| 1. |
- Acharya, B. S., et al.
(författare)
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Introducing the CTA concept
- 2013
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Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 43, s. 3-18
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Actis, M., et al.
(författare)
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Design concepts for the Cherenkov Telescope Array CTA : an advanced facility for ground-based high-energy gamma-ray astronomy
- 2011
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Ingår i: Experimental astronomy. - : Springer. - 0922-6435 .- 1572-9508. ; 32:3, s. 193-316
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Tidskriftsartikel (refereegranskat)abstract
- Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
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| 3. |
- Ferreira, MA, et al.
(författare)
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Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer
- 2019
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1, s. 1741-
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.
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| 4. |
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| 6. |
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| 7. |
- Rosenhahn, Erik, et al.
(författare)
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Bi-allelic loss-of-function variants in PPFIBP1 cause a neurodevelopmental disorder with microcephaly, epilepsy, and periventricular calcifications
- 2022
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Ingår i: American Journal of Human Genetics. - : Cell Press. - 0002-9297 .- 1537-6605. ; 109:8, s. 1421-1435
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Tidskriftsartikel (refereegranskat)abstract
- PPFIBP1 encodes for the liprin-β1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.
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| 8. |
- Biazar, C., et al.
(författare)
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Cutaneous lupus erythematosus : First multicenter database analysis of 1002 patients from the European Society of Cutaneous Lupus Erythematosus (EUSCLE)
- 2013
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Ingår i: Autoimmunity Reviews. - : Elsevier BV. - 1568-9972 .- 1873-0183. ; 12:3, s. 444-454
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Forskningsöversikt (refereegranskat)abstract
- In this prospective, cross-sectional, multicenter study, we assessed clinical and laboratory characteristics from patients with cutaneous lupus erythematosus (CLE) using the Core Set Questionnaire of the European Society of Cutaneous Lupus Erythematosus (EUSCLE). 1002 (768 females, 234 males) patients with different subtypes of CLE, such as acute CLE (ACLE, 304 patients), subacute CLE (SCLE, 236 patients), chronic CLE (CCLE, 397 patients), and intermittent CLE (ICLE, 65 patients), from 13 European countries were collected and statistically analyzed by an SPSS database. The main outcome measures included gender, age at onset of disease, LE-specific and LE-nonspecific skin lesions, photosensitivity, laboratory features, and the criteria of the American College of Rheumatology (ACR) for the classification of systemic lupus erythematosus. The mean age at onset of disease was 43.0±15.7 years and differed significantly between the CLE subtypes. In 347 (34.6%) of the 1002 patients, two or more CLE subtypes were diagnosed during the course of the disease and 453 (45.2%) presented with LE-nonspecific manifestations. Drug-induced CLE and SjögrenD́s Syndrome had the highest prevalence in SCLE patients (13.1% and 14.0%, respectively). Photosensitivity was significantly more frequent in patients with ACLE, SCLE, and ICLE compared with those with CCLE. The detection of antinuclear antibodies such as anti-Ro/SSA and anti-La/SSB antibodies revealed further significant differences between the CLE subtypes. In summary, the EUSCLE Core Set Questionnaire and its database facilitate the analysis of clinical and laboratory features in a high number of patients with CLE and will contribute to standardized assessment and monitoring of the disease in Europe.
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| 9. |
- Naghavi, N., et al.
(författare)
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Buffer layers and transparent conducting oxides for chalcopyrite Cu(In,Ga)(S,Se)(2) based thin film photovoltaics : Present status and current developments
- 2010
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Ingår i: Progress in Photovoltaics. - : Wiley. - 1062-7995 .- 1099-159X. ; 18:6, s. 411-433
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present contribution is to give a review on the recent work concerning Cd-free buffer and window layers in chalcopyrite solar cells using various deposition techniques as well as on their adaptation to chalcopyrite-type absorbers such as Cu(In,Ga)Se-2, CuInS2, or Cu(In,Ga)(S,Se)(2). The corresponding solar-cell performances, the expected technological problems, and current attempts for their commercialization will be discussed. The most important deposition techniques developed in this paper are chemical bath deposition, atomic layer deposition, ILGAR deposition, evaporation, and spray deposition. These deposition methods were employed essentially for buffers based on the following three materials: In2S3, ZnS, Zn1-xMgxO.
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| 10. |
- Rey, G., et al.
(författare)
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Absorption Coefficient of a Semiconductor Thin Film from Photoluminescence
- 2018
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Ingår i: Physical Review Applied. - : AMER PHYSICAL SOC. - 2331-7019. ; 9:6
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Tidskriftsartikel (refereegranskat)abstract
- The photoluminescence (PL) of semiconductors can be used to determine their absorption coefficient (a) using Planck's generalized law. The standard method, suitable only for self-supported thick samples, like wafers, is extended to multilayer thin films by means of the transfer-matrix method to include the effect of the substrate and optional front layers. a values measured on various thin-film solar-cell absorbers by both PL and photothermal deflection spectroscopy (PDS) show good agreement. PL measurements are extremely sensitive to the semiconductor absorption and allow us to advantageously circumvent parasitic absorption from the substrate; thus, a can be accurately determined down to very low values, allowing us to investigate deep band tails with a higher dynamic range than in any other method, including spectrophotometry and PDS.
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| 11. |
- Alexandridi, C., et al.
(författare)
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Attosecond photoionization dynamics in the vicinity of the Cooper minima in argon
- 2021
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Ingår i: Physical Review Research. - 2643-1564. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Using a spectrally resolved electron interferometry technique, we measure photoionization time delays between the 3s and 3p subshells of argon over a large 34-eV energy range covering the Cooper minima in both subshells. The observed strong variations of the 3s−3p delay difference, including a sign change, are well reproduced by theoretical calculations using the two-photon two-color random-phase approximation with exchange. Strong shake-up channels lead to photoelectrons spectrally overlapping with those emitted from the 3s subshell. These channels need to be included in our analysis to reproduce the experimental data. Our measurements provide a benchmark for multielectronic theoretical models aiming at an accurate description of interchannel correlation.
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| 12. |
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| 13. |
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| 14. |
- Grini, S., et al.
(författare)
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Dynamic Impurity Redistributions in Kesterite Absorbers
- 2020
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Ingår i: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951.
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Tidskriftsartikel (refereegranskat)abstract
- Cu2ZnSn(S,Se)4 is a promising nontoxic earth-abundant solar cell absorber. To optimize the thin films for solar cell device performance, postdeposition treatments at temperatures below the crystallization temperature are normally performed, which alter the surface and bulk properties. The polycrystalline thin films contain relatively high concentrations of impurities, such as sodium, oxygen and hydrogen. During the treatments, these impurities migrate and likely agglomerate at lattice defects or interfaces. Herein, impurity redistribution after air annealing for temperatures up to 200 °C and short heavy water treatments are studied. In addition, nonuniformities of the sodium distribution on a nanometer and micrometer scale are characterized by atom probe tomography and secondary ion mass spectrometry, respectively. Sodium and oxygen correlate to a greater extent after heat treatments, supporting strong binding between the two impurities. Redistributions of these impurities occur even at room temperature over longer time periods. Heavy water treatments confirm out-diffusion of sodium with more incorporation of oxygen and hydrogen. It is observed that the increased hydrogen content does not originate from the heavy water. The existence of an “ice-like” layer on top of the Cu2ZnSnS4 layer is proposed.
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| 15. |
- Grini, Sigbjörn, et al.
(författare)
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Strong Interplay between Sodium and Oxygen in Kesterite Absorbers : Complex Formation, Incorporation, and Tailoring Depth Distributions
- 2019
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Ingår i: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 9:27
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Tidskriftsartikel (refereegranskat)abstract
- Sodium and oxygen are prevalent impurities in kesterite solar cells. Both elements are known to strongly impact performance of the kesterite devices and can be connected to efficiency improvements seen after heat treatments. The sodium distribution in the kesterite absorber is commonly reported, whereas the oxygen distribution has received less attention. Here, a direct relationship between sodium and oxygen in kesterite absorbers is established using secondary ion mass spectrometry and explained by defect analyses within the density functional theory. The calculations reveal a binding energy of 0.76 eV between the substitutional defects Na-Cu and O-S in the nearest neighbor configuration, indicating an abundance of Na Symbol of the Klingon Empire O complexes in kesterite absorbers at relevant temperatures. Oxygen incorporation is studied by introducing isotopic O-18 at different stages of the Cu2ZnSnS4/Mo/soda-lime glass baseline processing. It is observed that oxygen from the Mo back contact and contaminations during the sulfurization are primary contributors to the oxygen distribution. Indeed, unintentional oxygen incorporation leads to immobilization of sodium. This results in a strong correlation between sodium and oxygen, in excellent agreement with the theoretical calculations. Consequently, oxygen availability should be monitored to optimize postdeposition heat treatments to control impurities in kesterite absorbers and ultimately, the solar cell efficiency.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Kon, E., et al.
(författare)
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A multilayer biomaterial for osteochondral regeneration shows superiority vs microfractures for the treatment of osteochondral lesions in a multicentre randomized trial at 2 years
- 2018
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Ingår i: Knee Surgery Sports Traumatology Arthroscopy. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 26:9, s. 2704-2715
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Tidskriftsartikel (refereegranskat)abstract
- Purpose The increasing awareness on the role of subchondral bone in the etiopathology of articular surface lesions led to the development of osteochondral scaffolds. While safety and promising results have been suggested, there are no trials proving the real potential of the osteochondral regenerative approach. Aim was to assess the benefit provided by a nanostructured collagen-hydroxyapatite (coll-HA) multilayer scaffold for the treatment of chondral and osteochondral knee lesions. Methods In this multicentre randomized controlled clinical trial, 100 patients affected by symptomatic chondral and osteochondral lesions were treated and evaluated for up to 2 years (51 study group and 49 control group). A biomimetic coll-HA scaffold was studied, and bone marrow stimulation (BMS) was used as reference intervention. Primary efficacy measurement was IKDC subjective score at 2 years. Secondary efficacy measurements were: KOOS, IKDC Knee Examination Form, Tegner and VAS Pain scores evaluated at 6, 12 and 24 months. Tissue regeneration was evaluated with MRI MOCART scoring system at 6, 12 and 24 months. An external independent agency was involved to ensure data correctness and objectiveness. Results A statistically significant improvement of all clinical scores was obtained from basal evaluation to 2-year follow-up in both groups, although no overall statistically significant differences were detected between the two treatments. Conversely, the subgroup of patients affected by deep osteochondral lesions (i.e. Outerbridge grade IV and OCD) showed a statistically significant better IKDC subjective outcome (+12.4 points, p = 0.036) in the coll-HA group. Statistically significant better results were also found for another challenging group: sport active patients (+16.0, p = 0.027). Severe adverse events related to treatment were documented only in three patients in the coll-HA group and in one in the BMS group. The MOCART score showed no statistical difference between the two groups. Conclusions This study highlighted the safety and potential of a biomimetic implant. While no statistically significant differences were found compared to BMS for chondral lesions, this procedure can be considered a suitable option for the treatment of osteochondral lesions.
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| 21. |
- Li, Shu-Yi, et al.
(författare)
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Optical properties of reactively sputtered Cu2ZnSnS4 solar absorbers determined by spectroscopic ellipsometry and spectrophotometry
- 2016
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Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 149, s. 170-178
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Tidskriftsartikel (refereegranskat)abstract
- We have determined for the first time the device-relevant optical constants of 500 nm and 800 nm-thick Cu2ZnSnS4 absorbers, grown on bare and Mo-coated soda-lime glass (SLG), using spectroscopic ellipsometry (SE). The composition, structure, phase purity and morphology were characterized by X-ray fluorescence, X-ray photoelectron spectroscopy depth profiling, X-ray diffraction, Raman spectroscopy, scanning-electron microscopy and atomic force microscopy. For the SE analysis, carefully determined sample characteristics were utilized to build a multilayer stack optical model, in order to derive the dielectric functions and refractive indices. The SE-derived absorption coefficients from CZTS/SLG samples were compared with those derived from complementary spectrophotometry measurements and found to be in good agreement. The bandgap determined from Tauc plots was E-g=1.57 +/- 0.02 eV. The absorption coefficients just above the bandgap were found to be a few 10(4) cm(-1) and to exceed 10(5) cm(-1) at energies above similar to 2.5 eV, which is much higher than previously found. The sub-bandgap k-value was found to be k similar to 0.05 or less, suggesting that a moderate band tail is present. Separate device characterization performed on identical samples allowed us to assign device efficiencies of, respectively, 2.8% and 5.3% to the 500 nm and 800 nm-thick samples featured in this study.
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| 22. |
- Mongstad, Trygve, et al.
(författare)
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MgyNi1-y(H-x) thin films deposited by magnetron co-sputtering
- 2012
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 527, s. 76-83
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Tidskriftsartikel (refereegranskat)abstract
- In this work we have synthesized thin films of MgyNi1-y(H-x) metal and metal hydride with y between 0 and 1. The films are deposited by magnetron co-sputtering of metallic targets of Mg and Ni. Metallic MgyNi1-y films were deposited with pure Ar plasma while MgyNi1-yHx hydride films were deposited reactively with 30% H-2 in the Ar plasma. The depositions were done with a fixed substrate carrier, producing films with a spatial gradient in the Mg and Ni composition. The combinatorial method of co-sputtering gives an insight into the phase diagram of MgyNi1-y and MgyNi1-yHx, and allows us to investigate structural, optical and electrical properties of the resulting alloys. Our results show that reactive sputtering gives direct deposition of metal hydride films, with high purity in the case of Mg similar to 2NiH similar to 4. We have observed limited oxidation after several months of exposure to ambient conditions. MgyNi1-y and MgyNi1-yHx films might be applied for optical control in smart windows, optical sensors and as a semiconducting material for photovoltaic solar cells.
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| 23. |
- Mongstad, Trygve, et al.
(författare)
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Surface oxide on thin films of yttrium hydride studied by neutron reflectometry
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:19, s. 191604-
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Tidskriftsartikel (refereegranskat)abstract
- The applicability of standard methods for compositional analysis is limited for H-containing films. Neutron reflectometry is a powerful, non-destructive method that is especially suitable for these systems due to the large negative scattering length of H. In this work, we demonstrate how neutron reflectometry can be used to investigate thin films of yttrium hydride. Neutron reflectometry gives a strong contrast between the film and the surface oxide layer, enabling us to estimate the oxide thickness and oxygen penetration depths. A surface oxide layer of 5-10nm thickness was found for unprotected yttrium hydride films.
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| 24. |
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| 25. |
- Mongstad, T, et al.
(författare)
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Transparent yttrium hydride thin films prepared by reactive sputtering
- 2011
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 509, s. S812-S816
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Tidskriftsartikel (refereegranskat)abstract
- Metal hydrides have earlier been suggested for utilization in solar cells. With this as a motivation we have prepared thin films of yttrium hydride by reactive magnetron sputter deposition. The resulting films are metallic for low partial pressure of hydrogen during the deposition, and black or yellow-transparent for higher partial pressure of hydrogen. Both metallic and semiconducting transparent YH(x) films have been prepared directly in situ without the need of capping layers and post-deposition hydrogenation. Optically the films are similar to what is found for YH(x) films prepared by other techniques, but the crystal structure of the transparent films differ from the well-known YH(3-eta) phase, as they have an fcc lattice instead of hcp.
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