| 1. |
- Söderström, Johan, et al.
(författare)
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Nonstoichiometric Intensities in Core Photoelectron Spectroscopy
- 2012
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 108:19, s. 193005-
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Tidskriftsartikel (refereegranskat)abstract
- X-ray photoemission spectroscopy is used in a great variety of research fields; one observable is the sample's stoichiometry. The stoichiometry can be deduced based on the expectation that the ionization cross sections for innershell orbitals are independent of the molecular composition. Here we used chlorine-substituted ethanes in the gas phase to investigate the apparent carbon stoichiometry. We observe a nonstoichiometric ratio for a wide range of photon energies, the ratio exhibits x-ray-absorption fine structure spectroscopy (EXAFS)-like oscillations and hundreds of eV above the C1s ionization approaches a value far from 1. These effects can be accounted for by considering the scattering of the outgoing photoelectron, which we model by multiple-scattering EXAFS calculations, and by considering the effects of losses due to monopole shakeup and shakeoff and to intramolecular inelastic scattering processes.
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| 2. |
- Bull, Peter, et al.
(författare)
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Förstudie obemannade farkoster
- 2012
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Rapport (populärvet., debatt m.m.)abstract
- Obemannade farkoster används allt oftare, och i allt fler roller, i dagens kon- flikter. Denna rapport ger en bred överblick över området militära obemannade farkoster, samt rekommendationer för inriktningen av framtida FoU-satsningar inom området.Överblicken över området har fokus på både system, förmågor och verksam- heter som är relevanta för Försvarsmakten. Genom att låta de insatsförmågor som definieras i FMUP (Försvarsmaktens utvecklingsplan) gå som en röd tråd genom rapporten, både när specifika system diskuteras och när möjliga scena- rier där obemannade farkoster kan vara till nytta beskrivs, har vi försökt hålla både bredd och relevans i dokumentet.Rekommendationerna vilar på en genomgång av de inriktningsdokument som producerats i Försvarsmakten, t.ex. Perspektivplanneringen och FMUP, besök vid de enheter som dagligen använder obemannade farkoster, UAV-enheten i Karlsborg och Swedec i Eksjö, samt den områdesöverblick som nämns ovan. Slutsatserna är att den effektivaste kompetensuppbyggnaden och kunskapsöver- föringen fås om man skapar breda tvärvetenskapliga projekt inom respektive systemkategori (UAV, UGV, etc) med nära kontakter till materielförsörjnings- processen och perspektivplaneringen. Dessa kan samla kompetensen inom FHS och FOI, övervaka forskningsfronten genom att bevaka tävlingar, konferenser samt delta i internationella samarbeten, samt överföra det samlade resultaten till Försvarsmakten genom demonstrationer av verkliga eller simulerade delsy- stem och interaktiva simuleringar av hela system. Just systemsimuleringar kan göras särskilt realistiska, eftersom interaktionen med de riktiga obemannade systemen till stor del sker igenom kontrollstationernas datorer. På så sätt ska- pas en känsla för både hot och möjligheter med de nya systemen, vilket gagnar både taktikutveckling och materielprocesser.
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| 3. |
- del Rio, J. S., et al.
(författare)
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CEPA: A LaBr 3 (Ce)/LaCl 3 (Ce) phoswich array for simultaneous detection of protons and gamma radiation emitted in reactions at relativistic energies
- 2014
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
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Konferensbidrag (refereegranskat)abstract
- A prototype CEPA4, made of four optically isolated phoswich-crystals of LaBr3(Ce)+LaCl3(Ce) packed together in one can of Al, was tested with high energy protons (70-230 MeV) at the cyclotron of Krakow. Further, the response to different gamma radiation standard sources and cosmic muons was determined. Shape analysis of the pulses derived from the four individually coupled PM-tubes was performed and were used as input functions for Monte Carlo simulations in order to simulate the efficiencies and resolutions of a final detector design consisting of 750 such phoswich crystals arranged in a cylindrical disc. © Owned by the authors, published by EDP Sciences, 2014.
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| 4. |
- del Rio, J. S., et al.
(författare)
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CEPA: A LaBr3(Ce)/LaCl3(Ce) Phoswich array for simultaneous detection of protons and gamma radiation emitted in reactions at relativistic energies
- 2014
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Ingår i: International Journal of Modern Physics: Conference Series. Applications of Nuclear Techniques (CRETE13). - 2010-1945. ; 27, s. 1460143-
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Konferensbidrag (refereegranskat)abstract
- A sophisticated design of 750 LaBr3(Ce):LaCl3(Ce) phoswich crystals (CEPA10) with a segmentation determined by the Doppler correction and an energy resolution of 5% at 1 MeV is presented. Monte Carlo simulations have been performed for high energy protons (50–500 MeV) and gamma radiation (0.5–30 MeV) to determine the length and shape of the crystals for optimum performance of the detector. In the case of protons, the two-layer detector can be used as a ΔELaBr3 − ETot telescope or, for very high energies, as a double energy loss detector (ΔELaBr3 + ΔELaCl3), in order to determine the initial energy. In addition, an experimental test with high energy protons (70–230 MeV) was performed at the cyclotron center in Krakow, Poland with a first prototype of 2 x 2 phoswich rectangular crystals (CEPA4) packed in an aluminum can (0.5 mm case). To simulate CEPA10 efficiencies and resolutions, optical pulses detected in CEPA4 by photomultiplier tubes with a DAQ system were used as energy input functions in Monte Carlo simulations.
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| 5. |
- Patanen, M., et al.
(författare)
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Laboratory-frame electron angular distributions : Probing the chemical environment through intramolecular electron scattering
- 2013
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 87:6, s. 063420-
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Tidskriftsartikel (refereegranskat)abstract
- Carbon 1s photoelectron asymmetry parameters beta for the chlorinated and the methyl carbon atom of CH3CH2Cl, CH3CHCl2, and CH3CCl3 have been measured using synchrotron radiation in the 340-600 eV energy range. We provide experimental evidence that the intramolecular scattering strongly affects beta values, even far from the ionization threshold. The results are in agreement with B-spline density functional theory calculations, making it possible to single out the behavior of the various continuum partial waves. We conclude that the intramolecular scattering makes electron angular distributions sensitive to the chemical environment, even in isolated gas phase molecules.
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| 6. |
- Travnikova, Oksana, et al.
(författare)
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The ESCA molecule-Historical remarks and new results
- 2012
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 185:8-9, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- The C is photoelectron spectrum of ethyl trifluoroacetate (CF3-CO-O-CH2-CH3), also known as the 'ESCA molecule', is the most illustrative showcase of chemical shifts in photoelectron spectroscopy. The binding energies of the four carbon atoms of this molecule spread over more than 8 eV with energy separations ranging from 1.7 to 3.1 eV owing to different chemical environments and hence different charge states of these atoms. The paper discusses history and importance of this spectrum in the field of photoelectron spectroscopy starting from the time of invention of the ESCA technique. The main focus of the paper is a 'revisit' of this spectrum using the most modern experimental and computational tools. Large geometrical changes, different for each ionization site, and the presence of two conformers of ethyl trifluoroacetate influence the spectral lineshapes of all four C 1s lines. These effects are carefully modeled by theory and investigated in the experimental spectrum.
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| 7. |
- Venkatesan, Meera, et al.
(författare)
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Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes : parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine.
- 2014
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Ingår i: The American journal of tropical medicine and hygiene. - : American Society of Tropical Medicine and Hygiene. - 1476-1645 .- 0002-9637. ; 91:4, s. 833-43
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Tidskriftsartikel (refereegranskat)abstract
- Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 - 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36-17.97, P < 0.001 : were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine.
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| 8. |
- Xu, Tianhua, 1984-, et al.
(författare)
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Frequency-domain chromatic dispersion equalization using overlap-add methods in coherent optical system
- 2011
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Ingår i: Journal of optical communications. - 0173-4911 .- 2191-6322. ; 27:2
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Tidskriftsartikel (refereegranskat)abstract
- The frequency domain equalizers (FDEs) employing two types of overlap-add zero-padding (OLA-ZP) methods are applied to compensate the chromatic dispersion in a 112-Gbit/s non-return-to-zero polarization division multiplexed quadrature phase shift keying (NRZ-PDM-QPSK) coherent optical transmission system. Simulation results demonstrate that the OLA-ZP methods can achieve the same acceptable performance as the overlap-save method. The required minimum overlap (or zero-padding) in the FDE is derived, and the optimum fast Fourier transform length to minimize the computational complexity is also analyzed.
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| 9. |
- Aydin-Schmidt, Berit, et al.
(författare)
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Loop mediated isothermal amplification (LAMP) accurately detects malaria DNA from filter paper blood samples of low density parasitaemias
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e103905-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Loop mediated isothermal amplification (LAMP) provides an opportunity for improved, field-friendly detection of malaria infections in endemic areas. However data on the diagnostic accuracy of LAMP for active case detection, particularly low-density parasitaemias, are lacking. We therefore evaluated the performance of a new LAMP kit compared with PCR using DNA from filter paper blood spots.METHODS AND FINDINGS:Samples from 865 fever patients and 465 asymptomatic individuals collected in Zanzibar were analysed for Pan (all species) and Pf (P. falciparum) DNA with the Loopamp MALARIA Pan/Pf kit. Samples were amplified at 65°C for 40 minutes in a real-time turbidimeter and results were compared with nested PCR. Samples with discordant results between LAMP and nested PCR were analysed with real-time PCR. The real-time PCR corrected nested PCR result was defined as gold standard. Among the 117 (13.5%) PCR detected P. falciparum infections from fever patients (mean parasite density 7491/µL, range 6-782,400) 115, 115 and 111 were positive by Pan-LAMP, Pf-LAMP and nested PCR, respectively. The sensitivities were 98.3% (95%CI 94-99.8) for both Pan and Pf-LAMP. Among the 54 (11.6%) PCR positive samples from asymptomatic individuals (mean parasite density 10/µL, range 0-4972) Pf-LAMP had a sensitivity of 92.7% (95%CI 80.1-98.5) for detection of the 41 P. falciparum infections. Pan-LAMP had sensitivities of 97% (95%CI 84.2-99.9) and 76.9% (95%CI 46.2-95) for detection of P. falciparum and P. malariae, respectively. The specificities for both Pan and Pf-LAMP were 100% (95%CI 99.1-100) in both study groups.CONCLUSION:Both components of the Loopamp MALARIA Pan/Pf detection kit revealed high diagnostic accuracy for parasite detection among fever patients and importantly also among asymptomatic individuals of low parasite densities from minute blood volumes preserved on filter paper. These data support LAMPs potential role for improved detection of low-density malaria infections in pre-elimination settings.
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| 10. |
- Carlsson, Anja M, et al.
(författare)
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Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment in Tanzanian children with acute uncomplicated malaria
- 2011
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Ingår i: Malaria Journal. - : Springer Science and Business Media LLC. - 1475-2875. ; 10, s. 380-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:This study aimed to explore Plasmodium falciparum population dynamics during the early phase of anti-malarial drug treatment with artemisinin-based combination therapy in children with clinical malaria in a high transmission area in Africa.METHODS:A total of 50 children aged 1-10 years with acute uncomplicated P. falciparum malaria in Bagamoyo District, Tanzania, were enrolled. Participants were hospitalized and received supervised standard treatment with artemether-lumefantrine according to body weight in six doses over 3 days. Blood samples were collected 11 times, i.e. at time of diagnosis (-2 h) and 0, 2, 4, 8, 16, 24, 36, 48, 60 and 72 h after initiation of treatment. Parasite population dynamics were assessed using nested polymerase chain reaction (PCR)-genotyping of merozoite surface protein (msp) 1 and 2.RESULTS:PCR-analyses from nine sequential blood samples collected after initiation of treatment identified 20 and 21 additional genotypes in 15/50 (30%) and 14/50 (28%) children with msp1 and msp2, respectively, non-detectable in the pre-treatment samples (-2 and 0 h combined). Some 15/20 (75%) and 14/21 (67%) of these genotypes were identified within 24 h, whereas 17/20 (85%) and 19/21 (90%) within 48 h for msp1 and msp2, respectively. The genotype profile was diverse, and varied considerably over time both within and between patients, molecular markers and their respective families.CONCLUSION:PCR analyses from multiple blood samples collected during the early treatment phase revealed a complex picture of parasite sub-populations. This underlines the importance of interpreting PCR-outcomes with caution and suggests that the present use of PCR-adjustment from paired blood samples in anti-malarial drug trials may overestimate assessment of drug efficacy in high transmission areas in Africa.The study is registered at http://www.clinicaltrials.gov with identifier NCT00336375.
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