| 1. |
- Ferreira, Daniel, et al.
(författare)
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The interactive effect of demographic and clinical factors on hippocampal volume : A multicohort study on 1958 cognitively normal individuals
- 2017
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Ingår i: Hippocampus. - : Wiley. - 1050-9631 .- 1098-1063. ; 27:6, s. 653-667
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease is characterized by hippocampal atrophy. Other factors also influence the hippocampal volume, but their interactive effect has not been investigated before in cognitively healthy individuals. The aim of this study is to evaluate the interactive effect of key demographic and clinical factors on hippocampal volume, in contrast to previous studies frequently investigating these factors in a separate manner. Also, to investigate how comparable the control groups from ADNI, AIBL, and AddNeuroMed are with five population-based cohorts. In this study, 1958 participants were included (100 AddNeuroMed, 226 ADNI, 155 AIBL, 59 BRC, 295 GENIC, 279 BioFiNDER, 398 PIVUS, and 446 SNAC-K). ANOVA and random forest were used for testing between-cohort differences in demographic-clinical variables. Multiple regression was used to study the influence of demographic-clinical variables on hippocampal volume. ANCOVA was used to analyze whether between-cohort differences in demographic-clinical variables explained between-cohort differences in hippocampal volume. Age and global brain atrophy were the most important variables in explaining variability in hippocampal volume. These variables were not only important themselves but also in interaction with gender, education, MMSE, and total intracranial volume. AddNeuroMed, ADNI, and AIBL differed from the population-based cohorts in several demographic-clinical variables that had a significant effect on hippocampal volume. Variability in hippocampal volume in individuals with normal cognition is high. Differences that previously tended to be related to disease mechanisms could also be partly explained by demographic and clinical factors independent from the disease. Furthermore, cognitively normal individuals especially from ADNI and AIBL are not representative of the general population. These findings may have important implications for future research and clinical trials, translating imaging biomarkers to the general population, and validating current diagnostic criteria for Alzheimer's disease and predementia stages.
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| 2. |
- Fransson, Göran, 1968-, et al.
(författare)
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On the Swedish National Grade School for Digital Technologies in Education – GRADE : Expectations and experiences of doctorial students and supervisors
- 2018
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Ingår i: ICERI2018 Proceedings. - Sevilla : IATED. - 9788409059485 ; , s. 769-774
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Konferensbidrag (refereegranskat)abstract
- The Swedish National Graduate School for Digital Technologies in Education (GRADE) is a cooperative venture between six Swedish universities established during 2018. Within the field of educational sciences and in the area of digital technologies in education, GRADE aims to strengthen the expertise in the area and to increase national and international cooperation in research training activities.Over a number of years, and from multitude of sources (cf. Brown & Davis, 2004; Fisher, Higgins & Loveless, 2006; Kafai & Resnick 1996), research has stressed that increased digitalization in schools leads to a complexity that needs to be taken into account on different levels, from different perspectives and with different designs, methodologies and theoretical perspectives (cf. Olofsson, Lindberg, Fransson & Hauge, 2015; Price, Jewitt & Brown, 2013; Tondeur, Valcke & van Braak, 2008). At a micro-level, the learning situation of students, teachers and school-leaders changes and it becomes important to deepen the knowledge about the impact digital technologies has on the fundamental conditions for teaching and learning of different school subjects (cf. Chun, Kern & Smith 2016; Leung & Baccaglini-Frank, 2017). On a macro-level, conditions for education as such changes and digital technologies becomes an important object of study as agents of change (Wong & Li, 2008). The digitalization of K-12 schools has long been highlighted in policy as a necessity (cf. Kirkman et al, 2002; OECD, 2010). However, research and evaluations (cf. Fransson et al, 2012; OECD, 2015; Wastiau et al, 2013) show that many substantial challenges remain. One of the fundamental pillars of GRADE is the interdisciplinary approach. Several disciplines are present (Applied IT, Curriculum studies, Education, Informatics, Technology and Learning, Educational work, Work-interated Learning) in researching digital technologies in K-12 schools with the ambition to contribute to the continued implementation, integration and use of digital technologies in Swedish K-12 schools that stems from the evidence-based knowledge produced within the activities of GRADE. The research within GRADE will be characterized by close cooperation with stakeholders from school practice, with the aim to contribute to concrete school development. In GRADE, a multi-level approach that involves multiple layers or levels of school activities will be encouraged. When possible, studies will be longitudinal. This will imply studies from an organizational and management perspective, e.g. studies of school leaders and other members of senior management positions responsible for digital technology use and implementation. Also implied are studies of teachers' teaching practices and didactical considerations, as well as studies of the students in classrooms and their learning using digital technologies. This will also imply that several issues with a bearing on the digitalization of education, for example regarding school policy, teaching, learning, assessment and professional development will be researched from different perspectives and with different methodological approaches. In this paper, these points of departure will be explored based on the expectations and experiences of the first twelve admitted doctoral students and their supervisors.
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| 3. |
- Svanes, C., et al.
(författare)
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Father's environment before conception and asthma risk in his children: a multi-generation analysis of the Respiratory Health In Northern Europe study
- 2017
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Ingår i: International Journal of Epidemiology. - : Oxford University Press (OUP). - 0300-5771 .- 1464-3685. ; 46:1, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- Background: Whereas it is generally accepted that maternal environment plays a key role in child health, emerging evidence suggests that paternal environment before conception also impacts child health. We aimed to investigate the association between children's asthma risk and parental smoking and welding exposures prior to conception. Methods: In a longitudinal, multi-country study, parents of 24 168 offspring aged 2-51 years provided information on their life-course smoking habits, occupational exposure to welding and metal fumes, and offspring's asthma before/after age 10 years and hay fever. Logistic regressions investigated the relevant associations controlled for age, study centre, parental characteristics (age, asthma, education) and clustering by family. Results: Non-allergic early-onset asthma (asthma without hay fever, present in 5.8%) was more common in the offspring with fathers who smoked before conception {odds ratio [OR] = 1.68 [95% confidence interval (CI) = 1.18-2.41]}, whereas mothers' smoking before conception did not predict offspring asthma. The risk was highest if father started smoking before age 15 years [3.24 (1.67-6.27)], even if he stopped more than 5 years before conception [2.68 (1.17-6.13)]. Fathers' pre-conception welding was independently associated with non-allergic asthma in his offspring [1.80 (1.29-2.50)]. There was no effect if the father started welding or smoking after birth. The associations were consistent across countries. Conclusions: Environmental exposures in young men appear to influence the respiratory health of their offspring born many years later. Influences during susceptible stages of spermatocyte development might be important and needs further investigation in humans. We hypothesize that protecting young men from harmful exposures may lead to improved respiratory health in future generations.
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| 4. |
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| 5. |
- Lindberg, Lars J., et al.
(författare)
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Risk of multiple colorectal cancer development depends on age and subgroup in individuals with hereditary predisposition
- 2019
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Ingår i: Familial Cancer. - : Springer Science and Business Media LLC. - 1389-9600 .- 1573-7292. ; 18:2, s. 183-191
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Tidskriftsartikel (refereegranskat)abstract
- Development of multiple colorectal cancers (CRCs), synchronously or metachronously, is associated with hereditary predisposition for cancer and accurate risk estimates of multiple tumour development are relevant to recommend rational surveillance programs. A cross-sectional study design was used to estimate the risks of synchronous CRC (SCRC) and metachronous CRC (MCRC) based on data from the National Danish Hereditary Nonpolyposis Register. In total, 7100 individuals from families within the subgroups Lynch syndrome, familial CRC (FCC) and moderate risk were used with estimates relative to a non-hereditary population control cohort. SCRC was diagnosed in 7.4% of the Lynch syndrome cases, in 4.2% of FCC cases and 2.5% of the moderate risk cases, which translated to relative risks of 1.9–5.6. The risk of MCRC was distinctively linked to Lynch syndrome with a life-time risk up to 70% and an incidence rate ratio of 5.0. The risk of SCRC was significantly increased in all subgroups of FCC and hereditary CRC, whereas the risk of MCRC was specifically linked to Lynch syndrome. These observations suggest that individuals with FCC or hereditary CRC should be carefully screened for second primary CRC at the time of diagnosis, whereas intensified surveillance for second primary CRC is motivated in Lynch syndrome with lower-intensity programs in families with yet unidentified genetic causes.
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| 6. |
- Liu, X. H., et al.
(författare)
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Polyamide 6/clay nanocomposites using a cointercalation organophilic clay via melt compounding
- 2003
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 88:4, s. 953-958
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Tidskriftsartikel (refereegranskat)abstract
- Polyamide 6/clay nanocomposites (PA6CN) were prepared via the melt compounding method by using a new kind of organophilic clay, which was obtained through cointercalation of epoxy resin and quaternary ammonium into Na-montmorillonite. The dispersion effect of this kind of organophilic clay in the matrix was studied by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM); the silicate layers were dispersed homogeneously and nearly exfoliated in the matrix. This was probably the result of the strong interaction between epoxy groups and amide end groups of PA6. The mechanical properties and heat distortion temperature (HDT) of PA6CN increased dramatically. The notched Izod impact strength of PA6CN was 80% higher than that of PA6 when the clay loading was 5 wt%. Even at 10 wt% clay content, the impact strength was still higher than that of PA6. The finely dispersed silicate layers and the strong interaction between silicate layers and matrix decreased the water absorption. At 10 wt% clay content, PA6CN only absorbs half the amount of water compared with PA6. The dynamic mechanical properties of PA6CN were also studied.
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| 7. |
- Strom, Peter, et al.
(författare)
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Artificial intelligence for diagnosis and grading of prostate cancer in biopsies : a population-based, diagnostic study
- 2020
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Ingår i: The Lancet Oncology. - : Elsevier. - 1470-2045 .- 1474-5488. ; 21:2, s. 222-232
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAn increasing volume of prostate biopsies and a worldwide shortage of urological pathologists puts a strain on pathology departments. Additionally, the high intra-observer and inter-observer variability in grading can result in overtreatment and undertreatment of prostate cancer. To alleviate these problems, we aimed to develop an artificial intelligence (AI) system with clinically acceptable accuracy for prostate cancer detection, localisation, and Gleason grading.MethodsWe digitised 6682 slides from needle core biopsies from 976 randomly selected participants aged 50–69 in the Swedish prospective and population-based STHLM3 diagnostic study done between May 28, 2012, and Dec 30, 2014 (ISRCTN84445406), and another 271 from 93 men from outside the study. The resulting images were used to train deep neural networks for assessment of prostate biopsies. The networks were evaluated by predicting the presence, extent, and Gleason grade of malignant tissue for an independent test dataset comprising 1631 biopsies from 246 men from STHLM3 and an external validation dataset of 330 biopsies from 73 men. We also evaluated grading performance on 87 biopsies individually graded by 23 experienced urological pathologists from the International Society of Urological Pathology. We assessed discriminatory performance by receiver operating characteristics and tumour extent predictions by correlating predicted cancer length against measurements by the reporting pathologist. We quantified the concordance between grades assigned by the AI system and the expert urological pathologists using Cohen's kappa.FindingsThe AI achieved an area under the receiver operating characteristics curve of 0·997 (95% CI 0·994–0·999) for distinguishing between benign (n=910) and malignant (n=721) biopsy cores on the independent test dataset and 0·986 (0·972–0·996) on the external validation dataset (benign n=108, malignant n=222). The correlation between cancer length predicted by the AI and assigned by the reporting pathologist was 0·96 (95% CI 0·95–0·97) for the independent test dataset and 0·87 (0·84–0·90) for the external validation dataset. For assigning Gleason grades, the AI achieved a mean pairwise kappa of 0·62, which was within the range of the corresponding values for the expert pathologists (0·60–0·73).InterpretationAn AI system can be trained to detect and grade cancer in prostate needle biopsy samples at a ranking comparable to that of international experts in prostate pathology. Clinical application could reduce pathology workload by reducing the assessment of benign biopsies and by automating the task of measuring cancer length in positive biopsy cores. An AI system with expert-level grading performance might contribute a second opinion, aid in standardising grading, and provide pathology expertise in parts of the world where it does not exist.
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| 8. |
- Woll, Petter S, et al.
(författare)
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Myelodysplastic Syndromes Are Propagated by Rare and Distinct Human Cancer Stem Cells In Vivo.
- 2014
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Ingår i: Cancer Cell. - : Elsevier BV. - 1878-3686 .- 1535-6108. ; 25:6, s. 794-808
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Tidskriftsartikel (refereegranskat)abstract
- Evidence for distinct human cancer stem cells (CSCs) remains contentious and the degree to which different cancer cells contribute to propagating malignancies in patients remains unexplored. In low- to intermediate-risk myelodysplastic syndromes (MDS), we establish the existence of rare multipotent MDS stem cells (MDS-SCs), and their hierarchical relationship to lineage-restricted MDS progenitors. All identified somatically acquired genetic lesions were backtracked to distinct MDS-SCs, establishing their distinct MDS-propagating function in vivo. In isolated del(5q)-MDS, acquisition of del(5q) preceded diverse recurrent driver mutations. Sequential analysis in del(5q)-MDS revealed genetic evolution in MDS-SCs and MDS-progenitors prior to leukemic transformation. These findings provide definitive evidence for rare human MDS-SCs in vivo, with extensive implications for the targeting of the cells required and sufficient for MDS-propagation.
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| 9. |
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| 10. |
- 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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