| 1. |
- Aad, G., et al.
(author)
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- 2014
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Journal article (peer-reviewed)
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| 2. |
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| 3. |
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Cockell, C.S., et al.
(author)
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Darwin - an experimental astronomy mission to search for extrasolar planets
- 2009
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In: Experimental Astronomy. - 0922-6435 .- 1572-9508. ; 23:1, s. 435-461
-
Journal article (peer-reviewed)abstract
- As a response to ESA call for mission concepts for its Cosmic Vision 2015–2025 plan, we propose a mission called Darwin. Its primary goal is the study of terrestrial extrasolar planets and the search for life on them. In this paper, we describe different characteristics of the instrument.
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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. |
- Borge, M. J. G., et al.
(author)
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Scattering of the halo nucleus 11Li and its core 9Li on 208Pb at energies around the Coulomb barrier
- 2012
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 381:1, s. Art. no. 012085-
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Conference paper (peer-reviewed)abstract
- The first measurement of the elastic scattering of the halo nucleus 11Li and its core 9Li on 208Pb at energies around the Coulomb barrier is presented. The 11Li reaction showed a large cross section for the breakup channel, even at energies well below the barrier. The analysis of the 11Li + 208Pb scattering data in terms of the continuum-discretized coupled-channel calculations indicates that the effect of the coupling to the breakup channels produces a strong suppression of the elastic cross section at energies above and below the barrier. This effect is mainly due to the strong Coulomb coupling to the dipole states in the low-lying continuum of 11Li.
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| 13. |
- Borge, M. J. G., et al.
(author)
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Scattering of the halo nucleus Li-11 and its core Li-9 on Pb-208 at energies around the Coulomb barrier
- 2012
-
In: Journal of Physics: Conference Series. - 1742-6588 .- 1742-6596. ; 381
-
Conference paper (peer-reviewed)abstract
- The first measurement of the elastic scattering of the halo nucleus Li-11 and its core Li-9 on Pb-208 at energies around the Coulomb barrier is presented. The Li-11 reaction showed a large cross section for the breakup channel, even at energies well below the barrier. The analysis of the Li-11 + Pb-208 scattering data in terms of the continuum-discretized coupled-channel calculations indicates that the effect of the coupling to the breakup channels produces a strong suppression of the elastic cross section at energies above and below the barrier. This effect is mainly due to the strong Coulomb coupling to the dipole states in the low-lying continuum of Li-11.
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| 14. |
- Cubero, M., et al.
(author)
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Do Halo Nuclei Follow Rutherford Elastic Scattering at Energies Below the Barrier? The Case of 11Li
- 2012
-
In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 109:26
-
Journal article (peer-reviewed)abstract
- The first measurement of the elastic scattering of the halo nucleus 11Li and its core 9Li on 208Pb at energies near the Coulomb barrier is presented. The 11Li+208Pb elastic scattering shows a strong reduction with respect to the Rutherford cross section, even at energies well below the barrier and down to very small scattering angles. This drastic change of the elastic differential cross section observed in 11Li+208Pb is the consequence of the halo structure of 11Li, as it is not observed in the elastic scattering of its core 9Li at the same energies. Four-body continuum-discretized coupled-channels calculations, based on a three-body model of the 11Li projectile, are found to explain the measured angular distributions and confirm that the observed reduction is mainly due to the strong Coulomb coupling to the dipole states in the low-lying continuum of 11Li. These calculations suggest the presence of a low-lying dipole resonance in 11Li close to the breakup threshold.
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| 15. |
- Cubero, M., et al.
(author)
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Elastic scattering of 9Li on 208Pb at energies around the Coulomb barrier
- 2011
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In: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735409378 ; 1377, s. 338-340
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Conference paper (peer-reviewed)abstract
- We have studied the dynamical effects of the halo structure of 11Li on the scattering on heavy targets at energies around the Coulomb barrier. This experiment was performed at ISAC‐II at TRIUMF with a world record in production of the post‐accelerated 11Li beam. As part of this study we report here on the first measurement of the elastic cross section of the core nucleus, i.e. 9Li on 208Pb, at energies around the Coulomb barrier. A preliminary optical model analysis has been performed in order to extract a global optical potential to describe the measured angular distributions.
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| 16. |
- Cubero, M., et al.
(author)
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Scattering of 9Li on 208Pb at energies around the Coulomb barrier
- 2011
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. - 9782759806935 ; 17, s. Art. no. 16002-
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Conference paper (peer-reviewed)abstract
- In order to study the dynamics of 11Li and 9Li beams in a strong electric field at energies around the Coulomb barrier, we measured at the ISACII-TRIUMF Facility the angular distribution of elastic and inelastic scattering of 11Li+208Pb at 24.2 and 29.7 MeV and 9Li+208Pb at 24, 29.5 and 33 MeV laboratory energies. We present here the first determination of the angular distribution of the cross section of 9Li+208Pb. The results are compared with theoretical calculations using the double-folding São Paulo Potential (SPP) for the real part and a for the imaginary part a Woods-Saxon potential. A good overall agreement is obtained.
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| 17. |
- Fernandez-Garcia, J. P., et al.
(author)
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11Li Breakup on 208Pb at Energies Around the Coulomb Barrier
- 2013
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In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 110:14
-
Journal article (peer-reviewed)abstract
- The inclusive breakup for the Li-11 + Pb-208 reaction at energies around the Coulomb barrier has been measured for the first time. A sizable yield of Li-9 following the Li-11 dissociation has been observed, even at energies well below the Coulomb barrier. Using the first-order semiclassical perturbation theory of Coulomb excitation it is shown that the breakup probability data measured at small angles can be used to extract effective breakup energy as well as the slope of B(E1) distribution close to the threshold. Four-body continuum-discretized coupled-channels calculations, including both nuclear and Coulomb couplings between the target and projectile to all orders, reproduce the measured inclusive breakup cross sections and support the presence of a dipole resonance in the Li-11 continuum at low excitation energy.
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| 18. |
- Fernandez-Garcia, J. P., et al.
(author)
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Li-11 structural information from inclusive break-up measurements
- 2015
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In: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 88
-
Conference paper (peer-reviewed)abstract
- Structure information of Li-11 halo nucleus has been obtained from the inclusive break-up measurements of the Li-11+Pb-208 reactions at energies around the Coulomb barrier (E-lab = 24.3 and 29.8 MeV). The effective break-up energy and the slope of B(E1) distribution close to the threshold have been extracted from the experimental data.
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| 19. |
- Fernandez-Garcia, J. P., et al.
(author)
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Simultaneous analysis of the elastic scattering and breakup channel for the reaction Li-11+Pb-208 at energies near the Coulomb barrier
- 2015
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In: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 92:4
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Journal article (peer-reviewed)abstract
- We present a detailed analysis of the elastic scattering and breakup channel for the reaction of Li-11 on Pb-208 at incident laboratory energies of 24.3 and 29.8 MeV, measured at the radioactive ion beam facility of TRIUMF, in Vancouver, Canada. A large yield of Li-9 fragments was detected by four charged particle telescopes in a wide angular range. The experimental angular and energy distributions of these Li-9 fragments have been compared to coupled-reaction-channel and continuum-discretized coupled-channel calculations. The large production of Li-9 fragments at small angles can be explained by considering a direct breakup mechanism, while at medium-large angles a competition between direct breakup and neutron transfer to the continuum of the Pb-208 target was observed.
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| 20. |
- Fernandez-Garcia, J. P., et al.
(author)
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Study of the break-up channel in 11Li+208Pb collisions at energies around the Coulomb barrier
- 2014
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 515:1
-
Conference paper (peer-reviewed)abstract
- We present a study of 11Li+208Pb collisions at energies around the Coulomb barrier (Elab 24.3 and 29.8 MeV), measured at the post-accelerated beam facility, ISAC II, at TRIUMF (Vancouver, Canada). A remarkably large yield of 9Li has been observed, a result that is attributed to the weak binding of the 11Li nucleus. The angular distribution of this 9Li yield, relative to the elastic one, has been analysed in terms of first-order semiclassical calculations as well as four-body and three-body Continuum-Discretized Coupled-Channels (CDCC) calculations, based on a three-body and di-neutron model of the 11Li nucleus, respectively. The calculations reproduce well the trend of the data and support the existence of a large concentration of B(E1) strength at very low excitation energies. The connection of this large B(E1) with a possible low-lying dipole resonance is discussed. © Published under licence by IOP Publishing Ltd.
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| 21. |
- Fridlund, M., et al.
(author)
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The Search for Worlds Like Our Own
- 2010
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In: Astrobiology. - : Mary Ann Liebert Inc. - 1531-1074 .- 1557-8070. ; 10:1, s. 5-17
-
Journal article (peer-reviewed)abstract
- The direct detection of Earth-like exoplanets orbiting nearby stars and the characterization of such planets particularly, their evolution, their atmospheres, and their ability to host life-constitute a significant problem. The quest for other worlds as abodes of life has been one of mankind's great questions for several millennia. For instance, as stated by Epicurus similar to 300 BC: "Other worlds, with plants and other living things, some of them similar and some of them different from ours, must exist.'' Demokritos from Abdera (460-370 BC), the man who invented the concept of indivisible small parts-atoms-also held the belief that other worlds exist around the stars and that some of these worlds may be inhabited by life-forms. The idea of the plurality of worlds and of life on them has since been held by scientists like Johannes Kepler and William Herschel, among many others. Here, one must also mention Giordano Bruno. Born in 1548, Bruno studied in France and came into contact with the teachings of Nicolas Copernicus. He wrote the book De l'Infinito, Universo e Mondi in 1584, in which he claimed that the Universe was infinite, that it contained an infinite amount of worlds like Earth, and that these worlds were inhabited by intelligent beings. At the time, this was extremely controversial, and eventually Bruno was arrested by the church and burned at the stake in Rome in 1600, as a heretic, for promoting this and other equally confrontational issues (though it is unclear exactly which idea was the one that ultimately brought him to his end). In all the aforementioned cases, the opinions and results were arrived at through reasoning-not by experiment. We have only recently acquired the technological capability to observe planets orbiting stars other than our Sun; acquisition of this capability has been a remarkable feat of our time. We show in this introduction to the Habitability Primer that mankind is at the dawning of an age when, by way of the scientific method and 21(st)-century technology, we will be able to answer this fascinating controversial issue that has persisted for at least 2500 years.
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| 22. |
- Le Lay, G., et al.
(author)
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STM and synchrotron radiation studies of "prototypical" metal{plus 45 degree rule}semiconductor systems
- 1994
-
In: Surface Science. - 0039-6028. ; 307-309:PART A, s. 280-294
-
Journal article (peer-reviewed)abstract
- Since the origin of surface science noble metal{plus 45 degree rule}elemental semiconductor couples have been considered as "prototypical" systems. After three decades of research their structural and electronic properties remain an intriguing maze despite recent advances made, especially thanks to the development of the near-field microscopies and the extensive use of synchrotron radiation in surface crystallography and in high-resolution photoelectron spectroscopy. In the last few years, lead, as a replacement inert metal, has nearly gained the pole position in the display of exotic behaviour. This paper gives a flavour of this mystery story and highlights some puzzling questions. © 1994.
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| 23. |
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| 24. |
- Razi, Nahid, et al.
(author)
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Identification of O-sulphate substituents on D-glucuronic acid units in heparin-related glycosaminoglycans using novel synthetic disaccharide standards.
- 1995
-
In: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 5:8, s. 807-811
-
Journal article (peer-reviewed)abstract
- The two disaccharides, methyl 4-O-(2-O-sulpho-beta-D-glucopyranosyl-uronic acid)-2-deoxy-2-amino-alpha-D-glucopyranoside and methyl 4-O-(3-O-sulpho-beta-D-glucopyranosyluronic acid)-2-deoxy-2-amino-alpha-D-glucopyranoside, were prepared by de novo synthesis, and converted to the corresponding 2,5-anhydro-D-[1-3H]mannitol derivatives by deamination with nitrous acid followed by reduction with NaB3H4. The resultant labelled products were used as standards in the identification, by anion-exchange high-performance liquid chromatography (HPLC), of disaccharides generated by HNO2/NaB3H4 treatment of heparan sulphate isolated from human brain. The two standards, containing 2-O- and 3-O-sulphated glucuronic acid, respectively, were clearly separated by the HPLC procedure. Comparison with the deamination products derived from heparan sulphate showed that the mono-O-sulphated disaccharide species containing a sulphated glucuronic acid unit co-eluted with the 2-O-sulphated standard. The corresponding component isolated from other heparan sulphate preparations, or from heparin, also eluted at the same position. No disaccharide derived from heparin or heparan sulphate appeared at the elution position of the 3-O-sulphated standard. It is concluded that D-glucuronic acid units in heparin-related glycosaminoglycans may be sulphated at C2, whereas no evidence has been found for sulphation at C3. By contrast, analysis of mono-O-sulphated disaccharides derived from a chemically sulphated, bacterial capsular polysaccharide (generated by Escherichia coli K5) clearly demonstrated the occurrence of O-sulphate groups at C-3 of D-glucuronic acid units.
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| 25. |
- Brial, François, et al.
(author)
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Human and preclinical studies of the host-gut microbiome co-metabolite hippurate as a marker and mediator of metabolic health
- 2021
-
In: Gut. - : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 70:11, s. 2105-2114
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Gut microbial products are involved in regulation of host metabolism. In human and experimental studies, we explored the potential role of hippurate, a hepatic phase 2 conjugation product of microbial benzoate, as a marker and mediator of metabolic health.DESIGN: In 271 middle-aged non-diabetic Danish individuals, who were stratified on habitual dietary intake, we applied 1H-nuclear magnetic resonance (NMR) spectroscopy of urine samples and shotgun-sequencing-based metagenomics of the gut microbiome to explore links between the urine level of hippurate, measures of the gut microbiome, dietary fat and markers of metabolic health. In mechanistic experiments with chronic subcutaneous infusion of hippurate to high-fat-diet-fed obese mice, we tested for causality between hippurate and metabolic phenotypes.RESULTS: In the human study, we showed that urine hippurate positively associates with microbial gene richness and functional modules for microbial benzoate biosynthetic pathways, one of which is less prevalent in the Bacteroides 2 enterotype compared with Ruminococcaceae or Prevotella enterotypes. Through dietary stratification, we identify a subset of study participants consuming a diet rich in saturated fat in which urine hippurate concentration, independently of gene richness, accounts for links with metabolic health. In the high-fat-fed mice experiments, we demonstrate causality through chronic infusion of hippurate (20 nmol/day) resulting in improved glucose tolerance and enhanced insulin secretion.CONCLUSION: Our human and experimental studies show that a high urine hippurate concentration is a general marker of metabolic health, and in the context of obesity induced by high-fat diets, hippurate contributes to metabolic improvements, highlighting its potential as a mediator of metabolic health.
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| 26. |
- Conti, S., et al.
(author)
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Nanopaper-Based Organic Inkjet-Printed Diodes
- 2020
-
In: Advanced Materials Technologies. - : Wiley-Blackwell. - 2365-709X.
-
Journal article (peer-reviewed)abstract
- The rise of internet of things (IoTs) applications has led to the development of a new generation of light-weight, flexible, and cost-effective electronics. These devices and sensors have to be simultaneously easily replaceable and disposable while being environmentally sustainable. Thus, the introduction of new functionalized materials with mechanical flexibility that can be processed using large-area and facile fabrication methods (as, for example, printing technologies) has become a matter of great interest in the scientific community. In this context, cellulose nanofibers (CNFs) are renewable, affordable, robust, and nontoxic materials that are rapidly emerging as components for eco-friendly electronics. Their combination with conductive polymers (CPs) to obtain conductive nanopapers (CNPs) allows moving their functionality from just substrates to active components of the device. In this work, a route for the inkjet-printing of organic diodes is outlined. The proposed strategy is based on the use of CNPs as both substrates and bottom electrodes onto which insulator and organic semiconducting layers are deposited to fabricate novel diode structures. Remarkable rectification ratios of up to 1.2 × 103 at |3 V| and a current density up to 5.1 µA cm−2 are achieved. As a proof-of-concept of the potentiality of the approach for versatile, low-temperature, and disposable sensing applications, an NO2 gas sensor is presented.
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| 27. |
- Giovanelli, L., et al.
(author)
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Electronic structure of self-assembled organic/inorganic semiconductor interfaces : lead phthalocyanine on InSb and InAs(100)-4X2/c(8 X2)
- 2001
-
In: Journal of Electron Spectroscopy and Related Phenomena. - 0368-2048 .- 1873-2526. ; 114, s. 375-381
-
Journal article (peer-reviewed)abstract
- The interfacial properties of ultra thin films of lead-phthalocyanine deposited in situ onto InSb and InAs(100)-4X2/c(8X2) clean surfaces have been studied by synchrotron radiation core level and valence band photoelectron spectroscopy. The interaction between the overlayers and the substrates was determined upon analyzing the changes in the photoemission spectra between room and higher annealing temperatures, leading to ordered monolayer films. While weaker than on other substrates, a reactivity is nevertheless present: the organic macrocycle preserves its integrity up to 320 degreesC but the Pb central atom first leaves the molecules most probably to be incorporated in the substrate surface, before being desorbed at higher temperatures.
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| 28. |
- Giovanelli, L., et al.
(author)
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Synchrotron radiation photoelectron spectroscopy study of Pb-Pc thin films on InSb(100)-(4x2)/c(8x2)
- 2001
-
In: Surface Science. - 0039-6028 .- 1879-2758. ; 486:02-jan, s. 55-64
-
Journal article (peer-reviewed)abstract
- The electronic properties and the thermal stability of a thin film of lead-phthalocyanine deposited on the InSb(100)-(4 x 2)/c(8 x 2) surface were studied by synchrotron radiation core level and valence band photoelectron spectroscopy. The interaction between the overlayer and the substrate was determined by analyzing the photoemission spectra of a thin film and of a single monolayer of adsorbed molecules. Subsequently the monolayer was annealed at increasing temperatures, leading first to a gradual change of the oxidation state of the central lead atom, then to a fragmentation of the macrocycle itself.
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| 29. |
- Karpus, V., et al.
(author)
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Mg 2p shallow core-level and local atomic structure of i-ZnMgRE quasicrystals
- 2006
-
In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 252:15, s. 5411-5414
-
Journal article (peer-reviewed)abstract
- We present a detailed analysis of the Mg 2p shallow core-levels measured on icosahedral single-grain ZnMgY, ZnMgHo, and ZnMgEr quasicrystals during a photoelectron microscopy study. The synchrotron radiation photoemission measurements were performed on in situ cleaved samples at a pressure of 10(-10) mbar and at low temperature, typically 90-150 K. The Mg 2p photoemission lines are essentially broadened as compared to those of the Mg 2p spin-orbit doublet recorded on the Zn2Mg crystalline Laves phase. The broadening is associated to the coordination shifts of the Mg 2p level due to the inequivalent magnesium sites in the quasicrystalline lattice. The coordination shifts are calculated on the basis of i-ZnMg(Ho, Y) atomic structure data, recently determined from the pair distribution function analysis. The coordination shifts obtained are up to 0.2 eV. The Mg 2p experimental spectral intensity is nicely reproduced by a superposition of coordination-shifted Mg 2p spin-orbit doublets.
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| 30. |
- Lassinantti, Lena, et al.
(author)
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Enterococcal PrgU Provides Additional Regulation of Pheromone-Inducible Conjugative Plasmids
- 2021
-
In: mSphere. - : American Society for Microbiology (ASM). - 2379-5042. ; 6:3
-
Journal article (peer-reviewed)abstract
- Efficient horizontal gene transfer of the conjugative plasmid pCF10 from Enterococcus faecalis depends on the expression of its type 4 secretion system (T4SS) genes, controlled by the PQ promoter. Transcription from the PQ promoter is tightly regulated, partially to limit cell toxicity caused by overproduction of PrgB, a T4SS adhesin. PrgU plays an important role in regulating this toxicity by decreasing PrgB levels. PrgU has an RNA-binding fold, prompting us to test whether PrgU exerts its regulatory control through binding of prgQ transcripts. We used a combination of in vivo methods to quantify PrgU effects on prgQ transcripts at both single-cell and population levels. PrgU function requires a specific RNA sequence within an intergenic region (IGR) about 400 bp downstream of PQ. PrgU interaction with the IGR reduces levels of downstream transcripts. Single-cell expression analysis showed that cells expressing prgU decreased transcript levels more rapidly than isogenic prgU-minus cells. PrgU bound RNA in vitro without sequence specificity, suggesting that PrgU requires a specific RNA structure or one or more host factors for selective binding in vivo. PrgU binding to its IGR target might recruit RNase(s) for targeted degradation of downstream transcripts or reduce elongation of nascent transcripts beyond the IGR.IMPORTANCE: Bacteria utilize type 4 secretion systems (T4SS) to efficiently transfer DNA between donor and recipient cells, thereby spreading genes encoding antibiotic resistance as well as various virulence factors. Regulation of expression of the T4SS proteins and surface adhesins in Gram-positive bacteria is crucial, as some of these are highly toxic to the cell. The significance of our research lies in identifying the novel mechanism by which PrgU performs its delicate fine-tuning of the expression levels. As prgU orthologs are present in various conjugative plasmids and transposons, our results are likely relevant to understanding of diverse clinically important transfer systems.
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| 31. |
- Papageorgiou, N., et al.
(author)
-
High resolution synchrotron radiation PES study of PbPc deposited on Pt(111)
- 2000
-
In: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 162, s. 178-183
-
Journal article (peer-reviewed)abstract
- We studied lead phthalocyanine (PbPc) films sublimated under UHV conditions on a clean Pt(111) substrate. We report results from high resolution photoelectron spectra of the Pb 5d, Ph 4f, C 1s, N 1s and Pt 4f core level using synchrotron radiation. Comparison between ultra thin films and thicker films shows that the first molecular adlayer interacts strongly with the substrate and we report evidence of Pb-Pt alloy formation on the surface. For the thick films, the C Is and N Is core level spectra show usual characteristics, however in the case of ultra thin films, we note important differences with respect to some previous results.
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| 32. |
- Papageorgiou, N., et al.
(author)
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Lead phthalocyanine thin films on InAs(100)-(4 x 2)/c(8 x 2) studied by synchrotron radiation photoelectron spectroscopy
- 2001
-
In: Surface Science. - 0039-6028 .- 1879-2758. ; 482, s. 1199-1204
-
Journal article (peer-reviewed)abstract
- We used synchrotron radiation photoelectron spectroscopy to study the interface between a thin film and an ordered single monolayer of lead phthalocyanine (PbPc) deposited on the clean InAs(1 0 0)-(4 x 2)/c(8 x 2) reconstructed surface. Analysis of the core level and valence band spectra gave information about the electronic properties of the interface, the interaction between the molecule and the substrate and the valence band offset of the heterojunction.
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| 33. |
- Sinner-Hettenbach, M., et al.
(author)
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Electronic structure of SnO2(110)-4 x 1 and sputtered SnO2(110) revealed by resonant photoemission
- 2002
-
In: Surface Science. - 0039-6028 .- 1879-2758. ; 499:1, s. 85-93
-
Journal article (peer-reviewed)abstract
- The surface properties of SnO2(1 1 0)-4 x 1 and sputtered SnO2(1 1 0) were studied comparatively by resonant photoemission of the valence band states in a photon energy range of 60-130 eV. Resonating energetic levels could be observed on the 4 x I reconstructed surface and the resonance behavior could be switched off by sputter treatment. Additionally, the Sn 4d core-levels were recorded at two photon energies in order to allow a statement about the surface's stoichiometry. A tentative explanation of the observed resonance and of the discrepancy between ordered and sputtered surface is given with regard to recent STM results on similar prepared surfaces.
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| 34. |
- Sinner-Hettenbach, M., et al.
(author)
-
High resolution photoemission study on SnO2 gas sensors
- 2001
-
In: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 391:2, s. 192-197
-
Journal article (peer-reviewed)abstract
- Pd-, Pt-doped and undoped SnO2 gas sensors were studied by synchrotron radiation photoelectron spectroscopy (SRPES) and laboratory source UPS (ultraviolet photoelectron spectroscopy). Valence band spectra were recorded for photon energies of 60-120 eV (SRPES) and for 40.81 eV (UPS). The spectra were analyzed by factor analysis and generation of difference spectra. A comparison of the samples shows that the doping material of these sensors is not introducing additional states to the surface electronic structure within the limit of detection. This leads to the conclusion that the surfaces of the grains are not enriched with the metal additives.
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| 35. |
- Suchodolskis, A., et al.
(author)
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Indication of van Hove singularities in the density of states of ZnMg(Y,Ho) quasicrystals
- 2003
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 68:5
-
Journal article (peer-reviewed)abstract
- We present a low-temperature synchrotron-radiation photoelectron microspectroscopy study of the valence bands of single-grain icosahedral ZnMgY and ZnMgHo quasicrystals. Their valence band photoemission spectra reveal in both cases a simple metal-type behavior with a clear metallic Fermi edge and a sharp pseudogap feature: the spectral intensity exhibits a maximum at approximate to0.7 eV below the chemical potential and a subsequent decrease as the Fermi level is approached. The analysis of the pseudogap feature, based on the band-structure hypothesis, shows that it corresponds to the van Hove singularities in the density of states (DOS), which originate from the intersections of the isoenergetic surface with the 222100 and 311111 Bragg planes. The reconstructed density of states agrees in general trends with the theoretical first-principles DOS of hexagonal ZnMgY approximants, and correctly reproduces the experimental value of i-ZnMgY electronic specific-heat coefficient.
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| 36. |
- Suchodolskis, A., et al.
(author)
-
Photoemission and optical spectroscopy of i-ZnMgEr quasicrystal
- 2005
-
In: Acta Physica Polonica. A. - 0587-4246 .- 1898-794X. ; 107:2, s. 412-419
-
Journal article (peer-reviewed)abstract
- The results of photoemission and optical studies of icosahedral single-grain ZnMgEr quasicrystals are presented. Synchrotron radiation photoemission measurements were performed on in situ cleaved samples at 10(-10) mbar pressure and low, 140-150 K temperature. The valence band photoemission spectra measured reveal a simple metal-type valence band of icosahedral ZnMgEr with a distinct Fermi edge cut-off and with a sharp pseudogap feature. The photoemission spectra of shallow Mg 2p and Zn 3d core levels indicate a coordination shift of Mg 2p spin-orbit doublet and an oscillating dependence of Zn 3d photoemission line components on the photon energy within the hv = 20-160 eV range investigated. The optical response of icosahedral ZnMgEr, a dispersion of the dielectric function, was measured by the spectroscopic ellipsometry technique in the 0.5-5.0 eV spectral range. The optical spectra of the quasicrystal indicate the Drude-type optical response superimposed with a peak of interband optical transitions. The interband optical transitions can be modelled with the pseudogap parameters which agree with those deduced in an analysis of the photoemission valence band spectra.
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| 37. |
- Suchodolskis, A., et al.
(author)
-
Pseudogap structure in icosahedral ZnMgY and ZnMgHo quasicrystals
- 2003
-
In: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 212, s. 485-490
-
Journal article (peer-reviewed)abstract
- The results of a photoemission study of icosahedral single-grain ZnMg(Y, Ho) quasicrystals and their crystalline approximant Zn2Mg are presented. Synchrotron radiation photoemission measurements have been performed on in situ cleaved samples at low temperature of approximate to90 K and 10(-10) mbar pressure. The spectra obtained indicate simple metal-type valence bands (VB) with distinct Fermi edge cutoff. Analysis of the Fermi edge spectra reveals the presence of a pseudogap in i-ZnMg(Y, Ho) quasicrystals. The pseudogap corresponds to a rather sharp DOS dip at the Fermi level with th approximate to50% (of the normal DOS) depth and the approximate to0.8 eV width. The values of i-ZnMg(Y, Ho) pseudogap parameters are comparable with those of other quasicrystals.
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| 38. |
- Suchodolskis, A., et al.
(author)
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Valence band structure of i-ZnMgEr quasicrystal : photoemission study
- 2004
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In: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 16:50, s. 9137-9142
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Journal article (peer-reviewed)abstract
- The results of photoemission study of icosahedral single-grain ZnMgEr quasicrystals are presented. Synchrotron radiation photoemission measurements were performed on in situ cleaved samples at 10(-10) mbar pressure and low, 140-150 K, temperature. The valence band photoemission spectra measured reveal a simple-metal type valence band of i-ZnMgEr with a distinct Fermi edge cutoff and a spectral feature at 0.7 eV below epsilon(F). Analysis of the PE spectra shows that the spectral feature observed corresponds to the van Hove singularities in the density of states, which are due to intersections of the Fermi surface with the 222100 and 311111 Bragg planes.
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| 39. |
- Szamota-Leandersson, Karolina, et al.
(author)
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Creation of a metallic channel at the Sn/InAs(111)B surface studied using synchrotron-radiation photoelectron spectroscopy
- 2006
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In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 74:205406
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Journal article (peer-reviewed)abstract
- The properties of a Sn-induced two-dimensional electron gas at the As-terminated InAs(111)B(1x1) surface was studied by synchrotron radiation photoelectron spectroscopy. The two-dimensional electron gas reveals itself via a narrow structure at the Fermi level, visible close to normal emission for tin coverage in the range 0.5 to 2 monolayers. Although this electron gas exhibits properties that in several respects resemble those of intrinsic charge accumulation layers on free InAs surfaces, our observations suggest that the present electron gas is much more linked to the Sn adlayer.
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| 40. |
- Wang, Xin, et al.
(author)
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Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018 : a systematic review and modelling study
- 2020
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In: The Lancet Global Health. - : Elsevier. - 2214-109X. ; 8:4, s. E497-E510
-
Research review (peer-reviewed)abstract
- Background: Seasonal influenza virus is a common cause of acute lower respiratory infection (ALRI) in ung children. In 2008, we estimated that 20 million influenza-virus-associated ALRI and 1 million fluenza-virus-associated severe ALRI occurred in children under 5 years globally. Despite this bstantial burden, only a few low-income and middle-income countries have adopted routine influenza ccination policies for children and, where present, these have achieved only low or unknown levels of ccine uptake. Moreover, the influenza burden might have changed due to the emergence and rculation of influenza A/H1N1pdm09. We aimed to incorporate new data to update estimates of the obal number of cases, hospital admissions, and mortality from influenza-virus-associated respiratory fections in children under 5 years in 2018.Methods: We estimated the regional and global burden of influenza-associated respiratory infections in ildren under 5 years from a systematic review of 100 studies published between Jan 1, 1995, and Dec , 2018, and a further 57 high-quality unpublished studies. We adapted the Newcastle-Ottawa Scale to sess the risk of bias. We estimated incidence and hospitalisation rates of influenza-virus-associated spiratory infections by severity, case ascertainment, region, and age. We estimated in-hospital deaths om influenza virus ALRI by combining hospital admissions and in-hospital case-fatality ratios of fluenza virus ALRI. We estimated the upper bound of influenza virus-associated ALRI deaths based on e number of in-hospital deaths, US paediatric influenza-associated death data, and population-based ildhood all-cause pneumonia mortality data in six sites in low-income and lower-middle-income untries.Findings: In 2018, among children under 5 years globally, there were an estimated 109.5 million fluenza virus episodes (uncertainty range [UR] 63.1-190.6), 10.1 million influenza-virus-associated ALRI ses (6.8-15.1); 870 000 influenza-virus-associated ALRI hospital admissions (543 000-1 415 000), 15 300 -hospital deaths (5800-43 800), and up to 34 800 (13 200-97 200) overall influenza-virus-associated ALRI deaths. Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. About 82% of the in-hospital deaths occurred in low-income and lower-middle-income countries.Interpretation: A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. Our findings provide new and important evidence for maternal and paediatric influenza immunisation, and should inform future immunisation policy particularly in low-income and middle-income countries.
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| 41. |
- Westfall, John M., et al.
(author)
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Changes in primary care visits for respiratory illness during the COVID-19 pandemic : a multinational study by the International Consortium of Primary Care Big Data Researchers (INTRePID)
- 2024
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In: Frontiers in Medicine. - : Frontiers Media S.A.. - 2296-858X. ; 11
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Journal article (peer-reviewed)abstract
- Objectives The majority of patients with respiratory illness are seen in primary care settings. Given COVID-19 is predominantly a respiratory illness, the INTernational ConsoRtium of Primary Care BIg Data Researchers (INTRePID), assessed the pandemic impact on primary care visits for respiratory illnesses.Design Definitions for respiratory illness types were agreed on collectively. Monthly visit counts with diagnosis were shared centrally for analysis.Setting Primary care settings in Argentina, Australia, Canada, China, Norway, Peru, Singapore, Sweden and the United States.Participants Over 38 million patients seen in primary care settings in INTRePID countries before and during the pandemic, from January 1st, 2018, to December 31st, 2021.Main outcome measures Relative change in the monthly mean number of visits before and after the onset of the pandemic for acute infectious respiratory disease visits including influenza, upper and lower respiratory tract infections and chronic respiratory disease visits including asthma, chronic obstructive pulmonary disease, respiratory allergies, and other respiratory diseases.Results INTRePID countries reported a marked decrease in the average monthly visits for respiratory illness. Changes in visits varied from -10.9% [95% confidence interval (CI): -33.1 to +11.3%] in Norway to -79.9% (95% CI: -86.4% to -73.4%) in China for acute infectious respiratory disease visits and - 2.1% (95% CI: -12.1 to +7.8%) in Peru to -59.9% (95% CI: -68.6% to -51.3%) in China for chronic respiratory illness visits. While seasonal variation in allergic respiratory illness continued during the pandemic, there was essentially no spike in influenza illness during the first 2 years of the pandemic.Conclusion The COVID-19 pandemic had a major impact on primary care visits for respiratory presentations. Primary care continued to provide services for respiratory illness, although there was a decrease in infectious illness during the COVID pandemic. Understanding the role of primary care may provide valuable information for COVID-19 recovery efforts and planning for future global emergencies.
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