| 1. |
- Akbari, Saeed, et al.
(författare)
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Large-Scale Robot-Based Polymer and Composite Additive Manufacturing : Failure Modes and Thermal Simulation
- 2022
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Ingår i: Polymers. - : MDPI. - 2073-4360. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing (AM) of large-scale polymer and composite parts using robotic arms integrated with extruders has received significant attention in recent years. Despite the contributions of great technical progress and material development towards optimizing this manufacturing method, different failure modes observed in the final printed products have hindered its application in producing large engineering structures used in aerospace and automotive industries. We report failure modes in a variety of printed polymer and composite parts, including fuel tanks and car bumpers. Delamination and warpage observed in these parts originate mostly from thermal gradients and residual stresses accumulated during material deposition and cooling. Because printing large structures requires expensive resources, process simulation to recognize the possible failure modes can significantly lower the manufacturing cost. In this regard, accurate prediction of temperature distribution using thermal simulations is the first step. Finite element analysis (FEA) was used for process simulation of large-scale robotic AM. The important steps of the simulation are presented, and the challenges related to the modeling are recognized and discussed in detail. The numerical results showed reasonable agreement with the temperature data measured by an infrared camera. While in small-scale extrusion AM, the cooling time to the glassy state is less than 1 s, in large-scale AM, the cooling time is around two orders of magnitudes longer. © 2022 by the authors
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| 2. |
- Chuang, Shu-Chun, et al.
(författare)
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Circulating Biomarkers of Tryptophan and the Kynurenine Pathway and Lung Cancer Risk
- 2014
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 23:3, s. 461-468
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Tidskriftsartikel (refereegranskat)abstract
- Background: Imbalances in tryptophan metabolism have been linked to cancer-related immune escape and implicated in several cancers, including lung cancer. Methods: We conducted a nested case-control study within the European Prospective Investigation into Cancer andNutrition (EPIC) that included 893 incident lung cancer cases and 1,748matched controls. Circulating levels of tryptophan and six of its metabolites were measured and evaluated in relation to lung cancer risk. Results: Tryptophan (P-trend = 2 Chi 10(-5)) and the kynurenine/ tryptophan ratio (KTR; P-trend 4 Chi 10(-5)) were associated with lung cancer risk overall after adjusting for established risk factors. The ORs comparing the fifth and first quintiles (OR5th (vs. 1st)) were 0.52 [ 95% confidence interval (CI), 0.37-0.74] for tryptophan and 1.74 (95% CI, 1.24-2.45) for KTR. After adjusting for plasma methionine (available fromprevious work, which was strongly correlated with tryptophan), the associations of tryptophan (adjusted P-trend 0.13) and KTR (P-trend = 0.009) were substantially attenuated. KTR was positively associated with squamous cell carcinoma, the OR5th vs. 1st being 2.83 (95% CI, 1.62-4.94, P-trend -3 Chi 10(-5)) that was only marginally affected by adjusting for methionine. Conclusions: This study indicates that biomarkers of tryptophan metabolism are associated with subsequent lung cancer risk. Although this result would seem consistent with the immune system having a role in lung cancer development, the overall associations were dependent on methionine, and further studies are warranted to further elucidate the importance of these metabolites in lung cancer etiology. Impact: This is the first prospective study investigating the tryptophan pathway in relation to lung cancer risk.
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| 3. |
- David, Jennifer, 1987-, et al.
(författare)
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Design and Development of a Hexacopter for the Search and Rescue of a Lost Drone
- 2019
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Konferensbidrag (refereegranskat)abstract
- Search and rescue with an autonomous robot is an attractive and challenging task within the research community. This paper presents the development of an autonomous hexacopter that is designed for retrieving a lost object, like a drone, from a vast-open space, like a desert area. Navigating its path with a proposed coverage path planning strategy, the hexacopter can efficiently search for a lost target and locate it using an image-based object detection algorithm. Moreover, after the target is located, our hexacopter can grasp it with a customised gripper and transport it back to a destined location. It is also capable of avoiding static obstacles and dynamic objects. The proposed system was realised in simulations before implementing it in a real hardware setup, i.e. assembly of the drone, crafting of the gripper, software implementation and testing under real-world scenarios. The designed hexacopter won the best UAV design award at the CPS-VO 2018 Competition held in Arizona, USA.
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| 4. |
- Fanidi, Anouar, et al.
(författare)
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A prospective study of one-carbon metabolism biomarkers and cancer of the head and neck and esophagus
- 2015
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Ingår i: International Journal of Cancer. - : Wiley-Blackwell. - 0020-7136 .- 1097-0215. ; 136:4, s. 915-927
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and epidemiological data suggest that factors of one-carbon metabolism are important in the pathogenesis of several cancers, but prospective data on head and neck cancer (HNC) and esophagus cancer are limited. The European Prospective Investigation into Cancer and Nutrition (EPIC) study recruited 385,747 participants from 10 countries who donated a blood sample. The current study included 516 cancer cases of the head and neck and esophagus and 516 individually matched controls. Plasma levels of vitamins B2, B6, B9 (folate), B12, and methionine and homocysteine were measured in pre-diagnostic plasma samples and analyzed in relation to HNC and esophagus cancer risk, as well as post-diagnosis all-cause mortality. After controlling for risk factors, study participants with higher levels of homocysteine had elevated risk of HNC, the odds ratio (OR) in conditional analysis when comparing the top and bottom quartiles of homocysteine [ORQ4vs. Q1] being 2.13 (95% confidence interval [95% CI] 1.13-4.00, p for trend 0.009). A slight decrease in HNC risk was also seen among subjects with higher levels of folate (ORQ4vs. Q1 0.63, 95% CI 0.35-1.16, p for trend 0.02). Subgroup analyses by anatomical sub-site indicated particularly strong associations with circulating homocysteine for oral cavity and gum cancer (p for trend 8 x 10(-4)), as well as for oropharynx cancer (p for trend 0.008). Plasma concentrations of the other investigated biomarkers did not display any clear association with risk or survival. In conclusion, study participants with elevated circulating levels of homocysteine had increased risk of developing squamous cell carcinoma of the head and neck. What's new? One-carbon metabolism (OCM) involves the transfer of a carbon unit from methyl donor nutrients to molecules involved in the synthesis and methylation of DNA. As a result, dietary imbalances or deficiencies in nutrients crucial for OCM may affect DNA replication, repair, and regulation, potentially facilitating cancer development. This analysis of circulating levels of OCM nutrients in head and neck cancer and esophageal cancer patients and matched controls reveals an association between elevated levels of the amino acid homocysteine and increased risk of squamous cell carcinoma of the head and neck. Risk was decreased slightly by elevated folate levels.
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| 5. |
- Fanidi, Anouar, et al.
(författare)
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Circulating vitamin D in relation to cancer incidence and survival of the head and neck and oesophagus in the EPIC cohort
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and epidemiological data suggest that vitamin D play a role in pathogenesis and progression of cancer, but prospective data on head and neck cancer (HNC) and oesophagus cancer are limited. The European Prospective Investigation into Cancer and Nutrition (EPIC) study recruited 385,747 participants with blood samples between 1992 and 2000. This analysis includes 497 case-control pairs of the head and neck and oesophagus, as well as 443 additional controls. Circulating 25(OH)D3 were measured in pre-diagnostic samples and evaluated in relation to HNC and oesophagus cancer risk and post-diagnosis all-cause mortality. After controlling for risk factors, a doubling of 25(OH)D3 was associated with 30% lower odds of HNC (OR 0.70, 95% confidence interval [95% CI] 0.56-0.88, Ptrend = 0.001). Subsequent analyses by anatomical sub-site indicated clear inverse associations with risk of larynx and hypopharynx cancer combined (OR 0.55, 95CI% 0.39-0.78) and oral cavity cancer (OR 0.60, 95CI% 0.42-0.87). Low 25(OH)D3 concentrations were also associated with higher risk of death from any cause among HNC cases. No clear association was seen with risk or survival for oesophageal cancer. Study participants with elevated circulating concentrations of 25(OH)D3 had decreased risk of HNC, as well as improved survival following diagnosis.
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| 6. |
- Johansson, Emil, et al.
(författare)
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Influence of Resin Composition on the Defect Formation in Alumina Manufactured by Stereolithography
- 2017
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Stereolithography (SL) is a technique allowing additive manufacturing of complex ceramic parts by selective photopolymerization of a photocurable suspension containing photocurable monomer, photoinitiator, and a ceramic powder. The manufactured three-dimensional object is cleaned and converted into a dense ceramic part by thermal debinding of the polymer network and subsequent sintering. The debinding is the most critical and time-consuming step, and often the source of cracks. In this study, photocurable alumina suspensions have been developed, and the influence of resin composition on defect formation has been investigated. The suspensions were characterized in terms of rheology and curing behaviour, and cross-sections of sintered specimens manufactured by SL were evaluated by SEM. It was found that the addition of a non-reactive component to the photocurable resin reduced polymerization shrinkage and altered the thermal decomposition of the polymer matrix, which led to a reduction in both delamination and intra-laminar cracks. Using a non-reactive component that decomposed rather than evaporated led to less residual porosity.
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| 7. |
- Persson, Mia, et al.
(författare)
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A new improved distributed e-healthcare system based on open standards for depression treatment
- 2012
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Ingår i: ICICS '12 Proceedings of the 3rd International Conference on Information and Communication Systems. - New York, NY, USA : ACM Digital Library. - 9781450313278 ; , s. 1-6
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of open standards to promote responsible and available design in Internet-based healthcare systems is examined by using theoretical notations and recent research results from the literature. Moreover, empirical data will be gathered from a case study on an e-healthcare system for depression treatment. Our contribution is to initiate a discussion aiming at increasing the awareness on appropriate conceptual models for Internet-based depression treatment. Moreover, an up-to-date e-healthcare system, based on open standards and implemented with requirements of an Internet-based system treating patients suffering from depressions, is proposed.
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| 8. |
- Abouelkomsan, Ahmed, 1995-
(författare)
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Geometry, Topology and Emergence in Moiré Systems
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The experimental discovery of correlated insulators and superconductivity in highly tunable Van der Waals heterostructures, such as twisted bilayer graphene, has highlighted the role of moiré patterns, resulting from tiny relative twists or lattice constant mismatches, in realizing strongly correlated physics. A key ingredient is the existence of very narrow flat bands where interaction effects are dominant.In this thesis and the accompanying papers, we theoretically study a number of experimentally relevant moiré systems. We generally show that strong interactions combined with the geometry and the topology of the underlying flat bands can result in a plethora of distinct quantum many-body phases ranging from topological order to multiferroicity. Of particular importance are lattice analogues of the fractional quantum Hall effect known as fractional Chern insulators. They harbour peculiar phenomena such as fractional charge and statistics and provide a route towards realizing topologically ordered states at high temperature. A ubiquitous feature of the many-body physics is the emergence of unique particle-hole dualities driven by the geometry of band-projected interactions.
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| 9. |
- Abouelkomsan, Ahmed, 1995-, et al.
(författare)
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Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Van der Waals heterostructures have recently emerged as an exciting platform for investigating the effects of strong electronic correlations, including various forms of magnetic or electrical orders. Here, we perform an unbiased exact diagonalization study of the effects of interactions on topological flat bands of twisted transition metal dichalcogenides (TMDs) at odd integer fillings. We find that Chern insulator phases, expected from interaction-induced spin and valley polarization of the bare band structure, are quite fragile, and give way to spontaneous multiferroic order -- coexisting ferroelectricity and ferromagnetism, in presence of long-range Coulomb repulsion. We provide a simple real-space picture to understand the phase diagram as a function of interaction range and strength. Our findings establish twisted TMDs as a novel and highly tunable platform for multiferroicity, with potential applications to electrical control of magnetism.
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| 10. |
- Abouelkomsan, Ahmed, 1995-, et al.
(författare)
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Quantum metric induced phases in Moiré materials
- 2023
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Ingår i: Physical Review Research. - 2643-1564. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- We show that, quite generally, quantum geometry plays a major role in determining the low-energy physics in strongly correlated lattice models at fractional band fillings. We identify limits in which the Fubini-Study metric dictates the ground states and show that this is highly relevant for Moiré materials leading to symmetry breaking and interaction driven Fermi liquids. This phenomenology stems from a remarkable interplay between the quantum geometry and interaction which is absent in continuum Landau levels but generically present in lattice models where these terms tend to destabilize, e.g., fractional Chern insulators. We explain this as a consequence of the fundamental asymmetry between electrons and holes for band projected normal ordered interactions, as well as from the perspective of a self-consistent Hartree-Fock calculation. These basic insights about the role of the quantum metric, when dominant, turn an extremely strongly coupled problem into an effectively weakly coupled one, and may also serve as a guiding principle for designing material setups. We argue that this is a key ingredient for understanding symmetry-breaking phenomena recently observed in Moiré materials.
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| 11. |
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| 12. |
- Afshin, Ashkan, et al.
(författare)
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Health effects of dietary risks in 195 countries, 1990-2017 : a systematic analysis for the Global Burden of Disease Study 2017
- 2019
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Ingår i: The Lancet. - : Elsevier. - 0140-6736 .- 1474-547X. ; 393:10184, s. 1958-1972
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Tidskriftsartikel (refereegranskat)abstract
- Background: Suboptimal diet is an important preventable risk factor for non-communicable diseases (NCDs); however, its impact on the burden of NCDs has not been systematically evaluated. This study aimed to evaluate the consumption of major foods and nutrients across 195 countries and to quantify the impact of their suboptimal intake on NCD mortality and morbidity.Methods: By use of a comparative risk assessment approach, we estimated the proportion of disease-specific burden attributable to each dietary risk factor (also referred to as population attributable fraction) among adults aged 25 years or older. The main inputs to this analysis included the intake of each dietary factor, the effect size of the dietary factor on disease endpoint, and the level of intake associated with the lowest risk of mortality. Then, by use of diseasespecific population attributable fractions, mortality, and disability-adjusted life-years (DALYs), we calculated the number of deaths and DALYs attributable to diet for each disease outcome.Findings: In 2017, 11 million (95% uncertainty interval [UI] 10-12) deaths and 255 million (234-274) DALYs were attributable to dietary risk factors. High intake of sodium (3 million [1-5] deaths and 70 million [34-118] DALYs), low intake of whole grains (3 million [2-4] deaths and 82 million [59-109] DALYs), and low intake of fruits (2 million [1-4] deaths and 65 million [41-92] DALYs) were the leading dietary risk factors for deaths and DALYs globally and in many countries. Dietary data were from mixed sources and were not available for all countries, increasing the statistical uncertainty of our estimates.Interpretation: This study provides a comprehensive picture of the potential impact of suboptimal diet on NCD mortality and morbidity, highlighting the need for improving diet across nations. Our findings will inform implementation of evidence-based dietary interventions and provide a platform for evaluation of their impact on human health annually.
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| 13. |
- Ahrentorp, Fredrik, et al.
(författare)
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Sensitive magnetic biodetection using magnetic multi-core nanoparticles and RCA coils
- 2017
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Ingår i: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 427, s. 14-18
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Tidskriftsartikel (refereegranskat)abstract
- We use functionalized iron oxide magnetic multi-core particles of 100 nm in size (hydrodynamic particle diameter) and AC susceptometry (ACS) methods to measure the binding reactions between the magnetic nanoparticles (MNPs) and bio-analyte products produced from DNA segments using the rolling circle amplification (RCA) method. We use sensitive induction detection techniques in order to measure the ACS response. The DNA is amplified via RCA to generate RCA coils with a specific size that is dependent on the amplification time. After about 75 min of amplification we obtain an average RCA coil diameter of about 1 mu m. We determine a theoretical limit of detection (LOD) in the range of 11 attomole (corresponding to an analyte concentration of 55 fM for a sample volume of 200 mu L) from the ACS dynamic response after the MNPs have bound to the RCA coils and the measured ACS readout noise. We also discuss further possible improvements of the LOD.
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| 14. |
- Aleksandrova, Krasimira, et al.
(författare)
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A prospective study of the immune system activation biomarker neopterin and colorectal cancer risk
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 107:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neopterin may be relevant for colorectal cancer (CRC) development, as a biomarker of cellular immune activity exerting pleiotropic effects on cellular ageing, oxidative stress, and inflammation. So far, the association between prediagnostic neopterin and colon and rectal cancer risk has not been evaluated in human populations. Methods: A nested case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition cohort using data on plasma concentrations of total neopterin (T-N, sum of neopterin and 7,8-dihydroneopterin) in 830 incident CRC case patients (561 colon and 269 rectal) matched within risk sets to 830 control participants. A subsequent replication study used data from the Hordaland Health Study, where 173 CRC case patients have been diagnosed among 6594 healthy participants over 12 years of follow-up. Results: After multivariable adjustment for a priori chosen CRC risk factors, a "U-shaped" association of T-N with CRC was revealed. Compared with the second quintile of the T-N distribution, the relative risks for the first, third, fourth, and fifth quintiles were 2.37 (95% CI = 1.66 to 3.39), 1.24 (95% CI = 0.87 to 1.77), 1.55 (95% CI = 1.08 to 2.22), and 2.31 (95% CI = 1.63 to 3.27), respectively. Replication of these associations within the Hordaland Health Study yielded similar results. No differences have been observed when the associations were explored by colon and rectal cancer site (two-sided P-difference = .87) and after excluding case patients diagnosed within the first four follow-up years. Conclusions: These novel findings provide evidence of the role of both suppressed and activated cell-mediated immunity as reflected by prediagnostic T-N concentrations in the development of CRC.
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| 15. |
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| 16. |
- Baltar, Valéria Troncoso, et al.
(författare)
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Smoking, secondhand smoke, and cotinine levels in a subset of EPIC cohort
- 2011
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 20:5, s. 869-875
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Tidskriftsartikel (refereegranskat)abstract
- Background: Several countries are discussing new legislation regarding the ban on smoking in public places, based on the growing evidence of the hazards of secondhand smoke (SHS) exposure. The objective of the present study is to quantitatively assess the relationship between smoking, SHS, and serum cotinine levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Methods: From a study on lung cancer in the EPIC cohort, questionnaire information on smoking was collected at enrolment, and cotinine was measured in serum. Three statistical models were applied by using samples available in a cross-section design: (i) cotinine levels by categories combining smoking and SHS (n = 859); (ii) the effect of hours of passive smoking exposure in nonsmokers only (n = 107); (iii) the effect of the number of cigarettes consumed per day in current smokers only (n = 832). All models were adjusted for country, sex, age, and body mass index. Results: Among nonsmokers, passive smokers presented significant differences in cotinine compared with nonexposed, with a marked (but not significant) difference among former-smokers. A one hour per day increment of SHS gave rise to a significant 2.58 nmol/L (0.45 ng/mL) increase in mean serum cotinine (P < 0.001). In current smokers, a one cigarette per day increment gave rise to a significant 22.44 nmol/L (3.95 ng/mL) increase in cotinine mean (P < 0.001). Conclusions: There is clear evidence that not only tobacco smoking but also involuntary exposure increases cotinine levels. Impact: This study strengthens the evidence for the benefits of a smoking ban in public places.
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| 17. |
- Bergholtz, Emil Johansson, et al.
(författare)
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Microscopic theory of the quantum Hall hierarchy
- 2007
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 99:25, s. 256803-1-256803-4
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Tidskriftsartikel (refereegranskat)abstract
- We solve the quantum Hall problem exactly in a limit and show that the ground states can be organized in a fractal pattern consistent with the Haldane-Halperin hierarchy, and with the global phase diagram. We present wave functions for a large family of states, including those of Laughlin and Jain and also for states recently observed by Pan et al., and show that they coincide with the exact ones in the solvable limit. We submit that they establish an adiabatic continuation of our exact results to the experimentally accessible regime, thus providing a unified approach to the hierarchy states.
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| 18. |
- Bergholtz, Emil Johansson, et al.
(författare)
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Quantum Hall hierarchy wave functions: From conformal correlators to Tao-Thouless states
- 2008
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 77:16, s. 165325-1-165325-9
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Tidskriftsartikel (refereegranskat)abstract
- Laughlin’s wave functions, which describe the fractional quantum Hall effect at filling factorsν=1/(2k+1), can be obtained as correlation functions in a conformal field theory, and recently, this construction was extended to Jain’s composite fermion wave functions at filling factors ν=n/(2kn+1). Here, we generalize this latter construction and present ground state wave functions for all quantum Hall hierarchy states that are obtained by successive condensation of quasielectrons (as opposed to quasiholes) in the original hierarchy construction. By considering these wave functions on a cylinder, we show that they approach the exact ground states, which are the Tao-Thouless states, when the cylinder becomes thin. We also present wave functions for the multihole states, make the connection to Wen’s general classification of Abelian quantum Hall fluids, and discuss whether the fractional statistics of the quasiparticles can be analytically determined. Finally, we discuss to what extent our wave functions can be described in the language of composite fermions.
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| 19. |
- Beske, Rasmus Paulin, et al.
(författare)
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The Effect of Targeted Temperature Management on the Metabolome Following Out-of-Hospital Cardiac Arrest
- 2023
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Ingår i: Therapeutic hypothermia and temperature management. - 2153-7658. ; 13:4, s. 208-215
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Tidskriftsartikel (refereegranskat)abstract
- Targeted temperature management (TTM) may moderate the injury from out-of-hospital cardiac arrest. Slowing the metabolism has been a suggested effect. Nevertheless, studies have found higher lactate levels in patients cooled to 33°C compared with 36°C even days from TTM cessation. Larger studies have not been performed on the TTM's effect on the metabolome. Accordingly, to explore the effect of TTM, we used ultra-performance liquid-mass spectrometry in a substudy of 146 patients randomized in the TTM trial to either 33°C or 36°C for 24 hours and quantified 60 circulating metabolites at the time of hospital arrival (T0) and 48 hours later (T48). From T0 to T48, profound changes to the metabolome were observed: tricarboxylic acid (TCA) cycle metabolites, amino acids, uric acid, and carnitine species all decreased. TTM significantly modified these changes in nine metabolites (Benjamini-Hochberg corrected false discovery rate <0.05): branched amino acids valine and leucine levels dropped more in the 33°C arm (change [95% confidence interval]: −60.9μM [−70.8 to −50.9] vs. −36.0μM [−45.8 to −26.3] and −35.5μM [−43.1 to −27.8] vs. −21.2μM [−28.7 to −13.6], respectively), whereas the TCA metabolites including malic acid and 2-oxoglutaric acid remained higher for the first 48 hours (−7.7μM [−9.7 to −5.7] vs. −10.4μM [−12.4 to −8.4] and −3μM [−4.3 to −1.7] vs. −3.7μM [−5 to −2.3]). Prostaglandin E2 only dropped in the TTM 36°C group. The results show that TTM affects the metabolism hours after normothermia have been reached.
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| 20. |
- Beyer, Sarah, 1982-, et al.
(författare)
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Fluorescent Molecularly Imprinted Polymer Layers against Sialic Acid on Silica-Coated Polystyrene Cores — Assessment of the Binding Behavior to Cancer Cells
- 2022
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Sialic acid (SA) is a monosaccharide usually linked to the terminus of glycan chains on the cell surface. It plays a crucial role in many biological processes, and hypersialylation is a common feature in cancer. Lectins are widely used to analyze the cell surface expression of SA. However, these protein molecules are usually expensive and easily denatured, which calls for the development of alternative glycan-specific receptors and cell imaging technologies. In this study, SA-imprinted fluorescent core-shell molecularly imprinted polymer particles (SA-MIPs) were employed to recognize SA on the cell surface of cancer cell lines. The SA-MIPs improved suspensibility and scattering properties compared with previously used core-shell SA-MIPs. Although SA-imprinting was performed using SA without preference for the α2,3-and α2,6-SA forms, we screened the cancer cell lines analyzed using the lectins Maackia Amurensis Lectin I (MAL I, α2,3-SA) and Sambucus Nigra Lectin (SNA, α2,6-SA). Our results show that the selected cancer cell lines in this study presented a varied binding behavior with the SA-MIPs. The binding pattern of the lectins was also demonstrated. Moreover, two different pentavalent SA conjugates were used to inhibit the binding of the SA-MIPs to breast, skin, and lung cancer cell lines, demonstrating the specificity of the SA-MIPs in both flow cytometry and confocal fluorescence microscopy. We concluded that the synthesized SA-MIPs might be a powerful future tool in the diagnostic analysis of various cancer cells.
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| 21. |
- Boersma, Greta J., et al.
(författare)
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Altered Glucose Uptake in Muscle, Visceral Adipose Tissue, and Brain Predict Whole-Body Insulin Resistance and may Contribute to the Development of Type 2 Diabetes: A Combined PET/MR Study
- 2018
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Ingår i: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 50:8
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Tidskriftsartikel (refereegranskat)abstract
- We assessed glucose uptake in different tissues in type 2 diabetes (T2D), prediabetes, and control subjects to elucidate its impact in the development of whole-body insulin resistance and T2D. Thirteen T2D, 12 prediabetes, and 10 control subjects, matched for age and BMI, underwent OGTT and abdominal subcutaneous adipose tissue (SAT) biopsies. Integrated whole-body 18F-FDG PET and MRI were performed during a hyperinsulinemic euglycemic clamp to asses glucose uptake rate (MRglu) in several tissues. MRglu in skeletal muscle, SAT, visceral adipose tissue (VAT), and liver was significantly reduced in T2D subjects and correlated positively with M-values (r = 0.884, r = 0.574, r = 0.707 and r = 0.403, respectively). Brain MRglu was significantly higher in T2D and prediabetes subjects and had a significant inverse correlation with M-values (r = -0.616). Myocardial MRglu did not differ between groups and did not correlate with the M-values. A multivariate model including skeletal muscle, brain and VAT MRglu best predicted the M-values (adjusted r2 = 0.85). In addition, SAT MRglu correlated with SAT glucose uptake ex vivo (r = 0.491). In different stages of the development of T2D, glucose uptake during hyperinsulinemia is elevated in the brain in parallel with an impairment in peripheral organs. Impaired glucose uptake in skeletal muscle and VAT together with elevated glucose uptake in brain were independently associated with whole-body insulin resistance, and these tissue-specific alterations may contribute to T2D development.
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| 22. |
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| 23. |
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| 24. |
- Bonham, Euan, et al.
(författare)
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Designing and Integrating a Digital Thread System for Customized Additive Manufacturing in Multi-Partner Kayak Production
- 2020
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Ingår i: Systems. - : MDPI AG. - 2079-8954. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing (AM) opens the vision of decentralised and individualised manufacturing, as a tailored product can be manufactured in proximity to the customers with minimal physical infrastructure required. Consequently, the digital infrastructure and systems solution becomes substantially more complex. There is always a need to design the entire digital system so that different partners (or stakeholders) access correct and relevant information and even support design iterations despite the heterogenous digital environments involved. This paper describes how the design and integration of a digital thread for AM can be approached. A system supporting a digital thread for AM kayak production has been designed and integrated in collaboration with a kayak manufacturer and a professional collaborative product lifecycle management (PLM) software and service provider. From the demonstrated system functionality, three key lessons learnt are clarified: (1) The need for developing a process model of the physical and digital flow in the early stages, (2) the separation between the data to be shared and the processing of data to perform each parties' task, and (3) the development of an ad-hoc digital application for the involvement of new stakeholders in the AM digital flow, such as final users. The application of the digital thread system was demonstrated through a test of the overall concept by manufacturing a functional and individually customised kayak, printed remotely using AM (composed of a biocomposite containing 20% wood-based fibre).
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| 25. |
- Carlsson, Emil, 1995, et al.
(författare)
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Learning Approximate and Exact Numeral Systems via Reinforcement Learning
- 2021
-
Ingår i: Proceedings of the 43rd Annual Meeting of the Cognitive Science Society: Comparative Cognition: Animal Minds, CogSci 2021. ; 43
-
Konferensbidrag (refereegranskat)abstract
- Recent work (Xu et al., 2020) has suggested that numeral systems in different languages are shaped by a functional need for efficient communication in an information-theoretic sense. Here we take a learning-theoretic approach and show how efficient communication emerges via reinforcement learning. In our framework, two artificial agents play a Lewis signaling game where the goal is to convey a numeral concept. The agents gradually learn to communicate using reinforcement learning and the resulting numeral systems are shown to be efficient in the information-theoretic framework of Regier et al.(2015); Gibson et al. (2017). They are also shown to be similar to human numeral systems of same type. Our results thus provide a mechanistic explanation via reinforcement learning of the recent results in Xu et al. (2020) and can potentially be generalized to other semantic domains.
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| 26. |
- Carlsson, Emil, 1995, et al.
(författare)
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Pure Exploration in Bandits with Linear Constraints
- 2024
-
Ingår i: Proceedings of the 38th Conference on Uncertainty in Artificial Intelligence, UAI 2022. - 2640-3498. ; 238, s. 334-342
-
Konferensbidrag (refereegranskat)abstract
- We address the problem of identifying the optimal policy with a fixed confidence level in a multi-armed bandit setup, when the arms are subject to linear constraints. Unlike the standard best-arm identification problem which is well studied, the optimal policy in this case may not be deterministic and could mix between several arms. This changes the geometry of the problem which we characterize via an information-theoretic lower bound. We introduce two asymptotically optimal algorithms for this setting, one based on the Track-and-Stop method and the other based on a game-theoretic approach. Both these algorithms try to track an optimal allocation based on the lower bound and computed by a weighted projection onto the boundary of a normal cone. Finally, we provide empirical results that validate our bounds and visualize how constraints change the hardness of the problem.
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| 27. |
- Carlsson, Emil, 1995, et al.
(författare)
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Thompson Sampling for Bandits with Clustered Arms
- 2021
-
Ingår i: Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence. - California : International Joint Conferences on Artificial Intelligence Organization. - 9780999241196
-
Konferensbidrag (refereegranskat)abstract
- We propose algorithms based on a multi-level Thompson sampling scheme, for the stochastic multi-armed bandit and its contextual variant with linear expected rewards, in the setting where arms are clustered. We show, both theoretically and empirically, how exploiting a given cluster structure can significantly improve the regret and computational cost compared to using standard Thompson sampling. In the case of the stochastic multi-armed bandit we give upper bounds on the expected cumulative regret showing how it depends on the quality of the clustering. Finally, we perform an empirical evaluation showing that our algorithms perform well compared to previously proposed algorithms for bandits with clustered arms.
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| 28. |
- Carlsson Tedgren, Åsa, et al.
(författare)
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Experience from long-term monitoring of RAKR ratios in Ir-192 brachytherapy
- 2008
-
Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 89:2, s. 217-221
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Ratios of values of brachytherapy source strengths, as measured by hospitals and vendors, comprise constant differences as, e.g., systematic errors in ion chamber calibration factors and measurement setup. Such ratios therefore have the potential to reveal the systematic changes in routines or calibration services at either the hospital or the vendor laboratory, which could otherwise be hidden by the uncertainty in the source strength values. Methods: The RAKR of each new source in 13 afterloading units at five hospitals were measured by well-type ion chambers and compared to values for the same source stated on vendor certificates. Results: Differences from unity in the ratios of RAKR values determined by hospitals and vendors are most often small and stable around their mean values to within +/- 11.5%. Larger deviations are rare but occur. A decreasing ratio, seen at two hospitals for the same source, was useful in detecting an erroneous pressure gauge at the vendors site. Conclusions: Establishing a mean ratio of RAKR values, as measured at the hospital and supplied on the vendor certificate, and monitoring this as a function of time are an easy way for the early detection of problems with equipment or routines at either the hospital or the vendor site.
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| 29. |
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| 30. |
- Della Penda, Demia, 1984-
(författare)
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Resource management for network-assisted D2D communication
- 2016
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the last decade, the widespread use of smart devices and mobile applications has led to a massive growth of the mobile traffic demand. Efficiency and scalability are therefore key criteria for the development of future cellular systems, in which device-to-device (D2D) communication is recognized as one of the promising technologies. D2D communication allows mobile users in physical proximity to communicate directly, bypassing the base station as in conventional cellular networks.In this thesis, we investigate some of the possible benefits and challenges brought by the introduction of D2D communication in cellular systems. In particular, we focus on resource management techniques for network-assisted D2D communication using cellular spectrum. Our main contributions lie in the context of mode selection, power control and (frequency/time) resource allocation mechanisms, recognized as key techniques to realize the promises of this technology.First, we investigate how the integration of D2D communication in cellular systems operating under dynamic Time Division Duplex (TDD) can enhance their energy efficiency. We perform joint optimization of mode selection, uplink/downlink transmission period, and power allocation to minimize the transmission energy consumption. The resource management problems for different scenarios are formulated as mixed-integer nonlinear programming problems. In several cases, we exploit the problems’ structure to design efficient algorithms that achieve optimal solutions in polynomial time. In the remaining cases, we propose a heuristic algorithm that computes near-optimal solutions while respecting practical constraints in terms of execution times and signalling overhead. Our simulations demonstrate that D2D communications in dynamic TDD systems can yield significant energy savings and improved spectral efficiency compared to traditional cellular communication.Second, we study the performance of various power control strategies applicable to D2D communications in 3GPP LTE networks. We compare them with an utility maximization approach that trades off spectrum efficiency and total transmit power consumption. Our numerical results suggest that the LTE power control scheme is well prepared for network-assisted D2D communications, especially from the cellular user perspective. However, for D2D users, the utility based scheme can provide gains in terms of SINR and power consumption.Finally, we investigate the subcarrier allocation problem for uplink transmissions ina D2D-enabled network. We focus on maximizing the aggregate transmission rate of the system. In addition to the traditional inter-cell interference, we also account for the intra-cell interference caused by D2D pairs reusing cellular resources. This problem is computationally hard due to its nonconvex and combinatorial nature. However, we show that it can be described as a potential game; hence, we can find a Nash equilibrium using iterative algorithms based on best/better response dynamics.
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| 31. |
- Ekblom Bak, Elin, 1981-, et al.
(författare)
-
Accelerometer derived physical activity patterns in 27.890 middle‐aged adults : The SCAPIS cohort study
- 2022
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 32:5, s. 866-880
-
Tidskriftsartikel (refereegranskat)abstract
- The present study aims to describe accelerometer-assessed physical activity (PA) patterns and fulfillment of PA recommendations in a large sample of middle-aged men and women, and to study differences between subgroups of socio-demographic, socio-economic, and lifestyle-related variables. A total of 27 890 (92.5% of total participants, 52% women, aged 50–64 years) middle-aged men and women with at least four days of valid hip-worn accelerometer data (Actigraph GT3X+, wGT3X+ and wGT3X-BT) from the Swedish CArdioPulmonary bioImage Study, SCAPIS, were included. In total, 54.5% of daily wear time was spent sedentary, 39.1% in low, 5.4% in moderate, and only 0.1% in vigorous PA. Male sex, higher education, low financial strain, born in Sweden, and sedentary/light working situation were related to higher sedentary time, but also higher levels of vigorous PA. High BMI and having multiple chronic diseases associated strongly with higher sedentary time and less time in all three PA intensities. All-year physically active commuters had an overall more active PA pattern. The proportion fulfilling current PA recommendations varied substantially (1.4% to 92.2%) depending on data handling procedures and definition used. Twenty-eight percent was defined as having an “at-risk” behavior, which included both high sedentary time and low vigorous PA. In this large population-based sample, a majority of time was spent sedentary and only a fraction in vigorous PA, with clinically important variations between subgroups. This study provides important reference material and emphasizes the importance of a comprehensive assessment of all aspects of the individual PA pattern in future research and clinical practice.
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| 32. |
- El-Schich, Zahra, et al.
(författare)
-
Sialic acid as a biomarker studied in breast cancer cell lines in vitro using fluorescent molecularly imprinted polymers
- 2021
-
Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 11:7
-
Tidskriftsartikel (refereegranskat)abstract
- Sialylations are post-translational modifications of proteins and lipids that play important roles in many cellular events, including cell-cell interactions, proliferation, and migration. Tumor cells express high levels of sialic acid (SA), which are often associated with the increased invasive potential in clinical tumors, correlating with poor prognosis. To overcome the lack of natural SA-receptors, such as antibodies and lectins with high enough specificity and sensitivity, we have used molecularly imprinted polymers (MIPs), or “plastic antibodies”, as nanoprobes. Because high expression of epithelial cell adhesion molecule (EpCAM) in primary tumors is often associated with proliferation and a more aggressive phenotype, the expression of EpCAM and CD44 was initially analyzed. The SA-MIPs were used for the detection of SA on the cell surface of breast cancer cells. Lectins that specifically bind to the a-2,3 SA and a-2,6 SA variants were used for analysis of SA expression, with both flow cytometry and confocal microscopy. Here we show a correlation of EpCAM and SA expression when using the SA-MIPs for detection of SA. We also demonstrate the binding pattern of the SA-MIPs on the breast cancer cell lines using confocal microscopy. Pre-incubation of the SA-MIPs with SA-derivatives as inhibitors could reduce the binding of the SA-MIPs to the tumor cells, indicating the specificity of the SA-MIPs. In conclusion, the SA-MIPs may be a new powerful tool in the diagnostic analysis of breast cancer cells.
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| 33. |
- Eussen, Simone J. P. M., et al.
(författare)
-
North-south gradients in plasma concentrations of B-vitamins and other components of one-carbon metabolism in Western Europe: results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study
- 2013
-
Ingår i: British Journal of Nutrition. - 1475-2662 .- 0007-1145. ; 110:2, s. 363-374
-
Tidskriftsartikel (refereegranskat)abstract
- Different lifestyle patterns across Europe may influence plasma concentrations of B-vitamins and one-carbon metabolites and their relation to chronic disease. Comparison of published data on one-carbon metabolites in Western European regions is difficult due to differences in sampling procedures and analytical methods between studies. The present study aimed, to compare plasma concentrations of one-carbon metabolites in Western European regions with one laboratory performing all biochemical analyses. We performed the present study in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort among 5446 presumptively healthy individuals. Quantile regression was used to compare sex-specific median concentrations between Northern (Denmark and Sweden), Central (France, Germany, The Netherlands and United Kingdom) and Southern (Greece, Spain and Italy) European regions. The lowest folate concentrations were observed in Northern Europe (men, 10.4 nmol/l; women, 10.7 nmol/l) and highest concentrations in Central Europe. Cobalamin concentrations were slightly higher in Northern Europe (men, 330 pmol/l; women, 352 pmol/l) compared with Central and Southern Europe, but did not show a clear north-south gradient. Vitamin B-2 concentrations were highest in Northern Europe (men, 22.2 nmol/l; women, 26.0 nmol/l) and decreased towards Southern Europe (P-trend < 0.001). Vitamin B-6 concentrations were highest in Central Europe in men (77.3 nmol/l) and highest in the North among women (70.4 nmol/l), with decreasing concentrations towards Southern Europe in women (P-trend < 0.001). In men, concentrations of serine, glycine and sarcosine increased from the north to south. In women, sarcosine increased from Northern to Southern Europe. These findings may provide relevant information for the study of regional differences of chronic disease incidence in association with lifestyle.
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| 34. |
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| 35. |
- Fallah, Mahsa, 1986-, et al.
(författare)
-
Plasminogen is a master regulator and a potential drug candidate for the healing of radiation wounds
- 2020
-
Ingår i: Cell Death and Disease. - : Nature Publishing Group. - 2041-4889. ; 11:3
-
Tidskriftsartikel (refereegranskat)abstract
- Around 95% of cancer patients undergoing radiotherapy experience cutaneous side effects, and some develop radiation wounds or fibrosis. Currently, there is no effective treatment for these indications. We show here that plasminogen administration enhanced the healing of radiation wounds via pleiotropic effects on gene expression. Using RNA sequencing, we found that plasminogen downregulated the expression of genes in the TLR, TNF, WNT, MAPK, and TGF-β signaling pathways, and enhanced the anti-inflammatory effect of arachidonic acid, leading to significantly decreased inflammation and improved remodeling of granulation tissue compared with placebo treatment. In addition, plasminogen induced metabolic changes, including decreased glycolysis. Importantly, many of the factors downregulated by plasminogen are pro-fibrotic. Therefore, in radiation wounds with excessive inflammation, plasminogen is able to enhance and redirect the healing process, such that it more closely resembles physiological healing with significantly reduced risk for developing fibrosis. This makes plasminogen an attractive drug candidate for the treatment of radiation wounds in cancer patients.
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| 36. |
- Feng, Yi, et al.
(författare)
-
Effects of androgen and leptin on behavioral and cellular responses in female rats.
- 2011
-
Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 60:4, s. 427-38
-
Tidskriftsartikel (refereegranskat)abstract
- The causes of anxiety and depression in women with polycystic ovary syndrome (PCOS) remain elusive. To identify steps linking androgen signaling to the regulation of affective symptoms in vivo, we compared behavioral responses in female rats continuously exposed to DHT from puberty (a model of DHT-induced PCOS) and in rats exposed to DHT for 1week. Continuous and 1week of DHT exposure resulted in a general decrease in locomotor activity and time spent on the open arms in the elevated plus maze, indicating anxiety-like behavior. Rats with DHT-induced PCOS have increases in adiposity and circulating leptin levels accompanied by leptin resistance. One week of DHT exposure decreased androgen receptor (AR) expression in the hypothalamus and leptin synthesis and function in adipocytes; it also inhibited signal transducer and activator of transcription 3 (STAT3) and attenuated leptin activity by increasing levels of soluble leptin receptor, a leptin-binding protein, in the hypothalamus. This may affect the androgen-induced anxiety-related behavior in female rats. In conclusion, our results highlight the central role of androgens in behavioral function in female rats and suggest that androgens directly regulate the AR by decreasing its hypothalamic expression. Androgens also increase leptin synthesis in adipocytes, which drives central leptin signaling, and may regulate anxiety-related behaviors. Elucidating mechanisms by which androgens modulate female anxiety-like behavior may uncover useful approaches for treating women with PCOS who have symptoms of anxiety.
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| 37. |
- Fleckenstein, Christoph, et al.
(författare)
-
Non-Hermitian topology in monitored quantum circuits
- 2022
-
Ingår i: Physical Review Research. - : American Physical Society (APS). - 2643-1564. ; 4:3
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that genuinely non-Hermitian topological phases and corresponding topological phase transitions can be naturally realized in monitored quantum circuits, exemplified by the paradigmatic non-Hermitian Su-Schrieffer-Heeger model. We emulate this model by a 1D chain of spinless electrons evolving under unitary dynamics and subject to periodic measurements that are stochastically invoked. The non-Hermitian topology is visible in topological invariants adapted to the context of monitored circuits. For instance, the topological phase diagram of the monitored realization of the non-Hermitian Su-Schrieffer-Heeger model is obtained from the biorthogonal polarization computed from an effective Hamiltonian of the monitored system. Importantly, our monitored circuit realization allows direct access to steady-state biorthogonal expectation values of generic observables, and hence, to measure physical properties of a genuine non-Hermitian model. We expect our results to be applicable more generally to a wide range of models that host non-Hermitian topological phases.
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| 38. |
- Ghazanfari, Amin, 1983-
(författare)
-
Power Control for Multi-Cell Massive MIMO
- 2019
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The cellular network operators have witnessed significant growth in data traffic in the past few decades. This growth occurs due to the increases in the number of connected mobile devices, and further, the emerging mobile applications developed for rendering video-based on-demand services. As the frequency bandwidth for cellular communication is limited, significant effort was dedicated to improve the utilization of the available spectrum and increase the system performance via new technologies. For example, 3G and 4G networks were designed to facilitate high data traffic in cellular networks in past decades. Nevertheless, there is a necessity for new cellular network technologies to accommodate the ever-growing data traffic demand. 5G is behind the corner to deal with the tremendous data traffic requirements that will appear in cellular networks in the next decade.Massive MIMO (multiple-input-multi-output) is one of the backbone technologies in 5G networks. Massive MIMO originated from the concept of multi-user MIMO. It consists of base stations (BSs) implemented with a large number of antennas to increase the signal strengths via adaptive beamforming and concurrently serving many users on the same time-frequency blocks. As an outcome of using Massive MIMO technology, there is a notable enhancement of both sum spectral efficiency (SE) and energy efficiency (EE) in comparison with conventional MIMO based cellular networks. Resource allocation is an imperative factor to exploit the specified gains of Massive MIMO. It corresponds to properly allocating resources in the time, frequency, space, and power domains for cellular communication. Power control is one of the resource allocation methods to deliver high spectral and energy efficiency of Massive MIMO networks. Power control refers to a scheme that allocates transmit powers to the data transmitters such that the system maximizes some desirable performance metric.In the first part of this thesis, we investigate reusing the resources of a Massive MIMO system, for direct communication of some specific user pairs known as device-to-device (D2D) underlay communication. D2D underlay can conceivably increase the SE of traditional Massive MIMO systems by enabling more simultaneous transmissions on the same frequencies. Nevertheless, it adds additional mutual interference to the network. Consequently, power control is even more essential in this scenario in comparison with conventional Massive MIMO systems to limit the interference that is caused between the cellular network and the D2D communication, thereby enabling their coexistence. In this part, we propose a novel pilot transmission scheme for D2D users to limit the interference to the channel estimation phase of cellular users in comparison with the case of sharing pilot sequences for cellular and D2D users. We also introduce a novel pilot and data power control scheme for D2D underlaid Massive MIMO systems. This method aims at assuring that D2D communication enhances the SE of the network in comparison with conventional Massive MIMO systems.In the second part of this thesis, we propose a novel power control approach for multi-cell Massive MIMO systems. The new power control approach solves the scalability issue of two well-known power control schemes frequently used in the Massive MIMO literature, which are based on the network-wide max-min and proportional fairness performance metrics. We first explain the scalability issue of these existing approaches. Additionally, we provide mathematical proof for the scalability of our proposed method. Our scheme aims at maximizing the geometric mean of the per-cell max-min SE. To solve this optimization problem, we prove that it can be rewritten in a convex form and then be solved using standard optimization solvers.
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| 39. |
- Greiff, Marcus, et al.
(författare)
-
Gamma-Ray Imaging with Spatially Continuous Intensity Statistics
- 2021
-
Ingår i: Proc. 2021 IEEE/RSJ Int. Conf.Intelligent Robots and Systems (IROS2021), Sep 27 - Oct 1, 2021, Prague, Czech Republic. ; , s. 5234-5239
-
Konferensbidrag (refereegranskat)abstract
- Novel methods for the inference of radiation intensityfunctions defined over known surfaces are proposed, intendedfor use in surveying applications with mobile spectrometers.Previous approaches, based on the maximum likelihoodexpectation maximization (ML-EM) framework with Poissonlikelihoods, are extended to better handle spatially continuousintensity statistics using ideas from Gaussian filtering. Theresulting algorithm is evaluated against a classical ML-EMmethod, and a recently proposed sparse additive point sourcelocalization (APSL) algorithm in a Monte-Carlo simulationstudy. The new generalized ASPL (GASPL) is shown tocompare favorably in terms of estimation accuracy when thetrue intensity is not well described by a set of point sources.Finally, the GASPL is used in an experiment where a detector ismounted to an unmanned aerial vehicle to estimate the intensityand location of radioactive sources placed in a meadow.
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| 40. |
- Guglielmo, Priscilla, et al.
(författare)
-
Validation of automated whole-body analysis of metabolic and morphological parameters from an integrated FDG-PET/MRI acquisition
- 2020
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Automated quantification of tissue morphology and tracer uptake in PET/MR images could streamline the analysis compared to traditional manual methods. To validate a single atlas image segmentation approach for automated assessment of tissue volume, fat content (FF) and glucose uptake (GU) from whole-body [18F]FDG-PET/MR images. Twelve subjects underwent whole-body [18F]FDG-PET/MRI during hyperinsulinemic-euglycemic clamp. Automated analysis of tissue volumes, FF and GU were achieved using image registration to a single atlas image with reference segmentations of 18 volume of interests (VOIs). Manual segmentations by an experienced radiologist were used as reference. Quantification accuracy was assessed with Dice scores, group comparisons and correlations. VOI Dice scores ranged from 0.93 to 0.32. Muscles, brain, VAT and liver showed the highest scores. Pancreas, large and small intestines demonstrated lower segmentation accuracy and poor correlations. Estimated tissue volumes differed significantly in 8 cases. Tissue FFs were often slightly but significantly overestimated. Satisfactory agreements were observed in most tissue GUs. Automated tissue identification and characterization using a single atlas segmentation performs well compared to manual segmentation in most tissues and will be valuable in future studies. In certain tissues, alternative quantification methods or improvements to the current approach is needed.
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| 41. |
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| 42. |
- Gustafsson, Emil, et al.
(författare)
-
Direct Adhesive Measurements between Wood Biopolyrner Model Surfaces
- 2012
-
Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 13:10, s. 3046-3053
-
Tidskriftsartikel (refereegranskat)abstract
- For the first time the dry adhesion was measured for an all-wood biopolymer system using Johnson-Kendall-Roberts (JKR) contact mechanics. The polydimethylsiloxane hemisphere was successfully surface-modified with a Cellulose I model surface using layer-by-layer assembly of nanofibrillated cellulose and polyethyleneimine. Flat surfaces of cellulose were equally prepared on silicon dioxide substrates, and model surfaces of glucomannan and lignin were prepared on silicon dioxide using spin-coating. The measured work of adhesion on loading and the adhesion hysteresis was found to be very similar between cellulose and all three wood polymers, suggesting that the interaction between these biopolymers do not differ greatly. Surface energy calculations from contact angle measurements indicated similar dispersive surface energy components for the model surfaces. The dispersive component was dominating the surface energy for all surfaces. The JKR work of adhesion was lower than that calculated from contact angle measurements, which partially can be ascribed to surface roughness of the model surfaces and overestimation of the surface energies from contact angle determinations.
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| 43. |
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| 44. |
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| 45. |
- Hagström, Emil, et al.
(författare)
-
Plasma-parathyroid hormone is associated with subclinical and clinical atherosclerotic disease in 2 community-based cohorts
- 2014
-
Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642 .- 1524-4636. ; 34:7, s. 1567-1579
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Cardiovascular risk factors have different impact on different arterial territories. Diseases with elevated circulating parathyroid hormone (PTH) such as primary hyperparathyroidism and chronic renal failure have been shown to be associated with an increased risk of cardiovascular disease, predominantly heart or cerebrovascular diseases. However, data on the associations between circulating PTH and peripheral atherosclerosis are limited.APPROACH AND RESULTS: Two prospective, community-based studies were used. In 306 men and women, who were 70 years old, from the Prospective investigation of the vasculature in Uppsala seniors (PIVUS) study, cross-sectional relations between PTH and atherosclerotic burden assessed by whole-body magnetic resonance angiography were investigated. In 998 men, who were 71 years old, from the Uppsala longitudinal study of adult men (ULSAM) study, the association between PTH concentration and risk of subsequent nonfatal atherosclerotic disease (excluding coronary or cerebrovascular disease) was investigated. Adjusting for established vascular risk factors, PTH was associated with burden of atherosclerosis (increase in total atherosclerotic score per SD PTH increase: 0.04, 0.003-0.08; P=0.03) in the PIVUS study. During follow-up in the ULSAM study (median 16.7 years), 89 men were diagnosed with nonfatal atherosclerotic disease. In Cox-regression analyses adjusting for established vascular risk factors and mineral metabolism, higher PTH was associated with an increased risk of nonfatal atherosclerotic disease (hazard ratio for 1 SD increase of PTH: 1.55, 1.33-1.88; P<0.0001). Results were similar when including fatal atherosclerotic disease in the outcome.CONCLUSIONS: In 2 independent community-based cohorts, PTH was associated to the degree of atherosclerosis and risk of clinically overt atherosclerotic disease, respectively. Our data confirm and extend previous studies supporting a role for PTH in the development of atherosclerotic disease.
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| 46. |
- Hagström, Emil, et al.
(författare)
-
Plasma parathyroid hormone is associated with vascular dementia and cerebral hyperintensities in two community-based cohorts
- 2014
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 99:11, s. 4181-4189
-
Tidskriftsartikel (refereegranskat)abstract
- Context: In diseases with increased PTH such as hyperparathyroidism and chronic renal failure, dementia is common. Little is known of PTH and dementia in the community.Objective: We sought to investigate relations between PTH, clinical dementia and cerebral micro-vascular disease. Setting and Design: The Uppsala Longitudinal Study Of Adult Men (ULSAM) was prospective, baseline, 1991-1995; followup, 15.8 years. The Prospective Investigation Of The Vasculature In Uppsala Seniors (PIVUS) was cross-sectional, baseline, 2001. Both settings were community based.Participants and Main Outcome Measure: In the ULSAM study of 998 men (age 71) the association between PTH and dementia was investigated. In the PIVUS study of 406 men and women (age 70) the relation between PTH and magnetic resonance imaging signs of cerebral small vascular disease was investigated.Results: During followup, 56 individuals were diagnosed with vascular, 91 with Alzheimer's, and 59 with other dementias. In Cox-regression analyses, higher PTH was associated with vascular dementia (hazard ratio per 1 SD increase of PTH, 1.41; P < .01), but not with other dementias. The top tertile of PTH accounted for 18.5% of the population-attributable risk for vascular dementia, exceeding all other risk factors. In linear regression analysis in PIVUS, PTH was associated with increasing white matter hyperintensities (WMHI), reflecting increasing burden of cerebral small vessel disease (1 SD PTH increase, 0.31 higher category of WMHI; P = .016). All models were adjusted for vascular risk factors and mineral metabolism.Conclusions: In two community-based samples, PTH predicted clinically diagnosed and neuroimaging indices of vascular dementia and cerebral small vessel disease. Our data suggest a role for PTH in the development of vascular dementia.
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| 47. |
- Haldar, Dhruv, et al.
(författare)
-
IMPLEMENTATION OF WING ICE PROTECTION SYSTEM IN MORE ELECTRIC AIRCRAFT TECHNOLOGIES
- 2022
-
Ingår i: 33rd Congress of the International Council of the Aeronautical Sciences, ICAS 2022. - : International Council of the Aeronautical Sciences. ; , s. 296-311
-
Konferensbidrag (refereegranskat)abstract
- More Electric Aircraft (MEA) technologies aim at reducing greenhouse gas emissions to make local and global air transport easier [6], while at the same time being cost-effective, reliable and promoting the production of more energy-efficient vehicles. The primary goal of this research is, therefore, to establish a framework for determining whether MEA technology applied to a specific aircraft subsystem will be useful. Goal of this paper is the development of a tool that can assist in evaluating the Wing Ice Protection System (WIPS) fuel consumption of MEA airliners of any size and flight. A method is provided for calculating the mass of ice formed when an Airbus A320 aircraft is subjected to a series of in-flight icing conditions during Climb and Descent. These in-flight icing conditions consist of humidity due to precipitation, and the air temperatures lying between the freezing ranges of 273.15 K to 253.15 K. The case study used in this paper modifies the existing study by using an icing air temperature of 256 K and an icing duration of 130.5 seconds for the Climb Case and 151.5 seconds for the Descent Case. The study utilizes publicly available aircraft data and Appendix C, CS-25 EASA icing aviation standards [6]. Power and fuel consumption of conventional Wing Ice Protection System (p-WIPS) and electro thermal Wing Ice Protection System (e-WIPS) was computed. Results revealed a significant reduction in e-WIPS power usage, ranging from 13% to 50% depending on the p-WIPS configuration chosen.
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| 48. |
- He, Yuchi, et al.
(författare)
-
Superconductivity of repulsive spinless fermions with sublattice potentials
- 2023
-
Ingår i: Physical Review Research. - 2643-1564. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- We explore unconventional superconductivity of repulsive spinless fermions on square and honeycomb lattices with staggered sublattice potentials. The two lattices can exhibit staggered d-wave and f-wave pairing, respectively, at low doping stemming from an effective two-valley band structure. At higher doping, in particular, the square lattice displays a much richer phase diagram including topological p+ip superconductivity which is induced by a qualitatively different mechanism compared to the d-wave pairing. We illuminate this from several complementary perspectives: We analytically perform sublattice projection to analyze the effective continuum low-energy description and we numerically calculate the binding energies for pair and larger bound states for few-body doping near half filling. Furthermore, for finite doping, we present phase diagrams based on extensive functional renormalization group and and density matrix renormalization group calculations.
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| 49. |
- Hermanns, Maria, et al.
(författare)
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Quantum Hall wave functions on the torus
- 2008
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Ingår i: Physical Review B Condensed Matter. - : American Physical Society. - 0163-1829 .- 1095-3795. ; 77:12, s. 125321-1-125321-16
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Tidskriftsartikel (refereegranskat)abstract
- We present explicit expressions for a large set of hierarchy wave functions on the torus. Included are the Laughlin states, the states in the positive Jain series, and recently observed states at, e.g., ν=4∕11. The techniques we use constitute a nontrivial extension of the conformal field theory methods developed earlier to construct the corresponding wave functions in disk geometry.
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| 50. |
- Holm, Fanny, 1980-, et al.
(författare)
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Hanteringen av svenska IS-resenärer i Syrien ur folkrättsligt perspektiv
- 2022
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Ingår i: Svensk Juristtidning. - Uppsala : Svensk juristtidning. - 0039-6591. ; :3, s. 250-277
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Så många som 40 000 personer tros ha rest från andra länder för att ansluta sig till IS i Syrien och Irak. Många av dessa s.k. terroristresenärer hålls idag internerade i det kurdiska självstyrets läger i Syrien och bland dem finns män, kvinnor och barn från Sverige. Situationen i lägren väcker en rad folkrättsliga frågor. Artikeln belyser den svenska regeringens agerande utifrån de folkrättsliga ramarna för frihetsberövande, straffrättsligt ansvarsutkrävande och repatriering av medborgare. Den visar att den svenska hanteringen av lägren präglats av ambivalens, och diskuterar om detta kan förklaras utifrån de folkrättsliga normernas vaghet och motstridighet, sambandet med internationell terrorism och den aktuella inrikespolitiska debatten
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