| 1. |
- Cox, D. M., et al.
(författare)
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Spectroscopy along flerovium decay chains. II. Fine structure in odd-A 289Fl
- 2023
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Ingår i: Physical Review C. - 2469-9985. ; 107:2
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Tidskriftsartikel (refereegranskat)abstract
- Fifteen correlated α-decay chains starting from the odd-A superheavy nucleus 289Fl were observed following the fusion-evaporation reaction 48Ca+244Pu. The results call for at least two parallel α-decay sequences starting from at least two different states of 289Fl. This implies that close-lying levels in nuclei along these chains have quite different spin-parity assignments. Further, observed α-electron and α-photon coincidences, as well as the α-decay fine structure along the decay chains, suggest a change in the ground-state spin assignment between 285Cn and 281Ds. Our experimental results, on the excited level structure of the heaviest odd-N nuclei to date, provide a direct testing ground for theory. This is illustrated by comparison with new nuclear structure calculations based on the symmetry-conserving configuration mixing theory.
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| 2. |
- Såmark-Roth, A., et al.
(författare)
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Spectroscopy along flerovium decay chains. III. Details on experiment, analysis, 282Cn, and spontaneous fission branches
- 2023
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Ingår i: Physical Review C. - 2469-9985. ; 107:2
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Tidskriftsartikel (refereegranskat)abstract
- Flerovium isotopes (element Z = 114) were produced in the fusion-evaporation reactions 48Ca+242,244Pu and studied with an upgraded TASISpec decay station placed in the focal plane of the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. Twenty-nine flerovium decay chains were identified by means of correlated implantation, α decay, and spontaneous fission events. Data analysis aspects and statistical assessments, primarily based on measured rates of various events, which laid the foundation for the comprehensive spectroscopic information on the flerovium decay chains, are presented in detail. Various decay scenarios of an excited state observed in 282Cn are examined in depth with the help of GEANT4 simulations and assessed by predictions of beyond mean-field calculations including triaxial shape degrees of freedom. Previous, revised, and newly derived fission probabilities of even-even superheavy nuclei are compared with various theoretical predictions.
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| 3. |
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| 4. |
- Aberg, S., et al.
(författare)
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Nuclear Structure Effects in Fission
- 2023. - 1
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Ingår i: Journal of Physics: Conference Series. - 1742-6588. ; 2586
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Konferensbidrag (refereegranskat)abstract
- Three examples of nuclear structure effects in fission dynamics are discussed: (i) The appearance of a super-short symmetric mode in the fission of nuclei around 264Fm leading to two double-magic 132Sn, (ii) Fission of some super-heavy elements where the heavy cluster is focused around double-magic 208Pb, and (iii) A saw-tooth distribution in angular momenta versus the fission fragment mass in the fission of 239U. The Metropolis random walk method is used to simulate the strongly damped fission dynamics on a 5D deformation grid. The dynamics is driven by pairing-, shape- and energy-dependent level densities. When available, a good agreement with experimental data is obtained.
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| 5. |
- Albertsson, Daniel M, 1957, et al.
(författare)
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Hip and fragility fracture prediction by 4-item clinical risk score and mobile heel BMD: a women cohort study
- 2010
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Ingår i: BMC Musculosceletal disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background One in four Swedish women suffers a hip fracture yielding high morbidity and mortality. We wanted to revalidate a 4-item clinical risk score and evaluate a portable heel bone mineral density (BMD) technique regarding hip and fragility fracture risk among elderly women. Methods In a population-based prospective cohort study we used clinical risk factors from a baseline questionnaire and heel BMD to predict a two-year hip and fragility fracture outcome for women, in a fracture preventive program. Calcaneal heel BMD was measured by portable dual X-ray laser absorptiometry (DXL) and compared to hip BMD, measured with stationary dual X-ray absorptiometry (DXA) technique. Results Seven women suffered hip fracture and 14 women fragility fracture/s (at hip, radius, humerus and pelvis) among 285 women; 60% having heel BMD ≤ -2.5 SD. The 4-item FRAMO (Fracture and Mortality) Index combined the clinical risk factors age ≥80 years, weight <60 kg, prior fragility fracture, and impaired rise-up ability. Women having 2-4 risk factors showed odds ratio (OR) for hip fracture of 5.9 and fragility fracture of 4.4. High risk group hip fracture risk was 2.8% annually compared to 0.5% for the low risk majority (69%). Heel BMD showed hip fracture OR of 3.1 and fragility fracture OR of 2.6 per SD decrease. For 30 DXA assessed participants mean hip BMD at -2.5 SD level corresponded to a lower BMD at the heel. Five of seven hip fractures occurred within a small risk group of 32 women, identified by high FRAMO Index + prior fragility fracture + heel T-score ≤-3.5 SD. Conclusions In a follow-up study we identified high risk groups for hip and fragility fracture with our plain 4-item risk model. Increased fracture risk was also related to decreasing heel BMD in calcaneal bone, measured with a mobile DXL technique. A combination of high FRAMO Index, prior fragility fracture, and very low BMD restricted the high risk group to 11%, among whom most hip fractures occurred (71%). These practical screening methods could eventually reduce hip fracture incidence by concentrating preventive resources to high fracture risk women.
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| 6. |
- Albertsson, Daniel M, 1957
(författare)
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Hip fracture prevention by screening and intervention of elderly women in primary health care
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hip fracture prevention by screening and intervention of elderly women in Primary Health Care Daniel Albertsson Background – One in four Swedish women suffers a hip fracture (HF). In order to identify high-risk women we developed clinical 4-item scores as the FRAMO (Fracture and Mortality) Index, evaluated heel bone mineral density (BMD) and undertook interventions to improve mobility, reduce falls and HF. Methods - In pilot study 1998, a questionnaire regarding HF risk factors was sent to100 elderly women, with follow-up in 2001. Based on questionnaire 2001 sent to 1498 women aged ≥70, participants were analyzed with FRAMO Index (Risk Model I) for HF, fragility fracture (FF) and mortality in 2002–2003. A questionnaire regarding HF risk was 2003 returned by 285/435 women in the intervention population and heel BMD was assessed by portable dual X-ray laser absorptiometry (DXL), and correlated with 2-year incident HF and FF. Heel BMD was compared to hip BMD. In the controlled cohort intervention study, 296 (I=103, C=193) women were at high risk for HF (in Risk Model II). House calls were made to 61 % in intervention group, initiating exercising and home hazard reduction. After BMD determination pharmacological treatment was considered for 80 %. We evaluated mobility outcomes from questionnaires 2001 and 2004 and incident fractures in 2004–2005. Results - The 1998 questionnaire was answered by 92%; 34% had needs for fracture prevention. The 2001 questionnaire was returned by 83% (n=1248). Four items – age ≥80, weight <60kg, prior fragility fracture and using arms to rise from sitting - were combined in FRAMO Index. The 2-year HF risk was 0.8% for 63% with scores 0–1, and 5.4% (OR 7.5; 95%CI 3.0–18.4) for remaining 37% women with scores 2–4, having a 23.7% mortality risk. During 2004–2005, 7 HFs and 14 FFs occurred among the 285 women in intervention group, 60% of whom had heel osteoporosis (≤ -2.5 SD). The revalidated FRAMO Index showed HF OR 5.9 and FF OR 4.4. Heel BMD showed HF OR 2.7 and FF OR 2.3 for each SD decrease. Combining FRAMO Index + prior fragility fracture + low heel BMD yielded an annual HF risk of 7.8% for 11% and 0.4% for 89%. In the intervention group, we found less women with inability to rise (OR 0.21) and fewer falls (OR 0.46) in 2004, in women with initially impaired mobility. Home exercise was more common in intervention group (RR 2.1). Women with impaired rising ability who home exercised improved (p=0.03). Three interventions seemed related to improvement in rising ability on multivariate analysis; current home exercise, calcium-vitamin D3 treatment and previous group exercise (p=0.04–0.06). Two HFs occurred in the intervention group vs 11 in controls (OR 0.33 and p=0.23). Conclusion – Study questionnaires were feasible in PHC. The FRAMO Index yielded good fracture and mortality prediction. Heel BMD showed increased HF and FF risk. Heel osteoporosis prevalence was high. Hip osteoporosis corresponded to a heel DXL level of around -3.3 SD. Clinical risk factors combined with very low heel BMD defined a small high risk group for HF. Intervention group subjects with impaired mobility and high HF risk improved their mobility more than controls, one year after major multi-factorial intervention. Home exercise, group exercise and calcium- vitamin D treatment seemed related to improved rising ability. This risk assessment and intervention program with 1–2 years duration appears useful in population-based HF prevention.
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| 7. |
- Albertsson, Daniel M, 1957, et al.
(författare)
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Risk group for hip fracture in elderly women identified by primary care questionnaire--clinical implications.
- 2006
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Ingår i: Upsala journal of medical sciences. - 0300-9734. ; 111:2, s. 179-87
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Every fourth Swedish woman suffers hip fracture during life-time. Several methods for fall and fracture prevention are known. In this study we identify women at high hip fracture risk in a primary care population, describing their needs for possible fracture prevention as well. METHODS: Cross-sectional questionnaire study for self-assessment by randomly chosen elderly women (n=100) over 70 years of age in a Primary health Care district at 1998. Questionnaire was designed from previous validated study. Follow-up study after three years performed at 2001. RESULTS: Response rate was 92% (n=92, mean age 78) and 90% (n=83) answered the main 40 questions. 30% had at least two of four major risk factors for hip fracture; age over 80 years, body weight below 60 kg, recent fall and previous fragility fracture. The recall ability for at least two of these four risk factors was 93% in follow-up study after three years (relative risk = 8.0 with 95% confidence interval 3.5 to 18). 34% of the women had experienced any fracture since the age of 50. Only 22% of the women with previous fragility fracture had any pharmacological treatment for osteoporosis. 26% had falls in the preceding 12 months, mainly at home. Needs for fracture prevention were found in 34% (27 women). CONCLUSIONS: Age, weight, recent falls or previous fragility fracture were common and important clinical risk factors for hip fracture with good recall ability after three years. By using this questionnaire in a Primary health Care district we identified women at high fracture risk. Needs for fracture prevention were observed for one third.
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| 8. |
- Albertsson, Daniel M, 1957, et al.
(författare)
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Validation of a 4-item score predicting hip fracture and mortality risk among elderly women.
- 2007
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Ingår i: Annals of family medicine. - : Annals of Family Medicine. - 1544-1717 .- 1544-1709. ; 5:1, s. 48-56
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: One in 4 Swedish women experiences a hip fracture, an event that has high concomitant morbidity and mortality. We developed and validated a clinical predictor of fracture and mortality risk, the Fracture and Mortality (FRAMO) Index. METHODS: This was a population-based prospective cohort study with a baseline questionnaire and 2-year outcomes of hip fracture, fragility fracture, and death. The questionnaire was sent to 1,498 women aged 70 years or older in 3 rural populations, asking them about their age, weight, height, mobility, previous fractures, smoking, medication use, and housing. Some women were also asked about previous vertebral radiographs. We defined 2 risk models before outcome data collection and subsequently renamed 1 model (age =80 years, weight <60 kg, previous fragility fracture, and the need to use arms to rise from the sitting position) the FRAMO Index. We used logistic regression analysis to study the association between the FRAMO Index and outcomes in all participants. RESULTS: The participation rate was 83% in this elderly female population (N = 1,248). The 63% of women with 0 to 1 risk factor had a 2-year hip fracture risk of 0.8% and mortality risk of 3.2%. In contrast, women with 2 to 4 risk factors had a 2-year hip fracture risk of 5.4% (odds ratio = 7.5; 95% confidence interval, 3.0-18.4) and mortality risk of 23.7% (odds ratio = 9.5; 95% confidence interval, 6.0-14.9). These differences remained significant after adjustment for age as a continuous variable. Mortality increased with the number of risk factors. The proportion of women reporting previous vertebral fractures was higher among the group specifically questioned about vertebral radiographs (P <.001). CONCLUSIONS: The FRAMO Index identified the majority of women who experienced hip fractures during a 2-year follow-up, who might have been candidates for intensified preventive measures. The FRAMO Index, based on 4 binary risk factors, would be practical for routine use in primary care.
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| 9. |
- Albertsson, M., et al.
(författare)
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Correlation studies of fission-fragment neutron multiplicities
- 2021
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Ingår i: Physical Review C. - 2469-9985. ; 103:1
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Tidskriftsartikel (refereegranskat)abstract
- We calculate neutron multiplicities from fission fragments with specified mass numbers for events having a specified total fragment kinetic energy. The shape evolution from the initial compound nucleus to the scission configurations is obtained with the metropolis walk method on the five-dimensional potential-energy landscape, calculated with the macroscopic-microscopic method for the three-quadratic-surface shape family. Shape-dependent microscopic level densities are used to guide the random walk, to partition the intrinsic excitation energy between the two proto-fragments at scission, and to determine the number of neutrons evaporated from the fragments. The contribution to the total excitation energy of the resulting fragments from statistical excitation and shape distortion at scission is studied. Good agreement is obtained with available experimental data on neutron multiplicities in correlation with fission fragments from U235(nth,f). With increasing neutron energy a superlong fission mode grows increasingly prominent, which affects the dependence of the observables on the total fragment kinetic energy.
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| 10. |
- Albertsson, M.
(författare)
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Energy dependence of fission-fragment neutron multiplicity in 235U(n, f)
- 2019
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 12:3, s. 499-506
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Tidskriftsartikel (refereegranskat)abstract
- A consistent framework for treating the energy dependence of fission-fragment neutron multiplicities is presented. The shape evolution of the compound nucleus towards scission is treated in the strong damping limit using the Metropolis walk method. The available excitation energy at scission is then divided statistically between the two fragments using microscopic level densities. Deformation energies, which contribute to the excitation energy when the fragments relax to their ground-state shapes, are also computed. From the total fragment excitation energies, the number of emitted neutrons is obtained and illustrated for neutron-induced fission of 235U.
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