| 1. |
- Walker, Anthony P, et al.
(författare)
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Horizon 2020 EuPRAXIA design study
- 2017
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 874:1
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Tidskriftsartikel (refereegranskat)abstract
- The Horizon 2020 Project EuPRAXIA ("European Plasma Research Accelerator with eXcellence In Applications") is preparing a conceptual design report of a highly compact and cost-effective European facility with multi-GeV electron beams using plasma as the acceleration medium. The accelerator facility will be based on a laser and/or a beam driven plasma acceleration approach and will be used for photon science, high-energy physics (HEP) detector tests, and other applications such as compact X-ray sources for medical imaging or material processing. EuPRAXIA started in November 2015 and will deliver the design report in October 2019. EuPRAXIA aims to be included on the ESFRI roadmap in 2020.
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| 2. |
- Clifford, B. L., et al.
(författare)
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FXR activation protects against NAFLD via bile-acid-dependent reductions in lipid absorption
- 2021
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Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 33:8
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Tidskriftsartikel (refereegranskat)abstract
- FXR agonists are used to treat non-alcoholic fatty liver disease (NAFLD), in part because they reduce hepatic lipids. Here, we show that FXR activation with the FXR agonist GSK2324 controls hepatic lipids via reduced absorption and selective decreases in fatty acid synthesis. Using comprehensive lipidomic analyses, we show that FXR activation in mice or humans specifically reduces hepatic levels of mono-and polyunsaturated fatty acids (MUFA and PUFA). Decreases in MUFA are due to FXR-dependent repression of Scd1, Dgat2, and Lpin1 expression, which is independent of SHP and SREBP1c. FXR-dependent decreases in PUFAs are mediated by decreases in lipid absorption. Replenishing bile acids in the diet prevented decreased lipid absorption in GSK2324-treated mice, suggesting that FXR reduces absorption via decreased bile acids. We used tissue-specific FXR KO mice to show that hepatic FXR controls lipogenic genes, whereas intestinal FXR controls lipid absorption. Together, our studies establish two distinct pathways by which FXR regulates hepatic lipids.
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| 3. |
- Mörtzell Henriksson, Monica, et al.
(författare)
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Adverse events in apheresis : an update of the WAA registry data
- 2016
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Ingår i: Transfusion and apheresis science. - : Elsevier. - 1473-0502 .- 1878-1683. ; 54:1, s. 2-15
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Forskningsöversikt (refereegranskat)abstract
- Apheresis with different procedures and devices are used for a variety of indications that may have different adverse events (AEs). The aim of this study was to clarify the extent and possible reasons of various side effects based on data from a multinational registry. The WAA-apheresis registry data focus on adverse events in a total of 50846 procedures in 7142 patients (42% women). AEs were graded as mild, moderate (need for medication), severe (interruption due to the AE) or death (due to AE). More AEs occurred during the first procedures versus subsequent (8.4 and 5.5%, respectively). AEs were mild in 2.4% (due to access 54%, device 7%, hypotension 15%, tingling 8%), moderate in 3% (tingling 58%, urticaria 15%, hypotension 10%, nausea 3%), and severe in 0.4% of procedures (syncope/hypotension 32%, urticaria 17%, chills/fever 8%, arrhythmia/asystole 4.5%, nausea/vomiting 4%). Hypotension was most common if albumin was used as the replacement fluid, and urticaria when plasma was used. Arrhythmia occurred to similar extents when using plasma or albumin as replacement. In 64% of procedures with bronchospasm, plasma was part of the replacement fluid used. Severe AEs are rare. Although most reactions are mild and moderate, several side effects may be critical for the patient. We present side effects in relation to the procedures and suggest that safety is increased by regular vital sign measurements, cardiac monitoring and by having emergency equipment nearby.
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| 4. |
- Ovadia, C., et al.
(författare)
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Ursodeoxycholic acid enriches intestinal bile salt hydrolase-expressing Bacteroidetes in cholestatic pregnancy
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Ursodeoxycholic acid (UDCA) treatment can reduce itch and lower endogenous serum bile acids in intrahepatic cholestasis of pregnancy (ICP). We sought to determine how it could influence the gut environment in ICP to alter enterohepatic signalling. The gut microbiota and bile acid content were determined in faeces from 35 pregnant women (14 with uncomplicated pregnancies and 21 with ICP, 17 receiving UDCA). Faecal bile salt hydrolase activity was measured using a precipitation assay. Serum fibroblast growth factor 19 (FGF19) and 7α-hydroxy-4-cholesten-3-one (C4) concentrations were measured following a standardised diet for 21 hours. Women with a high ratio of Bacteroidetes to Firmicutes were more likely to be treated with UDCA (Fisher’s exact test p = 0.0178) than those with a lower ratio. Bile salt hydrolase activity was reduced in women with low Bacteroidetes:Firmicutes. Women taking UDCA had higher faecal lithocholic acid (p < 0.0001), with more unconjugated bile acids than women with untreated ICP or uncomplicated pregnancy. UDCA-treatment increased serum FGF19, and reduced C4 (reflecting lower bile acid synthesis). During ICP, UDCA treatment can be associated with enrichment of the gut microbiota with Bacteroidetes. These demonstrate high bile salt hydrolase activity, which deconjugates bile acids enabling secondary modification to FXR agonists, enhancing enterohepatic feedback via FGF19. © 2020, The Author(s).
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| 5. |
- Pirozhkov, A. S., et al.
(författare)
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Diagnostic of laser contrast using target reflectivity
- 2009
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 94:24
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Tidskriftsartikel (refereegranskat)abstract
- Using three different laser systems, we demonstrate a convenient and simple plasma based diagnostic of the contrast of high-power short-pulse lasers. The technique is based on measuring the specular reflectivity from a solid target. The reflectivity remains high even at relativistic intensities above 10(19) W/cm(2) in the case of a high-contrast prepulse-free laser. On the contrary, the specular reflectivity drops with increasing intensities in the case of systems with insufficient contrast due to beam breakup and increased absorption caused by preplasma.
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| 6. |
- Giuffrida, L., et al.
(författare)
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Nano and micro structured targets to modulate the spatial profile of laser driven proton beams
- 2017
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 12:3, s. article no C03040 -
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Tidskriftsartikel (refereegranskat)abstract
- Nano and micro structured thin (μ m-scale) foils were designed, fabricated and irradiated with the high intensity laser system operating at LLC (Lund Laser Centre, Sweden) in order to systematically study and improve the main proton beam parameters. Nano-spheres deposited on the front (laser irradiated) surface of a flat Mylar foil enabled a small enhancement of the maximum energy and number of the accelerated protons. Nano-spheres on the rear side allowed to modify the proton beam spatial profile. In particular, with nanospheres deposited on the rear of the target, the proton beam spatial homogeneity was clearly enhanced. Silicon nitride thin foils having micro grating structures (with different step dimensions) on the rear surface were also used as targets to influence the divergence of the proton beam and drastically change its shape through a sort of stretching effect. The target fabrication process used for the different target types is described, and representative experimental results are shown and discussed along with supporting 3D particle-in-cell simulations. © 2017 IOP Publishing Ltd and Sissa Medialab srl.
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| 7. |
- Schneider, K. M., et al.
(författare)
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Gut microbiota depletion exacerbates cholestatic liver injury via loss of FXR signalling
- 2021
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Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 3:9, s. 1228-1241
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Tidskriftsartikel (refereegranskat)abstract
- Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology for which there are no approved therapeutic options. Patients with PSC display changes in gut microbiota and in bile acid (BA) composition; however, the contribution of these alterations to disease pathogenesis remains controversial. Here we identify a role for microbiota-dependent changes in BA synthesis that modulates PSC pathophysiology. In a genetic mouse model of PSC, we show that loss of microbiota-mediated negative feedback control of BA synthesis results in increased hepatic BA concentrations, disruption of bile duct barrier function and, consequently, fatal liver injury. We further show that these changes are dependent on decreased BA signalling to the farnesoid X receptor, which modulates the activity of the rate-limiting enzyme in BA synthesis, CYP7A1. Moreover, patients with advanced stages of PSC show suppressed BA synthesis as measured by serum C4 levels, which is associated with poor disease prognosis. Our preclinical data highlight the microbiota-dependent dynamics of BA metabolism in cholestatic liver disease, which could be important for future therapies targeting BA and gut microbiome interactions, and identify C4 as a potential biomarker to functionally stratify patients with PSC and predict disease outcomes. Patients with primary sclerosing cholangitis (PSC), a chronic cholestatic liver disease, display changes in the gut microbiota and in bile acid composition. Schneider, Candels and colleagues identify a role for microbiota-dependent regulation of bile acid synthesis through farnesoid X receptor signalling, which is relevant for PSC disease progression.
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| 8. |
- Shirazi, M., et al.
(författare)
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Effects on readiness to change of an educational intervention on depressive disorders for general physicians in primary care based on a modified Prochaska model : a randomized controlled study
- 2008
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Ingår i: Family Practice. - : Oxford University Press (OUP). - 0263-2136 .- 1460-2229. ; 25:2, s. 98-104
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Prochaska model of readiness to change has been proposed to be used in educational interventions to improve medical care. Objective: To evaluate the impact on readiness to change of an educational intervention on management of depressive disorders based on a modified version of the Prochaska model in comparison with a standard programme of continuing medical education (CME). Methods: This is a randomized controlled trial within primary care practices in southern Tehran, Iran. The participants included 192 general physicians working in primary care (GPs) were recruited after random selection and randomized to intervention (96) and control (96). Intervention consisted of interactive, learner-centred educational methods in large and small group settings depending on the GPs' stages of readiness to change. Change in stage of readiness to change measured by the modified version of the Prochaska questionnaire was the main outcome measure. Results The final number of participants was 78 (81%) in the intervention arm and 81 (84%) in the control arm. Significantly (P < 0.01), more GPs (57/96 = 59% versus 12/96 = 12%) in the intervention group changed to higher stages of readiness to change. The intervention effect was 46% points (P < 0.001) and 50% points (P < 0.001) in the large and small group setting, respectively. Conclusions: Educational formats that suit different stages of learning can support primary care doctors to reach higher stages of behavioural change in the topic of depressive disorders. Our findings have practical implications for conducting CME programmes in Iran and are possibly also applicable in other parts of the world.
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| 9. |
- Elliott, James A., et al.
(författare)
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Diabetes Self-Management and Education of People Living with Diabetes : A Survey in Primary Health Care in Muscat Oman
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:2, s. e57400-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although the prevalence of type 2 diabetes in Oman is high and rising, information on how people were self-managing their disease has been lacking. The objective of this study was therefore to assess diabetes self-management and education (DSME) among people living with type 2 diabetes in Oman. Methods: A questionnaire survey was conducted in public primary health care centres in Muscat. Diabetes self-management and education was assessed by asking how patients recognized and responded to hypo- and hyperglycaemia, and if they had developed strategies to maintain stable blood glucose levels. Patients' demographic information, self-treatment behaviours, awareness of potential long-term complications, and attitudes concerning diabetes management were also recorded. Associations between these factors and diabetes self-management and education were analysed. Results: In total, 309 patients were surveyed. A quarter (26%, n = 83) were unaware how to recognize hypoglycaemia or respond to it (26%, n = 81). Around half (49%, n = 151), could not recognize hyperglycaemia and more than half could not respond to it (60%, n = 184). Twelve percent (n = 37) of the patients did not have any strategies to stabilize their blood glucose levels. Patients with formal education generally had more diabetes self-management and education than those without (p<0.001), as had patients with longer durations of diabetes (p<0.01). Self-monitoring of blood glucose was practiced by 38% (n = 117) of the patients, and insulin was used by 22% (n = 67), of which about one third independently adjusted dosages. Patients were most often aware of complications concerning loss of vision, renal failure and cardiac problems. Many patients desired further health education. Conclusions: Many patients displayed dangerous diabetes self-management and education knowledge gaps. The findings suggest a need for improving knowledge transfer to people living with diabetes in the Omani clinical setting.
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| 10. |
- Giuffrida, L., et al.
(författare)
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Manipulation of laser-accelerated proton beam profiles by nanostructured and microstructured targets
- 2017
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Ingår i: Physical Review Accelerators and Beams. - 2469-9888. ; 20:8, s. 081301-
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured and microstructured thin foils have been fabricated and used experimentally as targets to manipulate the spatial profile of proton bunches accelerated through the interaction with high intensity laser pulses (6 x 1019 W/cm(2)). Monolayers of polystyrene nanospheres were placed on the rear surfaces of thin plastic targets to improve the spatial homogeneity of the accelerated proton beams. Moreover, thin targets with grating structures of various configurations on their rear sides were used tomodify the proton beam divergence. Experimental results are presented, discussed, and supported by 3D particle-in-cell numerical simulations.
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| 11. |
- Audet, T. L., et al.
(författare)
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Electron injector for compact staged high energy accelerator
- 2016
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 829, s. 304-308
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Tidskriftsartikel (refereegranskat)abstract
- An electron injector for multi-stage laser wakefield experiments is presented. It consists of a variable length gas cell of small longitudinal dimension (⩽10mm). The gas filling process in this cell was characterized both experimentally and with fluid simulation. Electron acceleration experiments were performed at two different laser facilities. Results show low divergence and low pointing fluctuation electron bunches suitable for transport to a second stage, and a peaked energy distribution suitable for injection into the second stage wakefield accelerator.
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| 12. |
- Audet, T. L., et al.
(författare)
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Investigation of ionization-induced electron injection in a wakefield driven by laser inside a gas cell
- 2016
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- Ionization-induced electron injection was investigated experimentally by focusing a driving laser pulse with a maximum normalized potential of 1.2 at different positions along the plasma density profile inside a gas cell, filled with a gas mixture composed of 99%H2+1%N2. Changing the laser focus position relative to the gas cell entrance controls the accelerated electron bunch properties, such as the spectrum width, maximum energy, and accelerated charge. Simulations performed using the 3D particle-in-cell code WARP with a realistic density profile give results that are in good agreement with the experimental ones. The interest of this regime for optimizing the bunch charge in a selected energy window is discussed.
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| 13. |
- Aurand, B., et al.
(författare)
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Manipulation of the spatial distribution of laser-accelerated proton beams by varying the laser intensity distribution
- 2016
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1089-7674 .- 1070-664X. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- We report on a study of the spatial profile of proton beams produced through target normal sheath acceleration using flat target foils and changing the laser intensity distribution on the target front surface. This is done by either defocusing a single laser pulse or by using a split-pulse setup and irradiating the target with two identical laser pulses with variable spatial separation. The resulting proton beam profile and the energy spectrum are recorded as functions of the focal spot size of the single laser pulse and of the separation between the two pulses. A shaping of the resulting proton beam profile, related to both an increase in flux of low-energy protons in the target normal direction and a decrease in their divergence, in one or two dimensions, is observed. The results are explained by simple modelling of rear surface sheath field expansion, ionization, and projection of the resulting proton beam.
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| 14. |
- Bauer, HCF, et al.
(författare)
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The Scandinavian Sarcoma Group Register
- 1999
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Ingår i: Acta orthopaedica Scandinavica. Supplementum. - : Medical Journals Sweden AB. - 0300-8827 .- 0001-6470. ; 70285, s. 41-44, s. 41-44
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Tidskriftsartikel (refereegranskat)
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| 15. |
- Coury, M., et al.
(författare)
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Injection and transport properties of fast electrons in ultraintense laser-solid interactions
- 2013
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 20:4
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Tidskriftsartikel (refereegranskat)abstract
- Fast electron injection and transport in solid foils irradiated by sub-picosecond-duration laser pulses with peak intensity equal to 4 x 10(20)W/cm(2) is investigated experimentally and via 3D simulations. The simulations are performed using a hybrid-particle-in-cell (PIC) code for a range of fast electron beam injection conditions, with and without inclusion of self-generated resistive magnetic fields. The resulting fast electron beam transport properties are used in rear-surface plasma expansion calculations to compare with measurements of proton acceleration, as a function of target thickness. An injection half-angle of similar to 50 degrees - 70 degrees is inferred, which is significantly larger than that derived from previous experiments under similar conditions. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4799726]
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| 16. |
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| 17. |
- Genoud, Guillaume, et al.
(författare)
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Laser-plasma electron acceleration in dielectric capillary tubes
- 2011
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 105:2, s. 309-316
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Tidskriftsartikel (refereegranskat)abstract
- Electron beams and betatron X-ray radiation generated by laser wakefield acceleration in long plasma targets are studied. The targets consist of hydrogen filled dielectric capillary tubes of diameter 150 to 200 microns and length 6 to 20 mm. Electron beams are observed for peak laser intensities as low as 5x10(17) W/cm(2). It is found that the capillary collects energy outside the main peak of the focal spot and contributes to keep the beam self-focused over a distance longer than in a gas jet of similar density. This enables the pulse to evolve enough to reach the threshold for wavebreaking, and thus trap and accelerate electrons. No electrons were observed for capillaries of large diameter (250 mu m), confirming that the capillary influences the interaction and does not have the same behaviour as a gas cell. Finally, X-rays are used as a diagnostic of the interaction and, in particular, to estimate the position of the electrons trapping point inside the capillary.
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| 18. |
- Gopal, A., et al.
(författare)
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MegaGauss magnetic field generation by ultra-short pulses at relativistic intensities
- 2013
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 55:3
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Tidskriftsartikel (refereegranskat)abstract
- We report the experimental studies on megaGauss magnetic field generation using a 35 femtosecond laser at relativistic intensities. The polarization change of the self-generated harmonics was recorded to estimate the magnetic field. A parameter scan was performed by varying the input laser intensity as well as the contrast ratio. External optical probing diagnostics were performed using the second harmonic of the incident laser. Additionally, the optical transition radiation from the rear of the target was also recorded.
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| 19. |
- Isasi, R., et al.
(författare)
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Disclosure and management of research findings in stem cell research and banking: policy statement
- 2012
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Ingår i: Regenerative Medicine. - : Future Medicine Ltd. - 1746-0751 .- 1746-076X. ; 7:3, s. 439-448
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Tidskriftsartikel (refereegranskat)abstract
- Prompted by an increased interest of both research participants and the patient advocacy community in obtaining information about research outcomes and on the use of their biological samples; the international community has begun to debate the emergence of an ethical 'duty' to return research results to participants. Furthermore, the use of new technologies (e.g., whole-genome and -exome sequencing) has revealed both genetic data and incidental findings with possible clinical significance. These technologies together with the proliferation of biorepositories, provide a compelling rationale for governments and scientific institutions to adopt prospective policies. Given the scarcity of policies in the context of stem cell research, a discussion on the scientific, ethical and legal implications of disclosing research results for research participants is needed. We present the International Stem Forum Ethics Working Party's Policy Statement and trust that it will stimulate debate and meet the concerns of researchers and research participants alike.
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| 20. |
- Krones, E., et al.
(författare)
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NorUrsodeoxycholic acid ameliorates cholemic nephropathy in bile duct ligated mice
- 2017
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Ingår i: Journal of Hepatology. - : Elsevier BV. - 0168-8278. ; 67:1, s. 110-119
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Severe cholestasis may cause cholemic nephropathy that can be modeled in common bile duct ligated (CBDL) mice. We aimed to explore the therapeutic efficacy and mechanisms of norursodeoxycholic acid (norUDCA) in cholemic nephropathy. Methods: In 8-week CBDL mice fed with norUDCA (prior or post CBDL) or chow we evaluated serum urea levels, urine cytology and urinary neutrophil gelatinase associated lipocalin (uNGAL), kidney and liver tissue quantification of fibrosis by hydroxyproline content and gene chip expression looking at key genes of inflammation and fibrosis. Moreover, we comprehensively analysed bile acid profiles in liver, kidney, serum and urine samples. Results: NorUDCA-fed CBDL mice had significantly lower serum urea and uNGAL levels and less severe cholemic nephropathy as demonstrated by normal urine cytology, significantly reduced tubulointerstitial nephritis, and renal fibrosis as compared to controls. NorUDCA underwent extensive metabolism to produce even more hydrophilic compounds that were significantly enriched in kidneys. Conclusion: NorUDCA ameliorates cholemic nephropathy due to the formation of highly hydrophilic metabolites enriched in kidney. Consequently, norUDCA may represent a medical treatment for cholemic nephropathy. Lay summary: The term cholemic nephropathy describes renal dysfunction together with characteristic morphological alterations of the kidney in obstructive cholestasis that can be mimicked by ligation of the common bile duct in mice. Feeding the hydrophilic bile acid norUDCA to bile duct ligated mice leads to a significant amelioration of the renal phenotype due to the formation of highly hydrophilic metabolites enriched in the kidney and may therefore represent a medical treatment for cholemic nephropathy. (C) 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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| 21. |
- MacLellan, D. A., et al.
(författare)
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Annular Fast Electron Transport in Silicon Arising from Low-Temperature Resistivity
- 2013
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Ingår i: Physical Review Letters. - 1079-7114. ; 111:9
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Tidskriftsartikel (refereegranskat)abstract
- Fast electron transport in Si, driven by ultraintense laser pulses, is investigated experimentally and via 3D hybrid particle-in-cell simulations. A transition from a Gaussian-like to an annular fast electron beam profile is demonstrated and explained by resistively generated magnetic fields. The results highlight the potential to completely transform the beam transport pattern by tailoring the resistivity-temperature profile at temperatures as low as a few eV.
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| 22. |
- MacLellan, D A, et al.
(författare)
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Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt.
- 2014
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Ingår i: Physical Review Letters. - 1079-7114. ; 113:18
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Tidskriftsartikel (refereegranskat)abstract
- The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, and symmetry to be actively tailored, and without recourse to complex target manufacture.
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| 23. |
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| 24. |
- Stjernbrandt, Albin, et al.
(författare)
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Occupational cold exposure and symptoms of carpal tunnel syndrome : a population-based study
- 2022
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Ingår i: BMC Musculoskeletal Disorders. - : BioMed Central. - 1471-2474. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cold exposure is an underrecognized occupational hazard that may increase the risk of peripheral nerve entrapment. The aim of this study was to determine if self-reported occupational exposure to contact and ambient cooling was associated with symptoms of carpal tunnel syndrome (CTS).METHODS: In this mainly cross-sectional study, surveys were conducted on a population-based sample of men and women between 18 and 70 years of age, living in northern Sweden. Cold exposure and presence of symptoms suggestive of CTS were subjectively reported. Associations between exposure and outcome were evaluated using logistic regression.RESULTS: The study included 2,703 women and 2,314 men, with a median age of 60 years (interquartile range 19). Symptoms of CTS were reported by 453 (9.2%). Being highly occupationally exposed (almost always) to contact cooling of the hands was associated with reporting CTS (OR 3.20; 95% CI 1.62-6.33), as was ambient cooling (OR 2.00; 95% CI 1.03-3.88) and severe ambient cooling (OR 4.02 95% CI 2.09-7.71), after adjusting for age, gender, body mass index, current daily smoking, diabetes mellitus, joint disease, and hand-arm vibration exposure. The point estimates increased with longer daily exposure duration. For workers exposed to severe ambient cooling for more than half of their working hours, in addition to performing heavy manual handling every day, the OR for reporting CTS was 7.25 (95% CI 3.88-13.53), with a positive additive interaction effect (expressed as relative excess risk due to interaction) of 4.67.CONCLUSIONS: Self-reported occupational exposure to contact and ambient cooling was associated with symptoms suggestive of CTS. There were statistically significant positive exposure-response patterns for time spent exposed to contact and ambient cooling at work in relation to reporting symptoms of CTS. Positive additive interaction effects between cold exposure and heavy manual handling were also found. Since there was important potential uncontrolled confounding regarding repetitive wrist movements and forceful gripping, the results need to be confirmed by other studies, preferably with longitudinal design and more detailed exposure assessment.
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| 25. |
- Stjernbrandt, Albin, et al.
(författare)
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Occupational cold exposure is associated with upper extremity pain
- 2023
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Ingår i: Frontiers in Pain Research. - : Frontiers Media S.A.. - 2673-561X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Occupational cold exposure is common in Sweden but potential impacts on musculoskeletal disorders have not been thoroughly investigated. The primary aim of this study was to determine the associations between occupational contact and ambient cooling in relation to pain in the upper extremity.Methods: In this cross-sectional study, a digital survey was conducted on a population-based sample of women and men between 24 and 76 years of age, living in northern Sweden. Occupational cold exposure, heavy manual handling, work with vibrating tools as well as the presence of upper extremity pain at different sites were subjectively reported. Associations between exposure and outcome were evaluated using multiple binary logistic regression.Results: The final study sample included 2,089 (54.4%) women and 1,754 men, with a mean age of 56 years. Hand pain was reported by 196 (5.2%), lower arm pain by 144 (3.8%), and upper arm pain by 451 (11.9%). Severe ambient cooling for more than half of the working time was statistically significantly associated with hand pain (OR: 2.30; 95% CI: 1.23–4.29) and upper arm pain (OR: 1.57; 95% CI: 1.00–2.47) but not lower arm pain (OR: 1.87; 95% CI: 0.96–3.65) after adjusting for gender, age, body mass index, current daily smoking, heavy manual handling, and work with vibrating tools.Conclusions: Occupational cold exposure was statistically significantly associated with hand pain and upper arm pain. Therefore, occupational cold exposure should be recognized as a potential risk factor for musculoskeletal disorders in the upper extremity.
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| 26. |
- Svanberg, Sune, et al.
(författare)
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Generation, characterization, and medical utilization of laser-produced emission continua
- 2000
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Ingår i: Laser and Particle Beams. - 0263-0346. ; 18:3, s. 563-570
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Tidskriftsartikel (refereegranskat)abstract
- Intense continua of electromagnetic radiation of very brief duration are formed in the interaction of focused ultra-short terawatt laser pulses with matter. Two different kinds of experiments, which have been performed utilizing the Lund 10 Hz titanium-doped sapphire terawatt laser system are being described, where visible radiation and X-rays, respectively, have been generated. Focusing into water leads to the generation of a light continuum through self-phase modulation. The propagation of the light through tissue was studied addressing questions related to optical mammography and specific chromophore absorption. When terawatt laser pulses are focused onto a solid target with high nuclear charge Z, intense X-ray radiation of few ps duration and with energies exceeding hundreds of keV is emitted. Biomedical applications of this radiation are described, including differential absorption and gated-viewing imaging.
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| 27. |
- Svensson, K., et al.
(författare)
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Transverse expansion of the electron sheath during laser acceleration of protons
- 2017
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1089-7674 .- 1070-664X. ; 24:12
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Tidskriftsartikel (refereegranskat)abstract
- The transverse expansion of the electrostatic sheath during target normal sheath acceleration of protons is investigated experimentally using a setup with two synchronized laser pulses. With the pulses spatially separated by less than three laser spot diameters, the resulting proton beam profiles become elliptical. By introducing a small intensity difference between the two pulses, the ellipses are rotated by a certain angle, except if the spatial separation of the two laser pulses is in the plane of incidence. The rotation angle is shown to depend on the relative intensity of the two pulses. The observed effects are found to require high temporal contrasts of the laser pulses. A simple model describing how the transverse shape of the electron sheath on the rear of the target depends on the relative intensity between the foci is presented. The model assumptions are verified, and the unknown dependence of the transverse extents of the sheaths are estimated self-consistently through a series of high resolution, two-dimensional particle-in-cell simulations. The results predicted by the model are also shown to be consistent with those obtained from the experiment.
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| 28. |
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| 29. |
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| 30. |
- Albert, F, et al.
(författare)
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Laser produced X-ray source in the 10-60 keV range at 1 kHz. Modified irradiation schemes in order to reach medical imaging quality
- 2001
-
Ingår i: Journal de Physique IV. - : EDP Sciences. - 1155-4339. ; 11:PR2, s. 429-432
-
Tidskriftsartikel (refereegranskat)abstract
- By tightly focusing ultra-short pulses from a Ti:sapphire terawatt laser onto a high-Z metallic target, hard x-ray pulses of short duration are produced. In most of our previous work concerning x-rays, a 150 mJ laser pulse with a 110 A duration has been used. Using mostly tin and tantalum targets, hard x-rays in the 10-60 keV range have been produced and used in differential absorption imaging around the K-alpha absorption edge of a contrast agent and also in imaging employing gated viewing for suppression of scattered radiation. In order to increase the x-ray yield (shortening the acquisition time) an increase in the laser repetition rate is desirable while still staying in the K-alpha energy regime. We have used a I kHz repetition-rate laser delivering 35 fs pulses in order to work towards these goals. We have clear evidence of hard x-ray generation above 30 keV, even for low laser pulse energies. We also studied the effect of a fs prepulse. The medical imaging capability of the source was explored. The use of a prepulse has been optimized in order to improve the image quality as well as the overall x-ray generation yield.
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| 31. |
- Amundsen, S. S., et al.
(författare)
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Genetic analysis of the CD28/CTLA4/ICOS (CELIAC3) region in coeliac disease.
- 2004
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Ingår i: Tissue antigens. - : Wiley. - 0001-2815 .- 1399-0039. ; 64:5, s. 593-9
-
Tidskriftsartikel (refereegranskat)abstract
- In order to extend our previous findings of genetic linkage to the CD28/CTLA4/ICOS region on chromosome 2q33 (CELIAC3) in coeliac disease (CD), we have investigated 22 genetic markers in 325 Norwegian/Swedish multiplex and simplex CD families. We found both linkage and association with several markers, primarily in the multiplex material. We observed strong linkage disequilibrium (LD) between SNPs (Single Nucleotide Polymorphisms) within an LD block delimited by MH30 and D2S72. A haplotype of this region marked by the alleles -1147*T: + 49*A:CT60*G:CT61*A was significantly associated with CD, suggesting that one or more polymorphisms of this haplotype, possibly -1147*T, are involved in CD susceptibility. The CT60 SNP, a polymorphism found to be most strongly associated with some other immune-mediated diseases, was not associated with CD, as this SNP was part of both associated and non-associated haplotypes. Moreover, our results suggest that CELIAC3 harbours several independent loci contributing to CD susceptibility.
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| 32. |
- André, Malin, et al.
(författare)
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Upper respiratory tract infections in general practice: diagnosis, antibiotic prescribing, duration of symptoms and use of diagnostic tests
- 2002
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 0036-5548 .- 1651-1980. ; 34, s. 880-
-
Tidskriftsartikel (refereegranskat)abstract
- A diagnosis/antibiotic prescribing study was performed in 5 counties in Sweden for 1 week in November 2000. As part of this study, the characteristics and clinical management of patients with upper respiratory tract infections (n = 2899) in primary care were analyzed. Almost half of the patients were aged < 15 y and one-fifth of the patients consulted out of hours. Of all patients seeking primary care for upper respiratory tract infections, 56.0% were prescribed an antibiotic. Almost all patients who were given the diagnoses streptococcal tonsillitis, acute otitis media or acute sinusitis were prescribed antibiotics, compared to 10% of patients with common cold or acute pharyngitis. The most frequently prescribed antibiotic was penicillin V (79.2%) and this was even more pronounced out of hours, when the diagnoses otitis media and streptococcal tonsillitis were more frequently used. In patients with common cold and acute pharyngitis, the percentage who received antibiotics increased with increasing length of symptoms and increasing CRP levels. In patients with acute pharyngitis or streptococcal tonsillitis, antibiotics were prescribed less frequently provided streptococcal tests were performed. The management of patients with upper respiratory tract infections in general practice seems to be in good agreement with current Swedish guidelines. However, the study indicates some areas for improvement. The diagnosis of acute sinusitis seems to have been overestimated and used only to justify antibiotic treatment.
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| 33. |
- Assmann, R. W., et al.
(författare)
-
EuPRAXIA Conceptual Design Report
- 2020
-
Ingår i: European Physical Journal: Special Topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 229:24, s. 3675-4284
-
Tidskriftsartikel (refereegranskat)abstract
- This report presents the conceptual design of a new European research infrastructure EuPRAXIA. The concept has been established over the last four years in a unique collaboration of 41 laboratories within a Horizon 2020 design study funded by the European Union. EuPRAXIA is the first European project that develops a dedicated particle accelerator research infrastructure based on novel plasma acceleration concepts and laser technology. It focuses on the development of electron accelerators and underlying technologies, their user communities, and the exploitation of existing accelerator infrastructures in Europe. EuPRAXIA has involved, amongst others, the international laser community and industry to build links and bridges with accelerator science — through realising synergies, identifying disruptive ideas, innovating, and fostering knowledge exchange. The Eu-PRAXIA project aims at the construction of an innovative electron accelerator using laser- and electron-beam-driven plasma wakefield acceleration that offers a significant reduction in size and possible savings in cost over current state-of-the-art radiofrequency-based accelerators. The foreseen electron energy range of one to five gigaelectronvolts (GeV) and its performance goals will enable versatile applications in various domains, e.g. as a compact free-electron laser (FEL), compact sources for medical imaging and positron generation, table-top test beams for particle detectors, as well as deeply penetrating X-ray and gamma-ray sources for material testing. EuPRAXIA is designed to be the required stepping stone to possible future plasma-based facilities, such as linear colliders at the high-energy physics (HEP) energy frontier. Consistent with a high-confidence approach, the project includes measures to retire risk by establishing scaled technology demonstrators. This report includes preliminary models for project implementation, cost and schedule that would allow operation of the full Eu-PRAXIA facility within 8—10 years. © 2020, The Author(s).
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| 34. |
- Aurelius, Kristina, et al.
(författare)
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Perceptions of mental health, suicide and working conditions in the construction industry-A qualitative study.
- 2024
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 19:7
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to explore perceptions of mental ill health, suicidal behaviour and working conditions among male construction workers, in order to gain an in-depth understanding of these phenomenon and to identify relevant avenues for workplace interventions.Data were collected in individual and group interviews, and 43 individuals from the Swedish construction industry, workers, union representative and managers, participated in the study. Inductive thematic analysis was used to analyse the data.Five main themes were found: Difficult to talk about mental health, Demanding working environment affects mental health, Substance abuse among construction workers, Importance of management, and Need for routines and social support in the workplace. Many participants reported that there was a stigma related to mental health. Suicides that had occurred among colleagues were perceived to come out of the blue. The working environment in the construction industry was perceived to have a negative effect on mental health, and it was reported that the management played an important role in both the cause and prevention of mental health problems.The results from this Swedish study are in accordance with previous international research regarding a macho culture, stigma of mental health and a demanding working environment in the construction industry. The study adds to existing knowledge by highlighting that suicides were perceived to be very unexpected, that poor physical health affected mental health and that many participants did not know how to deal with mental health issues in the workplace.
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| 35. |
- Baghdasaryan, A., et al.
(författare)
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Inhibition of intestinal bile acid absorption improves cholestatic liver and bile duct injury in a mouse model of sclerosing cholangitis
- 2016
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Ingår i: Journal of Hepatology. - : Elsevier BV. - 0168-8278. ; 64:3, s. 674-681
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Approximately 95% of bile acids (BAs) excreted into bile are reabsorbed in the gut and circulate back to the liver for further biliary secretion. Therefore, pharmacological inhibition of the ileal apical sodium-dependent BA transporter (ASBT/SLC10A2) may protect against BA-mediated cholestatic liver and bile duct injury. Methods: Eight week old Mdr2(-/-) (Abcb4(-/-)) mice (model of cholestatic liver injury and sclerosing cholangitis) received either a diet supplemented with A4250 (0.01% w/w) - a highly potent and selective ASBT inhibitor - or a chow diet. Liver injury was assessed biochemically and histologically after 4 weeks of A4250 treatment. Expression profiles of genes involved in BA homeostasis, inflammation and fibrosis were assessed via RT-PCR from liver and ileum homogenates. Intestinal inflammation was assessed by RNA expression profiling and immunohistochemistry. Bile flow and composition, as well as biliary and fecal BA profiles were analyzed after 1 week of ASBT inhibitor feeding. Results: A4250 improved sclerosing cholangitis in Mdr2(-/-) mice and significantly reduced serum alanine aminotransferase, alkaline phosphatase and BAs levels, hepatic expression of proinflammatory (Tnf-alpha, Vcam1, Mcp-1) and pro-fibrogenic (Col1a1, Col1a2) genes and bile duct proliferation (mRNA and immunohistochemistry for cytokeratin 19 (CK19)). Furthermore, A4250 significantly reduced bile flow and biliary BA output, which correlated with reduced Bsep transcription, while Ntcp and Cyp7a1 were induced. Importantly A4250 significantly reduced biliary BA secretion but preserved HCO3- and biliary phospholipid secretion resulting in an increased HCO3-/BA and PL/BA ratio. In addition, A4250 profoundly increased fecal BA excretion without causing diarrhea and altered BA pool composition, resulting in diminished concentrations of primary BAs tauro-beta-muricholic acid and taurocholic acid. Conclusions: Pharmacological ASBT inhibition attenuates cholestatic liver and bile duct injury by reducing biliary BA concentrations in mice. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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| 36. |
- Batani, D., et al.
(författare)
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Effects of laser prepulse on proton generation
- 2010
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 620:1, s. 76-82
-
Konferensbidrag (refereegranskat)abstract
- Low-intensity laser prepulse ( < 10(13) W/cm(2), ns duration) are a major issue in experiments on laser-generation of protons, often limiting the performances of proton sources produced by high-intensity lasers (approximate to 10(19) W/cm(2), ps or fs duration) Several effects are associated to the prepulse and are discussed in this contribution: i) Destruction of thin foil targets by the shock generated by the laser prepulse ii) Creation of preplasma on target front side affecting laser absorption iii) Deformation of target rear side iv) Whole displacement of thin foil targets affecting focusing condition In particular, we show that under oblique high-intensity irradiation and for low prepulse intensities, the proton beam is directed away from the target normal. Deviation is towards the laser forward direction, with an angle that increases with the level and duration of the ASE pedestal. Also, for a given laser pulse, beam deviation increases with proton energy. The observations are discussed in terms of Target Normal Sheath Acceleration, in combination with a laser-controllable shock wave locally deforming the target surface. (C) 2010 Elsevier B.V. All rights reserved.
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| 37. |
- Bellini, M, et al.
(författare)
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Temporal coherence of ultrashort high-order harmonic pulses
- 1998
-
Ingår i: Physical Review Letters. - 1079-7114. ; 81:2, s. 297-300
-
Tidskriftsartikel (refereegranskat)abstract
- We have studied the temporal coherence of high-order harmonics (up to the 15th order) produced by focusing 100 fs laser pulses into an argon gas jet. We measure the visibility of the interference fringes, produced when two spatially separated harmonic sources interfere in the far field, as a function of the time delay between the two sources. In general, we find long coherence times, comparable to the expected pulse durations of the harmonics. For some of the harmonics, the interference pattern exhibits two regions, with significantly different coherence times. These results are interpreted in terms of different electronic trajectories contributing to harmonic generation. [S0031-9007(98)05569-7].
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| 38. |
- Bergander, L, et al.
(författare)
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Characterization of in vitro metabolites of the aryl hydrocarbon receptor ligand 6-formylindolo[3,2-b] carbazole by liquid chromatography-mass spectrometry and NMR.
- 2003
-
Ingår i: Drug Metabolism And Disposition. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0090-9556 .- 1521-009X. ; 31:2, s. 233-241
-
Tidskriftsartikel (refereegranskat)abstract
- The tryptophan photoproduct 6-formylindolo[3,2-b] carbazole (FICZ) exhibits the highest aryl hydrocarbon receptor (AhR) binding affinity reported so far. In different cells, in vitro, both extracts of UV-irradiated tryptophan and the synthesized pure compound FICZ induce a rapid and transient expression of AhR-regulated genes. The transient induction suggests that the biotransformation gene battery induced by AhR activation takes part in a metabolic degradation of the ligand, whereby a low steady-state level is regained. The down-regulation of AhR-regulated gene expression was previously shown to be dependent on cytochrome P450 1A1 (CYP1A1). Metabolism of FICZ generates five major metabolites, which appeared as three peaks (M1-M3) in the high performance liquid chromatography. The aim of the present study was to use rat liver S9 from Aroclor-pretreated rats to produce large enough quantities of FICZ metabolites for structure characterization and to determine their product precursor relationship. NMR analysis of large combined fractions of the metabolites indicated that M3 and M2 contained 2 isomers, respectively. By means of liquid chromatography-mass spectrometry (negative ion electrospray mode) and NMR spectroscopy (by H-1-NMR, correlation spectroscopy, and nuclear Overhauser effect spectroscopy techniques) five metabolites of FICZ were identified, and their structures were elucidated. The molecular weights of the two M3 isomers were 300 and both M2 and M1 compounds demonstrated molecular weights of 316, corresponding to addition of one (M3) and of two oxygen (M2 and M1), respectively. The structures were assigned as 2- and 8-hydroxy (M3), 2,10- and 4,8-dihydroxy (M2) and 2,8-dihydroxy derivatives of indolo[3,2-b] carbazole-6-carboxaldehyde (6-formylindolo[ 3,2-b] carbazole).
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| 39. |
- Bergman, Frida, 1984-, et al.
(författare)
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Treadmill workstations in office workers who are overweight or obese : a randomised controlled trial
- 2018
-
Ingår i: The Lancet Public Health. - : The Lancet Publishing Group. - 2468-2667. ; 3:11
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Treadmill workstations that enable office workers to walk on a treadmill while working at their computers might increase physical activity in offices, but long-term effects are unknown. We therefore investigated whether treadmill workstations in offices increased daily walking time.Methods: We did a randomised controlled trial of healthy office workers who were either overweight or obese. We recruited participants from 13 different companies, which comprised 17 offices, in Umeå, Sweden. We included people who were aged 40-67 years, had sedentary work tasks, and had a body-mass index (BMI) between 25 kg/m2 and 40 kg/m2. After the baseline measurement, we stratified participants by their BMI (25-30 kg/m2 and >30 to 40 kg/m2); subsequently, an external statistician randomly assigned these participants (1:1) to either the intervention group (who received treadmill workstations for optional use) or the control group (who continued to work at their sit-stand desks as usual). Participants in the intervention group received reminders in boosting emails sent out to them at four occasions during the study period. Researchers were masked to group assignment until after analysis of the primary outcome. After the baseline measurement, participants were not masked to group belongings. The primary outcome was total daily walking time at weekdays and weekends, measured at baseline, 2 months, 6 months, 10 months, and 13 months with the accelerometer activPAL (PAL Technologies, Glasgow, UK), which was worn on the thigh of participants for 24 h a day for 7 consecutive days. We used an intention-to-treat approach for our analyses. This trial is registered with ClinicalTrials.gov, number NCT01997970, and is closed to new participants.Findings: Between Nov 1, 2013, and June 30, 2014, a total of 80 participants were recruited and enrolled (n=40 in both the intervention and control groups). Daily walking time during total time awake at weekdays increased between baseline and 13 months by 18 min (95% CI 9 to 26) in the intervention group and 1 min (-7 to 9) in the control group (difference 22 min [95% CI 7 to 37], pinteraction=0·00045); for weekend walking, the change from baseline to 13 months was 5 min (-8 to 18) in the intervention group and 8 min (-5 to 21) in the control group (difference -1 min [-19 to 17]; pinteraction=0·00045). Neither measure met our predetermined primary outcome of 30 min difference in total walking time between the intervention and control group, so the primary outcome of the trial was not met. One adverse event was reported in a participant who accidently stepped on their Achilles tendon.Interpretation: In a sedentary work environment, treadmill workstations result in a statistically significant but smaller-than-expected increase in daily walking time. Future studies need to investigate how increasing physical activity at work might have potentially compensatory effects on non-work activity.
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| 40. |
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| 41. |
- Brenner, C. M., et al.
(författare)
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Dependence of laser accelerated protons on laser energy following the interaction of defocused, intense laser pulses with ultra-thin targets
- 2011
-
Ingår i: Laser and Particle Beams. - 0263-0346. ; 29:3, s. 345-351
-
Tidskriftsartikel (refereegranskat)abstract
- The scaling of the flux and maximum energy of laser-driven sheath-accelerated protons has been investigated as a function of laser pulse energy in the range of 15-380 mJ at intensities of 10(16)-10(18) W/cm(2). The pulse duration and target thickness were fixed at 40 fs and 25 nm, respectively, while the laser focal spot size and drive energy were varied. Our results indicate that while the maximum proton energy is dependent on the laser energy and laser spot diameter, the proton flux is primarily related to the laser pulse energy under the conditions studied here. Our measurements show that increasing the laser energy by an order of magnitude results in a more than 500-fold increase in the observed proton flux. Whereas, an order of magnitude increase in the laser intensity generated by decreasing the laser focal spot size, at constant laser energy, gives rise to less than a tenfold increase in observed proton flux.
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| 42. |
- Cassou, K., et al.
(författare)
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Optimization toward a high-average-brightness soft-x-ray laser pumped at grazing incidence
- 2007
-
Ingår i: Optics Letters. - 0146-9592. ; 32:2, s. 139-141
-
Tidskriftsartikel (refereegranskat)abstract
- We report the near-field imaging characterization of a 10 Hz Ni-like 18.9 nm molybdenum soft-x-ray laser pumped in a grazing incidence pumping (GRIP) geometry with a table-top laser driver. We investigate the effect of varying the GRIP angle on the spatial behavior of the soft-x-ray laser source. After multiparameter optimization, we were able to find conditions to generate routinely a high-repetition-rate soft-x-ray laser with an energy level of up to 3 mu J/pulse and to 6 x 10(17) photons/s/mm(2)/mrad(2)/(0.1% bandwidth) average brightness and 1 x 10(28) photons/s/mm(2)/mrad(2)/(0.1% bandwidth) peak brightness. (c) 2006 Optical Society of America.
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| 43. |
- Coury, M., et al.
(författare)
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Influence of laser irradiated spot size on energetic electron injection and proton acceleration in foil targets
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:7
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of irradiated spot size on laser energy coupling to electrons, and subsequently to protons, in the interaction of intense laser pulses with foil targets is investigated experimentally. Proton acceleration is characterized for laser intensities ranging from 2 x 10(18) - 6 x 10(20) W/cm(2), by (1) variation of the laser energy for a fixed irradiated spot size, and (2) by variation of the spot size for a fixed energy. At a given laser pulse intensity, the maximum proton energy is higher under defocus illumination compared to tight focus and the results are explained in terms of geometrical changes to the hot electron injection. (C) 2012 American Institute of Physics. [doi:10.1063/1.3685615]
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| 44. |
- Delfin, C, et al.
(författare)
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Influence of laser pulse duration on relativistic channels
- 2002
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 9:3, s. 937-940
-
Tidskriftsartikel (refereegranskat)abstract
- A high-power (10 TW) laser is employed to generate relativistic channels in an underdense plasma. The lengths of the channels are measured by imaging the Thomson-scattered light, and the gas densities are determined through the forward Raman scattered light. The laser-pulse parameters are varied and their impact on the channel formation is studied. It is found that increasing the laser pulse duration in many cases produces longer channels, even as this implies reducing the laser peak power. A theoretical discussion is presented, proposing an explanation of the experimental results. (C) 2002 American Institute of Physics.
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| 45. |
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| 46. |
- Desforges, F. G., et al.
(författare)
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Analysis of Electron Injection in Laser Wakefield Acceleration Using Betatron Emission in Capillary Tubes
- 2015
-
Ingår i: Laser Acceleration of Electrons, Protons, and Ions III; and Medical Applications of Laser-Generated Beams of Particles III. - : SPIE. - 1996-756X .- 0277-786X. ; 9514, s. 95140-95140
-
Konferensbidrag (refereegranskat)abstract
- The dynamics of ionization-induced electron injection in the high density (similar to 1.2 x 10(19)cm(-3)) regime of Laser Wakefield Acceleration (LWFA) was investigated by analyzing betatron X-ray emission inside dielectric capillary tubes. A comparative study of the electron and betatron X-ray properties was performed for both self-injection and ionization-induced injection. Direct experimental evidence of early onset of ionization-induced injection into the plasma wave was obtained by mapping the X-ray emission zone inside the plasma. Particle-In-Cell (PIC) simulations showed that the early onset of ionization-induced injection, due to its lower trapping threshold, suppresses self-injection of electrons. An increase of X-ray fluence by at least a factor of two was observed in the case of ionization-induced injection due to an increased trapped charge compared to self-injection mechanism.
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| 47. |
- Desforges, F. G., et al.
(författare)
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Dynamics of ionization-induced electron injection in the high density regime of laser wakefield acceleration
- 2014
-
Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 21:12
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamics of ionization-induced electron injection in high density (similar to 1.2 x 10(19) cm(-3)) regime of laser wakefield acceleration is investigated by analyzing the betatron X-ray emission. In such high density operation, the laser normalized vector potential exceeds the injection-thresholds of both ionization-injection and self-injection due to self-focusing. In this regime, direct experimental evidence of early on-set of ionization-induced injection into the plasma wave is given by mapping the X-ray emission zone inside the plasma. Particle-In-Cell simulations show that this early on-set of ionization-induced injection, due to its lower trapping threshold, suppresses the trapping of self-injected electrons. A comparative study of the electron and X-ray properties is performed for both self-injection and ionization-induced injection. An increase of X-ray fluence by at least a factor of two is observed in the case of ionization-induced injection due to increased trapped charge compared to self-injection mechanism. (C) 2014 AIP Publishing LLC.
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| 48. |
- Einbeigi, Z., et al.
(författare)
-
A founder mutation of the BRCA1 gene in Western Sweden associated with a high incidence of breast and ovarian cancer
- 2001
-
Ingår i: European Journal of Cancer. - : Elsevier. - 0959-8049 .- 1879-0852. ; 37:15, s. 1904-1909
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to describe and characterise a founder mutation of the BRCA1 gene in western Sweden. Of 62 families screened for BRCA mutations, 24 had BRCA1 mutations and two had BRCA2 mutations. Tumours that occurred in family members were histologically reviewed and mutational status was analysed using archival paraffin-embedded tissues. The same BRCA1 mutation, 3171ins5, was found in 16 families who were clustered along the western coast of Sweden. Mutation analysis revealed a maternal linkage in 13 families and a paternal linkage in 3. There was complete agreement between mutation analysis results obtained from blood and archival tissues. The penetrance of breast or ovarian cancer by age 70 years was estimated to be between 59 and 93%. There were no differences in survivals between breast or ovarian cancer patients with the mutation and age-matched controls. Thus, a predominant BRCA1 gene founder mutation associated with a high risk of breast and ovarian cancer has been identified and found to occur in a restricted geographical area, thereby allowing timely and cost-effective mutation screening using blood samples or archival histological material.
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| 49. |
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| 50. |
- Erman, P, et al.
(författare)
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Autoionization Widths of the No Rydberg-valence State Complex In the 11-12 Ev Region
- 1995
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 239:1-3, s. 6-10
-
Tidskriftsartikel (refereegranskat)abstract
- The photoion excitation spectra of (NO)-N-14 and (NO)-N-15 have been studied in the 105-112 Mn excitation region using high-order harmonic laser spectroscopy. Utilizing the small bandwidth offered by this technique, the natural widths of prominent lines in this region have been measured. These lines originate from interactions between high-lying Rydberg levels converging to the NO+ electronic ground state and a 'new' NO valence state situated close to the latter state. The present measurements show broad resonances corresponding to a decay time of 20-50 fs. This supports the interpretation that the decay takes place via rapid electronic autoionization.
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