| 1. |
- Berg Marklund, Björn, 1988-
(författare)
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Unpacking Digital Game-Based Learning : The complexities of developing and using educational games
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Digital game-based learning has traditionally been examined from an ‘artefact-centric’ perspective that focuses on understanding how game design and principles of learning are, or can be, intertwined. These types of examinations have resulted in many descriptions of games’ educational potential, which has subsequently led to many types of arguments for why games should be used more extensively in formal education. However, comparatively little research has been done to understand the educational settings in which many game-based learning processes and educational games are intended to be applied. The relative lack of research on formal education settings has resulted in a scenario where the educational potential of games is well detailed through theory and understood independently of their actual contexts of use, while successful examples of games “making good” on their promises as educational tools remain rare.This thesis explores and describes the various challenges that the realities of formal education present to developers and educators who attempt to work with educational games. In order to examine the multi-faceted nature of educational games, the research has used a qualitative mixed-method approach that entails extensive literature reviews coupled with several case studies that involve educators, students, and developers. Interviews were conducted in order to investigate these actors’ various attitudes towards, and experiences of, educational games and game-based learning. In addition, more in-depth researcher participation methods were employed during case studies to examine the processes involved in developing, integrating, and using educational games in formal settings. The research revealed obstacles which indicate that processes associated with “traditional” game development are incommensurable with educational game development. Furthermore, the research demonstrates that the use of games in formal education introduces heavy demands on the recipient organisations’ infrastructures, cultures, and working processes. So, while games created for “formal” and “informal” use are superficially similar, the different contexts in which they are used make them distinctly different from one another. The conclusion of this research is that educational games manifest a unique mixture of utility, gameplay, and context-dependent meaning-making activities. Educational games cannot be understood if they are only seen as a teaching utility or only as a game experience. To make educational games viable, both educators and developers need to alter their working processes, their own perceptions of games and teaching, as well as the way they collaborate and communicate with each other and other actors within the educational game ‘system’. The thesis thus argues that a more systems-oriented understanding of educational games, where the game artefact is not treated separately from the context of use, is necessary for both research and practice in the field to progress. To contribute to such an understanding of educational games, a comprehensive model (dubbed the Utility, Gameplay, and Meaning Model) of the ‘educational game system’ is presented, as well as a series of recommendations and considerations to help developers and educators navigate the complex processes involved in creating and using educational games.
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| 2. |
- Sayols-Baixeras, Sergi, et al.
(författare)
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Streptococcus Species Abundance in the Gut Is Linked to Subclinical Coronary Atherosclerosis in 8973 Participants From the SCAPIS Cohort
- 2023
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 0009-7322 .- 1524-4539. ; 148:6, s. 459-472
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Tidskriftsartikel (refereegranskat)abstract
- Background: Gut microbiota have been implicated in atherosclerotic disease, but their relation with subclinical coronary atherosclerosis is unclear. This study aimed to identify associations between the gut microbiome and computed tomography-based measures of coronary atherosclerosis and to explore relevant clinical correlates.Methods: We conducted a cross-sectional study of 8973 participants (50 to 65 years of age) without overt atherosclerotic disease from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study). Coronary atherosclerosis was measured using coronary artery calcium score and coronary computed tomography angiography. Gut microbiota species abundance and functional potential were assessed with shotgun metagenomics sequencing of stool, and associations with coronary atherosclerosis were evaluated with multivariable regression models adjusted for cardiovascular risk factors. Associated species were evaluated for association with inflammatory markers, metabolites, and corresponding species in saliva.Results: The mean age of the study sample was 57.4 years, and 53.7% were female. Coronary artery calcification was detected in 40.3%, and 5.4% had at least 1 stenosis with >50% occlusion. Sixty-four species were associated with coronary artery calcium score independent of cardiovascular risk factors, with the strongest associations observed for Streptococcus anginosus and Streptococcus oralis subsp oralis (P<1×10-5). Associations were largely similar across coronary computed tomography angiography-based measurements. Out of the 64 species, 19 species, including streptococci and other species commonly found in the oral cavity, were associated with high-sensitivity C-reactive protein plasma concentrations, and 16 with neutrophil counts. Gut microbial species that are commonly found in the oral cavity were negatively associated with plasma indole propionate and positively associated with plasma secondary bile acids and imidazole propionate. Five species, including 3 streptococci, correlated with the same species in saliva and were associated with worse dental health in the Malmö Offspring Dental Study. Microbial functional potential of dissimilatory nitrate reduction, anaerobic fatty acid β-oxidation, and amino acid degradation were associated with coronary artery calcium score.Conclusions: This study provides evidence of an association of a gut microbiota composition characterized by increased abundance of Streptococcus spp and other species commonly found in the oral cavity with coronary atherosclerosis and systemic inflammation markers. Further longitudinal and experimental studies are warranted to explore the potential implications of a bacterial component in atherogenesis.
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| 3. |
- Al-Gburi, Majid
(författare)
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Restraint Effects in Early Age Concrete Structures
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. These situations could result in reduced service life and in significantly increased maintenance cost of structures. Therefore it is important for construction companies to avoid these cracks.Volumetric deformations in early age concrete are caused by changes in temperature and/or the moisture state. If such movements are restrained, stresses will occur. If the tensile stresses are high enough, there will be a damage failure in tension and visible cracks arise. These stresses are always resulting from a self-balancing of forces, either within the young concrete bodyalone, i.e. without structural joints to other structures, or from the young concrete in combination with adjacent structures through structural joints.The decisive situation within a young concrete body alone is typically high stresses at the surface when the temperature is near the peak temperature within the body. This situation occur rather early for ordinary structures, say within a few days after casting for structures up to about some meters thickness, but for very massive structures like large concrete dams, it might take months and even years to reach the maximum tensile stresses at the surface. Usually this type of cracks is denoted "surface cracks", and in some cases only a temperature calculation may give a good perception to make decisions of the risk of surface cracking.On the other hand, the decisive situation within a young concrete body connected to adjacent structures, might include both risk of surface cracking at some distance away from the structural joint and risk of through cracking starting in the neighborhood of the structural joint. If the young concrete body is small in accordance to the adjacent structure, or, in other words, if thereis an overall high restraint situation in the young concrete, the risk of early surface cracking might be out of question. So, restraint from adjacent structures represents one of the main sources of thermal and shrinkage stresses in a young concrete body.This study is mainly concentrated on establishing the restraint inside the young concrete body counteracted by adjacent structures, and how to estimate the risk of through cracking based on such restraint distributions. The restraint values in the young concrete are calculated with use of the finite element method, FEM. Any spatial structure may be analyzed with respect to the level of restraint. Calculations of risk of cracking are demonstrated with use of existing compensation plane methods, and a novel method denoted equivalent restraint method, ERM, is developed for the use of restraint curves. ERM enables the use of both heating ofthe adjacent structure and/or cooling of the young concrete, which are the most common measures used on site to reduce the risk of early cracking.In a design situation many parameters are to be considered, like type of cement, different concrete mixes, temperature in the fresh concrete, surrounding temperatures, temperature in the adjacent structure, measures on site (heating/cooling/insulation), sequence order of casting.Therefore, in general a lot of estimations concerning risks of cracking are to be performed. The main objective with the present study is to develop methods speeding up and shorten the design process.Furthermore, established restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the slab, wall, and roof for the typical structure Tunnel. It has been shown that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, results from the neural network can be represented by a series of basic weight and response functions, which enables that the restraint curves easily can be made available to any engineer without use of complicated software.A new casting technique is proposed to reduce restraint in the newly cast concrete with a new arrangement of the structural joint to the existing old concrete. The proposed technique is valid for the typical structure wall-on-slab using one structural joint. This casting method means that the lower part of the wall is cast together with the slab, and that part is called a kicker. It hasbeen proven by the beam theory and demonstrated by numerical calculations that there is a clear reduction in the restraint from the slab to the wall using kickers.Restraint is affected by casting sequence as well as boundary conditions and joint position between old and new concrete elements. This study discusses the influence of different possible casting sequences for the typical structure wall-on-slab and slab-on-ground. The aim is to identify the sequence with the lowest restraint to reduce the risk of cracking.
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| 4. |
- Baldanzi, Gabriel, et al.
(författare)
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OSA Is Associated With the Human Gut Microbiota Composition and Functional Potential in the Population-Based Swedish CardioPulmonary bioImage Study
- 2023
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Ingår i: Chest. - : Elsevier. - 0012-3692 .- 1931-3543. ; 164:2, s. 503-516
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obstructive sleep apnea (OSA) is a common sleep-breathing disorder linked to increased risk of cardiovascular disease. Intermittent hypoxia and intermittent airway obstruction, hallmarks of OSA, have been shown in animal models to induce substantial changes to the gut microbiota composition and subsequent transplantation of fecal matter to other animals induced changes in blood pressure and glucose metabolism.RESEARCH QUESTION: Does obstructive sleep apnea in adults associate with the composition and metabolic potential of the human gut microbiota?STUDY DESIGN AND METHODS: We used respiratory polygraphy data from up to 3,570 individuals aged 50-64 from the population-based Swedish CardioPulmonary bioImage Study combined with deep shotgun metagenomics of fecal samples to identify cross-sectional associations between three OSA parameters covering apneas and hypopneas, cumulative sleep time in hypoxia and number of oxygen desaturation events with gut microbiota composition. Data collection about potential confounders was based on questionnaires, on-site anthropometric measurements, plasma metabolomics, and linkage with the Swedish Prescribed Drug Register.RESULTS: We found that all three OSA parameters were associated with lower diversity of species in the gut. Further, the OSA-related hypoxia parameters were in multivariable-adjusted analysis associated with the relative abundance of 128 gut bacterial species, including higher abundance of Blautia obeum and Collinsela aerofaciens. The latter species was also independently associated with increased systolic blood pressure. Further, the cumulative time in hypoxia during sleep was associated with the abundance of genes involved in nine gut microbiota metabolic pathways, including propionate production from lactate. Lastly, we observed two heterogeneous sets of plasma metabolites with opposite association with species positively and negatively associated with hypoxia parameters, respectively.INTERPRETATION: OSA-related hypoxia, but not the number of apneas/hypopneas, is associated with specific gut microbiota species and functions. Our findings lay the foundation for future research on the gut microbiota-mediated health effects of OSA.
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| 5. |
- Bergström, Göran, 1964, et al.
(författare)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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Ingår i: Circulation. - Philadelphia : American Heart Association. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 6. |
- Blissing, Björn
(författare)
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Driving in Virtual Reality : Investigations in Effects of Latency and Level of Virtuality
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When developing new active safety systems or improving existing systems, conducting performance evaluations is necessary. By performing these evaluations during early development stages, potential problems can be identified and mitigated before the system moves into the production phase.Testing active safety systems can be difficult since the characteristic scenarios may have complex interactions. Using real vehicles for performing these types of scenarios is difficult, expensive, and potentially dangerous. Alternative methods, such as using inflatable targets, scale models, computer simulations or driving simulators, also suffer from drawbacks. Consequently, using virtual reality as an alternative to the traditional methods has been proposed. In this case, a real vehicle is driven while wearing a head-mounted display that presents the scenario to the driver.This research aims to investigate the potential of such technology. Specifically, this work investigates how the chosen technology affects the driver. This investigation has been conducted through a literature review. A test platform was constructed, and two user studies using normal drivers were performed. The first study focused on the effects of visual time delays on driver behavior. This study revealed that lateral behavior changes with added time delays, whereas longitudinal behavior appears unaffected. The second study investigated how driver behavior is affected by different modes of virtuality. This study demonstrated that drivers perceived mixed reality as more difficult than virtual reality.The main contribution of this work is the detailed understanding of how time delays and different modes of virtuality affect drivers. This is important knowledge for selecting which scenarios are suitable for evaluation using virtual reality.
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| 7. |
- Dekkers, Koen, et al.
(författare)
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An online atlas of human plasma metabolite signatures of gut microbiome composition.
- 2022
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Human gut microbiota produce a variety of molecules, some of which enter the bloodstream and impact health. Conversely, dietary or pharmacological compounds may affect the microbiota before entering the circulation. Characterization of these interactions is an important step towards understanding the effects of the gut microbiota on health. In this cross-sectional study, we used deep metagenomic sequencing and ultra-high-performance liquid chromatography linked to mass spectrometry for a detailed characterization of the gut microbiota and plasma metabolome, respectively, of 8583 participants invited at age 50 to 64 from the population-based Swedish CArdioPulmonary bioImage Study. Here, we find that the gut microbiota explain up to 58% of the variance of individual plasma metabolites and we present 997 associations between alpha diversity and plasma metabolites and 546,819 associations between specific gut metagenomic species and plasma metabolites in an online atlas ( https://gutsyatlas.serve.scilifelab.se/ ). We exemplify the potential of this resource by presenting novel associations between dietary factors and oral medication with the gut microbiome, and microbial species strongly associated with the uremic toxin p-cresol sulfate. This resource can be used as the basis for targeted studies of perturbation of specific metabolites and for identification of candidate plasma biomarkers of gut microbiota composition.
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| 8. |
- Engström, Rickard, 1972-
(författare)
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Den oberoende mellanmannen : En studie av fastighetsmäklarprofessionen och begreppet ”god fastighetsmäklarsed” i teori och praktik
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Den svenska fastighetsmäklaren intar en roll som oberoende mellanman medomsorgsplikt mot både köpare och säljare, vilket skiljer sig från hurfastighetsmäklaryrket är organiserat på de flesta andra håll i världen. Därav är densvenska modellen värd att studera och analysera. I Sverige regleras yrket i lag.Utövarnas regelefterlevnad kontrolleras av Fastighetsmäklarinspektionen (FMI). Ettviktigt begrepp är ”god fastighetsmäklarsed”. Vad som bedöms vara ”godfastighetsmäklarsed” bestäms genom praxis från FMI och förvaltningsdomstolarna.En disciplinpåföljd från FMI kan bestå av erinran, varning eller återkallelse avregistrering, vilket medför ett yrkesförbud. En disciplinpåföljd kan överklagas tillförvaltningsdomstolarna.Denna avhandling består av en sammanhållande kappa och fyra artiklar sombeskriver fyra olika studier som gjorts för att bättre förstå förutsättningarna för deindivider som verkar som fastighetsmäklare på den svenska bostadsmarknaden. Detövergripande syftet är att beskriva och analysera fastighetsmäklares yrkesroll i ensvensk kontext och speciellt deras roll som oberoende mellanman. Med utgångspunkti tre forskningsfrågor används både kvalitativa och kvantitativa metoder för att samlain och analysera primära och sekundära data. Resultaten visar att verksamma svenskafastighetsmäklare balanserar de utmaningar som kan rymmas inom rollen somoberoende mellanman, men det finns också vissa gränsdragningsproblem avseende”god fastighetsmäklarsed”.FMI utdelar disciplinpåföljder till fastighetsmäklare vid regelöverträdelser. Att ivardagen förhålla sig till regelverk och praxis är svårare för vissa kategorierfastighetsmäklare: yngre fastighetsmäklare får oftare än äldre påföljden erinran, äldrefår oftare än yngre påföljden varning, och fastighetsmäklare verksamma i storstad fåroftare påföljden varning jämfört med fastighetsmäklare på landsbygden.Fastighetsmäklaryrket och professionsutvecklingen studeras i en jämförande studiemellan Australien (Victoria) och Sverige. De svenska branschorganisationerna –Mäklarsamfundet och Fastighetsmäklarförbundet (FMF) – är delaktiga i professionsutvecklingen,bland annat som huvudmän för Fastighetsmarknadens Reklamationsnämnd(FRN) som agerar enligt lagen (2015:671) om alternativ tvistlösning ikonsumentförhållanden. Avhandlingen ger vidare förslag till utveckling av såvälytterligare forskning som av praktiken.
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| 9. |
- Grundmark, Birgitta
(författare)
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Prostate Cancer; Metabolic Risk Factors, Drug Utilisation, Adverse Drug Reactions
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Increased possibilities during the last decades for early detection of prostate cancer have sparked research on preventable or treatable risk factors and on improvements in therapy. Treatments of the disease still entail significant side effects potentially affecting men during the rest of their lives. The studies of the present thesis concern different aspects of prostate cancer from etiological risk factors and factors influencing treatment to an improved methodology for the detection of treatment side effects.Papers I, II, both based in the population based cohort ULSAM (Uppsala Longitudinal Study of Adult Men), investigate possible risk factors of prostate cancer with options for intervention: selenium levels and the metabolic syndrome. The phenomenon of competing risk of death from other causes than prostate cancer and its impact on and importance for choice of statistical methods is also exemplified and discussed for the first time in prostate cancer research.-Smokers with low selenium status have an increased future risk of later development of prostate cancer. Influence of genetic variability appears plausible.-The metabolic syndrome and especially its increased waist circumference component are associated with later development of prostate cancer – taking competing risks of death from other causes into account.Papers III and IV using pharmacoepidemiological methods investigate aspects of drug utilisation in prostate cancer using nationwide and international databases. In Paper III factors influencing anti-androgen use in prostate cancer are investigated, both from a prescriber- and patient perspective. The age and disease risk group of the patient, unsupported scientifically, influence both the prescribers’ choice of dose and the patients’ adherence to treatment.-Adherence, not previously investigated in male cancer patients, was considerably higher than reported for adjuvant breast cancer treatment. Subgroups of men suitable for intervention to increase adherence were identified.Paper IV, investigates the feasibility of improving an established method for screening large adverse drug reactions databases, the proportional reporting ratio (PRR), this by using restricted sub-databases according to treatment area (TA), introducing the concept of PRR-TA.-The PRR-TA method increases the signal-noise relationship of analyses; a finding highly relevant for possibly conserving manual resources in Pharmacovigilance work in a drug-authority setting.
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| 10. |
- Gustafsson, Stefan, et al.
(författare)
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Markers of imminent myocardial infarction
- 2024
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Ingår i: Nature Cardiovascular Research. - : Springer Nature. - 2731-0590.
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Tidskriftsartikel (refereegranskat)abstract
- Myocardial infarction is a leading cause of death globally but is notoriously difficult to predict. We aimed to identify biomarkers of an imminent first myocardial infarction and design relevant prediction models. Here, we constructed a new case–cohort consortium of 2,018 persons without prior cardiovascular disease from six European cohorts, among whom 420 developed a first myocardial infarction within 6 months after the baseline blood draw. We analyzed 817 proteins and 1,025 metabolites in biobanked blood and 16 clinical variables. Forty-eight proteins, 43 metabolites, age, sex and systolic blood pressure were associated with the risk of an imminent first myocardial infarction. Brain natriuretic peptide was most consistently associated with the risk of imminent myocardial infarction. Using clinically readily available variables, we devised a prediction model for an imminent first myocardial infarction for clinical use in the general population, with good discriminatory performance and potential for motivating primary prevention efforts.
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