calculations based on M06-2X/aug-cc-pVTZ quantum chemistry results and master equation modeling of the pivotal reaction steps. The quantum chemistry calculations reproduce the experimental rate coefficient of the AMP + OH reaction, aligning k(T) = 5.2 x 10(-12) x exp (505/T) cm(3) molecule(-1) s(-1) to the experimental value k(exp,300K) = 2.8 x 10(-11) cm(3) molecule(-1) s(-1). The theoretical calculations predict that the AMP + OH reaction proceeds via hydrogen abstraction from the -CH3 groups (5-10%), -CH2- group, (>70%) and -NH2 group (5-20%), whereas hydrogen abstraction from the -OH group can be disregarded under atmospheric conditions. A detailed mechanism for atmospheric AMP degradation was obtained as part of the theoretical study. The photo-oxidation experiments show 2-amino-2-methylpropanal [CH3C(NH2)(CH3)CHO] as the major gas-phase product and propan-2-imine [(CH3)(2)C=NH], 2-iminopropanol [(CH3)(CH2OH)C=NH], acetamide [CH3C(O)NH2], formaldehyde (CH2O), and nitramine 2-methyl-2-(nitroamino)-1-propanol [AMPNO(2), CH3C(CH3)(NHNO2)-CH2OH] as minor primary products; there is no experimental evidence of nitrosamine formation. The branching in the initial H abstraction by OH radicals was derived in analyses of the temporal gas-phase product profiles to be B-CH3/B-CH2/B-NH2 = 6:70:24. Secondary photo-oxidation products and products resulting from particle and surface processing of the primary gas-phase products were also observed and quantified. All the photo-oxidation experiments were accompanied by extensive particle formation that was initiated by the reaction of AMP with nitric acid and that mainly consisted of this salt. Minor amounts of the gas-phase photo-oxidation products, including AMPNO(2), were detected in the particles by CHARON-PTR-ToF-MS and GCxGC-NCD. Volatility measurements of laboratory-generated AMP nitrate nanoparticles gave Delta H-vap = 80 +/- 16 kJ mol(-1) and an estimated vapor pressure of (1.3 +/- 0.3) x 10(-5) Pa at 298 K. The atmospheric chemistry of AMP is evaluated and a validated chemistry model for implementation in dispersion models is presented.
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| 3. |
- Tomić, I., et al.
(författare)
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Shake-table testing of a stone masonry building aggregate : overview of blind prediction study
- 2023
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Ingår i: Bulletin of Earthquake Engineering. - : Springer Science and Business Media LLC. - 1570-761X .- 1573-1456.
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Tidskriftsartikel (refereegranskat)abstract
- City centres of Europe are often composed of unreinforced masonry structural aggregates, whose seismic response is challenging to predict. To advance the state of the art on the seismic response of these aggregates, the Adjacent Interacting Masonry Structures (AIMS) subproject from Horizon 2020 project Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA) provides shake-table test data of a two-unit, double-leaf stone masonry aggregate subjected to two horizontal components of dynamic excitation. A blind prediction was organized with participants from academia and industry to test modelling approaches and assumptions and to learn about the extent of uncertainty in modelling for such masonry aggregates. The participants were provided with the full set of material and geometrical data, construction details and original seismic input and asked to predict prior to the test the expected seismic response in terms of damage mechanisms, base-shear forces, and roof displacements. The modelling approaches used differ significantly in the level of detail and the modelling assumptions. This paper provides an overview of the adopted modelling approaches and their subsequent predictions. It further discusses the range of assumptions made when modelling masonry walls, floors and connections, and aims at discovering how the common solutions regarding modelling masonry in general, and masonry aggregates in particular, affect the results. The results are evaluated both in terms of damage mechanisms, base shear forces, displacements and interface openings in both directions, and then compared with the experimental results. The modelling approaches featuring Discrete Element Method (DEM) led to the best predictions in terms of displacements, while a submission using rigid block limit analysis led to the best prediction in terms of damage mechanisms. Large coefficients of variation of predicted displacements and general underestimation of displacements in comparison with experimental results, except for DEM models, highlight the need for further consensus building on suitable modelling assumptions for such masonry aggregates.
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| 4. |
- Acciarresi, M., et al.
(författare)
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Prestroke CHA(2)DS(2)-VASc Score and Severity of Acute Stroke in Patients with Atrial Fibrillation: Findings from RAF Study
- 2017
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Ingår i: Journal of Stroke & Cerebrovascular Diseases. - : Elsevier BV. - 1052-3057. ; 26:6, s. 1363-1368
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: The aim of this study was to investigate for a possible association between both prestroke CHA(2)DS(2)-VASc score and the severity of stroke at presentation, as well as disability and mortality at 90 days, in patients with acute stroke and atrial fibrillation (AF). Methods: This prospective study enrolled consecutive patients with acute ischemic stroke, AF, and assessment of prestroke CHA2DS2-VASc score. Severity of stroke was assessed on admission using the National Institutes of Health Stroke Scale (NIHSS) score (severe stroke: NIHSS >= 10). Disability and mortality at 90 days were assessed by the modified Rankin Scale (mRS < 3 or >= 3). Multiple logistic regression was used to correlate prestroke CHA(2)DS(2)-VASc and severity of stroke, as well as disability and mortality at 90 days. Results: Of the 1020 patients included in the analysis, 606 patients had an admission NIHSS score lower and 414 patients higher than 10. At 90 days, 510 patients had mRS >= 3. A linear correlation was found between the prestroke CHA(2)DS(2)-VASc score and severity of stroke (P = .001). On multivariate analysis, CHA(2)DS(2)-VASc score correlated with severity of stroke (P = .041) and adverse functional outcome (mRS = 3) (P = .001). A logistic regression with the receiver operating characteristic graph procedure (C-statistics) evidenced an area under the curve of .60 (P = .0001) for severe stroke. Furthermore, a correlation was found between prestroke CHA(2)DS(2)-VASc score and lesion size. Conclusions: In patients with AF, in addition to the risk of stroke, a high CHA(2)DS(2)-VASc score was independently associated with both stroke severity at onset and disability and mortality at 90 days.
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| 5. |
- Altavilla, R., et al.
(författare)
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Anticoagulation After Stroke in Patients With Atrial Fibrillation: To Bridge or Not With Low-Molecular-Weight Heparin?
- 2019
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 50:8, s. 2093-2100
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose- Bridging therapy with low-molecular-weight heparin reportedly leads to a worse outcome for acute cardioembolic stroke patients because of a higher incidence of intracerebral bleeding. However, this practice is common in clinical settings. This observational study aimed to compare (1) the clinical profiles of patients receiving and not receiving bridging therapy, (2) overall group outcomes, and (3) outcomes according to the type of anticoagulant prescribed. Methods- We analyzed data of patients from the prospective RAF and RAF-NOACs studies. The primary outcome was defined as the composite of ischemic stroke, transient ischemic attack, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding observed at 90 days after the acute stroke. Results- Of 1810 patients who initiated oral anticoagulant therapy, 371 (20%) underwent bridging therapy with full-dose low-molecular-weight heparin. Older age and the presence of leukoaraiosis were inversely correlated with the use of bridging therapy. Forty-two bridged patients (11.3%) reached the combined outcome versus 72 (5.0%) of the nonbridged patients (P=0.0001). At multivariable analysis, bridging therapy was associated with the composite end point (odds ratio, 2.3; 95% CI, 1.4-3.7; P<0.0001), as well as ischemic (odds ratio, 2.2; 95% CI, 1.3-3.9; P=0.005) and hemorrhagic (odds ratio, 2.4; 95% CI, 1.2-4.9; P=0.01) end points separately. Conclusions- Our findings suggest that patients receiving low-molecular-weight heparin have a higher risk of early ischemic recurrence and hemorrhagic transformation compared with nonbridged patients.
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| 6. |
- Cerny, Radovan, et al.
(författare)
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NaSc(BH4)(4): A Novel Scandium-Based Borohydride
- 2010
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:2, s. 1357-1364
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Tidskriftsartikel (refereegranskat)abstract
- A new alkaline transition-metal borohydride, NaSc(BH4)(4), is presented. The compound has been studied using a combination of in situ synchrotron radiation powder X-ray diffraction, thermal analysis, and vibrational and NMR spectroscopy. NaSc(BH4)(4) forms at ambient conditions in ball-milled mixtures of sodium borohydride and ScCl3. A new tertiary chloride Na3ScCl6 (P2(1)/n, a = 6.7375(3) angstrom, b = 7.1567(3) angstrom, c = 9,9316(5) angstrom, beta = 90.491(3)degrees, V = 478.87(4) angstrom(3)), isostructural to Na3TiCl6, was identified as an additional phase in all samples. This indicates that the formation of NaSc(BH4)(4) differs from a simple metathesis reaction, and the highest scandium borohydride yield (22 wt %) was obtained with a reactant ratio of ScCl3/NaBH4 of 1:2. NaSc(BH4)(4) crystallizes in the orthorhombic crystal system with the space group symmetry Cmcm (a = 8.170(2) angstrom, b = 11.875(3) angstrom, c = 9.018(2) angstrom, V = 874.9(3) angstrom(3)). The Structure of NaSc(BH4)(4) consists of isolated homoleptic scandium tetraborohydride anions, [Sc(BH4)(4)](-), located inside slightly distorted trigonal Na-6 prisms (each second prism is empty, triangular angles of 55.5 and 69.1 degrees). The experimental results show that each Sc3+ is tetrahedrally Surrounded by four BH4 tetrahedra with a 12-fold coordination of H to Sc, while Na+ is surrounded by six BH4 tetrahedra in a quite regular octahedral coordination with a (6 + 12)-fold coordination of H to Na. The packing of Na+ cations and [Sc(BH)(4))(4)](-) anions in NaSc(BH4)(4) is a deformation variant of the hexagonal NiAs structure type. NaSc(BH4)(4) is stable from RT up to similar to 410 K, Where the compound melts and then releases hydrogen in two rapidly occurring steps between 440 and 490 K and 495 and 540 K. Thermal expansion of NaSc(BH4)(4) between RT and 408 K is anisotropic, and lattice parameter b shows strong anomaly close to the melting temperature.
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| 7. |
- McGinnis, Paul B, et al.
(författare)
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Transitioning from CHIP to CHIRP: blending community health development with community-based participatory research.
- 2010
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Ingår i: Family & community health. - 1550-5057. ; 33:3, s. 228-37
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Tidskriftsartikel (refereegranskat)abstract
- In 2006, a community health development model was used to engage citizens in Jefferson County, Oregon, around local health concerns. Childhood obesity emerged as a priority health issue. In 2007, a research component was introduced by Oregon Health & Science University to help the community garner resources and inform the field. This case study describes the collaboration between the Mountain View Community Health Improvement Partnership and Oregon Health & Science University to increase the number of county children at a healthy weight. Research and projects occurred simultaneously since community members are motivated by action, and research is a slower process.
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| 8. |
- Michelsen, Hope A., et al.
(författare)
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A Review of Terminology Used to Describe Soot Formation and Evolution under Combustion and Pyrolytic Conditions
- 2020
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 14:10, s. 12470-12490
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Tidskriftsartikel (refereegranskat)abstract
- This review presents a glossary and review of terminology used to describe the chemical and physical processes involved in soot formation and evolution and is intended to aid in communication within the field and across disciplines. There are large gaps in our understanding of soot formation and evolution and inconsistencies in the language used to describe the associated mechanisms. These inconsistencies lead to confusion within the field and hinder progress in addressing the gaps in our understanding. This review provides a list of definitions of terms and presents a description of their historical usage. It also addresses the inconsistencies in the use of terminology in order to dispel confusion and facilitate the advancement of our understanding of soot chemistry and particle characteristics. The intended audience includes senior and junior members of the soot, black carbon, brown carbon, and carbon black scientific communities, researchers new to the field, and scientists and engineers in associated fields with an interest in carbonaceous material production via high-temperature hydrocarbon chemistry.
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| 9. |
- Paciaroni, M., et al.
(författare)
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Hemorrhagic transformation in patients with acute ischemic stroke and atrial fibrillation: Time to initiation of oral anticoagulant therapy and outcomes
- 2018
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Ingår i: Journal of the American Heart Association. - 2047-9980. ; 7:22
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Tidskriftsartikel (refereegranskat)abstract
- Background—In patients with acute ischemic stroke and atrial fibrillation, early anticoagulation prevents ischemic recurrence but with the risk of hemorrhagic transformation (HT). The aims of this study were to evaluate in consecutive patients with acute stroke and atrial fibrillation (1) the incidence of early HT, (2) the time to initiation of anticoagulation in patients with HT, (3) the association of HT with ischemic recurrences, and (4) the association of HT with clinical outcome at 90 days. Methods and Results—HT was diagnosed by a second brain computed tomographic scan performed 24 to 72 hours after stroke onset. The incidence of ischemic recurrences as well as mortality or disability (modified Rankin Scale scores >2) were evaluated at 90 days. Ischemic recurrences were the composite of ischemic stroke, transient ischemic attack, or systemic embolism. Among the 2183 patients included in the study, 241 (11.0%) had HT. Patients with and without HT initiated anticoagulant therapy after a mean 23.3 and 11.6 days, respectively, from index stroke. At 90 days, 4.6% (95% confidence interval, 2.3-8.0) of the patients with HT had ischemic recurrences compared with 4.9% (95% confidence interval, 4.0-6.0) of those without HT; 53.1% of patients with HT were deceased or disabled compared with 35.8% of those without HT. On multivariable analysis, HT was associated with mortality or disability (odds ratio, 1.71; 95% confidence interval, 1.24-2.35). Conclusions—In patients with HT, anticoagulation was initiated about 12 days later than patients without HT. This delay was not associated with increased detection of ischemic recurrence. HT was associated with increased mortality or disability. © 2018 The Authors.
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| 10. |
- Paciaroni, M., et al.
(författare)
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Prediction of Early Recurrent Thromboembolic Event and Major Bleeding in Patients With Acute Stroke and Atrial Fibrillation by a Risk Stratification Schema The ALESSA Score Study
- 2017
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 48:3, s. 726-732
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purposes-This study was designed to derive and validate a score to predict early ischemic events and major bleedings after an acute ischemic stroke in patients with atrial fibrillation. Methods-The derivation cohort consisted of 854 patients with acute ischemic stroke and atrial fibrillation included in prospective series between January 2012 and March 2014. Older age (hazard ratio 1.06 for each additional year; 95% confidence interval, 1.00-1.11) and severe atrial enlargement (hazard ratio, 2.05; 95% confidence interval, 1.08-2.87) were predictors for ischemic outcome events (stroke, transient ischemic attack, and systemic embolism) at 90 days from acute stroke. Small lesions (1.5 cm) were inversely correlated with both major bleeding (hazard ratio, 0.39; P=0.03) and ischemic outcome events (hazard ratio, 0.55; 95% confidence interval, 0.30-1.00). We assigned to age 80 years 2 points and between 70 and 79 years 1 point; ischemic index lesion >1.5 cm, 1 point; severe atrial enlargement, 1 point (ALESSA score). A logistic regression with the receiver-operating characteristic graph procedure (C statistic) showed an area under the curve of 0.697 (0.632-0.763; P=0.0001) for ischemic outcome events and 0.585 (0.493-0.678; P=0.10) for major bleedings. Results-The validation cohort consisted of 994 patients included in prospective series between April 2014 and June 2016. Logistic regression with the receiver-operating characteristic graph procedure showed an area under the curve of 0.646 (0.529-0.763; P=0.009) for ischemic outcome events and 0.407 (0.275-0.540; P=0.14) for hemorrhagic outcome events. Conclusions-In acute stroke patients with atrial fibrillation, high ALESSA scores were associated with a high risk of ischemic events but not of major bleedings.
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