1. |
- Aasa, Ulrika, et al.
(författare)
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The Swedish physical activity and fitness cohort born in 1958 - dropout analysis and overview at 36-year follow-up
- 2017
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 27:4, s. 418-429
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Tidskriftsartikel (refereegranskat)abstract
- The main aim of the Swedish physical activity and fitness cohort study (SPAF-1958) was to describe physical fitness, physical activity, health, and lifestyle across part of the lifespan, and to assess the influences on these factors from the environment, personal factors, and genetics. There is inevitable dropout from longitudinal studies, and it may be systematic. The aim of this first paper of the second follow-up of SPAF-1958 was to provide a dropout analysis to consider to what extent the participants, at 52 years of age, remain a representative sample of the original adolescent study population. Additional aims were to provide an overview of the study protocol and the ongoing study population. Ongoing study participants in SPAF born in 1958 were, at the second follow-up at the age of 52, still representative of the study cohort in terms of sex, adolescent geographical area, upper secondary school program, adolescent body composition, muscular strength, and muscular endurance. However, a higher physical activity and, among women, a higher aerobic capacity in adolescence decreased the risk for dropout. It is important when interpreting results from longitudinal studies to adjust for the systematic dropout that could bias the conclusions drawn from the results.
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2. |
- Alkner, Sara, et al.
(författare)
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Quality assessment of radiotherapy in the prospective randomized SENOMAC trial
- 2024
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Ingår i: Radiotherapy and Oncology. - : Elsevier. - 0167-8140 .- 1879-0887. ; 197
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Recommendations for regional radiotherapy (RT) of sentinel lymph node (SLN)-positive breast cancer are debated. We here report a RT quality assessment of the SENOMAC trial. Materials and Methods: The SENOMAC trial randomized clinically node-negative breast cancer patients with 1-2 SLN macrometastases to completion axillary lymph node dissection (cALND) or SLN biopsy only between 2015-2021. Adjuvant RT followed national guidelines. RT plans for patients included in Sweden and Denmark until June 2019 were collected (N = 1176) and compared to case report forms (CRF). Dose to level I (N = 270) and the humeral head (N = 321) was analyzed in detail.
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3. |
- Appelgren, M., et al.
(författare)
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Patient-reported outcomes one year after positive sentinel lymph node biopsy with or without axillary lymph node dissection in the randomized SENOMAC trial
- 2022
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Ingår i: Breast. - : Elsevier BV. - 0960-9776 .- 1532-3080. ; 63, s. 16-23
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: This report evaluates whether health related quality of life (HRQoL) and patient-reported arm morbidity one year after axillary surgery are affected by the omission of axillary lymph node dissection (ALND). Methods: The ongoing international non-inferiority SENOMAC trial randomizes clinically node-negative breast cancer patients (T1-T3) with 1-2 sentinel lymph node (SLN) macrometastases to completion ALND or no further axillary surgery. For this analysis, the first 1181 patients enrolled in Sweden and Denmark between March 2015, and June 2019, were eligible. Data extraction from the trial database was on November 2020. This report covers the secondary outcomes of the SENOMAC trial: HRQoL and patient-reported arm morbidity. The EORTC QLQC30, EORTC QLQ-BR23 and Lymph-ICF questionnaires were completed in the early postoperative phase and at one-year follow-up. Adjusted one-year mean scores and mean differences between the groups are presented corrected for multiple testing.
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4. |
- Bergkvist, Göran, et al.
(författare)
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Clover cover crops under-sown in winter wheat increase yield of subsequent spring barley-Effect of N dose and companion grass
- 2011
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Ingår i: Field Crops Research. - : Elsevier BV. - 0378-4290 .- 1872-6852. ; 120, s. 292-298
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Tidskriftsartikel (refereegranskat)abstract
- Four two-year field trials, arranged in randomised split-plots, were carried out in southern Sweden with the aim of determining whether reduced N fertiliser dose in winter wheat production with spring under-sown clover cover crops, with or without perennial ryegrass in the seed mixture, would increase the clover biomass and hence the benefits of the cover crops in terms of the effect on the wheat crop, on a subsequent barley crop and on the risk of N leaching. Four doses of nitrogen (0, 60, 120 or 180 kg N ha(-1)) constituted the main plots and six cover crop treatments the sub-plots. The cover crop treatments were red clover (Trifolium pratense L). white clover (Trifolium repens L) and perennial ryegrass (Lolium perenne L.) in pure stands and in mixtures. The winter wheat (Triticum aestivum L.) was harvested in August and the cover crops were ploughed under in November. The risk of N leaching was assessed in November by measuring the content of mineral N in the soil profile (0-30, 30-90 cm). In the following year, the residual effects of the cover crops were investigated in spring barley (Hordeum distichon L) without additional N. Under-sowing of cover crops did not influence wheat yield, while reduced N fertiliser dose decreased yield and increased the clover content of the cover crops. When N was applied, the mixed cover crops were as effective in depleting soil mineral nitrogen as a pure ryegrass cover crop, while pure clover was less efficient. The clover content at wheat harvest as well as the amount of N incorporated with the cover crops had a positive correlation with barley yield. Spring barley in the unfertilised treatments yielded, on average, 1.9-2.4 Mg DM ha(-1) more in treatments with clover cover crops than in the treatment without cover crops. However, this positive effect decreased as the N dose to the preceding wheat crop increased, particularly when the clover was mixed with grass. (C) 2010 Elsevier B.V. All rights reserved.
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5. |
- Bergkvist, Max, et al.
(författare)
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Assessment of oxygenation with polarized light spectroscopy enables new means for detecting vascular events in the skin
- 2020
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Ingår i: Microvascular Research. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0026-2862 .- 1095-9319. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Impaired oxygenation in the skin may occur in disease states and after reconstructive surgery. We used tissue viability imaging (TiVi) to measure changes in oxygenation and deoxygenation of haemoglobin in an in vitro model and in the dermal microcirculation of healthy individuals. Materials and methods: Oxygenation was measured in human whole blood with different levels of oxygenation. In healthy subjects, changes in red blood cell concentration (C-RBC,(TiVi)), oxygenation (Delta C-OH,(TiVi)) and deoxygenation (Delta C-DOH,(TiVi)) of haemoglobin were measured during and after arterial and venous occlusion using TiVi and were compared with measurements from the enhanced perfusion and oxygen saturation system (EPOS). Results: During arterial occlusion, C-RBC,(TiVi) remained unchanged while Delta C-OH,(TiVi) decreased to -44.2 (10.4) AU (p = 0.04), as compared to baseline. After release, C-RBC,C-TiVi increased to 39.2 (18.8) AU (p < 0.001), Delta C-OH,C-TiVi increased to 38.5. During venous occlusion, C-RBC,C-TiVi increased to 28.9 (11.2) AU (p < 0.001), Delta C-OH,C-TiVi decreased to -52.2 (46.1) AU (p < 0.001) compared to baseline after 5 min of venous occlusion. There was a significant correlation between the TiVi Oxygen Mapper and EPOS, for arterial (r = 0.92, p < 0.001) and venous occlusion (r = 0.87, p < 0.001), respectively. Conclusion: This study shows that TiVi can measure trends in oxygenation and deoxygenation of haemoglobin during arterial and venous stasis in healthy individuals.
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6. |
- Bergkvist, Sara, et al.
(författare)
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Ground state of the random-bond spin-1 Heisenberg chain
- 2002
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 66, s. 134407-1-134407-9
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Tidskriftsartikel (refereegranskat)abstract
- Stochastic series expansion quantum Monte Carlo is used to study the ground state of the antiferromagnetic spin-1 Heisenberg chain with bond disorder. Typical spin- and string-correlation functions behave in accordance with real-space renormalization group predictions for the random-singlet phase. The average string-correlation function decays algebraically with an exponent of -0.378(6), in very good agreement with the prediction of -(3-root5)/2similar or equal to-0.382, while the average spin-correlation function is found to decay with an exponent of about -1, quite different from the expected value of -2. By implementing the concept of directed loops for the spin-1 chain we show that autocorrelation times can be reduced by up to two orders of magnitude.
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7. |
- Bergkvist, Sara, et al.
(författare)
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Local-density approximation for confined bosons in an optical lattice
- 2004
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 70, s. 053601-1-053601-7
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Tidskriftsartikel (refereegranskat)abstract
- We investigate local and global properties of the one-dimensional Bose-Hubbard model with an external confining potential, describing an atomic condensate in an optical lattice. Using quantum Monte Carlo techniques we demonstrate that a local-density approximation, which relates the unconfined and the confined model, yields quantitatively correct results in most of the interesting parameter range. We also examine claims of universal behavior in the confined system, and demonstrate the origin of a previously calculated fine structure in the experimentally accessible momentum distribution.
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8. |
- Bergkvist, Sara, et al.
(författare)
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Reduction of the sign problem using the meron-cluster approach
- 2003
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Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - 1063-651X .- 1095-3787. ; 68, s. 016122-1-016122-8
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Tidskriftsartikel (refereegranskat)abstract
- The sign problem in quantum Monte Carlo calculations is analyzed using the meron-cluster solution. A meron is a loop that alters the sign of the configuration, and the concept of merons can be used to solve the sign problem for a limited class of models. Here we show that the method can be used to reduce the sign problem in a wider class of models. We investigate how the meron solution evolves between a point in parameter space where it eliminates the sign problem and a point where it does not affect the sign problem at all. In this intermediate regime, the merons can be used to reduce the sign problem. The average sign still decreases exponentially with system size and inverse temperature, but with a different prefactor. The sign exhibits the slowest decrease in the vicinity of points where the meron-cluster solution eliminates the sign problem. We have used stochastic series expansion quantum Monte Carlo combined with the concept of directed loops.
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9. |
- Bergkvist, Sara, et al.
(författare)
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Spinful bosons in an optical lattice
- 2006
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 74:5, s. 053419-1-053419-8
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Tidskriftsartikel (refereegranskat)abstract
- We analyze the behavior of cold spin-1 particles with antiferromagnetic interactions in a one-dimensional optical lattice using density matrix renormalization group calculations. Correlation functions and the dimerization are shown and we also present results for the energy gap between ground state and the spin excited states. We confirm the anticipated phase diagram, with Mott-insulating regions of alternating dimerized S=1 chains for odd particle density versus on-site singlets for even density. We find no evidence for any additional ordered phases in the physically accessible region, however for sufficiently large spin interaction, on-site singlet pairs dominate leading, for odd density, to a breakdown of the Mott insulator or, for even density, a real-space singlet superfluid.
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10. |
- Bergkvist, Sara, et al.
(författare)
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Transition from a two-dimensional superfluid to a one-dimensional mott insulator
- 2007
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 99:11, s. 110401-1-110401-5
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Tidskriftsartikel (refereegranskat)abstract
- A two-dimensional system of atoms in an anisotropic optical lattice is studied theoretically. If the system is finite in one direction, it is shown to exhibit a transition between a two-dimensional superfluid and a one-dimensional Mott insulating chain of superfluid tubes. Monte Carlo simulations are consistent with the expectation that the phase transition is of Kosterlitz-Thouless type. The effect of the transition on experimental time-of-flight images is discussed.
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