| 1. |
- Kirsebom, O. S., et al.
(author)
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Measurement of the 2+→0+ ground-state transition in the β decay of F 20
- 2019
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In: Physical Review C. - 2469-9985. ; 100:6
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Journal article (peer-reviewed)abstract
- We report the first detection of the second-forbidden, nonunique, 2+→0+, ground-state transition in the β decay of F20. A low-energy, mass-separated F+20 beam produced at the IGISOL facility in Jyväskylä, Finland, was implanted in a thin carbon foil and the β spectrum measured using a magnetic transporter and a plastic-scintillator detector. The β-decay branching ratio inferred from the measurement is bβ=[0.41±0.08(stat)±0.07(sys)]×10-5 corresponding to logft=10.89(11), making this one of the strongest second-forbidden, nonunique β transitions ever measured. The experimental result is supported by shell-model calculations and has significant implications for the final evolution of stars that develop degenerate oxygen-neon cores. Using the new experimental data, we argue that the astrophysical electron-capture rate on Ne20 is now known to within better than 25% at the relevant temperatures and densities.
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| 2. |
- Lieder, R M, et al.
(author)
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Gamma-ray tracking arrays
- 2001
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In: PROGRESS IN PARTICLE AND NUCLEAR PHYSICS, VOL 46. ; , s. 399-407
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Conference paper (peer-reviewed)abstract
- The next generation of 4 pi arrays for high-precision gamma -ray spectroscopy will involve "gamma -ray tracking front-end on digital signal processing techniques, which allows to extract energy, timing and spatial information on the interactions of a gamma -ray in the Ge detector by pulse shape analysis of its signals. Utilizing the information on the positions of the interaction points and the energies released at each point the tracks of the gamma -rays in a Ge shell can be reconstructed in three dimensions.
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| 3. |
- Caamano, M, et al.
(author)
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Isomers in neutron-rich A approximate to 190 nuclides from Pb-208 fragmentation
- 2005
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In: European Physical Journal A. Hadrons and Nuclei. - : Springer Science and Business Media LLC. - 1434-6001. ; 23:2, s. 201-215
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Journal article (peer-reviewed)abstract
- Relativistic projectile fragmentation of Pb-208 has been used to produce isomers in neutron-rich, A approximate to 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in Ta-188, W-190, Re-192, Re-193, Os-195, Ir-197, Ir-198, Pt-200, Pt-201, Pt-202 and Au-203, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for Er-174, Er-175, Hf-185, Re-191, Re-194 and Ir-199. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In Pt-200 and Pt-201. the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics.
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| 4. |
- Giot, L., et al.
(author)
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Isotopic production cross sections of the residual nuclei in spallation reactions induced by 136Xe projectiles on proton at 500 A MeV
- 2013
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In: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 899, s. 116-132
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Journal article (peer-reviewed)abstract
- Around 270 medium-mass residual nuclei, formed in spallation reactions induced by 136Xe projectiles impinging on a liquid hydrogen target at 500 A MeV, have been unambiguously identified at GSI using the magnetic spectrometer FRS. The individual production cross sections and the longitudinal momentum distributions have been determined with high accuracy. These data represent an important constraint for theoretical models describing spallation reactions. © 2013 Elsevier B.V.
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| 5. |
- Lieder, R. M., et al.
(author)
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Development of gamma-ray tracking detectors
- 2001
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In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 32:9, s. 2395-2401
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Journal article (peer-reviewed)abstract
- The next generation of 4 pi arrays for high-precision gamma -ray spectroscopy AGATA will consist of gamma -ray tracking detectors. They represent high-fold segmented Ge detectors and a front-end electronics, based on digital signal processing techniques, which allows to extract energy, timing and spatial information on the interactions of a gamma -ray in the Ge detector by pulse shape analysis of its signals. Utilizing the information on the positions of the interaction points and the energies released at each point the tracks of the gamma -rays in a Ge shell can be reconstructed in three dimensions on the basis of the Compton-scattering formula.
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| 6. |
- Lieder, R. M., et al.
(author)
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The TMR network project Development of gamma-ray tracking detectors
- 2001
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In: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 682, s. 279C-285C
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Journal article (peer-reviewed)abstract
- The next generation of 4 pi arrays for high-precision gamma -ray spectroscopy will involve gamma -ray tracking detectors. They consist of high-fold segmented Ge detectors and a front-end electronics, based on new digital signal processing techniques, which allows to extract energy, timing and spatial information for a gamma -ray by pulse shape analysis of the Ge detector signals. Utilizing the information on the positions of the interaction points and the energies released at each point the tracks of the gamma -rays in a Ge shell can be reconstructed in three dimensions.
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| 7. |
- Mineva, AN, et al.
(author)
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A new mu s isomer in Sb-136 produced in the projectile fission of U-238
- 2001
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In: EUROPEAN PHYSICAL JOURNAL A. - : SPRINGER-VERLAG. - 1434-6001. ; 11:1, s. 9-13
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Journal article (peer-reviewed)abstract
- The neutron-rich isotope Sb-136 has been produced following the relativistic projectile fission of U-238 in an experiment performed at the Fragment Separator at GSI, Darmstadt. Delayed gamma -ray spectroscopy of the fission products has been performed aft
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| 8. |
- Mineva, Milena, et al.
(author)
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A New us Isomer in 136Sb Produced in the Projectile Fission of 238U
- 2001
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In: European Physical Journal A. Hadrons and Nuclei. - 1434-6001. ; 11, s. 9-13
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Journal article (peer-reviewed)abstract
- The neutron-rich isotope Sb-136 has been produced following the relativistic projectile fission of U-238 in an experiment performed at the Fragment Separator at GSI, Darmstadt. Delayed gamma -ray spectroscopy of the fission products has been performed after isotope separation. A new isomeric state in Sb-136 has been populated, and its lifetime measured as T-1/2 = 565(50) ns. Realistic and empirical shell-model calculations have been performed and are compared to the experimental observables.
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| 9. |
- Paradela, C., et al.
(author)
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Isotopic production cross sections of residual nuclei in the spallation reaction Xe-136 (200A MeV) + p
- 2017
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In: Physical Review C. - 2469-9985 .- 2469-9993. ; 95:4
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Journal article (peer-reviewed)abstract
- The residual nuclei produced in the spallation reaction of Xe-136 nuclei at 200A MeV on protons have been studied by measuring the isotopic distributions for the elements from cadmium (Z = 48) to cesium (Z = 55) by using the fragment separator (FRS) spectrometer at GSI and the inverse kinematics technique. This is one of the few measurements performed at such a low projectile energy, close to the validity limit for intranuclear cascade models such as INCL or ISABEL. The experimental results have been compared to these intranuclear cascade codes coupled to the evaporation code ABLA. Both code combinations reproduce qualitatively the measured isotopic distributions; however, both underestimate the production of residues with mass numbers between 126 and 134. The measured cross sections are of interest for the planning of future radioactive beam or neutron source facilities.
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| 10. |
- Podolyak, Z, et al.
(author)
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Isomer spectroscopy of neutron rich W-190(116)
- 2000
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In: PHYSICS LETTERS B. - : ELSEVIER SCIENCE BV. - 0370-2693. ; 491:3-4, s. 225-231
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Journal article (other academic/artistic)abstract
- Gamma-rays de-exciting a millisecond isomer in the neutron-rich nucleus W-190(74)116 have been observed following relativistic projectile fragmentation of a I GeV per nucleon Pb-208 beam. Th, isomeric decay populates the ground-state rotational band, with
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| 11. |
- Sahlin, Kent, et al.
(author)
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Ultra-endurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle.
- 2010
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In: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 108:4, s. 780-787
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Journal article (peer-reviewed)abstract
- Exercise-induced oxidative stress is important for the muscular adaptation to training but may also cause muscle damage. We hypothesized that prolonged exercise would increase mitochondrial production of reactive oxygen species (ROS) measured in vitro and that this correlates with oxidative damage. Eight male athletes (24-32 years) performed ultra-endurance exercise (kayaking/running/cycling) with an average work intensity of 55% VO2peak for 24 h. Muscle biopsies were taken from vastus lateralis before exercise, immediately after exercise and after 28 h of recovery. The production of H2O2 was measured fluorometrically in isolated mitochondria with the Amplex red and peroxidase system. Succinate-supported mitochondrial H2O2 production was significantly increased after exercise (73% higher, P=0.025) but restored to the initial level at recovery. Plasma level of free fatty acids (FFA) increased 4-fold and exceeded 1.2 mmol l(-1) during the last 6 h of exercise. Plasma FFA at the end of exercise was significantly correlated to mitochondrial ROS production (r=0.74, P<0.05). Mitochondrial content of 4-hydroxy-nonenal-adducts (a marker of oxidative damage) was increased only after recovery and was not correlated with mitochondrial ROS production. Total thiol-group level and glutathione peroxidase activity were elevated after recovery. In conclusion: ultra-endurance exercise increases ROS production in isolated mitochondria but this is reversed after 28 h recovery. Mitochondrial ROS production was not correlated with oxidative damage of mitochondrial proteins, which was increased at recovery but not immediately after exercise. Key words: antioxidative defence, fatty acids, oxidative stress.
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| 12. |
- Trägårdh, Elin, et al.
(author)
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RECOMIA-a cloud-based platform for artificial intelligence research in nuclear medicine and radiology
- 2020
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In: Ejnmmi Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 7:1
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Journal article (peer-reviewed)abstract
- Background: Artificial intelligence (AI) is about to transform medical imaging. The Research Consortium for Medical Image Analysis (RECOMIA), a not-for-profit organisation, has developed an online platform to facilitate collaboration between medical researchers and AI researchers. The aim is to minimise the time and effort researchers need to spend on technical aspects, such as transfer, display, and annotation of images, as well as legal aspects, such as de-identification. The purpose of this article is to present the RECOMIA platform and its AI-based tools for organ segmentation in computed tomography (CT), which can be used for extraction of standardised uptake values from the corresponding positron emission tomography (PET) image. Results: The RECOMIA platform includes modules for (1) local de-identification of medical images, (2) secure transfer of images to the cloud-based platform, (3) display functions available using a standard web browser, (4) tools for manual annotation of organs or pathology in the images, (5) deep learning-based tools for organ segmentation or other customised analyses, (6) tools for quantification of segmented volumes, and (7) an export function for the quantitative results. The AI-based tool for organ segmentation in CT currently handles 100 organs (77 bones and 23 soft tissue organs). The segmentation is based on two convolutional neural networks (CNNs): one network to handle organs with multiple similar instances, such as vertebrae and ribs, and one network for all other organs. The CNNs have been trained using CT studies from 339 patients. Experienced radiologists annotated organs in the CT studies. The performance of the segmentation tool, measured as mean Dice index on a manually annotated test set, with 10 representative organs, was 0.93 for all foreground voxels, and the mean Dice index over the organs were 0.86 (0.82 for the soft tissue organs and 0.90 for the bones). Conclusion: The paper presents a platform that provides deep learning-based tools that can perform basic organ segmentations in CT, which can then be used to automatically obtain the different measurement in the corresponding PET image. The RECOMIA platform is available on request atfor research purposes.
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| 13. |
- Ying, T. M., et al.
(author)
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Automated artificial intelligence-based analysis of skeletal muscle volume predicts overall survival after cystectomy for urinary bladder cancer
- 2021
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In: European Radiology Experimental. - : Springer Science and Business Media LLC. - 2509-9280. ; 5:1
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Journal article (peer-reviewed)abstract
- Background Radical cystectomy for urinary bladder cancer is a procedure associated with a high risk of complications, and poor overall survival (OS) due to both patient and tumour factors. Sarcopenia is one such patient factor. We have developed a fully automated artificial intelligence (AI)-based image analysis tool for segmenting skeletal muscle of the torso and calculating the muscle volume. Methods All patients who have undergone radical cystectomy for urinary bladder cancer 2011-2019 at Sahlgrenska University Hospital, and who had a pre-operative computed tomography of the abdomen within 90 days of surgery were included in the study. All patients CT studies were analysed with the automated AI-based image analysis tool. Clinical data for the patients were retrieved from the Swedish National Register for Urinary Bladder Cancer. Muscle volumes dichotomised by the median for each sex were analysed with Cox regression for OS and logistic regression for 90-day high-grade complications. The study was approved by the Swedish Ethical Review Authority (2020-03985). Results Out of 445 patients who underwent surgery, 299 (67%) had CT studies available for analysis. The automated AI-based tool failed to segment the muscle volume in seven (2%) patients. Cox regression analysis showed an independent significant association with OS (HR 1.62; 95% CI 1.07-2.44; p = 0.022). Logistic regression did not show any association with high-grade complications. Conclusion The fully automated AI-based CT image analysis provides a low-cost and meaningful clinical measure that is an independent biomarker for OS following radical cystectomy.
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