| 1. |
- Abazov, V. M., et al.
(författare)
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The upgraded DO detector
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 565:2, s. 463-537
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Tidskriftsartikel (refereegranskat)abstract
- The DO experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid -argon calorimeters and central muon detector, remaining from Run 1, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DO.
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| 2. |
- Abazov, V. M., et al.
(författare)
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Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using secondary vertex b tagging
- 2006
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-7998 .- 1550-2368. ; 74:11, s. 112004-
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Tidskriftsartikel (refereegranskat)abstract
- We report a new measurement of the t (t) over bar production cross section in p (beta) over bar collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425 pb(-1) of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the t (t) over bar content of the sample by tagging b jets with a secondary vertex tagging algorithm, the t (t) over bar production cross section is measured to be sigma(p (t) over bar -> t (t) over bar +X)=6.6 +/- 0.9(stat+syst) +/- 0.4(lum) pb. This cross section is the most precise D0 measurement to date for t (t) over bar production and is in good agreement with standard model expectations.
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| 3. |
- Scott, E. A. S., et al.
(författare)
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Bi2CoO2F4─A Polar, Ferrimagnetic Aurivillius Oxide-Fluoride
- 2022
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 34:21, s. 9775-9785
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Tidskriftsartikel (refereegranskat)abstract
- Aurivillius oxides have been a research focus due to their ferroelectric properties, but by replacing oxide ions by fluoride, divalent magnetic cations can be introduced, giving Bi2MO2F4(M = Fe, Co, and Ni). Our combined experimental and computational study on Bi2CoO2F4 indicates a low-temperature polar structure of P21ab symmetry (analogous to ferroelectric Bi2WO6) and a ferrimagnetic ground state. These results highlight the potential of Aurivillius oxide-fluorides for multiferroic properties. Our research has also revealed some challenges associated with the reduced tendency for polar displacements in the more ionic fluoride-based systems.
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| 4. |
- Varju, Katalin, et al.
(författare)
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Experimental studies of attosecond pulse trains
- 2005
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Ingår i: Laser Physics. - 1054-660X. ; 15:6, s. 888-898
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Tidskriftsartikel (refereegranskat)abstract
- We present experimental measurements of attosecond pulse trains. The characterization of the pulses uses a spectral interferometry technique that is implemented with a Mach-Zehnder interferometer. This allows us to manipulate independently the pump and probe pulses for a wide range of applications. By letting the attosecond pulses pass through metallic films, we can in particular compensate for the intrinsic chirp of the attosecond pulses corresponding to the plateau spectral region, thus getting pulses as short as 170 attoseconds-only 1.2 optical cycles at the central frequency. The measurement technique is also applicable for determination of the group delay of thin XUV-transparent films and relative delay in the photoionization process. Our experimental method is applied to attosecond pulse trains created by 35- and 9-fs laser pulses, and the shortest train observed consists of three or four pulses.
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| 5. |
- Barillot, T., et al.
(författare)
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Angular asymmetry and attosecond time delay from the giant plasmon resonance in C60 photoionization
- 2015
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 91
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Tidskriftsartikel (refereegranskat)abstract
- This combined experimental and theoretical study demonstrates that the surface plasmon resonance in C 60 alters the valence photoemission quantum phase, resulting in strong effects in the photoelectron angular distribution and emission time delay. Electron momentum imaging spectroscopy is used to measure the photoelectron angular distribution asymmetry parameter that agrees well with our calculations from the time-dependent local density approximation (TDLDA). Significant structure in the valence photoemission time delay is simultaneously calculated by TDLDA over the plasmon active energies. Results reveal a unified spatial and temporal asymmetry pattern driven by the plasmon resonance and offer a sensitive probe of electron correlation. A semiclassical approach facilitates further insights into this link that can be generalized and applied to other molecular systems and nanometer-sized metallic materials exhibiting plasmon resonances.
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| 6. |
- Kukk, E., et al.
(författare)
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Formative period in the x-ray-induced photodissociation of organic molecules
- 2021
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Ingår i: Physical Review Research. - 2643-1564. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Absorption of x-ray photons by atomic inner shells of light-element organics and biomolecules often leads to formation of dicationic electronic states and to molecular fragmentation. We investigated the x-ray-induced dissociation landscape of a representative medium-sized organic molecule, thiophene, by femtosecond x-ray pulses from the Super Photon Ring-8 GeV (SPring-8) Angstrom Compact Free-Electron Laser (SACLA). Holes, created in the sulfur 2p orbital by photoemission, were filled by the Auger process that created dicationic molecular states within a broad range of internal energies—a starting point particular to x-ray-induced dynamics. The evolution of the ionized molecules was monitored by a pump-probe experiment using a near-infrared (800 nm) laser pulse. Ion-ion coincidence and ion momentum analysis reveals enhanced yields of ionic fragments from multibody breakup of the ring, attributed to additional ionization of the highly excited fraction of the dicationic parent molecular states. The transient nature of the enhancement and its decay with about a 160-fs time constant indicate formation of an open-ring parent geometry and the statistical survival time of the parent species before the dissociation events. By probing specific Auger final states of transient, highly excited nature by near-infrared light, we demonstrate how pump-probe signatures can be related to the key features in dynamics during the early period of the x-ray-induced damage of organic molecules and biomolecules.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Sola, I. J., et al.
(författare)
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Temporal and spectral studies of high-order harmonics generated by polarization-modulated infrared fields
- 2006
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 74:1
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Tidskriftsartikel (refereegranskat)abstract
- The temporal confinement of high harmonic generation (HHG) via modulation of the polarization of the fundamental pulse is studied in both temporal and spectral domains. In the temporal domain, a collinear cross-correlation setup using a 40 fs IR pump for the HHG and a 9 fs IR pulse to probe the generated emission is used to measure the XUV pulse duration. The observed temporal confinement is found to be consistent with theoretical predictions. An increased confinement is observed when a 9 fs pulse is used to generate the harmonics. An important spectral broadening, including a continuum background, is also measured. Theoretical calculations show that with 10 fs driving pulses, either one or two main attosecond pulses are created depending on the value of the carrier envelope phase.
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| 13. |
- Zaïr, A., et al.
(författare)
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Confinement of attosecond train pulses by using a modulated polarization IR pulse
- 2005
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Ingår i: 2005 Conference on Lasers and Electro-Optics Europe. - 0780389743 - 9780780389748
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Konferensbidrag (refereegranskat)abstract
- We study the temporal and spectral behaviour of high order harmonics generated by pulses with temporally modulated polarization. We observe a harmonic temporal confinement and a harmonic spectral broadening, compatible with 1 -or-2 attosecond pulse emission.
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| 14. |
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| 15. |
- Zettergren, Henning, et al.
(författare)
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Roadmap on dynamics of molecules and clusters in the gas phase
- 2021
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 75:5
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Tidskriftsartikel (refereegranskat)abstract
- This roadmap article highlights recent advances, challenges and future prospects in studies of the dynamics of molecules and clusters in the gas phase. It comprises nineteen contributions by scientists with leading expertise in complementary experimental and theoretical techniques to probe the dynamics on timescales spanning twenty order of magnitudes, from attoseconds to minutes and beyond, and for systems ranging in complexity from the smallest (diatomic) molecules to clusters and nanoparticles. Combining some of these techniques opens up new avenues to unravel hitherto unexplored reaction pathways and mechanisms, and to establish their significance in, e.g. radiotherapy and radiation damage on the nanoscale, astrophysics, astrochemistry and atmospheric science.
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| 16. |
- Arnold, C. L., et al.
(författare)
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Stabilized interferometric attosecond timing measurements
- 2013
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Ingår i: CLEO : QELS_Fundamental Science, CLEO:QELS FS 2013 - QELS_Fundamental Science, CLEO:QELS FS 2013. - 9781557529725
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Konferensbidrag (refereegranskat)abstract
- We perform interferometric attosecond timing measurements to study XUV photoionization in noble gases, to diagnose macroscopic phase-matching conditions in high-order harmonic generation, and to investigate single-photon double-ionization by detecting electron pairs in coincidence.
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| 17. |
- Berggård, Karin, et al.
(författare)
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Binding of human C4BP to the hypervariable region of M protein: a molecular mechanism of phagocytosis resistance in Streptococcus pyogenes
- 2001
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 42:2, s. 539-551
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Tidskriftsartikel (refereegranskat)abstract
- The amino-terminal hypervariable region (HVR) of streptococcal M protein is required for the ability of this virulence factor to confer phagocytosis resistance. The function of the HVR has remained unknown, but the finding that many HVRs with extremely divergent sequences bind the human complement regulator C4b-binding protein (C4BP) has suggested that this ligand may play a role in phagocytosis resistance. We used the M22 system to study the function of bound C4BP and provide several lines of evidence that C4BP indeed contributes to phagocytosis resistance. First, the ability of anti-HVR antibodies to cause opsonization correlated with their ability to inhibit binding of C4BP. Secondly, a short deletion in the HVR eliminated C4BP binding and also reduced the ability of M22 to confer phagocytosis resistance. Thirdly, the addition of an excess of pure C4BP to a phagocytosis system almost completely blocked the effect of opsonizing anti-HVR antibodies. Together, our data indicate that binding of C4BP to the HVR of M22 plays an important role in phagocytosis resistance, but other properties of M22 also contribute. This study provides the first molecular insight into the mechanisms by which the HVR of an M protein confers phagocytosis resistance.
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| 18. |
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| 19. |
- Buckley, Patrick G, et al.
(författare)
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A full-coverage, high-resolution human chromosome 22 genomic microarrayfor clinical and research applications
- 2002
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 11:25, s. 3221-3229
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Tidskriftsartikel (refereegranskat)abstract
- We have constructed the first comprehensive microarray representing a human chromosome for analysis of DNA copy number variation. This chromosome 22 array covers 34.7 Mb, representing 1.1% of the genome, with an average resolution of 75 kb. To demonstrate the utility of the array, we have applied it to profile acral melanoma, dermatofibrosarcoma, DiGeorge syndrome and neurofibromatosis 2. We accurately diagnosed homozygous/heterozygous deletions, amplifications/gains, IGLV/IGLC locus instability, and breakpoints of an imbalanced translocation. We further identified the 14-3-3 eta isoform as a candidate tumor suppressor in glioblastoma. Two significant methodological advances in array construction were also developed and validated. These include a strictly sequence defined, repeat-free, and non-redundant strategy for array preparation. This approach allows an increase in array resolution and analysis of any locus; disregarding common repeats, genomic clone availability and sequence redundancy. In addition, we report that the application of phi29 DNA polymerase is advantageous in microarray preparation. A broad spectrum of issues in medical research and diagnostics can be approached using the array. This well annotated and gene-rich autosome contains numerous uncharacterized disease genes. It is therefore crucial to associate these genes to specific 22q-related conditions and this array will be instrumental towards this goal. Furthermore, comprehensive epigenetic profiling of 22q-located genes and high-resolution analysis of replication timing across the entire chromosome can be studied using our array.
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| 20. |
- Cucherousset, J., et al.
(författare)
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Growth-enhanced salmon modify stream ecosystem functioning
- 2021
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 99:6, s. 1978-1989
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Tidskriftsartikel (refereegranskat)abstract
- Use of fast-growing domesticated and/or genetically modified strains of fish is becoming increasingly common in aquaculture, increasing the likelihood of deliberate or accidental introductions into the wild. To date, their ecological impacts on ecosystems remain to be quantified. Here, using a controlled phenotype manipulation by implanting growth hormone in juvenile Atlantic salmon (Salmo salar), we found that growth-enhanced fish display changes in several phenotypic traits known to be important for ecosystem functioning, such as habitat use, morphology and excretion rate. Furthermore, these phenotypic changes were associated with significant impacts on the invertebrate community and key stream ecosystem functions such as primary production and leaf-litter decomposition. These findings provide novel evidence that introductions of growth-enhanced fish into the wild can affect the functioning of natural ecosystems and represent a form of intraspecific invasion. Consequently, environmental impact assessments of growth-enhanced organisms need to explicitly consider ecosystem-level effects.
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| 21. |
- Fukuzawa, H., et al.
(författare)
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Deep Inner-Shell Multiphoton Ionization by Intense X-Ray Free-Electron Laser Pulses
- 2013
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 110:17
-
Tidskriftsartikel (refereegranskat)abstract
- We have investigated multiphoton multiple ionization dynamics of xenon atoms using a new x-ray free-electron laser facility, SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan, and identified that Xen+ with n up to 26 is produced at a photon energy of 5.5 keV. The observed high charge states (n >= 24) are produced via five-photon absorption, evidencing the occurrence of multiphoton absorption involving deep inner shells. A newly developed theoretical model, which shows good agreement with the experiment, elucidates the complex pathways of sequential electronic decay cascades accessible in heavy atoms. The present study of heavy-atom ionization dynamics in high-intensity hard-x-ray pulses makes a step forward towards molecular structure determination with x-ray free-electron lasers. DOI: 10.1103/PhysRevLett.110.173005
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| 22. |
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| 23. |
- Gryzlova, E. V., et al.
(författare)
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Influence of an atomic resonance on the coherent control of the photoionization process
- 2022
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Ingår i: Physical Review Research. - 2643-1564. ; 4:3
-
Tidskriftsartikel (refereegranskat)abstract
- In coherent control schemes, pathways connecting an initial and a final state can be independently controlled by manipulating the complex amplitudes of their transition matrix elements. For paths characterized by the absorption of multiple photons, these quantities depend on the magnitude and phase between the intermediate steps, and are expected to be strongly affected by the presence of resonances. We investigate the coherent control of the photoemission process in neon using a phase-controlled two-color extreme ultraviolet pulse with frequency in proximity of an excited energy state. Using helium as a reference, we show that the presence of such a resonance in neon modifies the amplitude and phase of the asymmetric emission of photoelectrons. Theoretical simulations based on perturbation theory are in fair agreement with the experimental observations.
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| 24. |
- Guenot, Diego, et al.
(författare)
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Measurements of relative photoemission time delays in noble gas atoms
- 2014
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 47:24, s. 245602-
-
Tidskriftsartikel (refereegranskat)abstract
- We determine relative photoemission time delays between valence electrons in different noble gas atoms (Ar, Ne and He) in an energy range between 31 and 37 eV. The atoms are ionized by an attosecond pulse train synchronized with an infrared laser field and the delays are measured using an interferometric technique. We compare our results with calculations using the random phase approximation with exchange and multi-configurational Hartree-Fock. We also investigate the influence of the different ionization angular channels.
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| 25. |
- Hagman, H., et al.
(författare)
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A randomized study of KRAS-guided maintenance therapy with bevacizumab, erlotinib or metronomic capecitabine after first-line induction treatment of metastatic colorectal cancer : the Nordic ACT2 trial
- 2016
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 27:1, s. 140-147
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Tidskriftsartikel (refereegranskat)abstract
- Maintenance treatment (mt) with bevacizumab (bev) +/- erlotinib (erlo) has modest effect after induction chemotherapy in metastatic colorectal cancer (mCRC). We hypothesized the efficacy of erlo to be dependent on KRAS mutational status and investigated this by exploring mt strategies with bev +/- erlo and low-dose capecitabine (cap). Included patients had mCRC scheduled for first-line therapy, Eastern Cooperative Oncology Group (ECOG) 0-1 and no major comorbidities. Treatment with XELOX/FOLFOX or XELIRI/FOLFIRI + bev was given for 18 weeks. After induction, patients without progression were eligible for randomization to mt; KRAS wild-type (wt) patients were randomized to bev +/- erlo (arms wt-BE, N = 36 versus wt-B, N = 35), KRAS mutated (mut) patients were randomized to bev or metronomic cap (arms mut-B, N = 34 versus mut-C, N = 33). Primary end point was progression-free survival (PFS) rate (PFSr) at 3 months after start of mt. A pooled analysis of KRAS wt patients from the previous ACT study was performed. We included 233 patients. Median age was 64 years, 62% male, 68% ECOG 0, 52% with primary tumor in situ. A total of 138 patients started mt after randomization. PFSr was 64.7% versus 63.6% in wt-B versus wt-BE, P = 1.000; and 75% versus 66.7% in mut-B versus mut-C, P = 0.579, with no significant difference in median PFS and overall survival (OS). In the pooled cohort, median PFS was 3.7 months in wt-B (N = 64) and 5.7 months in wt-BE (N = 62) (hazard ratios 1.03, 95% confidence interval 0.70-1.50, P = 0.867). The frequency of any grade 3/4 toxicities during mt was: 28%/58%/18%/15% (wt-B/wt-BE/mut-B/mut-C). Addition of erlo to bev as mt in KRAS wt mCRC did not significantly improve PFS or OS, but it did increase toxicity. KRAS status does not seem to influence the outcome of treatment with erlotinib. Metronomic cap warrants further investigation in mt strategies, given our explorative results. NCT01229813.
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| 26. |
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| 27. |
- Iablonskyi, D., et al.
(författare)
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Interatomic Coulombic Decay Processes after Multiple Valence Excitations in Ne Clusters
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 635, s. 112067-112067
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Konferensbidrag (refereegranskat)abstract
- We present a comprehensive analysis of autoionization processes in Ne clusters (similar to 5000 atoms) after multiple valence excitations by free electron laser radiation. The evolution from 2-body interatomic Coulombic decay (ICD) to 3-body ICD is demonstrated when changing from surface to bulk Frenkel exciton excitation. Super Coster-Kronig type 2-body ICD is observed at Wannier exciton which quenches the main ICD channel.
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| 28. |
- Iablonskyi, D., et al.
(författare)
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Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters
- 2016
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Ingår i: Physical Review Letters. - 0031-9007. ; 117:27
-
Tidskriftsartikel (refereegranskat)abstract
- Ne clusters (∼5000 atoms) were resonantly excited (2p→3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.
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| 29. |
- Johnsson, A., et al.
(författare)
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A randomized phase III trial on maintenance treatment with bevacizumab alone or in combination with erlotinib after chemotherapy and bevacizumab in metastatic colorectal cancer : the Nordic ACT Trial
- 2013
-
Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 24:9, s. 2335-2341
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Tidskriftsartikel (refereegranskat)abstract
- Background: The main objective was to study the effect on progression-free survival (PFS) of adding erlotinib to bevacizumab as maintenance treatment following chemotherapy and bevacizumab as first-line treatment of metastatic colorectal cancer (mCRC). Patients and methods: Patients with untreated mCRC received doublet chemotherapy + bevacizumab during 18 weeks and those without tumor progression were eligible for randomization to bevacizumab + erlotinib (arm A) or bevacizumab alone (arm B), until progression or unacceptable toxic effect. Results: Of the 249 patients enrolled, 80 started maintenance treatment in arm A and 79 in arm B. The rate of any grade 3/4 toxic effect was 53% in arm A and 13% in arm B. Median PFS was 5.7 months in arm A and 4.2 months in arm B (HR = 0.79; 95% confidence interval 0.55-1.12; P = 0.19). Overall survival (OS) from start of induction chemotherapy was 26.7 months in the randomized population, with no difference between the two arms. Conclusions: The addition of erlotinib to bevacizumab as maintenance treatment after first-line chemotherapy in mCRC did not improve PFS significantly. On-going clinical and translational studies focus on identifying subgroups of patients that may benefit from erlotinib in the maintenance setting.
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| 30. |
- Johnsson, JI, et al.
(författare)
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Fitness-related effects of growth investment in brown trout under field and hatchery conditions
- 2000
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Ingår i: JOURNAL OF FISH BIOLOGY. - : ACADEMIC PRESS LTD. - 0022-1112. ; 57:2, s. 326-336
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Tidskriftsartikel (refereegranskat)abstract
- The mortality of brown trout Salmo trutta over winter in a near-natural stream was not significantly increased by growth hormone (GH) treatment, but lipid reserves were lower in GN-treated fish. As GH-treated trout grew Faster than controls. GH appears to
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| 31. |
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| 32. |
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| 33. |
- Lopez, Rodrigo, et al.
(författare)
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Time-resolved ellipticity gating of high-order harmonic emission
- 2004
-
Ingår i: Physical Review A. ; 69, s. 1-053811
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Tidskriftsartikel (refereegranskat)abstract
- We present time-resolved cross-correlation measurements of extreme ultraviolet (xuv) pulses generated as high-order harmonics of intense 35 fs pulses, using a short (12 fs) probe pulse. We modulate the ellipticity of the laser driving the generation process such that the polarization is linear for short times around the temporal peak of the pulse. Since harmonic generation is strongly suppressed for very small amounts of driving laser ellipticity, the emission of xuv radiation can therefore be confined to times much shorter than the laser pulse duration. In addition, our setup allows us to continuously confine the xuv emission as well as to determine its frequency sweep during the pulse.
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| 34. |
- Mazza, T., et al.
(författare)
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Mapping Resonance Structures in Transient Core-Ionized Atoms
- 2020
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Ingår i: Physical Review X. - 2160-3308. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- The nature of transient electronic states created by photoabsorption critically determines the dynamics of the subsequently evolving system. Here, we investigate K-shell photoionized atomic neon by absorbing a second photon within the Auger-decay lifetime of 2.4 fs using the European XFEL, a unique high-repetition-rate, wavelength-tunable x-ray free-electron laser. By high-resolution electron spectroscopy, we map out the transient Rydberg resonances unraveling the details of the subsequent decay of the hollow atom. So far, ultra-short-lived electronic transients, which are often inaccessible by experiments, were mainly inferred from theory but are now addressed by nonlinear x-ray absorption. The successful characterization of these resonances with femtosecond lifetimes provides the basis for a novel class of site-specific, nonlinear, and time-resolved studies with strong impact for a wide range of topics in physics and chemistry.
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| 35. |
- Morfeldt, E, et al.
(författare)
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Isolated hypervariable regions derived from streptococcal M proteins specifically bind human C4b-binding protein : implications for antigenic variation.
- 2001
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 167:7, s. 3870-7
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Tidskriftsartikel (refereegranskat)abstract
- Antigenic variation in microbial surface proteins represents an apparent paradox, because the variable region must retain an important function, while exhibiting extensive immunological variability. We studied this problem for a group of streptococcal M proteins in which the approximately 50-residue hypervariable regions (HVRs) show essentially no residue identity but nevertheless bind the same ligand, the human complement regulator C4b-binding protein (C4BP). Synthetic peptides derived from different HVRs were found to retain the ability to bind C4BP, implying that the HVR corresponds to a distinct ligand-binding domain that can be studied in isolated form. This finding allowed direct characterization of the ligand-binding properties of isolated HVRs and permitted comparisons between different HVRs in the absence of conserved parts of the M proteins. Affinity chromatography of human serum on immobilized peptides showed that they bound C4BP with high specificity and inhibition experiments indicated that different peptides bound to the same site in C4BP. Different C4BP-binding peptides did not exhibit any immunological cross-reactivity, but structural analysis suggested that they have similar folds. These data show that the HVR of streptococcal M protein can exhibit extreme variability in sequence and immunological properties while retaining a highly specific ligand-binding function.
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| 36. |
- Motomura, K., et al.
(författare)
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Sequential multiphoton multiple ionization of atomic argon and xenon irradiated by X-ray free-electron laser pulses from SACLA
- 2013
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:16
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated multiphoton multiple ionization of argon and xenon atoms at 5 keV using a new x-ray free electron laser (XFEL) facility, the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. The experimental results are compared with the new theoretical results presented here. The absolute fluence of the XFEL pulse has been determined with the help of the calculations utilizing two-photon processes in the argon atom. The high charge states up to +22 observed for Xe in comparison with the calculations point to the occurrence of sequential L-shell multiphoton absorption and of resonance-enabled x-ray multiple ionization.
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| 37. |
- Rouzee, A., et al.
(författare)
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Angle-resolved photoelectron spectroscopy of sequential three-photon triple ionization of neon at 90.5 eV photon energy
- 2011
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 83:3
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Tidskriftsartikel (refereegranskat)abstract
- Multiple photoionization of neon atoms by a strong 13.7 nm (90.5 eV) laser pulse has been studied at the FLASH free electron laser in Hamburg. A velocity map imaging spectrometer was used to record angle-resolved photoelectron spectra on a single-shot basis. Analysis of the evolution of the spectra with the FEL pulse energy in combination with extensive theoretical calculations allows the ionization pathways that contribute to be assigned, revealing the occurrence of sequential three-photon triple ionization.
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| 38. |
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| 39. |
- Takanashi, T, et al.
(författare)
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Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne2
- 2017
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Ingår i: Physical Review Letters. - 0031-9007. ; 118:3
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Tidskriftsartikel (refereegranskat)abstract
- The hitherto unexplored two-photon doubly excited states [Ne∗(2p-13s)]2 were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of Ne2+ ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, 390(-130/+450) fs, and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.
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| 40. |
- Torén, Kjell, 1952, et al.
(författare)
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Vital capacity and COPD: the Swedish CArdioPulmonary bioImage Study (SCAPIS)
- 2016
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Ingår i: International Journal of Chronic Obstructive Pulmonary Disease. - : Informa UK Limited. - 1178-2005. ; 11:1, s. 927-933
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Tidskriftsartikel (refereegranskat)abstract
- Background: Spirometric diagnosis of chronic obstructive pulmonary disease (COPD) is based on the ratio of forced expiratory volume in 1 second (FEV1)/vital capacity (VC), either as a fixed value <0.7 or below the lower limit of normal (LLN). Forced vital capacity (FVC) is a proxy for VC. The first aim was to compare the use of FVC and VC, assessed as the highest value of FVC or slow vital capacity (SVC), when assessing the FEV1/VC ratio in a general population setting. The second aim was to evaluate the characteristics of subjects with COPD who obtained a higher SVC than FVC. Methods: Subjects (n=1,050) aged 50-64 years were investigated with FEV1, FVC, and SVC after bronchodilation. Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPDFVC was defined as FEV1/FVC <0.7, GOLDCOPD(VC) as FEV1/VC <0.7 using the maximum value of FVC or SVC, LLNCOPDFVC as FEV1/FVC below the LLN, and LLNCOPDVC as FEV1/VC below the LLN using the maximum value of FVC or SVC. Results: Prevalence of GOLDCOPD(FVC) was 10.0% (95% confidence interval [CI] 8.2-12.0) and the prevalence of LLNCOPDFVC was 9.5% (95% CI 7.8-11.4). When estimates were based on VC, the prevalence became higher; 16.4% (95% CI 14.3-18.9) and 15.6% (95% CI 13.5-17.9) for GOLDCOPD(VC) and LLNCOPDVC, respectively. The group of additional subjects classified as having COPD based on VC, had lower FEV1, more wheeze and higher residual volume compared to subjects without any COPD. Conclusion: The prevalence of COPD was significantly higher when the ratio FEV1/VC was calculated using the highest value of SVC or FVC compared with using FVC only. Subjects classified as having COPD when using the VC concept were more obstructive and with indications of air trapping. Hence, the use of only FVC when assessing airflow limitation may result in a considerable under diagnosis of subjects with mild COPD.
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| 41. |
- Veyrinas, K., et al.
(författare)
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Chromatic aberrations correction of attosecond high-order harmonic beams by flat-top spatial shaping of the fundamental beam
- 2023
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 25:2
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Tidskriftsartikel (refereegranskat)abstract
- Attosecond pulses created by high-order harmonic generation in gases often exhibit strong chromatic aberrations, arising from the broad bandwidth and wavelength-dependent nonlinear light-matter interaction. When the driving laser intensity varies spatially, as for Gaussian driving beams, the apparent source position of the harmonics differs significantly from one order to the next, thus affecting the achievable intensity and duration of the attosecond pulses when they are focused on a target. We show that these chromatic aberrations can be reduced by spatially shaping the fundamental beam to generate high-order harmonics with a driver having a flat-top profile inside the gas medium. By measuring both the intensity profile and wavefront for each harmonic in a plane, we access the extreme ultra-violet (XUV) beam properties and investigate these properties near focus. We observe that controlling chromatic aberrations by flat-top spatial shaping strongly reduces the variation of the XUV spectrum on the beam axis during propagation and, in return, the longitudinal sensitivity of both the temporal profiles and the temporal shifts of the focused attosecond pulses.
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| 42. |
- Veyrinas, K., et al.
(författare)
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High order harmonic generation with spatially shaped flat top driver to control XUV chromatic aberrations
- 2023
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Ingår i: 2023 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2023. - 9798350345995
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Konferensbidrag (refereegranskat)abstract
- The XUV beams generated via high order harmonic generation (HHG) in gases have spatial properties evolving with the harmonic order. It leads to chromatic aberrations when the harmonics are focussed so that, locally, the spectral content can change significantly during propagation [1-3] especially near focus.
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| 43. |
- Vilsboll, T., et al.
(författare)
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Dapagliflozin Plus Saxagliptin Add-on Therapy Compared With Insulin in Patients With Type 2 Diabetes Poorly Controlled by Metformin With or Without Sulfonylurea Therapy: A Randomized Clinical Trial
- 2019
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 42:8, s. 1464-1472
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE This study evaluated whether an oral combination of a sodium-glucose cotransporter 2 inhibitor and a dipeptidyl peptidase 4 inhibitor achieved glycemic control similar to basal insulin in patients with type 2 diabetes, poorly controlled with metformin, without increasing hypoglycemia or body weight. RESEARCH DESIGN AND METHODS In a multinational, open-label, randomized, phase 3 trial ( reg. no. ), adults with type 2 diabetes inadequately controlled on metformin, with or without sulfonylurea, were randomized (1:1) to receive dapagliflozin (DAPA) plus saxagliptin (SAXA) or titrated insulin glargine (INS). The primary end point was change in glycated hemoglobin A(1c) (HbA(1c)) from baseline to week 24. DAPA + SAXA treatment was tested for noninferiority versus INS. RESULTS The efficacy data set included 643 patients (mean +/- SD HbA(1c), 9.1 +/- 1.0% [75 +/- 11 mmol/mol]). At week 24, DAPA + SAXA treatment versus INS resulted in noninferior reductions in HbA(1c) (adjusted mean +/- SE change, -1.7 +/- 0.1% vs. -1.5 +/- 0.1% [18.3 +/- 0.7 mmol/mol vs. 16.8 +/- 0.7 mmol/mol]; P = 0.118), significantly different body weight change (between-group difference, -3.64 kg [95% CI -4.20 to -3.09]; P < 0.001), fewer patients with confirmed hypoglycemia (21.3% vs. 38.4%, P < 0.001), more patients achieving HbA(1c) <7.0% (53 mmol/mol) without hypoglycemia (20.9% vs. 13.1%, P = 0.008), and a similar proportion of patients achieving HbA(1c) <7.0% (33.2% vs. 33.5%, P = 0.924). Mean reductions in 24-h glucose measurements from baseline to week 2 were greater with DAPA + SAXA than with INS (P < 0.0001). No patients in the DAPA + SAXA group and three patients (0.9%) in the INS group experienced severe hypoglycemia. CONCLUSIONS Adding DAPA + SAXA to insulin-naive patients with poorly controlled type 2 diabetes achieved similar glycemic control, a lower risk of hypoglycemia, and a clinically relevant body weight difference compared with basal INS.
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| 44. |
- Vilsboll, T., et al.
(författare)
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Efficacy and safety of dapagliflozin plus saxagliptin versus insulin glargine over 52 weeks as add-on to metformin with or without sulphonylurea in patients with type 2 diabetes: A randomized, parallel-design, open-label, Phase 3 trial
- 2020
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Ingår i: Diabetes, obesity and metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 22:6, s. 957-968
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Tidskriftsartikel (refereegranskat)abstract
- Aim Efficacy and safety of dapagliflozin plus saxagliptin (DAPA + SAXA) were compared with insulin glargine (INS) in patients with type 2 diabetes (T2D) in a 52-week extension study. Materials and methods This international Phase 3 study randomized adults with T2D on metformin with/without sulphonylurea. They received DAPA + SAXA or INS for 24 weeks (short-term) with a 28-week (long-term) extension. Week 52 exploratory endpoints included adjusted mean change from baseline in glycated haemoglobin A(1c) (HbA1c) and body weight, and a proportion of patients achieving optimal glycaemic response without hypoglycaemia and without requiring rescue medication. Results Of the 1163 patients enrolled, 643 received treatment; 600 (DAPA + SAXA, 306; INS, 294) entered the long-term phase. At 52 weeks, HbA1c [adjusted least squares (LS) mean; 95% confidence interval (CI)] decreased more with DAPA + SAXA (-1.5% [-1.6%, -1.4%]) than with INS (-1.3% [-1.4%, -1.1%]); the LS mean difference (95% CI) was -0.25% (-0.4%, -0.1%; P = 0.009). Total body weight reduced with DAPA + SAXA [LS mean (95% CI): -1.8 kg (-2.4, -1.3)] and increased with INS [LS mean (95% CI): +2.8 kg (2.2, 3.3)]. More patients on DAPA + SAXA (17.6%) achieved HbA1c <7.0% without hypoglycaemia versus those on INS (9.1%). Rescue medication was required by 77 patients (23.8%) and 97 patients (30.4%) in the DAPA + SAXA and INS groups, respectively. Conclusion DAPA + SAXA treatment was non-inferior to INS in reducing HbA1c and body weight, and in achieving optimal glycaemic control without hypoglycaemia in patients with T2D 52 weeks after initiation.
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| 45. |
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| 46. |
- Zair, A, et al.
(författare)
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Time-resolved measurements of high order harmonics confined by polarization gating
- 2004
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 78:7-8, s. 869-872
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the temporal confinement of high order harmonic pulses generated by a femtosecond (fs) infrared (IR) pulse with a time varying polarization. We use a set of two birefringent quartz plates to modulate the IR polarization. It produces a short temporal gate of linear polarization where harmonics are efficiently generated during a small fraction of the IR pulse. By rotating one of the plates, the gate width can be continuously varied between 70 fs down to 7 fs. The XUV pulse duration is measured by cross-correlation with a probe IR pulse of 12 fs. When the gate width is decreased, a clear temporal confinement of the XUV emission is observed through the cross correlation signal. This experiment is the first direct experimental evidence in the temporal domain that the polarization gating technique can be used to significantly shorten the harmonic pulse duration.
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| 47. |
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| 48. |
- Akyürek, L M, et al.
(författare)
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Tolerance induction ameliorates allograft vasculopathy in rat aortic transplants. Influence of Fas-mediated apoptosis.
- 1998
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Ingår i: The Journal of clinical investigation. - 0021-9738. ; 101:12, s. 2889-99
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Tidskriftsartikel (refereegranskat)abstract
- Based on successful induction of donor-specific unresponsiveness by alloantigenic stimulation in several animal models of acute rejection, we hypothesized that similar immune manipulations would also inhibit the evolution of chronic rejection and transplant vasculopathy. To induce immune tolerance, DA rats received a PVG heart allograft and were immunosuppressed with cyclosporine for 30 d. At day 100 the animals were challenged with a PVG aortic allograft after either 1 or 18 h of cold ischemia. 8 wk after the aortic transplantation, the grafts were investigated for morphological changes, infiltrating cells, apoptosis, and Fas-Fas ligand expression. Control allografts showed advanced transplant arteriosclerosis, whereas tolerance-induced aortic allografts displayed reduced neointimal formation, less medial atrophy, fewer apoptotic cells, and fewer Fas- and FasL-expressing cells. Prolonged ischemic storage time did not profoundly alter the morphological changes of the allografts. Fas expression was found in T cells, macrophages, vascular smooth muscle cells, and endothelial cells, whereas FasL was expressed mainly by T cells and macrophages. FasL mRNA expression was evident throughout the entire allograft wall. In conclusion, induction of allospecific tolerance can effectively prevent transplant arteriosclerosis. Cold ischemia damage does not abrogate the beneficial effect of tolerance, but creates a separate identity of mainly endothelial lesions. Furthermore, Fas-mediated apoptosis appears to be involved in the pathological lesions seen in chronic rejection.
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| 49. |
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| 50. |
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