1. |
- Michelsen, B., et al.
(författare)
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Drug retention, inactive disease and response rates in 1860 patients with axial spondyloarthritis initiating secukinumab treatment: routine care data from 13 registries in the EuroSpA collaboration
- 2020
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Ingår i: RMD open. - : BMJ. - 2056-5933. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To explore 6-month and 12-month secukinumab effectiveness in patients with axial spondyloarthritis (axSpA) overall, as well as across (1) number of previous biologic/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs), (2) time since diagnosis and (3) different European registries. METHODS: Real-life data from 13 European registries participating in the European Spondyloarthritis Research Collaboration Network were pooled. Kaplan-Meier with log-rank test, Cox regression, χ² and logistic regression analyses were performed to assess 6-month and 12-month secukinumab retention, inactive disease/low-disease-activity states (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) <2/<4, Ankylosing Spondylitis Disease Activity Score (ASDAS) <1.3/<2.1) and response rates (BASDAI50, Assessment of Spondyloarthritis International Society (ASAS) 20/40, ASDAS clinically important improvement (ASDAS-CII) and ASDAS major improvement (ASDAS-MI)). RESULTS: We included 1860 patients initiating secukinumab as part of routine care. Overall 6-month/12-month secukinumab retention rates were 82%/72%, with significant (p<0.001) differences between the registries (6-month: 70-93%, 12-month: 53-86%) and across number of previous b/tsDMARDs (b/tsDMARD-naïve: 90%/73%, 1 prior b/tsDMARD: 83%/73%, ≥2 prior b/tsDMARDs: 78%/66%). Overall 6-month/12-month BASDAI<4 were observed in 51%/51%, ASDAS<1.3 in 9%/11%, BASDAI50 in 53%/47%, ASAS40 in 28%/22%, ASDAS-CII in 49%/46% and ASDAS-MI in 25%/26% of the patients. All rates differed significantly across number of previous b/tsDMARDs, were numerically higher for b/tsDMARD-naïve patients and varied significantly across registries. Overall, time since diagnosis was not associated with secukinumab effectiveness. CONCLUSIONS: In this study of 1860 patients from 13 European countries, we present the first comprehensive real-life data on effectiveness of secukinumab in patients with axSpA. Overall, secukinumab retention rates after 6 and 12months of treatment were high. Secukinumab effectiveness was consistently better for bionaïve patients, independent of time since diagnosis and differed across the European countries. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
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2. |
- Abramsson, Mia L, et al.
(författare)
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Charge engineering reveals the roles of ionizable side chains in electrospray ionization mass spectrometry
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The role of ionizable side chains in the electrospray ionization mass spectrometry of intact proteins remains hotly debated but has not been conclusively addressed because multiple chargeable sites are present in virtually all proteins. Using engineered soluble proteins, we show that ionizable side chains are completely dispensable for charging under native conditions, but if present, they are preferential protonation sites. The absence of ionizable side chains results in identical charge state distributions under native-like and denaturing conditions, whilst co-existing conformers can be distinguished using ion mobility separation. An excess of ionizable side chains, on the other hand, effectively modulates protein ion stability. We conclude that the sum of charges is governed solely by Coulombic terms, while their locations affect the stability of the protein in the gas phase.
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3. |
- Abramsson, Mia L., et al.
(författare)
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Charge Engineering Reveals the Roles of Ionizable Side Chains in Electrospray Ionization Mass Spectrometry
- 2021
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Ingår i: JACS Au. - : American Chemical Society (ACS). - 2691-3704. ; 1:12, s. 2385-2393
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Tidskriftsartikel (refereegranskat)abstract
- In solution, the charge of a protein is intricately linked to its stability, but electrospray ionization distorts this connection, potentially limiting the ability of native mass spectrometry to inform about protein structure and dynamics. How the behavior of intact proteins in the gas phase depends on the presence and distribution of ionizable surface residues has been difficult to answer because multiple chargeable sites are present in virtually all proteins. Turning to protein engineering, we show that ionizable side chains are completely dispensable for charging under native conditions, but if present, they are preferential protonation sites. The absence of ionizable side chains results in identical charge state distributions under native-like and denaturing conditions, while coexisting conformers can be distinguished using ion mobility separation. An excess of ionizable side chains, on the other hand, effectively modulates protein ion stability. In fact, moving a single ionizable group can dramatically alter the gas-phase conformation of a protein ion. We conclude that although the sum of the charges is governed solely by Coulombic terms, their locations affect the stability of the protein in the gas phase.
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4. |
- Alkhazov, GD, et al.
(författare)
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SPES4-pi: installation for exclusive study of nuclear reactions
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 551:2-3, s. 290-311
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Tidskriftsartikel (refereegranskat)abstract
- The paper describes the spectrometric system "SPES4-pi" used at the National Laboratory Saturne (CE Saclay, France) for the exclusive study of the baryon resonance excitation in inelastic alpha and d scattering on the proton, as well as coherent pion production in charge exchange reactions. The system consists of the magnetic spectrometer SPES4 and two wide-aperture position-sensitive detector arrays, equipped with wire chambers and scintillator hodoscopes, installed around a large-gap C-shape dipole magnet.
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5. |
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6. |
- Maeda, Y., et al.
(författare)
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Differential cross section and analyzing power measurements for (n)over-right-arrowd elastic scattering at 248 MeV
- 2007
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:1, s. 014004-
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Tidskriftsartikel (refereegranskat)abstract
- The differential cross sections and vector analyzing powers for nd elastic scattering at E-n=248 MeV were measured for 10 degrees-180 degrees in the center-of-mass (c.m.) system. To cover the wide angular range, the experiments were performed separately by using two different setups for forward and backward angles. The data are compared with theoretical results based on Faddeev calculations with realistic nucleon-nucleon (NN) forces such as AV18, CD Bonn, and Nijmegen I and II, and their combinations with the three-nucleon forces (3NFs), such as Tucson-Melbourne 99 (TM99), Urbana IX, and the coupled-channel potential with Delta-isobar excitation. Large discrepancies are found between the experimental cross sections and theory with only 2N forces for theta(c.m.)>90 degrees. The inclusion of 3NFs brings the theoretical cross sections closer to the data but only partially explains this discrepancy. For the analyzing power, no significant improvement is found when 3NFs are included. Relativistic corrections are shown to be small for both the cross sections and the analyzing powers at this energy. For the cross sections, these effects are mostly seen in the very backward angles. Compared with the pd cross section data, quite significant differences are observed at all scattering angles that cannot be explained only by the Coulomb interaction, which is usually significant at small angles.
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7. |
- Sagrado Garcia, I. C., et al.
(författare)
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Neutron production in neutron-induced reactions at 96 MeV on (56)Fe and (208)Pb
- 2011
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 84:4, s. 044619-
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Tidskriftsartikel (refereegranskat)abstract
- Double-differential cross sections for neutron production were measured in 96-MeV neutron-induced reactions at The Svedberg Laboratory in Uppsala, Sweden. Measurements for Fe and Pb targets were performed using two independent setups: DECOI-DEMON, time-of-flight telescope dedicated to the detection of emitted neutrons with energies between a few and 50 MeV and CLODIA-SCANDAL device devoted to measuring emitted neutrons with energies above 40 MeV. Double-differential cross sections were measured for an angular range between 15 and 98 deg and with low-energy thresholds (approximate to 2 MeV). Angular and energy distributions and total neutron emission cross sections have been obtained from those measurements. Results have been compared with predictions given by different models included in several transport codes (MCNPX, GEANT, TALYS, PHITS, and DYWAN) and with other experimental data (the EXFOR database).
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8. |
- Sorbye, H, et al.
(författare)
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Predictive and prognostic factors for treatment and survival in 305 patients with advanced gastrointestinal neuroendocrine carcinoma (WHO G3) : the NORDIC NEC study
- 2013
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 24:1, s. 152-160
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Tidskriftsartikel (refereegranskat)abstract
- As studies on gastrointestinal neuroendocrine carcinoma (WHO G3) (GI-NEC) are limited, we reviewed clinical data to identify predictive and prognostic markers for advanced GI-NEC patients. Data from advanced GI-NEC patients diagnosed 2000-2009 were retrospectively registered at 12 Nordic hospitals. The median survival was 11 months in 252 patients given palliative chemotherapy and 1 month in 53 patients receiving best supportive care (BSC) only. The response rate to first-line chemotherapy was 31% and 33% had stable disease. Ki-67 < 55% was by receiver operating characteristic analysis the best cut-off value concerning correlation to the response rate. Patients with Ki-67 < 55% had a lower response rate (15% versus 42%, P < 0.001), but better survival than patients with Ki-67 >= 55% (14 versus10 months, P < 0.001). Platinum schedule did not affect the response rate or survival. The most important negative prognostic factors for survival were poor performance status (PS), primary colorectal tumors and elevated platelets or lactate dehydrogenase (LDH) levels. Advanced GI-NEC patients should be considered for chemotherapy treatment without delay.PS, colorectal primary and elevated platelets and LDH levels were prognostic factors for survival. Patients with Ki-67 < 55% were less responsive to platinum-based chemotherapy, but had a longer survival. Our data indicate that it may not be correct to consider all GI-NEC as one single disease entity.
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9. |
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10. |
- Bevilacqua, R., et al.
(författare)
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Neutron induced light-ion production from Iron and Bismuth at 175 MeV
- 2010
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Ingår i: CNR*09 - Second International Workshop on Compound Nuclear Reactions and Related Topics. - : EDP Sciences. - 9782759805211 ; , s. 05005-
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Konferensbidrag (refereegranskat)abstract
- We have measured light-ion (p, d, t, 3He and α) production in the interaction of 175 MeV neutrons with iron and bismuth, using the MEDLEY setup. A large set of measurements at 96 MeV has been recently completed and published, and now higher energy region is under investigation. MEDLEY is a conventional spectrometer system that allows low-energy thresholds and offers measurements over a wide angular range. The system consists of eight telescopes, each of them composed of two silicon surface barrier detectors, to perform particle identification, and a CsI(Tl) scintillator to fully measure the kinetic energy of the produced light-ions. The telescopes are placed at angles from 20° to 160°, in steps of 20°. Measurements have been performed at The Svedberg Laboratory, Uppsala (Sweden), where a quasi mono-energetic neutron beam is available and well characterized. Time of flight techniques are used to select light-ion events induced by neutrons in the main peak of the source neutron spectrum. We report preliminary double differential cross sections for production of protons, deuterons and tritons in comparison with model calculations using TALYS-1.0 code.
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11. |
- Blideanu, V., et al.
(författare)
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Nucleon-induced reactions at intermediate energies : New data at 96 MeV and theoretical status
- 2004
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 70:1, s. 014607-
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Tidskriftsartikel (refereegranskat)abstract
- Double-differential cross sections for light charged particle production (up to A=4) were measured in 96 MeV neutron-induced reactions, at the TSL Laboratory Cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low-energy thresholds and for a wide angular range (20°–160°). The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approaches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature.
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12. |
- Khattab, Ibrahim A., et al.
(författare)
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Photocatalytic degradation of azo dye Reactive Red 15 over synthesized titanium and zinc oxides photocatalysts : a comparative study
- 2012
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Ingår i: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 48:1-3, s. 120-129
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Tidskriftsartikel (refereegranskat)abstract
- Nanoparticle TiO2 and ZnO were prepared by facile method. The XRD pattern study shows that there is no obvious difference in crystal composition of various shapes of TiO2 and ZnO. The photocatalytic degradation of Reactive Red 15, commonly used as a textile dye, using synthesized titanium and zinc oxides was investigated. The effects of influential parameters such as initial pH, catalyst loading, initial dye concentration and addition of hydrogen peroxide were studied. The degradation efficiency was expressed by the removal of color and chemical oxygen demand (COD). The study reveals that: (1) Both catalysts, under corresponding optimal conditions, can be employed as an effective photocatalyst for the elimination of color and COD from dye wastewater. Also, ZnO is more efficient catalyst than TiO2; (2) Addition of proper amount of hydrogen peroxide improves both the decolorization and the degradation of the dye; (3) The photocatalytic degradation of Reactive Red 15, in the presence of both photocatalysts, obeyed pseudo-first order kinetics. The biodegradability ratio BOD5/COD increases from original zero up to 0.52 and 0.6 within 90 minutes irradiation time using 1 and 0.75 g/L TiO2 and ZnO, respectively.
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13. |
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14. |
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15. |
- Pedersen, M O, et al.
(författare)
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Diffusion of N adatoms on the Fe(100) surface
- 2000
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 84:21, s. 4898-4901
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Tidskriftsartikel (refereegranskat)abstract
- The diffusion of individual N adatoms on Fe(100) has been studied using scanning tunneling microscopy and ab initio density functional theory (DFT) calculations. The measured diffusion barrier for isolated N adatoms is E-d = (0.92 +/- 0.04) eV, with a prefactor of nu(0) = 4.3 x 10(12) s(-1), which is in quantitative agreement with the DFT calculations. Thr; diffusion is strongly coupled to lattice distortions. and. as a consequence, the presence of other N adatoms introduces an anisotropy in the diffusion. Based on experimentally determined values of the diffusion barriers and adsorbate-adsorbate: interactions, the potential energy surface experienced by a N adatom is determined.
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19. |
- Ramstein, B, et al.
(författare)
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H-2(He-3, t)2p reaction at 2 GeV
- 2003
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Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 16:4, s. 583-597
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Tidskriftsartikel (refereegranskat)abstract
- The exclusive H-2 (He-3, t)2p reaction has been studied at 2 GeV for energy transfers up to 500 MeV and triton angles up to 3.4degrees. The protons were measured in the large acceptance magnetic detector DIOGENE, in coincidence with the forward tritons detected in a dedicated magnetic arm. The energy transfer spectra extend well above the pion threshold. However, in the region of Delta excitation, the yield is less than 10% of the inclusive H-2(He-3, t) cross-section, which indicates the small contribution of the DeltaN --> NN process. The angular distributions of the two protons in their center of mass have been analysed as a function of energy transfer and triton angle and a Legendre polynomial decomposition has been achieved. These data have been compared to a model based on a coupled-channel approach for describing the NN and NDelta systems.
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20. |
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21. |
- Sahin, Cagla, et al.
(författare)
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Structural basis for dityrosine-mediated inhibition of alpha-synuclein fibrillation
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- α-synuclein (aSyn) is a small intrinsically disordered protein which can self-assemble into highly organized β-sheet structures that are found to accumulate in plaques in the brain of Parkinson’s Disease patients. Oxidative stress has been shown to be important for aSyn and its self-assembly. Here we characterize the molecular and structural effects that mild oxidation has on aSyn monomer and its aggregation. Using a combination of biophysical methods, SAXS and native ion mobility mass spectrometry, we find that oxidation leads to formation of intramolecular dityrosine cross-linkages that reduce aSyn’s size by a factor of √2. MD simulations support our experimental results showing a stable and compact aSyn conformation that prevents self-assembly and amyloid formation by steric hindrance, suggesting an important role of mild oxidation in preventing amyloid formation.
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22. |
- Sidstedt, Maja, et al.
(författare)
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Ultrasensitive sequencing of STR markers utilizing unique molecular identifiers and the SiMSen-Seq method
- 2024
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Ingår i: Forensic Science International: Genetics. - : Elsevier Ireland Ltd. - 1872-4973 .- 1878-0326. ; 71
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Tidskriftsartikel (refereegranskat)abstract
- Massively parallel sequencing (MPS) is increasingly applied in forensic short tandem repeat (STR) analysis. The presence of stutter artefacts and other PCR or sequencing errors in the MPS-STR data partly limits the detection of low DNA amounts, e.g., in complex mixtures. Unique molecular identifiers (UMIs) have been applied in several scientific fields to reduce noise in sequencing. UMIs consist of a stretch of random nucleotides, a unique barcode for each starting DNA molecule, that is incorporated in the DNA template using either ligation or PCR. The barcode is used to generate consensus reads, thus removing errors. The SiMSen-Seq (Simple, multiplexed, PCR-based barcoding of DNA for sensitive mutation detection using sequencing) method relies on PCR-based introduction of UMIs and includes a sophisticated hairpin design to reduce unspecific primer binding as well as PCR protocol adjustments to further optimize the reaction. In this study, SiMSen-Seq is applied to develop a proof-of-concept seven STR multiplex for MPS library preparation and an associated bioinformatics pipeline. Additionally, machine learning (ML) models were evaluated to further improve UMI allele calling. Overall, the seven STR multiplex resulted in complete detection and concordant alleles for 47 single-source samples at 1 ng input DNA as well as for low-template samples at 62.5 pg input DNA. For twelve challenging mixtures with minor contributions of 10 pg to 150 pg and ratios of 1–15% relative to the major donor, 99.2% of the expected alleles were detected by applying the UMIs in combination with an ML filter. The main impact of UMIs was a substantially lowered number of artefacts as well as reduced stutter ratios, which were generally below 5% of the parental allele. In conclusion, UMI-based STR sequencing opens new means for improved analysis of challenging crime scene samples including complex mixtures.
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23. |
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24. |
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25. |
- Welearegay, T. G., et al.
(författare)
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Ultrapure Organically Modified Gold Nanoparticles for Breath Analysis
- 2016
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Ingår i: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 168, s. 133-136
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Tidskriftsartikel (refereegranskat)abstract
- In this study we present a new technological approach for the fabrication of ultrapure organically modified gold nanoparticles (AuNPs) for chemical sensing applied to exhaled breath analysis. To achieve a high purity level of the sensing films, we combined Advanced Gas Deposition (AGD) technique to deposit ultrapure monodispersed AuNPs, and dip coating process for functionalization of the AuNPs with thiolated organic ligands. Morphology and surface analysis revealed the deposition of ultrapure isolated AuNPs after the first processing step, and a network of nanoparticle–ligand nanoassemblies after the second processing step. Gas sensing measurements were performed with exhaled breath samples collected from a group of smokers, a group of non-smokers, and ambient air. Sensors responses towards these samples demonstrated characteristic responses for each study group. PCA analysis further revealed samples classification in three distinct characteristic clusters, which indicates the suitability of the molecularly modified AuNPs presented in this communication for breath analysis applications.
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26. |
- Widgren, K, et al.
(författare)
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Prevailing effectiveness of the 2009 influenza A(H1N1)pdm09 vaccine during the 2010/11 season in Sweden
- 2013
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Ingår i: Eurosurveillance. - : eurosurveillance. - 1025-496X .- 1560-7917. ; 18:15, s. Article 5-
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Tidskriftsartikel (refereegranskat)abstract
- Sixty per cent of the Swedish population received the monovalent AS03-adjuvanted pandemic influenza vaccine in the autumn of 2009. We assessed the age-specific effectiveness of this pandemic vaccine against hospitalisation with laboratory-confirmed influenza A(H1N1)pdm09 during the season 2010/11, in the age group from six months to 64 years in Sweden. The screening method was applied to available surveillance data. Our results suggest a prevailing effectiveness of 72% (95% confidence interval (CI): 63–80%) with the highest effectiveness among children, six months to nine years-old (92%, 95%CI: 80–97%). However, there were limitations in data quality and study design due to the lack of systematic recording of administered vaccinations, which underline the importance of preparing for an evaluation when planning for large public health actions. Despite these limitations, we believe the results reflect true, high prevailing vaccine effectiveness. Indeed, there were fewer deaths caused by influenza and the impact of influenza on intensive care units was less severe during the 2010/11 season in Sweden than in countries with lower pandemic vaccination coverage. The association between the pandemic vaccine and narcolepsy has increased the importance of assessing the risks and benefits of the vaccination; studies on the effectiveness and the duration of protection are needed for this.
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27. |
- Öhrn, Angelica, et al.
(författare)
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Elastic scattering of 96 MeV neutrons from iron, yttrium, and lead
- 2008
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 77:2, s. 024605-
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Tidskriftsartikel (refereegranskat)abstract
- Data on elastic scattering of 96 MeV neutrons from Fe-56, Y-89, and Pb-208 in the angular interval 10-70 degrees are reported. The previously published data on Pb-208 have been extended, as a new method has been developed to obtain more information from data, namely to increase the number of angular bins at the most forward angles. A study of the deviation of the zero-degree cross section from Wick's limit has been performed. It was shown that the data on Pb-208 are in agreement with Wick's limit while those on the lighter nuclei overshoot the limit significantly. The results are compared with modern optical model predictions, based on phenomenology and microscopic nuclear theory. The data on Fe-56, Y-89, and Pb-208 are in general in good agreement with the model predictions.
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28. |
- Österlund, Jens, M., et al.
(författare)
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A note on the overlap region in turbulent boundary layers
- 2000
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Ingår i: Physics of fluids. - : American Institute of Physics (AIP). - 1070-6631 .- 1089-7666. ; :12, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- Two independent experimental investigations of the behavior of turbulent boundary layers with increasing Reynolds number were recently completed. The experiments were performed in two facilities, the Minimum Turbulence Level (MTL) wind tunnel at Royal Institute of Technology (KTH) and the National Diagnostic Facility (NDF) wind tunnel at Illinois Institute of Technology (IIT). Both experiments utilized oil-film interferometry to obtain an independent measure of the wall-shear stress. A collaborative study by the principals of the two experiments, aimed at understanding the characteristics of the overlap region between the inner and outer parts of the boundary layer, has just been completed. The results are summarized here, utilizing the profiles of the mean velocity, for Reynolds numbers based on the momentum thickness ranging from 2500 to 27 000. Contrary to the conclusions of some earlier publications, careful analysis of the data reveals no significant Reynolds number dependence for the parameters describing the overlap region using the classical logarithmic relation. However, the data analysis demonstrates that the viscous influence extends within the buffer region to y+≈200, compared to the previously assumed limit of y+≈50.Therefore, the lowest Reθ value where a significant logarithmic overlap region exists is about 6000. This probably explains why a Reynolds number dependence had been found from the data analysis of many previous experiments. The parameters of the logarithmic overlap region are found to be constant and are estimated to be κ=0.38, B=4.1 and B1=3.6 (δ=δ95).
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29. |
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30. |
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31. |
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32. |
- Österlund, m, et al.
(författare)
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Tomography of canisters for spent nuclear fuel
- 2006
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Ingår i: International workshop on Fast Neutron Detectors and Applications,Cape Town, South Africa, April 3-6, 2006. ; , s. 030-
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Konferensbidrag (refereegranskat)
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33. |
- Al-Adili, Ali, et al.
(författare)
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Analysis of prompt fission neutrons in U-235(nth,f) and fission fragment distributions for the thermal neutron induced fission of U-234
- 2016
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Ingår i: CNR*15 - 5th International Workshop On Compound-Nuclear Reactions And Related Topics. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- This paper presents the ongoing analysis of two fission experiments. Both projects are part of the collaboration between the nuclear reactions group at Uppsala and the JRC-IRMM. The first experiment deals with the prompt fission neutron multiplicity in the thermal neutron induced fission of U-235(n,f). The second, on the fission fragment properties in the thermal fission of U-234(n,f). The prompt fission neutron multiplicity has been measured at the JRC-IRMM using two liquid scintillators in coincidence with an ionization chamber. The first experimental campaign focused on U-235(nth,f) whereas a second experimental campaign is foreseen later for the same reaction at 5.5 MeV. The goal is to investigate how the so-called saw-tooth shape changes as a function of fragment mass and excitation energy. Some harsh experimental conditions were experienced due to the large radiation background. The solution to this will be discussed along with preliminary results. In addition, the analysis of thermal neutron induced fission of U-234(n,f) will be discussed. Currently analysis of data is ongoing, originally taken at the ILL reactor. The experiment is of particular interest since no measurement exist of the mass and energy distributions for this system at thermal energies. One main problem encountered during analysis was the huge background of U-235(nth, f). Despite the negligible isotopic traces in the sample, the cross section difference is enormous. Solution to this parasitic background will be highlighted.
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34. |
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35. |
- Andersson, M., et al.
(författare)
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Microemulsion-mediated room-temperature synthesis of high-surface-area rutile and its photocatalytic performance
- 2007
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 111:18, s. 6789-6797
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Tidskriftsartikel (refereegranskat)abstract
- Nanosized titania having the rutile crystalline structure was synthesized at room temperature using a microemulsion-mediated system. The formed rutile particles had a diameter of 3 nm, which corresponds well with the droplet size of the water-in-oil microemulsion used for their preparation. The crystallinity was monitored by both X-ray diffraction (XRD) and electron diffraction, together with dark-field electron microscopy (TEM) and high-resolution TEM. The rutile had a high specific surface area (similar to 300 m(2)/g) according to N-2 adsorption and the BET equation. To our knowledge, this is the highest specific surface area ever reported for rutile. The rutile crystals aligned in a specific crystallographic direction forming elongated aggregates 200-1000 nm in size, as observed by TEM and high-resolution TEM. The titania formation was followed in situ using dynamic light scattering and UV-vis spectroscopy, and together with TEM and XRD performed on samples collected throughout the duration of the titania synthesis, the results gave support for a formation scheme involving the initial formation of amorphous titania followed by crystallization of rutile. The photocatalytic performance of the formed material was evaluated by in situ Fourier transform infrared spectroscopy and compared to that of a rutile sample having a lower specific surface area (similar to 40 m(2)/g). The TEM and formate adsorption experiments revealed that the high-surface-area rutile had a much higher fraction of (101) facets than the low-surface-area sample, which predominantly exposed (110) facets. In particular, a new bidentate formate (mu-formate) species bridge-bonded to the (101) facet could be identified with characteristic bands at 1547 and 1387 cm(-1). The photodegradation rate of this species was found to be similar to the mu-formate species on the (110) facet. However, the overall formate degradation rate was larger on the high-surface-area rutile sample because of a high concentration of the more readily photodegradable monodentate formate (eta(1)-formate) on that sample.
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36. |
- Andersson, M, et al.
(författare)
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Preparation of nanosize anatase and rutile TiO2 by hydrothermal treatment of microemulsions and their activity for photocatalytic wet oxidation of phenol
- 2002
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 106:41, s. 10674-10679
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Tidskriftsartikel (refereegranskat)abstract
- Titanium dioxide (TiO2) nanoparticles of both anatase and rutile phases were synthesized by hydrothermal treatment of microemulsions, and their photocatalytic activity for wet oxidation of phenol was studied. The only difference between the two syntheses used was that different acids were added to the microemulsions, making direct comparison of the catalytic activity of the two polymorphs possible. If hydrochloric acid was used, the rutile structure formed, and if nitric acid was used, anatase formed. The phase stability of the microemulsion was studied and according to conductivity and turbidity measurements the idea of a direct template effect could be discarded during the hydrothermal treatment. However, an initial size-templating phenomenon is possible during the mixing step. The particles, which were in the size range of a few nanometers were characterized with N-2-adsorption; XRD, SEM, and XPS. The activity of the two polymorphs for the photocatalytic oxidation of phenol in water was examined. It was shown that the rutile phase initially decomposed phenol much faster and follows a first-order process reasonably well (k = 4 x 10(-5) s(-1)). The photodecomposition process using the anatase phase led, however, to a much more rapid overall degradation following an initial slower rate of phenol oxidation. The results indicate that the observed difference of the photodecomposition process for the two TiO2 phases is due to the formation of different intermediates.
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37. |
- Bevilacqua, Riccardo, et al.
(författare)
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Light-ion Production from O, Si, Fe and Bi Induced by 175 MeV Quasi-monoenergetic Neutrons
- 2014
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Ingår i: Nuclear Data Sheets. - : Elsevier BV. - 0090-3752 .- 1095-9904. ; 119, s. 190-193
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Tidskriftsartikel (refereegranskat)abstract
- We have measured double-differential cross sections in the interaction of 175 MeV quasimonoenergetic neutrons with O, Si, Fe and Bi. We have compared these results with model calculations with INCL4.5-Abla07, MCNP6 and TALYS-1.2. We have also compared our data with PHITS calculations, where the pre-equilibrium stage of the reaction was accounted respectively using the JENDL/HE-2007 evaluated data library, the quantum molecular dynamics model (QMD) and a modified version of QMD (MQMD) to include a surface coalescence model. The most crucial aspect is the formation and emission of composite particles in the pre-equilibrium stage.
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38. |
- Bevilacqua, Riccardo, et al.
(författare)
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Light-Ion Production in the Interaction of 175 MeV Neutrons with Iron and Bismuth
- 2011
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Ingår i: Journal of the Korean Physical Society. - : Korean Physical Society. - 0374-4884 .- 1976-8524. ; 59:2, s. 1701-1704
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Tidskriftsartikel (refereegranskat)abstract
- We have measured double-differential (angle and energy) cross sections for light-ion (p, d, t, (3)He, and a) production in the interaction of quasi-monoenergetic 175 MeV neutrons with iron and bismuth. Measurements have been performed at the The Svedberg Laboratory, Uppsala (Sweden), using the Medley setup which allows low-energy thresholds and wide energy and angular ranges. Medley is a spectrometer system consisting of eight three-element telescopes placed at angles from 20 degrees to 160 degrees, in steps of 20 degrees. Each telescope is composed of two silicon surface barrier detectors and a CsI(Tl) scintillator, to perform particle identification, fully stop the produced light-ions and measure their kinetic energy. The time-of-flight was used to reduce the contribution from the low energy tail in the accepted incident neutron spectrum. We report double-differential production cross sections for protons, deuterons, tritons, (3)He and alpha particles and compare them with model calculations with TALYS-1.2.
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39. |
- Bevilacqua, Riccardo, et al.
(författare)
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Neutron induced light-ion production from iron and bismuth at 175 MeV
- 2010
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Ingår i: RADIATION MEASUREMENTS. - : Elsevier BV. ; 45:10, s. 1145-1150
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Konferensbidrag (refereegranskat)abstract
- We have measured light-ion (p, d, t, He-3 and alpha) production in the interaction of 175 MeV neutrons with iron and bismuth with low-energy thresholds and for a wide angular range (from 20 degrees to 160 degrees, in steps of 20 degrees). Measurements have been performed with the Medley setup, semi-permanently installed at the The Svedberg Laboratory, Uppsala (Sweden), where a quasi-monoenergetic neutron beam is available and well characterized. Medley is a conventional spectrometer system and consists of eight telescopes, each of them composed of two silicon surface barrier detectors, to perform particle identification, and a CsI(Tl) scintillator to fully measure the kinetic energy of the produced light-ions. We report preliminary double-differential cross sections for production of protons, deuterons and tritons in comparison with model calculations using TALYS-1.0 code. These show better agreement for the production of protons, while the theoretical calculations seem to overestimate the experimental production of deuterons and tritons.
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40. |
- Bevilacqua, Riccardo, 1974-, et al.
(författare)
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Study of pre-equilibrium emission of light complex particles from Fe and Bi induced by intermediate energy neutrons
- 2011
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 312:SECTION 8, s. 082013-, s. 082013-
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Tidskriftsartikel (refereegranskat)abstract
- We have measured double differential cross sections (DDX) for emission of hydrogen- and helium-isotopes in the interaction of 175 MeV quasi-monoenergetic neutrons with Fe and Bi using the Medley setup at the The Svedberg Laboratory (Uppsala, Sweden). We compared experimental DDX with calculations with the TALYS code, which includes exciton model and Kalbach systematics; the code fails to reproduce the emission of complex light ions, generally overestimating it. We propose an correction for the application of the Kalbach phenomenological model in the TALYS code by introducing a new energy dependence for the nucleon transfer mechanism in the pre-equilibrium emission region. Our results suggest also evidence for multiple pre-equilibrium emission of composite particles at 175 MeV.
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41. |
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42. |
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43. |
- Boyadjiev, Stefan I., et al.
(författare)
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Study of the electrochromic properties of MAPLE and PLD deposited WO3 thin films
- 2017
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Konferensbidrag (refereegranskat)abstract
- Tungsten trioxide (WO3) thin films were grown by matrix assisted pulsed laser evaporation (MAPLE) and pulsed laser deposition (PLD), and their properties were investigated for electrochromic applications. The structure, morphology and optical properties of these MAPLE and PLD grown from monoclinic WO3 nano-sized particles WO3 thin films were also studied. A KrF* excimer (λ=248 nm, ζFWHM=25 ns) laser source was used in all experiments. The films were studied by atomic force microscopy (AFM), grazing incidence X-ray diffraction (GIXRD) and Fourier transform infrared spectroscopy (FTIR). Cyclic voltammetry measurements were also performed in glove box with Ar atmosphere towards Li electrode, and the coloring and bleaching states were investigated. The morpho-structural investigations disclosed the synthesis of single-phase monoclinic WO3 films consisting of crystalline nano-grains embedded in an amorphous matrix. All thin films showed good electrochromic properties - strong coloration and fast and full bleaching. The effect was observed for many cycles, the strong coloration and full bleaching being preserved. These results are promising for future application of MAPLE and PLD deposited WO3 thin films in the development of electrochromic devices.
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44. |
- Bäckbro, Kristina, et al.
(författare)
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Unexpected binding mode of a cyclic sulfamide HIV-1 protease inhibitor
- 1997
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 40:6, s. 898-902
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Tidskriftsartikel (refereegranskat)abstract
- Two cyclic, C2-symmetric HIV-1 protease inhibitors, one sulfamide and one urea derivative, both comprising phenyl ether groups in the P1/P1‘ positions, were cocrystallized with HIV-1 protease, and the crystal structures were determined to 2.0 Å resolution. The structure of the urea 2 showed a conformation similar to that reported for the related urea 3 by Lam et al., while the sulfamide 1 adopted an unanticipated conformation in which the P1‘ and P2‘ side chains were transposed.
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45. |
- Cindemir, Umut, et al.
(författare)
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Nickel oxide thin film sensor for fluctuation-enhanced gas sensing of formaldehyde
- 2015
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Ingår i: 2015 IEEE Sensors. - 9781479982035
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Konferensbidrag (refereegranskat)abstract
- Nanocrystalline nickel-oxide-based thin films were prepared by advanced reactive gas deposition, and the response of these films to formaldehyde was studied by fluctuation-enhanced sensing. Morphological and structural analyses showed porous deposits of nickel oxide particles with face-centered cubic structure. Resistance fluctuations were measured upon exposure to ethanol, formaldehyde and methane at 200 degrees C. Power density spectra were used to quantify the response. The response to formaldehyde was higher than to ethanol at 200 degrees C, and no significant response was observed for methane thus demonstrating some gas-species selectivity.
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46. |
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47. |
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48. |
- Ekstrand-Hammarström, Barbro, et al.
(författare)
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Human primary bronchial epithelial cells respond differently to titanium dioxide nanoparticles than the lung epithelial cell lines A549 and BEAS-2B
- 2012
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Ingår i: Nanotoxicology. - : Informa UK Limited. - 1743-5390 .- 1743-5404. ; 6:6, s. 623-634
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Tidskriftsartikel (refereegranskat)abstract
- We have compared the cellular uptake and responses of five preparations of nanocrystalline titanium dioxide (TiO(2)) between normal human bronchial epithelial (NHBE) cells and epithelial cell lines (A549 and BEAS-2B). The P25 nanoparticles, containing both anatase and rutile modifications, induced reactive oxygen species (ROS) and secretion of the neutrophil chemoattractant IL-8 in all three cell types used. Pure anatase and rutile particles provoked differential IL-8 response in A549 and no response in BEAS-2B cells despite similar formation of ROS. The pure TiO(2) modifications also provoked release of the inflammatory mediators: IL-6, G-CSF and VEGF, in NHBE cells but not in the two cell lines. We conclude that the responsiveness of lung epithelial cells is strongly dependent on both the physicochemical properties of TiO(2) nanoparticles and the type of responder cells. The differential pro-inflammatory responsiveness of primary lung epithelial cells compared with immortalized cell lines should be considered in the assessment of adverse reactions to inhaled nanoparticles.
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49. |
- Ekstrand-Hammarström, Barbro, et al.
(författare)
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Oxidative stress and cytokine expression in respiratory epithelial cells exposed to well-characterized aerosols from Kabul, Afghanistan
- 2013
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Ingår i: Toxicology in Vitro. - : Elsevier BV. - 0887-2333 .- 1879-3177. ; 27:2, s. 825-833
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Tidskriftsartikel (refereegranskat)abstract
- In this study aerosol samples collected in an Asian mega-city (Kabul, Afghanistan) were compared to PM samples collected in a European location with traffic (Umea, Sweden) and a reference urban dust material (SRM 1649b). The toxicity of each sample towards normal human bronchial epithelial (NHBE) cells and a human bronchial epithelial cell line (BEAS-2B) was tested along with their ability to induce reactive oxygen species (ROS) formation and inflammatory responses. The extracts' morphology and elemental composition was studied by SEM-EDXRF, and filter samples were analyzed for metals and organic compounds. The PM from Kabul contained a larger fraction of fine particles, 19 times more polyaromatic hydrocarbons (PAH) and 37 times more oxygenated PAH (oxy-PAH) compared to samples from timed. The PM-samples from Kabul and the reference material (SRM 1649b) induced significantly stronger oxidative stress responses than the samples from Umea. Furthermore, samples collected in Kabul induced significantly higher secretion of the cytokines IL-6, IL-8 and GM-CSF while SRM1649b induced a cytokine pattern more similar to samples collected in Umea. Several properties of the particles could potentially explain these differences, including differences in their size distribution and contents of PAH and oxy-PAH, possibly in combination with their relative transition metal contents.
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50. |
- Esbjörnsson, M, et al.
(författare)
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Sprint exercise enhances skeletal muscle p70S6k phosphorylation and more so in women than in men.
- 2012
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 205:3, s. 411-22
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Sprint exercise is characterized by repeated sessions of brief intermittent exercise at a high relative workload. However, little is known about the effect on mTOR pathway, an important link in the regulation of muscle protein synthesis. An earlier training study showed a greater increase in muscle fibre cross-sectional area in women than men. Therefore, we tested the hypothesis that the activation of mTOR signalling is more pronounced in women than in men. Healthy men (n=9) and women (n=8) performed three bouts of 30-s sprint exercise with 20-min rest in between.METHODS: Multiple blood samples were collected over time, and muscle biopsy specimens were obtained at rest and 140 min after the last sprint.RESULTS: Serum insulin increased by sprint exercise and more so in women than in men [gender (g) × time (t)]: P=0.04. In skeletal muscle, phosphorylation of Akt increased by 50% (t, P=0.001) and mTOR by 120% (t, P=0.002) independent of gender. The elevation in p70S6k phosphorylation was larger in women (g × t, P=0.03) and averaged 230% (P=0.006) as compared to 60% in men (P=0.04). Phosphorylation rpS6 increased by 660% over time independent of gender (t, P=0.003). Increase in the phosphorylation of p70S6k was directly related to increase in serum insulin (r=0.68, P=0.004).CONCLUSION: It is concluded that repeated 30-s all-out bouts of sprint exercise separated by 20 min of rest increases Akt/mTOR signalling in skeletal muscle. Secondly, signalling downstream of mTOR was stronger in women than in men after sprint exercise indicated by the increased phosphorylation of p70S6k.
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