| 31. |
- Baev, A, et al.
(författare)
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Picturing molecular femtosecond processes through an ultra-fast controllable X-ray shutter
- 2003
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Ingår i: Chemical Physics. - 0301-0104 .- 1873-4421. ; 289, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- We show that frequency detuning in a resonant X-ray scattering experiment acts as an X-ray camera shutter by regulating the duration time of the scattering process. The camera shutter can be used to select processes at different time scales for observation. This is illustrated by a resonant Auger study of the ultra-fast dissociation of the core-excited HF molecule. We present experimental results and first principle simulations of the molecular fraction in the resonant Auger spectra of HF which is a dynamical parameter that well illustrates X-ray shutter controlled dissociation.
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| 32. |
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| 33. |
- Belitsky, Victor, 1955, et al.
(författare)
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Facility Heterodyne Receiver for the Atacama Pathfinder Experiment Telescope
- 2007
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Ingår i: Proceedings of Joint 32nd International Conference on Infrared Millimeter Waves and 15th International conference on Terahertz Electronics, Sept 3-7, 2007, City Hall, Cardiff, Wales, UK. ; , s. 326-328
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Konferensbidrag (refereegranskat)
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| 34. |
- Benetou, V, et al.
(författare)
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Mediterranean diet and incidence of hip fractures in a European cohort
- 2013
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Ingår i: Osteoporosis International. - : Springer London. - 0937-941X .- 1433-2965. ; 24:5, s. 1587-1598
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Tidskriftsartikel (refereegranskat)abstract
- Prevention of hip fractures is of critical public health importance. In a cohort of adults from eight European countries, evidence was found that increased adherence to Mediterranean diet, measured by a 10-unit dietary score, is associated with reduced hip fracture incidence, particularly among men. INTRODUCTION: Evidence on the role of dietary patterns on hip fracture incidence is scarce. We explored the association of adherence to Mediterranean diet (MD) with hip fracture incidence in a cohort from eight European countries. METHODS: A total of 188,795 eligible participants (48,814 men and 139,981 women) in the European Prospective Investigation into Cancer and nutrition study with mean age 48.6 years (±10.8) were followed for a median of 9 years, and 802 incident hip fractures were recorded. Diet was assessed at baseline through validated dietary instruments. Adherence to MD was evaluated by a MD score (MDs), on a 10-point scale, in which monounsaturated were substituted with unsaturated lipids. Association with hip fracture incidence was assessed through Cox regression with adjustment for potential confounders. RESULTS: Increased adherence to MD was associated with a 7 % decrease in hip fracture incidence [hazard ratio (HR) per 1-unit increase in the MDs 0.93; 95 % confidence interval (95 % CI) = 0.89-0.98]. This association was more evident among men and somewhat stronger among older individuals. Using increments close to one standard deviation of daily intake, in the overall sample, high vegetable (HR = 0.86; 95 % CI = 0.79-0.94) and high fruit (HR = 0.89; 95 % CI = 0.82-0.97) intake was associated with decreased hip fracture incidence, whereas high meat intake (HR = 1.18; 95 % CI = 1.06-1.31) with increased incidence. Excessive ethanol consumption (HR high versus moderate = 1.74; 95 % CI = 1.32-2.31) was also a risk factor. CONCLUSIONS: In a prospective study of adults, increased adherence to MD appears to protect against hip fracture occurrence, particularly among men.
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| 35. |
- Bergersen, Henrik, et al.
(författare)
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First observation of vibrations in core-level photoelectron spectra of free neutral molecular clusters
- 2006
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 429:1-3, s. 109-113
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Tidskriftsartikel (refereegranskat)abstract
- Core-level photoelectron spectra of free neutral methane clusters have been recorded. These spectra exhibit well-resolved surface and bulk features as well as vibrational fine structure. The vibrational structure in the cluster signal is well reproduced by a theoretical model that assumes independent contributions from inter- and intramolecular modes. The intramolecular contribution to the vibrational line-shape is taken to be equal to that of the monomer in the gas phase, while the intermolecular part is simplified to line broadening. An estimate of the cluster size has been made on the basis of the observed surface-to-bulk intensity ratio.
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| 36. |
- Bergersen, Henrik, 1978-
(författare)
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Free Neutral Clusters and Liquids Studied by Electron Spectroscopy and Lineshape Modeling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The electronic and geometrical structure of free neutral clusters and liquids have been studied using synchrotron-radiation based photoelectron and Auger electron spectroscopy in combination with lineshape modeling. A novel experimental setup has been developed for studies of liquids, based on the liquid microjet technique. Theoretical lineshapes have been computed using both classical (molecular dynamics) and quantum mechanical (mainly density functional theory) methods.Clusters are finite ensembles of atoms or molecules, ranging in size from a few to several thousand atoms. Apart from being fundamentally interesting, clusters are also promising as building blocks for nano-technology. In this thesis results are presented for rare-gas and molecular clusters, ranging from weakly van-deer-Waals bonded to hydrogen bonded. It is shown that the combination of core-level photoelectron spectroscopy (XPS) and lineshape modeling can be used to estimate the sizes of clusters. A model for treating the effect of inter-molecular nuclear relaxation upon ionization is proposed. The structure of single-component molecular clusters are investigated by molecular dynamics simulations, validated against XPS data. Finally, the radial structure of a two-component molecular cluster is investigated by XPS.Liquids have been studied for centuries, but still many questions remain regarding the microscopic properties. With the recent development of the liquid microjet technique, new insight into the atomic structure can be obtained. In this thesis we study aqueous solutions using photoelectron and Auger electron spectroscopy (AES). We investigate the structure of surface active molecules by XPS, study the Auger decay after core-level ionization in aqueous potassium chloride (KCl), and follow the changes in molecular structure of glycine as a function of pH.
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| 37. |
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| 38. |
- Bergersen, Henrik, et al.
(författare)
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Two size regimes of methanol clusters produced by adiabatic expansion
- 2006
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 125:18, s. 184303-
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Tidskriftsartikel (refereegranskat)abstract
- Free neutral methanol clusters produced by adiabatic expansion have been studied by photoelectron spectroscopy and line shape modeling. The results show that clusters belonging to two distinct size regimes can be produced by changing the expansion conditions. While the larger size regime can be well described by line shapes calculated for clusters consisting of hundreds of molecules, the smaller size regime corresponds to methanol oligomers, predominantly of cyclic structure. There is little contribution from dimers to the spectra.
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| 39. |
- Bergström, Ulrica, 1970-, et al.
(författare)
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Fracture mechanisms and fracture pattern in men and women aged 50 years and older : a study of a 12-year population-based injury register, Umeå, Sweden
- 2008
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Ingår i: Osteoporosis International. - London : Springer International. - 0937-941X .- 1433-2965. ; 19:9, s. 1267-1273
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Tidskriftsartikel (refereegranskat)abstract
- Summary: In a study of a 12-year population-based injury register, Umeå, Sweden, we analyzed the fracture mechanisms and fracture pattern in men and women 50 years and older. Low-energy trauma was responsible for the major and costliest part of the fracture panorama, but the pattern differs between age groups. Introduction: Osteoporosis-related fracture is a major health problem: the number of hip fractures is expected to double to 2030. While osteoporosis is one of many risk factors, trauma is almost always involved. Therefore, we analyzed injury mechanisms in patients aged over 50. Methods: We registered injury mechanism, cause, diagnosis in all trauma patients at Umeå University hospital, Sweden. This population-based register (1993–2004) comprises a total of 113,668 injuries (29,189 fractures). Patients ≥50 years contributed to 13,279 fractures. Results: Low-energy trauma (fall <1 m) caused 53% of all fractures ≥50 years and older. In those over 75 low-energy trauma caused >80%. The seasonal variation of fractures was maximally 25%. With increasing age, proximal fractures became more common, in both upper and lower extremities. Proximal locations predominate in older age groups. Conclusions: Low-energy trauma was responsible for the largest and costliest part of the fracture panorama. In fact, almost all fractures in middle-aged and old people were caused by low-energy mechanisms; thus, most fractures in these patients have a fragility component, and the contribution of osteoporosis-related fractures is more important than previously thought. A better understanding of injury mechanisms also in low-energy trauma is a prerequisite for preventive interventions.
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| 40. |
- Bergström, Ulrica, et al.
(författare)
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Fracture panorama in Umeå
- 2006
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Ingår i: Läkartidningen. - 0023-7205. ; 103:40, s. 2967-8
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Tidskriftsartikel (refereegranskat)
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