| 1. |
- Pennells, Lisa, et al.
(författare)
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Equalization of four cardiovascular risk algorithms after systematic recalibration : individual-participant meta-analysis of 86 prospective studies
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 40:7, s. 621-
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Tidskriftsartikel (refereegranskat)abstract
- Aims: There is debate about the optimum algorithm for cardiovascular disease (CVD) risk estimation. We conducted head-to-head comparisons of four algorithms recommended by primary prevention guidelines, before and after ‘recalibration’, a method that adapts risk algorithms to take account of differences in the risk characteristics of the populations being studied.Methods and results: Using individual-participant data on 360 737 participants without CVD at baseline in 86 prospective studies from 22 countries, we compared the Framingham risk score (FRS), Systematic COronary Risk Evaluation (SCORE), pooled cohort equations (PCE), and Reynolds risk score (RRS). We calculated measures of risk discrimination and calibration, and modelled clinical implications of initiating statin therapy in people judged to be at ‘high’ 10 year CVD risk. Original risk algorithms were recalibrated using the risk factor profile and CVD incidence of target populations. The four algorithms had similar risk discrimination. Before recalibration, FRS, SCORE, and PCE over-predicted CVD risk on average by 10%, 52%, and 41%, respectively, whereas RRS under-predicted by 10%. Original versions of algorithms classified 29–39% of individuals aged ≥40 years as high risk. By contrast, recalibration reduced this proportion to 22–24% for every algorithm. We estimated that to prevent one CVD event, it would be necessary to initiate statin therapy in 44–51 such individuals using original algorithms, in contrast to 37–39 individuals with recalibrated algorithms.Conclusion: Before recalibration, the clinical performance of four widely used CVD risk algorithms varied substantially. By contrast, simple recalibration nearly equalized their performance and improved modelled targeting of preventive action to clinical need.
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| 2. |
- Helgadottir, Anna, et al.
(författare)
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The same sequence variant on 9p21 associates with myocardial infarction, abdominal aortic aneurysm and intracranial aneurysm
- 2008
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 40:2, s. 217-224
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Tidskriftsartikel (refereegranskat)abstract
- Recently, two common sequence variants on 9p21, tagged by rs10757278-G and rs10811661-T, were reported to be associated with coronary artery disease (CAD)(1-4) and type 2 diabetes (T2D)(5-7), respectively. We proceeded to further investigate the contributions of these variants to arterial diseases and T2D. Here we report that rs10757278-G is associated with, in addition to CAD, abdominal aortic aneurysm (AAA; odds ratio (OR) 1.31, P = 1.2 x 10(-12)) and intracranial aneurysm (OR = 1.29, P = 2.5 x 10(-6)), but not with T2D. This variant is the first to be described that affects the risk of AAA and intracranial aneurysm in many populations. The association of rs10811661-T to T2D replicates in our samples, but the variant does not associate with any of the five arterial diseases examined. These findings extend our insight into the role of the sequence variant tagged by rs10757278-G and show that it is not confined to atherosclerotic diseases.
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| 3. |
- Li, Ka Lok, et al.
(författare)
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Seismicity of the Hengill area, SW Iceland : Details revealed by catalog relocation and collapsing
- 2019
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Ingår i: Journal of Volcanology and Geothermal Research. - : Elsevier BV. - 0377-0273 .- 1872-6097. ; 376, s. 15-26
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Tidskriftsartikel (refereegranskat)abstract
- The spatial distribution of seismicity in the Hengill region, SW Iceland, is analyzed by relocation and collapsing. The Hengill region is a diffuse triple junction with volcano-tectonic activity associated with rifting, tectonic activity on a transecting transform and induced seismicity due to drilling and injection of fluid into geothermal fields. The Icelandic Meteorological Office has compiled 114,000 events over a 20-year period within an area of approximately 600 km2. The events in their catalog are relocated by application of empirical travel-time tables using a non-linear location strategy. The relocations are then redone applying a Bayesian inversion using the catalog event density as a prior. Finally, they are collapsed using the same catalog density as an attractor. We show that this catalog processing reproduces details of the spatial pattern of seismicity that independently emerges from relative relocations of a small subset of the catalog events (swarm activity). In particular, the predominant faulting orientations are reproduced in different parts of the region and the depth distribution of events resembles that obtained by dense deployments in the area. Its depth extent varies between 5 and 7 km in the northern part of the region, where volcanic processes dominate, and between 7 and 8 km in the southern part, where tectonic deformation is predominant. Induced seismicity is shallower than adjacent natural seismicity. An intriguing lineation emerges in the lateral distribution of inferred depth to the brittle-ductile transition in the northern volcanic part of the region, which is parallel to the strike of the fissure swarms in the area. Associating this transition with an isotherm (650 °C), the Hengill volcanic system and its fissure swarm appear to be considerably cooler than the Hrómundartindur system. This may relate to a recent intrusion into the latter or more efficient cooling in the Hengill fissure swarm due to deeper penetrating permeability. In both cases this has potential consequences for geothermal exploitation in the area.
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| 4. |
- Pfeffer, M. A., et al.
(författare)
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SO 2 emission rates and incorporation into the air pollution dispersion forecast during the 2021 eruption of Fagradalsfjall, Iceland
- 2024
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Ingår i: Journal of Volcanology and Geothermal Research. - 0377-0273. ; 449
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Tidskriftsartikel (refereegranskat)abstract
- During the low-effusion rate Fagradalsfjall eruption (19 March – 18 September 2021), the emission of sulfur dioxide (SO2) was frequently measured using ground-based UV spectrometers. The total SO2 emitted during the entire eruption was 970 ± 540 kt, which is only about 6% of the SO2 emitted during the similar length Holuhraun eruption (2014–2015). The eruption was divided into five phases based on visual observations, including the number of active vents and the occurrence of lava fountaining. The SO2 emission rate ranged from 44 ± 19 kg/s in Phase 2 to 85 ± 29 kg/s in Phase 5, with an average of 64 ± 34 kg/s for the entire eruption. There was notable variability in SO2 on short timescales, with measurements on 11 August 2021 ranging from 17 to 78 kg/s. SO2 flux measurements were made using scanning DOAS instruments located at different distances from and orientations relative to the eruption site augmented by traverses. Four hundred and forty-four scan and traverse measurements met quality criteria and were used, along with plume height and meteorological data, to calculate SO2 fluxes while accounting for wind-related uncertainties. A tendency for stronger SO2 flux concurrent with higher amplitude seismic tremor and the occurrence of lava fountaining was observed during Phases 4 and 5 which were characterized by intermittent crater activity including observable effusion of lava and gas release interspersed with long repose times. This tendency was used to refine the calculation of the amount of SO2 emitted during variably vigorous activity. The continuous seismic tremor time series was used to quantify how long during these eruption phases strong/weak activity was exhibited to improve the calculated SO2 flux during these Phases. The total SO2 emissions derived from field measurements align closely with results obtained by combining melt inclusion and groundmass glass analyses with lava effusion rate measurements (910 ± 230 kt SO2). Specifically, utilizing the maximum S content found in evolved melt inclusions and the least remaining S content in accompanying quenched groundmasses provides an identical result between field measurements and the petrological calculations. This suggests that the maximum SO2 release calculated from petrological estimates should be preferentially used to initialize gas dispersion models for basaltic eruptions when other measurements are lacking. During the eruption, the CALPUFF dispersion model was used to forecast ground-level exposure to SO2. The SO2 emission rates measured by DOAS were used as input for the dispersion model, with updates made when a significant change was measured. A detailed analysis of one mid-distance station over the entire eruption shows that the model performed very well at predicting the presence of volcanic SO2 when it was measured. However, it frequently predicted the presence of SO2 that was not measured and the concentrations forecasted had no correlation with the concentrations measured. Various approaches to improve the model forecast were tested, including updating plume height and SO2 flux source terms based on measurements. These approaches did not unambiguously improve the model performance but suggest that improvements might be achieved in more-polluted conditions.
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| 5. |
- Fjalldal, Sigridur B., et al.
(författare)
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Smoking, stages of change and decisional balance in Iceland and Sweden
- 2011
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Ingår i: The Clinical Respiratory Journal. - 1752-6981. ; 5:2, s. 76-83
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Smoking remains a significant health problem. Smoking interventions are important but selection of successful quitters can be difficult. Objective: To characterise smokers with emphasis on two constructs of the transtheoretical model, the stages of change and decisional balance. Methods: A random sample from adults aged 40 and over in Reykjavik, Iceland, and Uppsala, Sweden. Smokers were defined as being in the stage of pre-contemplation (not thinking of quitting within the next 6 months), contemplation (thinking of quitting within the next 6 months) or preparation (thinking of quitting within the next 30 days, having managed to quit for at least 24 h within the last 12 months). Results: A total of 226 participants were smokers: 72 (32%) were in the pre-contemplation stage, 126 (56%) in the contemplation stage and 28 (12%) in the preparation stage. A younger age, higher body mass index (BMI) and higher educational level were significantly related to being in a more advanced stage. A significant association was observed between decisional balance and stages of change such that decreased importance of the positive aspects of smoking and increased importance of the negative aspects of smoking were independently associated with an increased readiness to quit. Conclusion: The motivated smoker is likely to be young and educated with an above average BMI. A smoker in the contemplation stage is likely to maintain the negative aspects of smoking at a high level. Decreasing the value of the pros of smoking may facilitate the shift towards the stage of preparation.
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| 6. |
- Kiemeney, Lambertus A, et al.
(författare)
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A sequence variant at 4p16.3 confers susceptibility to urinary bladder cancer.
- 2010
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 42:5, s. 415-9
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Tidskriftsartikel (refereegranskat)abstract
- Previously, we reported germline DNA variants associated with risk of urinary bladder cancer (UBC) in Dutch and Icelandic subjects. Here we expanded the Icelandic sample set and tested the top 20 markers from the combined analysis in several European case-control sample sets, with a total of 4,739 cases and 45,549 controls. The T allele of rs798766 on 4p16.3 was found to associate with UBC (odds ratio = 1.24, P = 9.9 x 10(-12)). rs798766 is located in an intron of TACC3, 70 kb from FGFR3, which often harbors activating somatic mutations in low-grade, noninvasive UBC. Notably, rs798766[T] shows stronger association with low-grade and low-stage UBC than with more aggressive forms of the disease and is associated with higher risk of recurrence in low-grade stage Ta tumors. The frequency of rs798766[T] is higher in Ta tumors that carry an activating mutation in FGFR3 than in Ta tumors with wild-type FGFR3. Our results show a link between germline variants, somatic mutations of FGFR3 and risk of UBC.
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| 7. |
- Waeijen-Smit, Kiki, et al.
(författare)
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Global mortality and readmission rates following COPD exacerbation-related hospitalisation : a meta-analysis of 65 945 individual patients
- 2024
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Ingår i: ERJ Open Research. - : European Respiratory Society. - 2312-0541. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Exacerbations of COPD (ECOPD) have a major impact on patients and healthcare systems across the world. Precise estimates of the global burden of ECOPD on mortality and hospital readmission are needed to inform policy makers and aid preventive strategies to mitigate this burden. The aims of the present study were to explore global in-hospital mortality, post-discharge mortality and hospital readmission rates after ECOPD-related hospitalisation using an individual patient data meta-analysis (IPDMA) design. Methods A systematic review was performed identifying studies that reported in-hospital mortality, postdischarge mortality and hospital readmission rates following ECOPD-related hospitalisation. Data analyses were conducted using a one-stage random-effects meta-analysis model. This study was conducted and reported in accordance with the PRISMA-IPD statement. Results Data of 65 945 individual patients with COPD were analysed. The pooled in-hospital mortality rate was 6.2%, pooled 30-, 90- and 365-day post-discharge mortality rates were 1.8%, 5.5% and 10.9%, respectively, and pooled 30-, 90- and 365-day hospital readmission rates were 7.1%, 12.6% and 32.1%, respectively, with noticeable variability between studies and countries. Strongest predictors of mortality and hospital readmission included noninvasive mechanical ventilation and a history of two or more ECOPD-related hospitalisations < 12 months prior to the index event. Conclusions This IPDMA stresses the poor outcomes and high heterogeneity of ECOPD-related hospitalisation across the world. Whilst global standardisation of the management and follow-up of ECOPD-related hospitalisation should be at the heart of future implementation research, policy makers should focus on reimbursing evidence-based therapies that decrease (recurrent) ECOPD.
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| 8. |
- Östling, Mikael, et al.
(författare)
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Nanoscaling of MOSFETs and the implementation of Schottky barrier S/D contacts
- 2010
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Ingår i: 2010 27th International Conference on Microelectronics, MIEL 2010 - Proceedings. - 9781424472017 ; , s. 9-13
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Konferensbidrag (refereegranskat)abstract
- This paper provides an overview of metallic source/drain (MSD) Schottky-barrier (SB) MOSFET technology. This technology offers several benefits for scaling CMOS, i.e., extremely low S/D series resistance, sharp junctions from S/D to channel and low temperature processing. A successful implementation of this technology needs to overcome new obstacles such as Schottky barrier height (SBH) engineering and careful control of SALICIDE process. Device design factors such as S/D to gate underlap, Si film thickness and oxide thickness affect device performance owing to their effects on the SB width. Recently, we have invested a lot of efforts on Pt- and Ni-silicide MSD SB-MOSFETs and achieved some promising results. The present work, together with the work of other groups in this field, places silicide MSD SB-MOSFETs as a competitive candidate for future generations of CMOS technology.
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| 9. |
- Östling, Mikael, et al.
(författare)
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Towards Schottky-Barrier Source/Drain MOSFETs
- 2008
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Ingår i: 2008 9TH INTERNATIONAL CONFERENCE ON SOLID-STATE AND INTEGRATED-CIRCUIT TECHNOLOGY, VOLS 1-4. - NEW YORK : IEEE. - 9781424421855 ; , s. 146-149
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Konferensbidrag (refereegranskat)abstract
- This paper provides an overview of metal source/drain (S/D) Schottky-barrier (SB) MOSFET technology. The technology offers several benefits for scaling CMOS, i.e., extremely low source/drain resistance, sharp junctions from S/D to channel and low temperature processing. A successful implementation of the technology needs to overcome new obstacles such as SB height engineering and precise control of silicide growth. Device design factors such as S/D to gate underlap, Si film thickness and oxide thickness affect device performance owing to their effects on the SB width. In the past two years several groups have demonstrated high-performance SB MOSFETs, which places the technology as a promising candidate for future generations of CMOS technology.
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