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| 2. |
- Maitrallain, A., et al.
(author)
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Parametric study of high-energy ring-shaped electron beams from a laser wakefield accelerator
- 2022
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In: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 24:1
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Journal article (peer-reviewed)abstract
- Laser wakefield accelerators commonly produce on-axis, low-divergence, high-energy electron beams. However, a high charge, annular shaped beam can be trapped outside the bubble and accelerated to high energies. Here we present a parametric study on the production of low-energy-spread, ultra-relativistic electron ring beams in a two-stage gas cell. Ring-shaped beams with energies higher than 750 MeV are observed simultaneously with on axis, continuously injected electrons. Often multiple ring shaped beams with different energies are produced and parametric studies to control the generation and properties of these structures were conducted. Particle tracking and particle-in-cell simulations are used to determine properties of these beams and investigate how they are formed and trapped outside the bubble by the wake produced by on-axis injected electrons. These unusual femtosecond duration, high-charge, high-energy, ring electron beams may find use in beam driven plasma wakefield accelerators and radiation sources.
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| 3. |
- Streeter, M. J.V., et al.
(author)
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Characterization of laser wakefield acceleration efficiency with octave spanning near-IR spectrum measurements
- 2022
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In: Physical Review Accelerators and Beams. - 2469-9888. ; 25:10
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Journal article (peer-reviewed)abstract
- We report on experimental measurements of energy transfer efficiencies in a GeV-class laser wakefield accelerator. Both the transfer of energy from the laser to the plasma wakefield and from the plasma to the accelerated electron beam was diagnosed by simultaneous measurement of the deceleration of laser photons and the acceleration of electrons as a function of plasma length. The extraction efficiency, which we define as the ratio of the energy gained by the electron beam to the energy lost by the self-guided laser mode, was maximized at 19±3% by tuning the plasma density and length. The additional information provided by the octave-spanning laser spectrum measurement allows for independent optimization of the plasma efficiency terms, which is required for the key goal of improving the overall efficiency of laser wakefield accelerators.
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| 4. |
- Wen, Qingfeng, et al.
(author)
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Lead-exposure associated miRNAs in humans and Alzheimer’s disease as potential biomarkers of the disease and disease processes
- 2022
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- Alzheimer’s disease (AD) is a neurodegenerative disease that eventually affects memory and behavior. The identification of biomarkers based on risk factors for AD provides insight into the disease since the exact cause of AD remains unknown. Several studies have proposed microRNAs (miRNAs) in blood as potential biomarkers for AD. Exposure to heavy metals is a potential risk factor for onset and development of AD. Blood cells of subjects that are exposed to lead detected in the circulatory system, potentially reflect molecular responses to this exposure that are similar to the response of neurons. In this study we analyzed blood cell-derived miRNAs derived from a general population as proxies of potentially AD-related mechanisms triggered by lead exposure. Subsequently, we analyzed these mechanisms in the brain tissue of AD subjects and controls. A total of four miRNAs were identified as lead exposure-associated with hsa-miR-3651, hsa-miR-150-5p and hsa-miR-664b-3p being negatively and hsa-miR-627 positively associated. In human brain derived from AD and AD control subjects all four miRNAs were detected. Moreover, two miRNAs (miR-3651, miR-664b-3p) showed significant differential expression in AD brains versus controls, in accordance with the change direction of lead exposure. The miRNAs’ gene targets were validated for expression in the human brain and were found enriched in AD-relevant pathways such as axon guidance. Moreover, we identified several AD relevant transcription factors such as CREB1 associated with the identified miRNAs. These findings suggest that the identified miRNAs are involved in the development of AD and might be useful in the development of new, less invasive biomarkers for monitoring of novel therapies or of processes involved in AD development.
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| 5. |
- Filippi, F., et al.
(author)
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Plasma density profile reconstruction of a gas cell for Ionization Induced Laser Wakefield Acceleration
- 2023
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In: Journal of Instrumentation. - 1748-0221. ; 18:5
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Journal article (peer-reviewed)abstract
- Laser-driven plasma wakefields can provide hundreds of MeV electron beam in mm-range distances potentially shrinking the dimension of the actual particle accelerators. The plasma density plays a fundamental role in the control and stability of the acceleration process, which is a key development for the future electron injector proposed by EuPRAXIA. A gas cell was designed by LPGP and LIDYL teams, with variable length and backing pressure, to confine the gas and tailor the gas density profile before the arrival of the laser. This cell was used during an experimental campaign with the multi TW-class laser at the Lund Laser Centre. Ionization assisted injection in a tailored density profile is used to tune the electron beam properties. During the experiment, we filled the gas cell with hydrogen mixed with different concentration of nitrogen. We also varied the backing pressure of the gas and the geometrical length of the gas cell. We used a transverse probe to acquire shadowgraphic images of the plasma and to measure the plasma electron density. Methods and results of the analysis with comparisons between shadowgraphic and interferometric images will be discussed.
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| 6. |
- Almerud, Pernilla, 1978, et al.
(author)
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Cadmium, total mercury, and lead in blood and associations with diet, sociodemographic factors, and smoking in Swedish adolescents
- 2021
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In: Environmental Research. - : Elsevier BV. - 0013-9351. ; 197
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Journal article (peer-reviewed)abstract
- Background: Despite their vulnerability to the toxic effects of certain metals, biomonitoring data on adolescents are limited. In the present study, we assessed blood concentrations of toxic metals (cadmium [Cd], total mercury [Hg], and lead [Pb] in a national representative sample of Swedish adolescents. We also examined the associations of Cd, total Hg and Pb with habitual intakes of major energy-providing food groups and other possible determinants such as age, sex, household education, Nordic or non-Nordic origin, and smoking. Methods: We analysed blood concentrations of Cd, total Hg, and Pb in a sample of 1099 adolescents from the Riksmaten Adolescents 2016–17 study in three age groups (mean age of 12, 15, and 18 years) using inductively coupled plasma mass spectrometry. The participants completed web-based questionnaires on food consumption frequency, sociodemographic factors and health status. Dietary data from two web-based 24-h dietary recalls were used to estimate the habitual intake of 10 major food groups. Results: Almost all participants had detectable concentrations of Cd, total Hg, and Pb in whole blood. The median blood concentrations were 0.12 μg/L for Cd, 0.72 μg/L for total Hg, and 7.1 μg/L for Pb. Higher blood concentrations of Cd were observed in girls than in boys, whereas concentrations of total Hg and Pb were higher in boys. We observed an inverse association between Cd and meat intake. Total Hg concentrations were positively associated with intakes of fish, eggs, meat, and vegetables, and Pb concentrations were inversely associated with intakes of dairy products. Furthermore, smokers had higher concentrations of Cd and Pb. Conclusions: We found that fish was a potentially important source of exposure to total Hg in Swedish adolescents. No other food group was identified to have a strong impact on the blood levels of Cd, total Hg and Pb. Thirteen per cent of the adolescents had blood Pb concentrations above 12 μg/L, the reference point used in the risk assessment of Pb by the European Food Safety Authority (EFSA). © 2021 The Authors
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| 7. |
- Aylward, K., et al.
(author)
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"Are You Planning to Follow Your Route?" The Effect of Route Exchange on Decision Making, Trust, and Safety
- 2020
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In: Journal of Marine Science and Engineering. - : MDPI AG. - 2077-1312. ; 8:4
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Journal article (peer-reviewed)abstract
- The Sea Traffic Management (STM) Validation project is a European based initiative which focuses on connecting and updating the maritime world in real time, with efficient information exchange. The purpose of this paper is to evaluate two functions developed during the project: a ship to ship route exchange (S2SREX) function and rendezvous (RDV) information layer, collectively referred to as S2SREX/RDV. S2SREX displays the route segment consisting of the next seven waypoints of the monitored route of a collaborating ship and the RDV layer that predicts a meeting point. S2SREX/RDV provides supplementary information to data acquired by existing navigation systems and is intended to improve situational awareness and safety through a more comprehensive understanding of the surrounding traffic. Chalmers University of Technology and Solent University completed an experiment using twenty-four experienced navigators in bridge simulators. Six traffic scenarios were developed by subject matter experts and tested with and without S2SREX/RDV functionalities. Qualitative data were collected using post-test questionnaires and group debriefs to evaluate the participants' perceptions of S2SREX/RDV in the various traffic scenarios, and quantitative data were collected to assess the ship distances and behavior in relation to the International Regulations for Preventing Collisions at Sea (COLREGs). The results revealed that participants generally trusted the S2SREX/RDV information, and most used S2SREX/RDV for decision support. The quantitative assessment revealed that the COLREGs were breached more often when S2SREX/RDV was used. Experimental findings are discussed in relation to safety, trust, reliance, situational awareness, and human-automation interaction constructs.
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| 8. |
- Barman, Malin, 1983, et al.
(author)
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Maternal dietary selenium intake is associated with increased gestational length and decreased risk of preterm delivery
- 2020
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In: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 123:2, s. 209-219
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Journal article (peer-reviewed)abstract
- The first positive genome-wide association study on gestational length and preterm delivery showed associations with a gene involved in the selenium metabolism. In this study we examine the associations between maternal intake of selenium and selenium status with gestational length and preterm delivery in 72,025 women with singleton live births from the population based, prospective Norwegian Mother, Father and Child Cohort Study (MoBa). A self-reported, semi-quantitativ food-frequency questionnaire answered in pregnancy week 22 was used to estimate selenium intake during the first half of pregnancy. Associations were analysed with adjusted linear and cox regressions. Selenium status was assessed in whole blood collected in gestational week 17 (n=2,637). Median dietary selenium intake was 53 (IQR: 44-62) μg/day, supplements provided additionally 50 (30-75) μg/day for supplement-users (n=23,409). Maternal dietary selenium intake was significantly associated with prolonged gestational length (β per SD=0.25, 95% CI=0.07-0.43) and decreased risk for preterm delivery (n=3,618, HR per SD=0.92, 95% CI=0.87-0.98). Neither selenium intake from supplements nor maternal blood selenium status was associated with gestational length or preterm delivery. Hence, this study showed that maternal dietary selenium intake, but not intake of selenium containing supplements, during the first half of pregnancy was significantly associated with decreased risk for preterm delivery. Further investigations, preferably in the form of a large RCT, are needed to elucidate the impact of selenium on pregnancy duration.
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| 9. |
- Barregård, Lars, 1948, et al.
(author)
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Cadmium Exposure and Coronary Artery Atherosclerosis: A Cross-Sectional Population-Based Study of Swedish Middle-Aged Adults
- 2021
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In: Environmental health perspectives. - 1552-9924 .- 0091-6765. ; 129:6
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Journal article (peer-reviewed)abstract
- The general population is ubiquitously exposed to the toxic metal cadmium through the diet and smoking. Cadmium exposure is associated with increased morbidity and mortality in myocardial infarction and stroke. Atherosclerosis is the main underlying mechanism of myocardial infarction. However, associations between cadmium and coronary artery atherosclerosis have not been examined.Our study sought to examine the hypothesis that blood cadmium (B-Cd) is positively associated with coronary artery calcification, as a measure of coronary artery atherosclerosis in the population-based Swedish SCAPIS study.Our analysis included 5,627 individuals (51% women), age 50-64 y, enrolled from 2013 to 2018. The coronary artery calcium score (CACS) was obtained from computed tomography. Blood cadmium was determined by inductively coupled plasma mass spectrometry (ICP-MS). Associations between B-Cd and coronary artery calcium score (CACS Agatston score) were evaluated using prevalence ratios (PRs) in models adjusted for sex, age, smoking, hypertension, diabetes, low-density cholesterol/high-density cholesterol ratio, and family history.The median B-Cd concentration was 0.24 μ g / L . The prevalence of positive coronary artery calcium ( CACS > 0 ) was 41% and the prevalence of CACS ≥ 100 was 13%. Relative to the lowest quartile (Q) of B-Cd ( < 0.16 μ g / L ), the highest quartile (median 0.63 μ g / L ) was associated with a small but significant increase in CACS > 0 (PR 1.1; 95% CI: 1.0, 1.3), and a greater relative increase in CACS ≥ 100 (PR 1.6; 95% CI: 1.3, 2.0). When restricted to 2,446 never-smokers, corresponding PRs were 1.1 (95% CI 0.9, 1.3) for CACS > 0 (63 cases in Q4) and 1.7 (95% CI 1.1, 2.7) for CACS ≥ 100 (17 cases in Q4).Blood cadmium in the highest quartile was associated with CACS in a general population sample with low to moderate cadmium exposure. This supports the hypothesis that atherosclerosis is an important mechanism underlying the associations between cadmium and incident cardiovascular disease. The findings suggest that public health measures to reduce cadmium exposure are warranted. https://doi.org/10.1289/EHP8523.
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| 10. |
- Bondesson, Johan, 1991, et al.
(author)
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Automated Quantification of Diseased Thoracic Aortic Longitudinal Centerline and Surface Curvatures
- 2020
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In: Journal of Biomechanical Engineering-Transactions of the Asme. - : ASME International. - 0148-0731 .- 1528-8951. ; 142:4
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Journal article (peer-reviewed)abstract
- Precise description of vascular morphometry is crucial to support medical device manufacturers and clinicians for improving device development and interventional outcomes. A compact and intuitive method is presented to automatically characterize the surface geometry of tubular anatomic structures and quantify surface curvatures starting from generic stereolithographic (STL) surfaces. The method was validated with software phantoms and used to quantify the longitudinal surface curvatures of 37 human thoracic aortas with aneurysm or dissection. The quantification of surface curvatures showed good agreement with analytic solutions from the software phantoms, and demonstrated better agreement as compared to estimation methods using only centerline geometry and cross-sectional radii. For the human thoracic aortas, longitudinal inner surface curvature was significantly higher than centerline curvature (0.33 +/- 0.06 versus 0.16 +/- 0.02cm(-1) for mean; 1.38 +/- 0.48 versus 0.45 +/- 0.11cm(-1) for peak; both p<0.001). These findings show the importance of quantifying surface curvatures in order to better describe the geometry and biomechanical behavior of the thoracic aorta, which can assist in treatment planning and supplying device manufactures with more precise boundary conditions for mechanical evaluation.
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