| 1. |
|
|
| 2. |
- Kondo, Y., et al.
(författare)
-
First observation of 28 O
- 2023
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 620:7976, s. 965-970
-
Tidskriftsartikel (refereegranskat)abstract
- Subjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10−21s), provide the most stringent tests of modern nuclear-structure theories. Here we report on the first observation of 28O and 27O through their decay into 24O and four and three neutrons, respectively. The 28O nucleus is of particular interest as, with the Z = 8 and N = 20 magic numbers1,2, it is expected in the standard shell-model picture of nuclear structure to be one of a relatively small number of so-called ‘doubly magic’ nuclei. Both 27O and 28O were found to exist as narrow, low-lying resonances and their decay energies are compared here to the results of sophisticated theoretical modelling, including a large-scale shell-model calculation and a newly developed statistical approach. In both cases, the underlying nuclear interactions were derived from effective field theories of quantum chromodynamics. Finally, it is shown that the cross-section for the production of 28O from a 29F beam is consistent with it not exhibiting a closed N = 20 shell structure.
|
|
| 3. |
- Moberg, Christina, et al.
(författare)
-
De unga gör helt rätt när de stämmer staten
- 2022
-
Ingår i: Aftonbladet. - 1103-9000.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
|
|
| 4. |
- Arnshav, Mirja, 1977-
(författare)
-
De små båtarna och den stora flykten : Arkeologi i spåren av andra världskrigets baltiska flyktbåtar
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Baltic states, Estonia, Latvia and Lithuania, were occupied no less than three times during the Second World War. Faced with a reign of terror, the threat of deportation, and compulsory conscription, over 30,000 people fled over the Baltic Sea to Sweden. On their arrival in Sweden, most escape boats were confiscated by the authorities and in 1945 were returned to the Soviet Union.This study, which began as an attempt to find out about the Baltic escape boats that ended up in Sweden, is inspired by a foreign boat in a small fishing harbour on the island of Gotland. My curiosity was piqued when I caught sight of the boat and heard that it had probably been an escape boat.The purpose of this thesis is to establish which, if any, Baltic escape boats survive in Sweden, in which contexts they remain, and to review their state of preservation, as well as to answer the question of their significance for the memory of the escape. It is an archaeology of the escape and its aftermath, based on the surviving escape boats – what the boats say about the escape, what happened to them afterwards, and how people relate to them and their historical legacy today.The study looks at 35 boats that have been described as Baltic escape boats in various contexts. It shows that they are found in a multitude of environments and in a range of different states of preservation. The boats illustrate experiences that few other source materials can convey, in a manner pertinent to the archaeological understanding of flight. In addition, the boats are rare traces of an earlier Estonian coastal culture eradicated by the second Soviet occupation.One of the most important outcomes of the study is the documentation from the survey and examinations carried out. Few of the boats were known outside their local context. A national compilation has been lacking, which has impeded research and ultimately our understanding of the breadth and complexity of the Swedish historical landscape when it comes to ship remains.
|
|
| 5. |
- Bergwik, Jesper, et al.
(författare)
-
Binding of the human antioxidation protein α1-microglobulin (A1M) to heparin and heparan sulfate. Mapping of binding site, molecular and functional characterization, and co-localization in vivo and in vitro
- 2021
-
Ingår i: Redox Biology. - : Elsevier BV. - 2213-2317. ; 41
-
Tidskriftsartikel (refereegranskat)abstract
- Heparin and heparan sulfate (HS) are linear sulfated disaccharide polymers. Heparin is found mainly in mast cells, while heparan sulfate is found in connective tissue, extracellular matrix and on cell membranes in most tissues. α1-microglobulin (A1M) is a ubiquitous protein with thiol-dependent antioxidant properties, protecting cells and matrix against oxidative damage due to its reductase activities and radical- and heme-binding properties. In this work, it was shown that A1M binds to heparin and HS and can be purified from human plasma by heparin affinity chromatography and size exclusion chromatography. The binding strength is inversely dependent of salt concentration and proportional to the degree of sulfation of heparin and HS. Potential heparin binding sites, located on the outside of the barrel-shaped A1M molecule, were determined using hydrogen deuterium exchange mass spectrometry (HDX-MS). Immunostaining of endothelial cells revealed pericellular co-localization of A1M and HS and the staining of A1M was almost completely abolished after treatment with heparinase. A1M and HS were also found to be co-localized in vivo in the lungs, aorta, kidneys and skin of mice. The redox-active thiol group of A1M was unaffected by the binding to HS, and the cell protection and heme-binding abilities of A1M were slightly affected. The discovery of the binding of A1M to heparin and HS provides new insights into the biological role of A1M and represents the basis for a novel method for purification of A1M from plasma.
|
|
| 6. |
- Ekström, Erik, et al.
(författare)
-
Microstructure control and property switching in stress-free van der Waals epitaxial VO2 films on mica
- 2023
-
Ingår i: Materials & design. - : ELSEVIER SCI LTD. - 0264-1275 .- 1873-4197. ; 229
-
Tidskriftsartikel (refereegranskat)abstract
- Realizing stress-free inorganic epitaxial films on weakly bonding substrates is of importance for applications that require film transfer onto surfaces that do not seed epitaxy. Film-substrate bonding is usually weakened by harnessing natural van der Waals layers (e.g., graphene) on substrate surfaces, but this is difficult to achieve in non-layered materials. Here, we demonstrate van der Waals epitaxy of stress-free films of a non-layered material VO2 on mica. The films exhibit out-of-plane 010 texture with three inplane orientations inherited from the crystallographic domains of the substrate. The lattice parameters are invariant with film thickness, indicating weak film-substrate bonding and complete interfacial stress relaxation. The out-of-plane domain size scales monotonically with film thickness, but the in-plane domain size exhibits a minimum, indicating that the nucleation of large in-plane domains supports subsequent island growth. Complementary ab initio investigations suggest that VO2 nucleation and van der Waals epitaxy involves subtle polarization effects around, and the active participation of, surface potassium atoms on the mica surface. The VO2 films show a narrow domain-size-sensitive electrical-conductiv ity-temperature hysteresis. These results offer promise for tuning the properties of stress-free van der Waals epitaxial films of non-layered materials such as VO2 through microstructure control (C) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 7. |
- Ekström, Simon, 1966-
(författare)
-
Alfred Nobels känsla för hummer
- 2021
-
Ingår i: Svenska dagbladet. - 1101-2412.
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Att läsa menyerna för de drygt hundra Nobelmiddagarna som hittills ordnats är att ta del av en veritabel kulinarisk teater. Inte minst belyser hummerns förändrade närvaro vid banketten en viktig förskjutning av idén om hur Sverige ska representeras vid dessa tillfällen.
|
|
| 8. |
|
|
| 9. |
- Ekström, Simon, 1991-
(författare)
-
Efficient GPU-based Image Registration : for Detailed Large-Scale Whole-body Analysis
- 2020
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Imaging has become an important aspect of medicine, enabling visualization of internals in a non-invasive manner. The rapid advancement and adoption of imaging techniques have led to a demand for tools able to take advantage of the information that is produced. Medical image analysis aims to extract relevant information from acquired images to aid diagnostics in healthcare and increase the understanding within medical research. The main subject of this thesis, image registration, is a widely used tool in image analysis that can be employed to find a spatial transformation aligning a set of images. One application, that is described in detail in this thesis, is the use of image registration for large-scale analysis of whole-body images through the utilization of the correspondences defined by the resulting transformations. To produce detailed results, the correspondences, i.e. transformations, need to be of high resolution and the quality of the result has a direct impact on the quality of the analysis. Also, this type of application aims to analyze large cohorts and the value of a registration method is not only weighted by its ability to produce an accurate result but also by its efficiency. This thesis presents two contributions on the subject; a new method for efficient image registration with the ability to produce dense deformable transformations, and the application of the presented method in large-scale analysis of a whole-body dataset acquired using an integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) system. In this thesis, it is shown that efficient and detailed image registration can be performed by employing graph cuts and a heuristic where the optimization is performed on subregions of the image. The performance can be improved further by the efficient utilization of a graphics processing unit (GPU). It is also shown that the method can be employed to produce a model on health based on a PET-MRI dataset which can be utilized to automatically detect pathology in the imaging.
|
|
| 10. |
- Ekström, Simon, 1991-, et al.
(författare)
-
Fast graph-cut based optimization for practical dense deformable registration of volume images
- 2020
-
Ingår i: Computerized Medical Imaging and Graphics. - : Elsevier. - 0895-6111 .- 1879-0771. ; 84
-
Tidskriftsartikel (refereegranskat)abstract
- Deformable image registration is a fundamental problem in medical image analysis, with applications such as longitudinal studies, population modeling, and atlas-based image segmentation. Registration is often phrased as an optimization problem, i.e., finding a deformation field that is optimal according to a given objective function. Discrete, combinatorial, optimization techniques have successfully been employed to solve the resulting optimization problem. Specifically, optimization based on α-expansion with minimal graph cuts has been proposed as a powerful tool for image registration. The high computational cost of the graph-cut based optimization approach, however, limits the utility of this approach for registration of large volume images. Here, we propose to accelerate graph-cut based deformable registration by dividing the image into overlapping sub-regions and restricting the α-expansion moves to a single sub-region at a time. We demonstrate empirically that this approach can achieve a large reduction in computation time - from days to minutes - with only a small penalty in terms of solution quality. The reduction in computation time provided by the proposed method makes graph-cut based deformable registration viable for large volume images. Graph-cut based image registration has previously been shown to produce excellent results, but the high computational cost has hindered the adoption of the method for registration of large medical volume images. Our proposed method lifts this restriction, requiring only a small fraction of the computational cost to produce results of comparable quality.
|
|
