| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
-
Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Singh, B. P., et al.
(författare)
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Experimental access to Transition Distribution Amplitudes with the PANDA experiment at FAIR
- 2015
-
Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 51:8
-
Tidskriftsartikel (refereegranskat)abstract
- Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (pi N) TDAs from (p) over barp -> e(+)e(-)pi(0) reaction with the future PANDA detector at the FAIR facility. At high center-of-mass energy and high invariant mass squared of the lepton pair q(2), the amplitude of the signal channel (p) over barp -> e(+)e(-)pi(0) admits a QCD factorized description in terms of pi N TDAs and nucleon Distribution Amplitudes (DAs) in the forward aid backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring (p) over barp -> e(+)e(-)pi(0) with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. (p) over barp -> pi(+)pi(-)pi(0) were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q(2) < 4.3 GeV2 and 5 < q(2) < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone vertical bar cos theta(pi 0)vertical bar > 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 . 10(7) (1 . 10(7)) at low (high) q(2) for s = 5 GeV2, and of 1 . 10(8) (6 . 10(6)) at low (high) q(2) for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing pi N TDAs.
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| 3. |
- Collaboration, The PANDA, et al.
(författare)
-
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
- 2016
-
Ingår i: European Physical Journal A. - : Springer Publishing Company. - 1434-6001 .- 1434-601X. ; 52:10
-
Tidskriftsartikel (refereegranskat)abstract
- Simulation results for future measurements of electromagnetic proton form factors at P ¯ ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel p¯ p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e.p¯ p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
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| 4. |
- Erni, W., et al.
(författare)
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Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
- 2013
-
Ingår i: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 49:2
-
Tidskriftsartikel (refereegranskat)abstract
- This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
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| 5. |
- Singh, B., et al.
(författare)
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Feasibility study for the measurement of pi N transition distribution amplitudes at (P)over-barANDA in (P)over-barp -> J/psi pi(0)
- 2017
-
Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 95:3
-
Tidskriftsartikel (refereegranskat)abstract
- The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.
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| 6. |
- Singh, B., et al.
(författare)
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Study of doubly strange systems using stored antiprotons
- 2016
-
Ingår i: Nuclear Physics A. - : Elsevier. - 0375-9474 .- 1873-1554. ; 954, s. 323-340
-
Tidskriftsartikel (refereegranskat)abstract
- Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Xi(-) -atoms will be feasible and even the production of Omega(-) -atoms will be within reach. The latter might open the door to the vertical bar S vertical bar = 3 world in strangeness nuclear physics, by the study of the hadronic Omega(-) -nucleus interaction. For the first time it will be possible to study the behavior of Xi(+) in nuclear systems under well controlled conditions.
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| 7. |
- Prusti, T., et al.
(författare)
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The Gaia mission
- 2016
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 595
-
Tidskriftsartikel (refereegranskat)abstract
- Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page.
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| 8. |
- Brown, A. G. A., et al.
(författare)
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Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties
- 2016
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 595
-
Tidskriftsartikel (refereegranskat)abstract
- Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of similar to 3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr(-1) for the proper motions. A systematic component of similar to 0.3 mas should be added to the parallax uncertainties. For the subset of similar to 94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr(-1). For the secondary astrometric data set, the typical uncertainty of the positions is similar to 10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to similar to 0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.
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| 9. |
- Clementini, G., et al.
(författare)
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Testing parallaxes with local Cepheids and RR Lyrae stars
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 605
-
Tidskriftsartikel (refereegranskat)abstract
- Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS.Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with sigma(omega)/omega < 0 : 5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with sigma(omega)/omega 0 : 5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with sigma(omega)/omega < 0 : 5). The new relations were computed using multi- band (V; I; J; K-s) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL; PW; PLZ, and MV [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods.Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the HIPPARCOS measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive.Conclusions. TGAS parallaxes bring a significant added value to the previous HIPPARCOS estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018.
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| 10. |
- Korablev, O., et al.
(författare)
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The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter
- 2018
-
Ingår i: Space Science Reviews. - : Springer. - 0038-6308 .- 1572-9672. ; 214:1
-
Tidskriftsartikel (refereegranskat)abstract
- The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described.
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| 11. |
- van Leeuwen, F., et al.
(författare)
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Gaia Data Release 1 : Open cluster astrometry: Performance, limitations, and future prospects
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601
-
Tidskriftsartikel (refereegranskat)abstract
- Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
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| 12. |
- Oberemok, Volodymyr V., et al.
(författare)
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Molecular Alliance of Lymantria dispar Multiple Nucleopolyhedrovirus and a Short Unmodified Antisense Oligonucleotide of Its Anti-Apoptotic IAP-3 Gene : A Novel Approach for Gypsy Moth Control
- 2017
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 18:11
-
Tidskriftsartikel (refereegranskat)abstract
- Baculovirus IAP (inhibitor-of-apoptosis) genes originated by capture of host genes. Unmodified short antisense DNA oligonucleotides (oligoDNAs) from baculovirus IAP genes can down-regulate specific gene expression profiles in both baculovirus-free and baculovirus-infected insects. In this study, gypsy moth (Lymantria dispar) larvae infected with multiple nucleopolyhedrovirus (LdMNPV), and LdMNPV-free larvae, were treated with oligoDNA antisense to the RING (really interesting new gene) domain of the LdMNPV IAP-3 gene. The results with respect to insect mortality, biomass accumulation, histological studies, RT-PCR, and analysis of DNA apoptotic fragmentation suggest that oligoRING induced increased apoptotic processes in both LdMNPV-free and LdMNPV-infected insect cells, but were more pronounced in the latter. These data open up possibilities for promising new routes of insect pest control using antisense phosphodiester DNA oligonucleotides.
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| 13. |
- Zuev, D. A., et al.
(författare)
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Multifunctional Sensing with Hybrid Nanophotonic Structures
- 2017
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. ; , s. 1491-1493
-
Konferensbidrag (refereegranskat)abstract
- The development of multifunctional systems for investigation of different parameters involved in chemical reactions is a vital problem in case of low concentrations of tested matter. Here, we investigate hybrid plasmonic-dielectric system and demonstrate possibility of such application for multifunctional sensing.
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| 14. |
- Makarov, D.V., et al.
(författare)
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Electrochemical oxidation of galenite in carbonate solutions
- 2004
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Ingår i: Russian journal of applied chemistry. - 1070-4272 .- 1608-3296. ; 77:6, s. 921-924
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Tidskriftsartikel (refereegranskat)abstract
- Linear voltammetry, X-ray phase and differential thermal analyses, diffuse reflection IR Fourier spectroscopy, Raman spectroscopy, and scanning electron microscopy (SEM) were used to study the electrochemical oxidation of galenite in carbonate electrolytes.
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| 15. |
- Makarov, D.V., et al.
(författare)
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Electrooxidation of pentlandite in a carbonate solution
- 2004
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Ingår i: Russian journal of electrochemistry. - 1023-1935 .- 1608-3342. ; 40:4, s. 420-423
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Tidskriftsartikel (refereegranskat)abstract
- Electrooxidation of pentlandite in a carbonate solution involves the formation of surface sulfide minerals of nickel and iron of variable composition, sulfur, and iron and nickel hydroxides. In parallel, sulfide sulfur oxidizes in a narrow potential range to sulfate ions.
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| 16. |
- Maslova, M. V., et al.
(författare)
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A study of structure and surface properties of cleaved mica particles
- 2003
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Ingår i: Russian journal of applied chemistry. - 1070-4272 .- 1608-3296. ; 76:6, s. 867-870
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Tidskriftsartikel (refereegranskat)abstract
- The structure of cleaved mica particles and the influence of cleavage conditions on surface prop- erties of mica were studied by IR spectroscopy.
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| 17. |
- Kalinkin, Alexander M., et al.
(författare)
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Surface oxidation of synthetic pyrrhotite during wetting-drying treatment
- 2000
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Ingår i: Environmental Engineering Science. - : Mary Ann Liebert Inc. - 1092-8758 .- 1557-9018. ; 17:6, s. 329-335
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Tidskriftsartikel (refereegranskat)abstract
- The surface changes of synthetic hexagonal pyrrhotite Fe[10]S[11] during laboratory wetting-drying treatment at 45°C were investigated using FTIR (DRIFT) spectroscopy, FTIR Raman microscopy, and scanning electron microscopy. α-FeO(OH) (goethite) and elemental sulphur were the main products of the surface pyrrhotite oxidation. The formation of goethite and elemental sulphur was studied on the basis of the corrosion theory and using a potential-pH (Pourbaix) diagram. The appearance of oxidation products on the surface of pyrrhotite grains was detected between 10 and 20 h of treatment. The obtained results can be used for comparison of oxidation processes of synthetic pyrrhotite with that of natural sulphide minerals in dumps.
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| 18. |
- Le, Trang, et al.
(författare)
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Analysis of the Human Protein Atlas Weakly Supervised Single-Cell Classification competition
- 2022
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Ingår i: Nature Methods. - : Springer Nature. - 1548-7091 .- 1548-7105. ; 19:10, s. 1221-1229
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Tidskriftsartikel (refereegranskat)abstract
- While spatial proteomics by fluorescence imaging has quickly become an essential discovery tool for researchers, fast and scalable methods to classify and embed single-cell protein distributions in such images are lacking. Here, we present the design and analysis of the results from the competition Human Protein Atlas – Single-Cell Classification hosted on the Kaggle platform. This represents a crowd-sourced competition to develop machine learning models trained on limited annotations to label single-cell protein patterns in fluorescent images. The particular challenges of this competition include class imbalance, weak labels and multi-label classification, prompting competitors to apply a wide range of approaches in their solutions. The winning models serve as the first subcellular omics tools that can annotate single-cell locations, extract single-cell features and capture cellular dynamics.
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| 19. |
- Maslova, M.V., et al.
(författare)
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Mica behavior in aqueous solutions with pH 3-9
- 2005
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Ingår i: Geochemistry International. - 0016-7029 .- 1556-1968. ; 43:7, s. 702-707
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Tidskriftsartikel (refereegranskat)abstract
- Muscovite and phlogopite behavior was examined in aqueous solutions with pH 3-9. Mica dissolution was demonstrated to involve ion exchange and adsorption and depend on the acid-basic properties of surface oxides. The rate of mica dissolution is limited by the rate of silicon leaching in acid solutions and by the rate of aluminum leaching in alkaline solutions
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| 20. |
- Milichko, V., et al.
(författare)
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Metal-dielectric nanocavity as a versatile optical sensing platform
- 2017
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Ingår i: Metamaterials. - 1873-1988. ; , s. 403-405
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Konferensbidrag (refereegranskat)abstract
- © 2017 IEEE. The control of various processes at nanoscale in a real time and easy manner is a challenge for different applications: from lab-on-A-chip to catalysis and medical diagnostic systems. Here, we demonstrate a new system, representing a metal-dielectric (hybrid) nanocavity for multifunctional sensing at nanoscale. The cavity provides enhancement of Raman signal and simultaneous control of the analyte temperature. We believe, the proposed concept provides a universal optical tool not only for the basic life sciences, but also for nanotechnology and nanomedicine.
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| 21. |
- Milichko, V., et al.
(författare)
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Metal-Dielectric Nanocavity for Real-Time Tracing Molecular Events with Temperature Feedback
- 2018
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Ingår i: Laser and Photonics Reviews. - : Wiley. - 1863-8899 .- 1863-8880. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Plasmonic nanoparticles coupled with metallic films forming nanometer scale cavities have recently emerged as a powerful tool for enhancement of light-matter interaction. Despite high efficiency for sensing and light emission, such nanocavities exhibit harmful and uncontrolled optical heating which limits the ranges of light intensities and working temperature. In contrast to plasmonic nanoparticles, all-dielectric counterparts possess low Ohmic losses, high temperature stability along with a strong temperature-dependent Raman response. Here, we demonstrate that a silicon nanoparticle coupled with a thin gold film can serve as a multifunctional metal-dielectric (hybrid) nanocavity operating up to 1200 K. Resonant interaction of light with such nanocavity enables molecular sensing, heat-induced molecular events (protein unfolding), and their real-time tracing with a nanoscale thermometry through the monitoring enhanced Raman scattering both from the nanoparticle and analyzed molecules. We model numerically the thermo-optical properties of the hybrid nanocavity and reveal two alternative regimes of operation - with and without strong optical heating while other functionalities are preserved. We believe that the concept of the multifunctional hybrid nanocavities holds great potential for diverse photochemical and photophysical applications.
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| 22. |
- Tiguntseva, Ekaterina, et al.
(författare)
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Room-Temperature Lasing from Mie-Resonant Nonplasmonic Nanoparticles
- 2020
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 14:7, s. 8149-8156
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Tidskriftsartikel (refereegranskat)abstract
- Subwavelength particles supporting Mie resonances underpin a strategy in nanophotonics for efficient control and manipulation of light by employing both an electric and a magnetic optically induced multipolar resonant response. Here, we demonstrate that monolithic dielectric nanoparticles made of CsPbBr3 halide perovskites can exhibit both efficient Mie-resonant lasing and structural coloring in the visible and near-IR frequency ranges. We employ a simple chemical synthesis with nearly epitaxial quality for fabricating subwavelength cubes with high optical gain and demonstrate single-mode lasing governed by the Mie resonances from nanocubes as small as 310 nm by the side length. These active nanoantennas represent the most compact room-temperature nonplasmonic nanolasers demonstrated until now.
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| 23. |
- Volkov, Oleksii M., et al.
(författare)
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Three-dimensional magnetic nanotextures with high-order vorticity in soft magnetic wireframes
- 2024
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Additive nanotechnology enable curvilinear and three-dimensional (3D) magnetic architectures with tunable topology and functionalities surpassing their planar counterparts. Here, we experimentally reveal that 3D soft magnetic wireframe structures resemble compact manifolds and accommodate magnetic textures of high order vorticity determined by the Euler characteristic, χ. We demonstrate that self-standing magnetic tetrapods (homeomorphic to a sphere; χ = + 2) support six surface topological solitons, namely four vortices and two antivortices, with a total vorticity of + 2 equal to its Euler characteristic. Alternatively, wireframe structures with one loop (homeomorphic to a torus; χ = 0) possess equal number of vortices and antivortices, which is relevant for spin-wave splitters and 3D magnonics. Subsequent introduction of n holes into the wireframe geometry (homeomorphic to an n-torus; χ < 0) enables the accommodation of a virtually unlimited number of antivortices, which suggests their usefulness for non-conventional (e.g., reservoir) computation. Furthermore, complex stray-field topologies around these objects are of interest for superconducting electronics, particle trapping and biomedical applications.
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| 24. |
- Zyuzin, Mikhail V., et al.
(författare)
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Photoluminescence quenching of dye molecules near a resonant silicon nanoparticle
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Luminescent molecules attached to resonant colloidal particles are an important tool to study light-matter interaction. A traditional approach to enhance the photoluminescence intensity of the luminescent molecules in such conjugates is to incorporate spacer-coated plasmonic nanoantennas, where the spacer prevents intense non-radiative decay of the luminescent molecules. Here, we explore the capabilities of an alternative platform for photoluminescence enhancement, which is based on low-loss Mie-resonant colloidal silicon particles. We demonstrate that resonant silicon particles of spherical shape are more efficient for photoluminescence enhancement than their plasmonic counterparts in spacer-free configuration. Our theoretical calculations show that significant enhancement originates from larger quantum yields supported by silicon particles and their resonant features. Our results prove the potential of high-index dielectric particles for spacer-free enhancement of photoluminescence, which potentially could be a future platform for bioimaging and nanolasers.
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| 25. |
- Dalin, Martin, 1982, et al.
(författare)
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Multi-dimensional genomic analysis of myoepithelial carcinoma identifies prevalent oncogenic gene fusions
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Myoepithelial carcinoma (MECA) is an aggressive salivary gland cancer with largely unknown genetic features. Here we comprehensively analyze molecular alterations in 40 MECAs using integrated genomic analyses. We identify a low mutational load, and high prevalence (70%) of oncogenic gene fusions. Most fusions involve the PLAG1 oncogene, which is associated with PLAG1 overexpression. We find FGFR1-PLAG1 in seven (18%) cases, and the novel TGFBR3-PLAG1 fusion in six (15%) cases. TGFBR3-PLAG1 promotes a tumorigenic phenotype in vitro, and is absent in 723 other salivary gland tumors. Other novel PLAG1 fusions include ND4-PLAG1; a fusion between mitochondrial and nuclear DNA. We also identify higher number of copy number alterations as a risk factor for recurrence, independent of tumor stage at diagnosis. Our findings indicate that MECA is a fusion-driven disease, nominate TGFBR3-PLAG1 as a hallmark of MECA, and provide a framework for future diagnostic and therapeutic research in this lethal cancer.
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| 26. |
- Kalinkina, Elena V., et al.
(författare)
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Sorption of atmospheric carbon dioxide and structural changes of Ca and Mg silicate minerals during grinding : I. Diopside
- 2001
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Ingår i: International Journal of Mineral Processing. - 0301-7516 .- 1879-3525. ; 61:4, s. 273-288
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Tidskriftsartikel (refereegranskat)abstract
- Processes which occur during dry grinding of the magnesium and calcium silicate minerals enstatite MgSiO3, åkermanite Ca2MgSi2O7 and wollastonite CaSiO3, have been studied with the use of diffuse reflectance Fourier transform infrared spectroscopy (DRIFT), powder X-ray diffraction, 29Si MAS-NMR spectroscopy, CO2-content analysis, and BET surface area measurements. It has been found that the extensive sorption of atmospheric CO2 (carbonization) by the ground mineral that was reported earlier for diopside CaMgSi2O6 also occurs for the minerals included in this study. The shape and position of the double peak of the CO32--group in the 1430-1515 cm-1 region in the FT-IR spectra of ground minerals are similar to that of ground diopside. CO2-content analysis and BET surface area measurements show that carbonate groups are present not only at the surface but also in the bulk of the ground minerals. The degree of carbonization of silicate depends on its calcium content. The higher the fraction of Ca in octahedral positions in the silicate structures, the higher the degree of carbonization. For synthetic wollastonite CaSiO3, which is a pure calcium silicate, the degree of carbonization is 102.6 mg CaCO3 per gram of sample after 36 h of grinding. The structure of silicate appears to be less important for the degree of carbonization during grinding.
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| 27. |
- Kalinkina, Elena V., et al.
(författare)
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Sorption of atmospheric carbon dioxide and structural changes of Ca and Mg silicate minerals during grinding: II. Enstatite, åkermanite and wollastonite
- 2001
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Ingår i: International Journal of Mineral Processing. - 0301-7516 .- 1879-3525. ; 61:4, s. 289-299
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Tidskriftsartikel (refereegranskat)abstract
- Processes which occur during dry grinding of the magnesium and calcium silicate minerals enstatite MgSiO3, åkermanite Ca2MgSi2O7 and wollastonite CaSiO3, have been studied with the use of diffuse reflectance Fourier transform infrared spectroscopy (DRIFT), powder X-ray diffraction, 29Si MAS-NMR spectroscopy, CO2-content analysis, and BET surface area measurements. It has been found that the extensive sorption of atmospheric CO2 (carbonization) by the ground mineral that was reported earlier for diopside CaMgSi2O6 also occurs for the minerals included in this study. The shape and position of the double peak of the CO32--group in the 1430-1515 cm-1 region in the FT-IR spectra of ground minerals are similar to that of ground diopside. CO2-content analysis and BET surface area measurements show that carbonate groups are present not only at the surface but also in the bulk of the ground minerals. The degree of carbonization of silicate depends on its calcium content. The higher the fraction of Ca in octahedral positions in the silicate structures, the higher the degree of carbonization. For synthetic wollastonite CaSiO3, which is a pure calcium silicate, the degree of carbonization is 102.6 mg CaCO3 per gram of sample after 36 h of grinding. The structure of silicate appears to be less important for the degree of carbonization during grinding.
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| 28. |
- Kharintsev, Sergey S., et al.
(författare)
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Light-Controlled Multiphase Structuring of Perovskite Crystal Enabled by Thermoplasmonic Metasurface
- 2023
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Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 17:10, s. 9235-9244
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Tidskriftsartikel (refereegranskat)abstract
- Halide perovskites belong to an important family of semiconducting materials with electronic properties that enable a myriad of applications, especially in photovoltaics and optoelectronics. Their optical properties, including photoluminescence quantum yield, are affected and notably enhanced at crystal imperfections where the symmetry is broken and the density of states increases. These lattice distortions can be introduced through structural phase transitions, allowing charge gradients to appear near the interfaces between phase structures. In this work, we demonstrate controlled multiphase structuring in a single perovskite crystal. The concept uses cesium lead bromine (CsPbBr3) placed on a thermoplasmonic TiN/Si metasurface and enables single-, double-, and triple-phase structures to form on demand above room temperature. This approach promises application horizons of dynamically controlled heterostructures with distinctive electronic and enhanced optical properties.
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| 29. |
- Kononenko, Artem V., et al.
(författare)
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GTP-dependent structural rearrangement of the eRF1:eRF3 complex and eRF3 sequence motifs essential for PABP binding
- 2010
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Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 38:2, s. 548-558
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Tidskriftsartikel (refereegranskat)abstract
- Translation termination in eukaryotes is governed by the concerted action of eRF1 and eRF3 factors. eRF1 recognizes the stop codon in the A site of the ribosome and promotes nascent peptide chain release, and the GTPase eRF3 facilitates this peptide release via its interaction with eRF1. In addition to its role in termination, eRF3 is involved in normal and nonsense-mediated mRNA decay through its association with cytoplasmic poly(A)-binding protein (PABP) via PAM2-1 and PAM2-2 motifs in the N-terminal domain of eRF3. We have studied complex formation between full-length eRF3 and its ligands (GDP, GTP, eRF1 and PABP) using isothermal titration calorimetry, demonstrating formation of the eRF1:eRF3:PABP:GTP complex. Analysis of the temperature dependence of eRF3 interactions with G nucleotides reveals major structural rearrangements accompanying formation of the eRF1:eRF3:GTP complex. This is in contrast to eRF1:eRF3:GDP complex formation, where no such rearrangements were detected. Thus, our results agree with the established active role of GTP in promoting translation termination. Through point mutagenesis of PAM2-1 and PAM2-2 motifs in eRF3, we demonstrate that PAM2-2, but not PAM2-1 is indispensible for eRF3:PABP complex formation.
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| 30. |
- Lamond, Angus I., et al.
(författare)
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Advancing Cell Biology Through Proteomics in Space and Time (PROSPECTS)
- 2012
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- The term "proteomics" encompasses the large-scale detection and analysis of proteins and their post-translational modifications. Driven by major improvements in mass spectrometric instrumentation, methodology, and data analysis, the proteomics field has burgeoned in recent years. It now provides a range of sensitive and quantitative approaches for measuring protein structures and dynamics that promise to revolutionize our understanding of cell biology and molecular mechanisms in both human cells and model organisms. The Proteomics Specification in Time and Space (PROSPECTS) Network is a unique EU-funded project that brings together leading European research groups, spanning from instrumentation to biomedicine, in a collaborative five year initiative to develop new methods and applications for the functional analysis of cellular proteins. This special issue of Molecular and Cellular Proteomics presents 16 research papers reporting major recent progress by the PROSPECTS groups, including improvements to the resolution and sensitivity of the Orbitrap family of mass spectrometers, systematic detection of proteins using highly characterized antibody collections, and new methods for absolute as well as relative quantification of protein levels. Manuscripts in this issue exemplify approaches for performing quantitative measurements of cell proteomes and for studying their dynamic responses to perturbation, both during normal cellular responses and in disease mechanisms. Here we present a perspective on how the proteomics field is moving beyond simply identifying proteins with high sensitivity toward providing a powerful and versatile set of assay systems for characterizing proteome dynamics and thereby creating a new "third generation"proteomics strategy that offers an indispensible tool for cell biology and molecular medicine.
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| 31. |
- Lewellen, JW, et al.
(författare)
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Present status and recent results from the APS SASE FEL
- 2002
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 483:1-2, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- The Low-Energy Undulator Test Line (LEUTL) at the Advanced Photon Source, Argonne National Laboratory, is intended to demonstrate the basic operation of a SASE-based free-electron laser. Goals include comparison of experimental results With theoretical predictions and scaling laws, identification of problems relevant to fourth-generation light source construction and operation and the means of addressing them, the development of operational and diagnostic techniques to optimize SASE FEL performance and increase repeatability from run to run. and performance of initial pioneering experiments capable of exploiting the unique properties of the laser. The basic layout and operational philosophy of the LEUTL experiment is presented. A summary of past results, including saturation, is reviewed, and a description of recent results is presented. We conclude with future plans, which include pressing to shorter wavelengths and incorporating user experiments into the LEUTL experimental program.
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| 32. |
- Loeb, Stacy, et al.
(författare)
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Five-year Nationwide Follow-up Study of Active Surveillance for Prostate Cancer
- 2015
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Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 67:2, s. 233-238
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Tidskriftsartikel (refereegranskat)abstract
- Background: Active surveillance (AS) is an important yet underutilized strategy to reduce prostate cancer (PCa) overtreatment. Objective: To examine the 5-yr outcomes of AS in a population-based setting. Design, setting, and participants: From the National Prostate Cancer Register of Sweden, we identified 11 726 men <= 70 yr diagnosed with very low-risk to intermediate-risk PCa from 2003 to 2007 who completed 5 yr of follow-up. Of these men, 1729 (15%) chose AS for the primary management strategy. Outcome measurements and statistical analysis: We calculated the probability of discontinuation of AS over time, and Cox proportional hazards models were used to determine factors associated with discontinuation. Reasons for discontinuation were assessed by data extraction from medical charts. Results and limitations: By 5 yr, 64% of the men remained on AS. Predictors of discontinuation were younger age, fewer comorbidities, more education, higher prostate-specific antigen (PSA), and clinical stage T2 disease; marital status did not predict discontinuation. In a subset with data on the reason for discontinuation (86%), 20% of men discontinued because of patient preference, 52% because of PSA progression, 24% because of biopsy progression, and 3% for other reasons. Conclusions: In a population-based setting, the majority of men remained on AS at 5 yr. However, one-fifth of the men who discontinued AS did so for nonbiologic reasons. Thus, there is a need for support and counseling for men to continue AS in the absence of signs of progression to improve adherence to AS and decrease overtreatment. Patient summary: Active surveillance (AS) is an important option to delay or avoid treatment for men with favorable prostate cancer features. This study shows that at 5 yr, 64% of men across an entire population remained on AS. We concluded that AS is a durable option and that counseling may be useful to promote adherence for men without progression.
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| 33. |
- Loeb, Stacy, et al.
(författare)
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Immediate versus delayed prostatectomy : Nationwide population-based study
- 2016
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Ingår i: Scandinavian journal of urology. - : Informa UK Limited. - 2168-1805 .- 2168-1813. ; 50:4, s. 246-254
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to compare the outcome of immediate versus delayed radical prostatectomy (RP) in men with low-grade prostate cancer. Materials and methods: The study included a nationwide population-based cohort in the National Prostate Cancer Register of Sweden, of 7608 men with clinically localized, biopsy Gleason score 6 prostate cancer who underwent immediate or delayed RP in 1997-2007. Multivariable models compared RP pathology, use of salvage radiotherapy and prostate cancer mortality based on timing of RP (< 1, 1-2 or > 2 years after diagnosis). Median follow-up was 8.1 years. Results: Men undergoing RP more than 2 years after diagnosis had a higher risk of Gleason upgrading [odds ratio 2.93, 95% confidence interval (CI) 2.34-3.68] and an increased risk of salvage radiotherapy [hazard ratio (HR) 1.90, 95% CI 1.41-2.55], but no significant increase in prostate cancer-specific mortality (HR 1.85, 95% CI 0.57-5.99). In competing risk analysis, 7 year prostate cancer-specific cumulative mortality was similar, at less than 1%, for immediate RP and active surveillance regardless of later intervention. Limitations of this study include the lack of data on follow-up biopsies and the limited follow-up time. Conclusion: Men undergoing RP more than 2 years after diagnosis had more adverse pathological features and second line therapy, highlighting the trade-off in deferring immediate curative therapy. However, men with delayed RP constitute a minority with higher risk cancer among the much larger group of low-risk men initially surveilled, and the overall risk of prostate cancer mortality at 7 years was similarly low with immediate RP or active surveillance.
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| 34. |
- Makarov, Alexandre A., et al.
(författare)
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Metastable entangled states of atomic systems in macroscale: radiation dynamics and spectrum
- 2004
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Ingår i: International Workshop on Quantum Optics 2003 (Proceedings of the SPIE). - : SPIE. - 0819453250 ; 5402, s. 54-64
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Konferensbidrag (refereegranskat)abstract
- Dynamics of spontaneous decay and corresponding emission spectrum areexactly treated for a system of two identical two-level atoms in 1D.Just a one-dimensional case is considered in order to maximally extractan information on mutual influence of spatially remote atoms through theradiation field. As a result, an effect is revealed and considered indetail that there exist stable (metastable) entangled states at definitedistances between the atoms. That state is supported by a(quasi)stationary field bounded between the atoms. Also, acorrespondence is established between the lifetime and emissionspectrum, and possibilities for observing the effect are discussed.
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| 35. |
- Makarov, Danil V., et al.
(författare)
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Prostate Cancer Imaging Trends After a Nationwide Effort to Discourage Inappropriate Prostate Cancer Imaging
- 2013
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 105:17, s. 1306-1313
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Tidskriftsartikel (refereegranskat)abstract
- Background Reducing inappropriate use of imaging to stage incident prostate cancer is a challenging problem highlighted recently as a Physician Quality Reporting System quality measure and by the American Society of Clinical Oncology and the American Urological Association in the Choosing Wisely campaign. Since 2000, the National Prostate Cancer Register (NPCR) of Sweden has led an effort to decrease national rates of inappropriate prostate cancer imaging by disseminating utilization data along with the latest imaging guidelines to urologists in Sweden. We sought to determine the temporal and regional effects of this effort on prostate cancer imaging rates. Methods We performed a retrospective cohort study among men diagnosed with prostate cancer from the NPCR from 1998 to 2009 (n = 99 879). We analyzed imaging use over time stratified by clinical risk category (low, intermediate, high) and geographic region. Generalized linear models with a logit link were used to test for time trend. Results Thirty-six percent of men underwent imaging within 6 months of prostate cancer diagnosis. Overall, imaging use decreased over time, particularly in the low-risk category, among whom the imaging rate decreased from 45% to 3% (P < .001), but also in the high-risk category, among whom the rate decreased from 63% to 47% (P < .001). Despite substantial regional variation, all regions experienced clinically and statistically (P < .001) significant decreases in prostate cancer imaging. Conclusions A Swedish effort to provide data on prostate cancer imaging use and imaging guidelines to clinicians was associated with a reduction in inappropriate imaging over a 10-year period, as well as slightly decreased appropriate imaging in high-risk patients. These results may inform current efforts to promote guideline-concordant imaging in the United States and internationally.
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| 36. |
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| 37. |
- Yang, W., et al.
(författare)
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Immunogenic neoantigens derived from gene fusions stimulate T cell responses
- 2019
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 25:5
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Tidskriftsartikel (refereegranskat)abstract
- Anti-tumor immunity is driven by self versus non-self discrimination. Many immunotherapeutic approaches to cancer have taken advantage of tumor neoantigens derived from somatic mutations. Here, we demonstrate that gene fusions are a source of immunogenic neoantigens that can mediate responses to immunotherapy. We identified an exceptional responder with metastatic head and neck cancer who experienced a complete response to immune checkpoint inhibitor therapy, despite a low mutational load and minimal pre-treatment immune infiltration in the tumor. Using whole-genome sequencing and RNA sequencing, we identified a novel gene fusion and demonstrated that it produces a neoantigen that can specifically elicit a host cytotoxic T cell response. In a cohort of head and neck tumors with low mutation burden, minimal immune infiltration and prevalent gene fusions, we also identified gene fusion-derived neoantigens that generate cytotoxic T cell responses. Finally, analyzing additional datasets of fusion-positive cancers, including checkpoint-inhibitor-treated tumors, we found evidence of immune surveillance resulting in negative selective pressure against gene fusion-derived neoantigens. These findings highlight an important class of tumor-specific antigens and have implications for targeting gene fusion events in cancers that would otherwise be less poised for response to immunotherapy, including cancers with low mutational load and minimal immune infiltration.
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