| 1. |
- Ding Yuan, Chen, 1991, et al.
(författare)
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Impact of in situ NH3 pre-treatment of LPCVD SiN passivation on GaN HEMT performance
- 2022
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 37:3
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Tidskriftsartikel (refereegranskat)abstract
- The impact on the performance of GaN high electron mobility transistors (HEMTs) of in situ ammonia (NH3) pre-treatment prior to the deposition of silicon nitride (SiN) passivation with low-pressure chemical vapor deposition (LPCVD ) is investigated. Three different NH3 pre-treatment durations (0, 3, and 10 min) were compared in terms of interface properties and device performance. A reduction of oxygen (O) at the interface between SiN and epi-structure is detected by scanning transmission electron microscopy (STEM )-electron energy loss spectroscopy (EELS) measurements in the sample subjected to 10 min of pre-treatment. The samples subjected to NH3 pre-treatment show a reduced surface-related current dispersion of 9% (compared to 16% for the untreated sample), which is attributed to the reduction of O at the SiN/epi interface. Furthermore, NH3 pre-treatment for 10 min significantly improves the current dispersion uniformity from 14.5% to 1.9%. The reduced trapping effects result in a high output power of 3.4 W mm(-1) at 3 GHz (compared to 2.6 W mm(-1) for the untreated sample). These results demonstrate that the in situ NH3 pre-treatment before LPCVD of SiN passivation is critical and can effectively improves the large-signal microwave performance of GaN HEMTs.
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| 2. |
- Gard, G, et al.
(författare)
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Stress and qualification of computer work
- 1989
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Ingår i: Work with display units 89: Selected papers from the second international conference of work with display units (Eds. L Berlinguet, D Berthelette.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Gogova, Daniela, et al.
(författare)
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Epitaxial growth of β -Ga 2 O 3 by hot-wall MOCVD
- 2022
-
Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226. ; 12:5, s. 055022-055022
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Tidskriftsartikel (refereegranskat)abstract
- The hot-wall metalorganic chemical vapor deposition (MOCVD) concept, previously shown to enable superior material quality and highperformance devices based on wide bandgap semiconductors, such as Ga(Al)N and SiC, has been applied to the epitaxial growth ofβ-Ga2O3. Epitaxial β-Ga2O3 layers at high growth rates (above 1 μm/h), at low reagent flows, and at reduced growth temperatures(740 ○C) are demonstrated. A high crystalline quality epitaxial material on a c-plane sapphire substrate is attained as corroborated by a combination of x-ray diffraction, high-resolution scanning transmission electron microscopy, and spectroscopic ellipsometry measurements. Thehot-wall MOCVD process is transferred to homoepitaxy, and single-crystalline homoepitaxial β-Ga2O3 layers are demonstrated with a 201 ¯rocking curve width of 118 arc sec, which is comparable to those of the edge-defined film-fed grown (201) ¯ β-Ga2O3 substrates, indicative ofsimilar dislocation densities for epilayers and substrates. Hence, hot-wall MOCVD is proposed as a prospective growth method to be furtherexplored for the fabrication of β-Ga2O3
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| 4. |
- Gogova, Daniela, 1967-, et al.
(författare)
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Epitaxial growth of β-Ga2O3 by hot-wall MOCVD
- 2022
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226. ; 12:5
-
Tidskriftsartikel (refereegranskat)abstract
- The hot-wall metalorganic chemical vapor deposition (MOCVD) concept, previously shown to enable superior material quality and high performance devices based on wide bandgap semiconductors, such as Ga(Al)N and SiC, has been applied to the epitaxial growth of beta-Ga2O3. Epitaxial beta-Ga2O3 layers at high growth rates (above 1 mu m/h), at low reagent flows, and at reduced growth temperatures (740 degrees C) are demonstrated. A high crystalline quality epitaxial material on a c-plane sapphire substrate is attained as corroborated by a combination of x-ray diffraction, high-resolution scanning transmission electron microscopy, and spectroscopic ellipsometry measurements. The hot-wall MOCVD process is transferred to homoepitaxy, and single-crystalline homoepitaxial beta-Ga2O3 layers are demonstrated with a 201 rocking curve width of 118 arc sec, which is comparable to those of the edge-defined film-fed grown (201) beta-Ga2O3 substrates, indicative of similar dislocation densities for epilayers and substrates. Hence, hot-wall MOCVD is proposed as a prospective growth method to be further explored for the fabrication of beta-Ga2O3.
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| 5. |
- Martinsson, Olof, et al.
(författare)
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Age and character of late-Svecokarelian monzonitic intrusions in northeastern Norrbotten, northern Sweden
- 2018
-
Ingår i: SGU Rapporter och meddelanden. - Uppsala : Sveriges geologiska undersökning. - 0349-2176. ; 141, s. 381-400
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Tidskriftsartikel (refereegranskat)abstract
- Palaeoproterozoic magmatism in northern Norrbotten shows a complex evolution, with several different plutonic suites ranging in age 1.93–1.70 Ga. Here we present data for three monzonitic intrusions from different parts of the area. They are petrographically and chemically similar, consisting mainly of perthite, augite and orthopyroxene, with megacrysts of poikilitic biotite as a characteristic minor component, and with high Sr and Ba. The intrusions have been dated at 1.80 Ga and may be part of a more extensive magmatic event in northern Sweden, including other chemically similar monzonitic and gabbroic intrusions, which often occur as ring dykes at the Merasjärvi gravity high (MGH) in northeastern Norrbotten. The monzonitic intrusions have A-type signatures and chemical characteristics overlapping those of rocks in arc and within-plate settings. These intrusions may thus have formed in either a back arc setting related to eastward subduction associated with the Transscandinavian Igneous Belt further west (TIB 1), or through a separate igneous event caused by a mantle plume.
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| 6. |
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| 7. |
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| 8. |
- Michaëlsson, Karl, 1959-, et al.
(författare)
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Hormone replacement therapy and hip fracture risk : population based case-control study
- 1998
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Ingår i: BMJ - British Medical Journal. - 1756-1833. ; 316:7148, s. 1858-63
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the relative risk of hip fracture associated with postmenopausal hormone replacement therapy including the effect of duration and recency of treatment, the addition of progestins, route of administration, and dose. DESIGN: Population based case-control study. Setting: Six counties in Sweden. SUBJECTS: 1327 women aged 50-81 years with hip fracture and 3262 randomly selected controls. MAIN OUTCOME MEASURE: Use of hormone replacement therapy. RESULTS: Compared with women who had never used hormone replacement therapy, current users had an odds ratio of 0.35 (95 % confidence interval 0.24 to 0.53) for hip fracture and former users had an odds ratio of 0.76 (0.57 to 1.01). For every year of therapy, the overall risk decreased by 6% (3% to 9%): 4% (1% to 8%) for regimens without progestin and 11% (6% to 16%) for those with progestin. Last use between one and five years previously, with a duration of use more than five years, was associated with an odds ratio of 0.27 (0.08 to 0.94). After five years without hormone replacement therapy the protective effect was substantially diminished (-7% to 48%). With current use, an initiation of therapy nine or more years after the menopause gave equally strong reduction in risk for hip fracture as an earlier start. Oestrogen treatment with skin patches gave similar risk estimates as oral regimens. CONCLUSIONS: Recent use of hormone replacement therapy is required for optimum fracture protection, but therapy can be started several years after the menopause. The protective effect increases with duration of use, and an oestrogen-sparing effect is achieved when progestins are included in the regimen.
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| 9. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 10. |
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| 11. |
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| 12. |
- Persson, Josefine, et al.
(författare)
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Aqueous polymer two-phase systems formed by new thermoseparating polymers
- 2000
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Ingår i: Bioseparation. - 1573-8272. ; 9:2, s. 105-116
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Tidskriftsartikel (refereegranskat)abstract
- A set of new polymers that can be used as phase forming components in aqueous two-phase systems is presented. All polymers studied have thermoseparating properties i.e. form one separate polymer enriched phase and one aqueous solution when heated above the critical temperature. This property makes the polymers attractive alternatives to the polymers used in traditional aqueous two-phase systems such as poly(ethylene glycol) (PEG) and dextran. The thermal phase separation simplifies recycling of the polymers, thus making the aqueous two-phase systems more cost efficient and suitable for use in large scale. Thermoseparating polymers studied have been copolymers of ethylene oxide and propylene oxide (EO-PO), poly (N-isopropylacrylamide) (poly-NIPAM), poly vinyl caprolactam (poly-VCL) and copolymers of N-isopropylacrylamide and vinyl caprolactam with vinyl imidazole (poly(NIPAM-VI) and poly(VCL-VI), respectively). In addition, the copolymer poly(NIPAM-VI) has the property to be uncharged at pH above 7.0 and positively charged at lower pH. This allows the partitioning of protein to be directed by changing the pH in the system instead of the traditional addition of salt to direct the partitioning. Hydrophobically modified EO-PO copolymer (HM-(EO-PO)) with alkyl groups (C_{14}) at both ends forms two-phase system with for example poly(NIPAM-VI). The phase diagram for poly(NIPAM-VI)/HM-(EO-PO) was determined and the model proteins lysozyme and BSA were partitioned in this system. For BSA in poly(NIPAM-VI)/HM-(EO-PO) system a change in pH from 8.0 to 5.4 results in a change of partition coefficient from K=0.8 to K=5.1, i.e. BSA could be transferred from the HM-(EO-PO) phase to the poly(NIPAM-VI) phase. BSA partitioning in poly(NIPAM-VI)/HM-(EO-PO) system allows quantitative BSA recovery, and recoveries of poly(NIPAM-VI) and HM-(EO-PO) were 53% and 92%, respectively, after the thermoseparation step.
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| 13. |
- Persson, Per, et al.
(författare)
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Gastrectomy causes bone loss in the rat: is lack of gastric acid responsible?
- 1993
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 28:4, s. 301-306
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Tidskriftsartikel (refereegranskat)abstract
- Total gastrectomy or resection of the acid-producing part of the stomach (fundectomy) in the rat induced a marked and rapid reduction in bone wet weight, ash weight, and density (expressed as ash weight in mg/mm3 bone). Bone volumes were also affected but not as much. The radius, sternum, tibia, and femur were studied. Three weeks after gastrectomy the bone ash weight was reduced by almost 30% and the density by more than 25%. Maximum bone loss (approximately 40%) occurred about 6 weeks after the operation. The bone loss after gastrectomy was somewhat greater than that after fundectomy, whereas antrectomy had a marginal effect only. The percentage trabecular bone volume, calculated from morphometric analysis of histologic sections of the tibia, was greatly reduced by gastrectomy (approximately 50%), somewhat less so by fundectomy, whereas antrectomy had little effect. We set out to study whether calcium malabsorption could explain the bone loss after gastrectomy. Gastric acid is thought to facilitate the intestinal absorption of ingested calcium by mobilizing calcium from insoluble complexes in the diet. The possibility that lack of acid might contribute to the bone loss after gastrectomy was examined in experiments in which the proton pump inhibitor omeprazole was given for 4-8 weeks at such a dose (400 mumol/kg/day) that acid secretion was blocked almost completely during the period of study. This treatment was without effect on bone. However, the possibility could not be excluded that gastrectomized rats develop calcium deficiency for some reason other than lack of acid.(
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| 14. |
- Pettersson, Ulrik, et al.
(författare)
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Provningsmetod för integrerade sol-biosystem : Årsverkningsgrad genom korttidsmätning
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Test method for integrated solar- biomass systems - Long term prediction trough short term measurements SP Technical Research Institute of Sweden and SERC, Dalarna University have in cooperation developed a test method for integrated solar and biomass systems. The test method is performed under six days including two summer days, two winter days and two spring/autumn days true to real weather conditions and loads for a single family house. The aim of the test method is to get information about a Combisystem’s annual performance and operation throughout a short term test. Seven different solar Combisystems have been tested within the project together with a pellet boiler without solar collectors. In addition to that a comparative testing has been performed at the two laboratories at SP and at SERC on the same Combisystem. The test method developed within the project has been proved to withstand the aim of the project, which is to be able to compare the performance between the systems. The test method is also suitable for identification of possible operation problems so they can be taken care of and consequently improves the system. The project and the system testing reveal that it is in general favorable to combine biomass pellets with solar heating. Pellet boilers has normally a low performance during the summer period but combined with a solar collector the boiler can be switch off during this period. There are however big differences in performance between the tested. The efficiency of the pellet boiler is highly dependent of the operating conditions and elements like heat losses from the system, system configuration and control strategy have great influence of the performance of the system and the emissions. On the other hand, the performance and the size of the solar collectors have a minor effect on the overall system performance. There is obviously a big potential for improvement of the system´s performance and the developed test method is an essential way to implement this perfection.
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| 15. |
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| 16. |
- Vertessy, Beata G., et al.
(författare)
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The complete triphosphate moiety of non-hydrolyzable substrate analogues is required for a conformational shift of the flexible C-terminus in E. coli dUTP pyrophosphatase
- 1998
-
Ingår i: FEBS Letters. - 1873-3468. ; 421:1, s. 83-88
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Tidskriftsartikel (refereegranskat)abstract
- The molecular mechanism of substrate analogue interaction with Escherichia coli dUTPase was investigated, using the non-hydrolyzable 2'-deoxyuridine 5'-(α,β-imido)triphosphate (α,β-imido-dUTP). Binding of this analogue induces a difference in the far UV circular dichroism (CD) spectrum arguing for a significant change in protein conformation. The spectral shift is strictly Mg2+-dependent, does not appear with dUDP instead of α,β-imido-dUTP and is not elicited if the flexible C-terminal arm is deleted from the protein by limited tryptic digestion. Involvement of the C-terminal arm in α,β-imido-dUTP binding is consistent with the finding that this analogue protects against tryptic hydrolysis at Arg-141. Near UV CD of ligand-enzyme complexes reveals a characteristic difference in the microenvironments of enzyme-bound dUDP and α,β-imido-dUTP, a difference not observable in C-terminally truncated dUTPase. The results suggest that (i) closing of the active site during the catalytic cycle, through the movement of the C-terminal arm, requires the presence of the complete triphosphate moiety of the substrate in complex with Mg2+, and (ii) after catalytic cleavage the active site pops open to facilitate product release.
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| 17. |
- Abdelhady, Dalia, et al.
(författare)
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The Nile and the Grand Ethiopian Renaissance Dam: Is There a Meeting Point between Nationalism and Hydrosolidarity?
- 2015
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Ingår i: Journal of Contemporary Water Research and Education. - 1936-704X. ; 155:1, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- The soon-to-be completed Grand Ethiopian Renaissance Dam (GERD), which will be the largest hydroelectric power plant and among the largest reservoirs in Africa, has highlighted the need for expanding traditional integrated water resources management to better include the cultural, social, and political complexities of large water infrastructure in development projects. The GERD will store a maximum of 74 billion cubic meters of water corresponding to approximately the average annual outflow of the Nile from the Aswan high dam. Undoubtedly, the GERD will be vital for energy production and a key factor for food production, economic development, and poverty reduction in Ethiopia and the Nile Basin. However, the GERD is also a political statement that in one stroke has re-written the hydropolitical map of the Nile Basin. The GERD has become a symbol of Ethiopian nationalism or “renaissance” (hidase in Amharic). A contrasting concept to nationalism is hydrosolidarity. This concept has been put forward to better stress equitable use of water in international water management challenges that would lead to sustainable socioeconomic development. We use the opposing notions of nationalism and hydrosolidarity at three different scales, everyday politics, state policies, and interstate and global politics to analyse some aspects of the new hydropolitical map of the Nile Basin. We argue that nationalism and national interests are not necessarily negative standpoints but that there may instead be a meeting point where regional and national interests join with hydrosolidarity principles. We believe that this meeting point can maximize not only the common good, but also the good from a national interest point of view. For this, it is important not increase collaboration instead of being locked in to the historical narrative of nationalistic culture and historical discourse. This would benefit and improve future sustainability.
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| 18. |
- Abrahamsson, Maria, et al.
(författare)
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A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays
- 2006
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 128:39, s. 12616-12617
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Tidskriftsartikel (refereegranskat)abstract
- A bistridentate RuII-polypyridine complex [Ru(bqp)2]2+ (bqp = 2,6-bis(8'-quinolinyl)pyridine) has been prepared, which has a coordination geometry much closer to a perfect octahedron than the typical Ru(terpyridine)2-type complex. Thus, the complex displays a 3.0 mus lifetime of the lowest excited metal-to-ligand charge transfer (3MLCT) state at room temperature. This is, to the best of our knowledge, the longest MLCT state lifetime reported for a RuII-polypyridyl complex at room temperature. The structure allows for the future construction of rod-like, isomer-free molecular arrays by substitution of donor and acceptor moieties on the central pyridine units. This makes it a promising photosensitizer for applications in molecular devices for artificial photosynthesis and molecular electronics.
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| 19. |
- Abrahamsson, Maria, et al.
(författare)
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Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes : Sensitizers for Rod-Like Molecular Arrays
- 2008
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Ingår i: Journal of the American Chemical Society. - : ACS. - 0002-7863 .- 1520-5126. ; 130:46, s. 15533-15542
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Tidskriftsartikel (refereegranskat)abstract
- A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DFT calculations performed on the parent [Ru(dqp) 2](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)2](2+) (tpy is 2,2':6',2"-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((3)MLCT) state that has a very long lifetime (tau = 3 micros). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (3)MLCT state lifetime of 5.5 micros was demonstrated for the homoleptic complex based on dqpCO2Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.
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| 20. |
- Abrahamsson, Maria, et al.
(författare)
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Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond (MLCT)-M-3 State Lifetimes: Sensitizers for Rod-Like Molecular Arrays
- 2008
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 130:46, s. 15533-15542
-
Tidskriftsartikel (refereegranskat)abstract
- A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C-2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DIFT calculations performed on the parent [Ru(dqp)(2)](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)(2)](2+) (tpy is 2,2':6',2 ''-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DIFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((MLCT)-M-3) state that has a very long lifetime (tau = 3 mu s). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (MLCT)-M-3 state lifetime of 5.5 mu s was demonstrated for the homoleptic complex based on dqpCO(2)Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.
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| 21. |
- Abrahamsson, Maria, et al.
(författare)
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Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.
- 2008
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Ingår i: Inorganic Chemistry. - : ACS. - 0020-1669 .- 1520-510X. ; 47:9, s. 3540-3548
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Tidskriftsartikel (refereegranskat)abstract
- The structural effect on the metal-to-ligand charge transfer (MLCT) excited-state lifetime has been investigated in bis-tridentate Ru(II)-polypyridyl complexes based on the terpyridine-like ligands [6-(2,2'-bipyridyl)](2-pyridyl)methane (1) and 2-[6-(2,2'-bipyridyl)]-2-(2-pyridyl)propane (2). A homoleptic ([Ru(2)(2)](2+)) and a heteroleptic complex ([Ru(ttpy)(2)](2+)) based on the new ligand 2 have been prepared and their photophysical and structural properties studied experimentally and theoretically and compared to the results for the previously reported [Ru(1)(2)](2+). The excited-state lifetime of the homoleptic Ru-II complex with the isopropylene-bridged ligand 2 was found to be 50 times shorter than that of the corresponding homoleptic Ru-II complex of ligand 1, containing a methylene bridge. A comparison of the ground-state geometries of the two homoleptic complexes shows that steric interactions involving the isopropylene bridges make the coordination to the central Ru-II ion less octahedral in [Ru(2)(2)](2+) than in [Ru(1)(2))(2+). Calculations indicate that the structural differences in these complexes influence their ligand field splittings as well as the relative stabilities of the triplet metal-to-ligand charge transfer ((MLCT)-M-3) and metal-centered ((MC)-M-3) excited states. The large difference in measured excited-state lifetimes for the two homoleptic Ru-II complexes is attributed to a strong influence of steric interactions on the ligand field strength, which in turn affects the activation barriers for thermal conversion from (MLCT)-M-3 states to short-lived (MC)-M-3 states.
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| 22. |
- Ahlborg, Tone, 1950, et al.
(författare)
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Assessing the quality of the dyadic relationship in first-time parents: development of a new instrument.
- 2005
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Ingår i: Journal of family nursing. - Thousand Oaks, Calif. : SAGE Publications. - 1074-8407 .- 1552-549X. ; 11:1, s. 19-37
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this research was to psychometrically evaluate the Dyadic Adjustment Scale (DAS), modified for use with new, first-time parents by extending the items of communication, sensuality, and sexuality. A total of 820 Swedish respondents, 6 months after the birth of their first child, participated in the study. Psychometric evaluation was conducted with factor analysis. The obtained factor structure was tested with multitrait analysis program. Thirty-three items were found to fit into a five-factor solution, explaining 50% of the total variance. Descriptive data revealed that most new parents were satisfied with their intimate relationship in general, but dissatisfied with their sexual lives. The modified DAS, now called the Quality of Dyadic Relationship Instrument includes 33 items and seems to be a useful, updated measurement for assessing quality of the intimate relationship in new first-time parents.
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| 23. |
- Ahlén, Olof, et al.
(författare)
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Fourier coefficients attached to small automorphic representations of SLn (A)
- 2018
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Ingår i: Journal of Number Theory. - : Elsevier BV. - 0022-314X .- 1096-1658. ; 192, s. 80-142
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Tidskriftsartikel (refereegranskat)abstract
- We show that Fourier coefficients of automorphic forms attached to minimal or next-to-minimal automorphic representations of SLn(A) are completely determined by certain highly degenerate Whittaker coefficients. We give an explicit formula for the Fourier expansion, analogously to the Piatetski-Shapiro–Shalika formula. In addition, we derive expressions for Fourier coefficients associated to all maximal parabolic subgroups. These results have potential applications for scattering amplitudes in string theory.
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| 24. |
- Alsén, Pia, 1956-, et al.
(författare)
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Fatigue after myocardial infarction : Relationships with indices of emotional distress, and sociodemographic and clinical variables
- 2010
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Ingår i: International Journal of Nursing Practice. - 1322-7114 .- 1440-172X. ; 16:4, s. 326-334
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Tidskriftsartikel (refereegranskat)abstract
- Fatigue and depressive symptoms are relatively common among patients recovering from myocardial infarction (MI). The symptoms of depression and fatigue overlap. The present study aimed at identifying patient fatigue and at examining the incidence of fatigue, particularly without coexisting depression, after MI. The sample comprised 204 consecutive patients who had completed the questionnaires Hospital Anxiety and Depression Scale and the Multidimensional Fatigue Inventory–20 after MI (1 week and 4 months). The results showed that fatigue had decreased after 4 months compared with the time of MI onset. Compared with the general population, patients reported significantly higher levels of fatigue. Furthermore, fatigue was associated with depression, but 33% of the sample reported fatigue without coexisting depression after 4 months. In order to prevent or treat patients' symptoms of fatigue after MI, the concepts of fatigue and depression should be assessed separately so as to exclude overlapping effects.
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| 25. |
- Alsén, Pia, 1956-, et al.
(författare)
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Illness perceptions after myocardial infarction : relations to fatigue, emotional distress, and health-related quality of life
- 2010
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Ingår i: Journal of Cardiovascular Nursing. - 0889-4655 .- 1550-5049. ; 25:2, s. E1-E10
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Tidskriftsartikel (refereegranskat)abstract
- Background and RESEARCH Objective: Health-related quality of life (HRQoL) is impaired in patients after a myocardial infarction (MI), and fatigue and depression are common health complaints among these patients. Patients' own beliefs about their illness (illness perceptions) influence health behavior and health outcomes. The aim of the present study was to examine illness perception and its association with self-reported HRQoL, fatigue, and emotional distress among patients with MI. Subjects and Methods: The sample consisted of 204 patients who had had MI and who completed the questionnaires during the first week in the hospital and 4 months after the MI. The questionnaires used were the Illness Perception Questionnaire, Multidimensional Fatigue Inventory, Hospital Anxiety and Depression Scale, and the Short Form Health Survey (SF-36). Results: Patient's illness perception changed over time from a more acute to a more chronic perception of illness, and beliefs in personal and treatment control of MI had decreased. Furthermore, these negative beliefs were associated with worse experiences of fatigue and lowered HRQoL. Conclusions: Patients' illness perceptions influence health outcomes after an MI. Supporting MI patients in increasing their perception of personal control could be a primary nursing strategy in rehabilitation programs aimed at facilitating health behavior, decreasing experiences of fatigue, and increasing HRQoL. Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.
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| 26. |
- Alsén, Pia, 1956, et al.
(författare)
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Illness perceptions after myocardial infarction: relations to fatigue, emotional distress, and health-related quality of life.
- 2010
-
Ingår i: Journal of Cardiovascular Nursing. - 1550-5049. ; 25:2
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Research Objective: Health-related quality of life (HRQoL) is impaired in patients after a myocardial infarction (MI), and fatigue and depression are common health complaints among these patients. Patients' own beliefs about their illness (illness perceptions) influence health behavior and health outcomes. The aim of the present study was to examine illness perception and its association with self-reported HRQoL, fatigue, and emotional distress among patients with MI. Subjects and Methods: The sample consisted of 204 patients who had had MI and who completed the questionnaires during the first week in the hospital and 4 months after the MI. The questionnaires used were the Illness Perception Questionnaire, Multidimensional Fatigue Inventory, Hospital Anxiety and Depression Scale, and the Short Form Health Survey (SF-36). Results: Patient's illness perception changed over time from a more acute to a more chronic perception of illness, and beliefs in personal and treatment control of MI had decreased. Furthermore, these negative beliefs were associated with worse experiences of fatigue and lowered HRQoL. Conclusions: Patients' illness perceptions influence health outcomes after an MI. Supporting MI patients in increasing their perception of personal control could be a primary nursing strategy in rehabilitation programs aimed at facilitating health behavior, decreasing experiences of fatigue, and increasing HRQoL.
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| 27. |
- Alsén, Pia, 1956-, et al.
(författare)
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Living with incomprehensible fatigue after recent myocardial infarction.
- 2008
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Ingår i: Journal of advanced nursing. - : Wiley. - 1365-2648 .- 0309-2402. ; 64:5, s. 459-68
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper is a report of a study of what fatigue means to patients with recent myocardial infarction (MI) and how they manage to deal with the consequences of this symptom. BACKGROUND: After MI, fatigue is a frequent and distressing symptom. In nursing practice and in everyday conversations, the term 'tiredness' has a broad meaning that is often used synonymously with fatigue. Fatigue may be defined as a state along an adaptation continuum with tiredness and exhaustion as distinct states at the ends of the continuum. METHOD: In accordance with a constructivist grounded theory method, 19 patients were interviewed four months after having a MI. The informants were chosen from a larger sample of patients admitted to a coronary care unit during the period October 2005 to September 2006. FINDINGS: Living with incomprehensible fatigue was identified as the central theme, which described what fatigue meant to patients 4 months after their MI and how they handled it. The core category was labelled incomprehensible fatigue. Two of the categories refer to consequences: being restricted and feeling defeated and one category describes management: fumbling coping strategies. Finally, one category concerns the outcome: moderate relief of fatigue. CONCLUSION: Nursing interventions could focus on identifying and reducing stressors as well as on increasing patients' ability to cope with stressors. Further research should focus on identifying stressors and useful coping strategies after MI, knowledge that could be used to prevent aggravation of fatigue.
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| 28. |
- Alsén, Pia, 1956-, et al.
(författare)
-
Patients' illness perception four months after a myocardial infarction.
- 2008
-
Ingår i: Journal of Clinical Nursing. - : Wiley. - 0962-1067 .- 1365-2702. ; 17:5A, s. 25-33
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS AND OBJECTIVES: The aim of this study was to explore patients' illness perception of myocardial infarction four months after a myocardial infarction. BACKGROUND: An important task for research on recovery from myocardial infarction is to understand the factors that influence an individual's adherence to secondary preventive strategies. Perceptual, cognitive and motivational factors have been found to influence adherence to a secondary preventive regimen. METHOD: Twenty-five patients were interviewed four months after a myocardial infarction. In accordance with grounded theory methodology, data collection and analysis were carried out simultaneously. RESULTS: The findings can be understood in light of two core categories: 'trust in oneself ' vs. 'trust in others'; belief in one's own efforts to control the illness; and 'illness reasoning', lines of thought about illness identity. In searching for relationships, six categories describing variation in illness perceptions of a myocardial infarction emerged: (i) 'sign of a chronic condition - feasible to influence'; (ii) 'sign of a chronic condition - uncontrollable'; (iii) 'acute event that can recur - feasible to influence'; (iv) 'acute event that can recur - uncontrollable'; (v) 'unthinkable acute event'; and (vi) 'non-recurring acute event'. CONCLUSION: The more reflective patients perceived the heart attack as a sign of a chronic condition; they also devoted time for reasoning about the possible causes of their illness. This is in contrast to patients who were less reflective and viewed their myocardial infarction as an acute event, which they avoided thinking about. The findings contribute to our understanding of variation in illness perceptions. RELEVANCE TO CLINICAL PRACTICE: The examination of how individuals perceive myocardial infarction may help health-care professionals individualize secondary preventive strategies, thereby improving adherence to health-care regimens. Nurse-patient discussions could begin with identification of the patient's variations of reflectiveness concerning his/her illness.
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| 29. |
- Altmejd, Adam, et al.
(författare)
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Inequality and COVID-19 in Sweden : Relative risks of nine bad life events, by four social gradients, in pandemic vs. prepandemic years
- 2023
-
Ingår i: Proceedings of the National Academy of Sciences - PNAS. - : National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 120:46
-
Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic struck societies directly and indirectly, not just challenging population health but disrupting many aspects of life. Different effects of the spreading virus—and the measures to fight it—are reported and discussed in different scientific fora, with hard-to-compare methods and metrics from different traditions. While the pandemic struck some groups more than others, it is difficult to assess the comprehensive impact on social inequalities. This paper gauges social inequalities using individual-level administrative data for Sweden’s entire population. We describe and analyze the relative risks for different social groups in four dimensions—gender, education, income, and world region of birth—to experience three types of COVID-19 incidence, as well as six additional negative life outcomes that reflect general health, access to medical care, and economic strain. During the pandemic, the overall population faced severe morbidity and mortality from COVID-19 and saw higher all-cause mortality, income losses and unemployment risks, as well as reduced access to medical care. These burdens fell more heavily on individuals with low income or education and on immigrants. Although these vulnerable groups experienced larger absolute risks of suffering the direct and indirect consequences of the pandemic, the relative risks in pandemic years (2020 and 2021) were conspicuously similar to those in prepandemic years (2016 to 2019).
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| 30. |
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| 31. |
- Amloy, Supaluck, et al.
(författare)
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Excitons and biexcitons in InGaN quantum dot like localization centers
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Indium segregation in a narrow InGaN single quantum well creates quantum dot (QD) like exciton localization centers. Cross section transmission electron microscopy reveals varying shapes and lateral sizes in the range ~1-5 nm of the QD-like features, while scanning near field optical microscopy demonstrates a highly inhomogeneous spatial distribution of optically active individual localization centers. Microphotoluminescence spectroscopy confirms the spectrally inhomogeneous distribution of localization centers, in which the exciton and the biexciton related emissions from single centers of varying geometry could be identified by means of excitation power dependencies. Interestingly, the biexciton binding energy (Ebxx) was found to vary from center to center, between 3 to -22 meV, in correlation with the exciton emission energy. Negative binding energies justify the three-dimensional quantum confinement, which confirms QD-like properties of the localization centers.! The observed energy correlation is proposed to be understood as variations of the lateral extension of the confinement potential, which would yield smaller values of Ebxx for reduced lateral extension and higher exciton emission energy. The proposed relation between lateral extension and Ebxx is further supported by the exciton and the biexciton recombination lifetimes of a single QD, which suggest a lateral extension of merely ~3 nm for a QD with strongly negative Ebxx = -15.5 meV.
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| 32. |
- Amloy, Supaluck, et al.
(författare)
-
Excitons and biexcitons in InGaN quantum dot like localization centers
- 2014
-
Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:49, s. 495702-
-
Tidskriftsartikel (refereegranskat)abstract
- Indium segregation in a narrow InGaN single quantum well creates quantum dot (QD) like exciton localization centers. Cross-section transmission electron microscopy reveals varying shapes and lateral sizes in the range ∼1–5 nm of the QD-like features, while scanning near field optical microscopy demonstrates a highly inhomogeneous spatial distribution of optically active individual localization centers. Microphotoluminescence spectroscopy confirms the spectrally inhomogeneous distribution of localization centers, in which the exciton and the biexciton related emissions from single centers of varying geometry could be identified by means of excitation power dependencies. Interestingly, the biexciton binding energy (Ebxx) was found to vary from center to center, between 3 to −22 meV, in correlation with the exciton emission energy. Negative binding energies are only justified by a three-dimensional quantum confinement, which confirms QD-like properties of the localization centers. The observed energy correlation is proposed to be understood as variations of the lateral extension of the confinement potential, which would yield smaller values of Ebxx for reduced lateral extension and higher exciton emission energy. The proposed relation between lateral extension and Ebxx is further supported by the exciton and the biexciton recombination lifetimes of a single QD, which suggest a lateral extension of merely ∼3 nm for a QD with strongly negative Ebxx = −15.5 meV.
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| 33. |
- Andersson, Inger, 1964, et al.
(författare)
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Health-related quality of life in patients undergoing allogeneic stem cell
- 2009
-
Ingår i: Cancer Nursing. - 0162-220X. ; 32:4
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this prospective study was to describe health-related quality of life (HRQOL) in patients during the first year after stem cell transplantation (SCT) who were undergoing reduced intensive conditioning (RIC) compared with patients undergoing myeloablative conditioning (MAC). Fifty-seven patients (25 for MAC and 32 for RIC) were enrolled in the study. HRQOL was assessed at 6 occasions during the first year after SCT using European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and the 19-item treatment-specific module High-Dose Chemotherapy. Both groups reported most symptoms and worst functioning 1 month after SCT, but there were substantial differences. The MAC group deteriorated considerably in 20 symptom scales compared with 8 in the RIC group (score differences <10; P values ranged from .001 to .05). Dry mouth, sore mouth, appetite loss, and change of taste were among the most frequent symptoms in both groups. Thereafter, the functioning improved and the symptom scores decreased and returned to baseline in both groups, except dry mouth, which remained a worse problem for the MAC group. Overall, the RIC group regained health and QOL faster than the MAC group did. However, there were no significant differences in global QOL between the groups 1 year after SCT.
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| 34. |
- Andersson, Inger, 1964, et al.
(författare)
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Health related quality of life in stem cell transplantation: clinical and psychometric validation of the questionnaire module, High Dose Chemotherapy (HDC-19).
- 2008
-
Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 47:2, s. 275-85
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to assess the psychometric properties of the HDC-19, a module questionnaire for assessing symptoms and problems of patients undergoing stem cell transplantation (SCT) following high-dose chemotherapy (HDC). It consists of 19 questions and was developed for use in conjunction with EORTC QLQ-C30. Psychometric evaluations were performed according to guidelines recommended by the EORTC. The principal component analyses suggested that nine of the HDC-19 items could be reduced to four components (sexual functioning, future health perspectives, skin irritations and joint/muscle pain). Multitrait scaling analysis showed that most item-scale correlation coefficients met the standards of convergent (>0.40) and discriminant validity. Test-retest reliability coefficients between assessments at inclusion and admission were high, indicating that perceived health status remained virtually unchanged during this period. As expected, correlations between admission and one month after transplantation were considerably lower. The internal consistency of the multi-item scales was also satisfactory, (Cronbach's alpha 0.59-0.87). Overall, the known-groups comparisons showed smaller differences between designated groups than expected. As expected, changes in the HDC-19 mirrored changes in QLQ-C30 'global quality of life'. These results lend support to the validity of the HDC-19 as a supplementary questionnaire for assessing specific health-related quality of life (HRQOL) issues relevant for SCT patients.
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| 35. |
- Andersson, Inger, 1964, et al.
(författare)
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Patients' perception of health-related quality of life during the first year after autologous and allogeneic stem cell transplantation.
- 2011
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Ingår i: European journal of cancer care. - : Hindawi Limited. - 1365-2354 .- 0961-5423. ; 20:3, s. 368-379
-
Tidskriftsartikel (refereegranskat)abstract
- Little attention has been paid to examine health-related quality of life (HRQoL) the first year post-transplant, despite that this period is crucial for returning to normal life and functioning and to prevent delayed psychosocial adjustment. The purpose of the present study was to describe HRQoL after autologous versus allogeneic stem cell transplantations during the first year post-transplant. The allogeneic group was further divided into two groups: allogeneic stem cell transplantation after reduced intensive conditioning and allogeneic stem cell transplantation after myeloablative conditioning. All together 202 patients were enrolled in the study. HRQoL was assessed by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and the treatment-specific module High-Dose Chemotherapy (HDC-19). The questionnaires were filled out at six occasions (from inclusion to 12 months after transplantation). The reduced intensive conditioning group seemed to recover in the same way as the autologous group and these two groups were closer in their scoring compared with the myeloablative conditioning group. One month after the transplantation there were no significant differences in change scores between the autologous and reduced intensive conditioning group, and 1 year after the transplantation levels of symptoms and functioning were back to baseline or better. The myeloablative conditioning group, who perceived more symptoms and lower levels of functioning during the whole period, was still impaired in 10 out of 29 scales 1 year after the transplantation and no significant improvements compared with baseline were observed for this group.
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| 36. |
- Andersson, Lars-Olof, et al.
(författare)
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Ice adhesion to rubber materials
- 1994
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Ingår i: Journal of Adhesion Science and Technology. - 0169-4243 .- 1568-5616. ; 8:2, s. 117-132
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the interfacial shear strength between ice and rubbers. Different rubber materials containing only a polymer and curing agent (peroxide) were tested with regard to surface wettability and interfacial shear strength. The effect of different grades and amounts of carbon black filler was also studied. The wettability was determined from contact angles, using water and diiodomethane as test liquids, measured on carefully cleaned and mirror smooth rubber sheets.
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| 37. |
- Andren, Henrik, et al.
(författare)
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De stora rovdjurens effekter på annat vilt och tamren
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den teoretiska bakgrunden ger en beskrivning av termer och fackuttryck, samt beskrivningar av hur olika faktorer påverkar relationerna mellan rovdjur och bytesdjur. Termen predator är synonymt med rovdjur, medan termen predation står för den process som består av dödande och konsumtion av bytesdjur, och omfattningen av den dödlighet hos bytesdjuren som rovdjuret orsakar. Rovdjurens påverkan på bytespopulationer varierar mellan områden och över tid, samtidigt som rovdjuren själva påverkas av bytespopulationerna. Rovdjur-bytesdjurssystemen är alltså inte bara dynamiska utan också interaktiva, d.v.s. de påverkar varandra. Rovdjurens påverkan på bytespopulationen beror i princip på fem faktorer: (1) bytespopulationens storlek, (2) bytespopulationens produktivitet/tillväxttakt, (3) rovdjurspopulationens storlek, (4) rovdjurspopulationens produktivitet/tillväxttakt samt (5) antalet bytesdjur tagna per rovdjur och tidsenhet (den s.k. funktionella responsen). Predation är ofta en kombination av additiv och kompensatorisk dödlighet. Med additiv dödlighet menar man att predationen läggs ovanpå (adderas till) annan dödlighet, med kompensatorisk dödlighet menar man att predationen ersätter annan typ av dödlighet. Ju större andel av predationen som är additiv desto större blir effekterna på bytesdjuren. Rovdjuren kan påverka sina bytesdjur inte bara genom direkt predation utan även genom att bytesdjuren ändrar sitt beteende i närvaron av rovdjuren. Rovdjuren är en del av ekosystemet, som förenklat består av producenter (växter), primärkonsumenter (växtätare) och sekundärkonsumenter (predatorer). Dessa delar kan också beskrivas som olika trofinivåer i ekosystemet. En mer komplex beskrivning av ett ekosystem är att arter är ordnade i ett nätverk av interaktioner både mellan och inom trofiska nivåer, s.k. näringsvävar. I komplexa näringsvävar ökar antalet interaktioner mellan arter både inom trofinivåer och mellan trofinivåer, vilket försvagar specifika interaktioner mellan enskilda arter. I Sverige saknas stora områden som är helt opåverkade av mänskliga aktiviteter, vilket gör människan till den viktigaste aktören för storskalig påverkan på ekosystem över hela landet. Människan påverkar ekosystemet på många sätt, t.ex. genom markanvändning, jakt, andra ingrepp och förvaltningsåtgärder, och kan helt förändra dynamiken mellan rovdjur och bytesdjur.Även ett kortfaktablad om rovdjurens effekter finns att ladda ned.Hur påverkar de stora rovdjuren bytesdjurens populationer?Grimsö forskningsstation vid Sveriges lantbruksuniversitet (SLU) har för Naturvårdsverkets räkning gjort en översikt av kunskapsläget om hur de stora rovdjuren påverkar de bytesdjur de jagar, det vill säga vilt och tamren. Hela rapporten, De stora rovdjurens effekter på annat vilt och tamren, kan du läsa här, eller på Naturvårdsverkets hemsida.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Averfalk, Helge, 1988-
(författare)
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Enhanced District Heating Technology : Maintaining Future System Feasibility
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- When heat demand and high temperature heat supply gradually decreases in the future, then it will effect district heating systems ability to compete on the heat market. A good way to mitigate less district heating feasibility is to operate systems with lower temperature levels and the most conceivable way to achieve lower temperature levels is to decrease return temperatures.Thus, this thesis emphasise temperature errors embedded in district heating systems. Only a selection of temperature errors are analysed in this thesis. First, the temperature error that occurs due to recirculation in distribution networks at low heat demands. Second, the temperature error that occurs due to hot water circulation in multi-family buildings. Third, the temperature error that occurs due to less than possible heat transfer in heat exchangers, i.e. too short thermal lengths.In order to address these temperature errors three technology changes have been proposed (i) three-pipe distribution network to separate the recirculation return flow from the delivery return flow, (ii) apartment substations to eliminate hot water circulation utilisation, and (iii) improved heat exchangers for lower return temperatures at a constant scenario. Analysis of proposed changes has resulted in annual average return temperatures between 17-21 °C.Furthermore, rapid introduction of intermittent renewable electricity supply in the energy system has prompted an increased necessity of power system balancing capacities. Large-scale conversion of power-to-heat in electric boilers and heat pumps is a feasible alternative to achieve such balancing capacities. Analysis of the unique Swedish experience with utilisation of large heat pumps installations connected to district heating systems show that since the 1980s 1527 MW of heat power has been installed, about 80 % of the capacity was still in use by 2013. Thus, a cumulative value of over three decades of operation and maintenance exists within Swedish district heating systems.The two papers presented in this thesis are related to future district heating systems through the five abilities of fourth generation district heating (4GDH), which are documented in the definition paper of 4GDH.
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| 42. |
- Bark, Björn, et al.
(författare)
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Importance of the Infusion Rate for the Plasma Expanding Effect of 5% Albumin, 6% HES 130/0.4, 4% Gelatin, and 0.9% NaCl in the Septic Rat.
- 2013
-
Ingår i: Critical Care Medicine. - 1530-0293. ; 41:3, s. 857-866
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES:: To compare the plasma volume (PV) expanding effect of a fast infusion rate with that of a slow infusion rate of a fixed volume of 5% albumin, of the synthetic colloids, 6% hydroxyethyl starch 130/0.4 and 4% gelatin, and of 0.9% NaCl in a rat sepsis model and to compare the plasma-expanding effect among these fluids. DESIGN:: Prospective, randomized animal study. SETTING:: University hospital laboratory. SUBJECTS:: One hundred and twelve adult male rats. INTERVENTIONS:: Sepsis was induced by cecal ligation and incision followed by closure of the abdomen. After 3 hrs, an infusion of the PV expander under study was started at a volume of 12 mL/kg for the colloids and of 48 mL/kg for 0.9% NaCl, either for 15 mins or for 3 hrs. A control group underwent the same experimental procedure but no fluid was given. MEASUREMENTS AND MAIN RESULTS:: Three hours after start of the infusion (end of experiment), the plasma-expanding effect was better with a slow than a fast infusion rate for the colloids, especially albumin, but the NaCl groups did not differ significantly from the control group. The PV for the control group was 28.7 ± 3 mL/kg. In the slow and the fast infusion groups, it was 38.9 ± 4.3 and 32.6 ± 4.2 mL/kg for albumin (p < 0.001), 32.9 ± 4.3 and 29.5 ± 4.4 mL/kg for hydroxyethyl starch 130/0.4 (p < 0.05), 31.8 ± 3.9 and 28.2 ± 4.1 mL/kg for gelatin (p < 0.05), and 31.8 ± 5.3 and 30.7 ± 6.6 mL/kg for NaCl (n.s), respectively. CONCLUSIONS:: The study showed that the PV expansion by a colloid was greater when given at a slow than at a fast infusion rate, an effect more pronounced for albumin. This difference was not seen for NaCl. The PV-expanding effect was poor for NaCl and better for albumin than for the other colloids.
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| 43. |
- Bergemalm, Per-Olof, et al.
(författare)
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Perception of the acoustic environment and neuroimaging findings : a report of six cases with a history of closed head injury
- 2009
-
Ingår i: ACTA OTO-LARYNGOLOGICA. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 129:7, s. 801-808
-
Tidskriftsartikel (refereegranskat)abstract
- Conclusion: The main finding was the relation between difficulty in determining the direction of movement of a sound source and frontal lesions and poor working memory. Poor correspondence in some cases between functional findings and imaging findings can be due to the possibility of axonal degeneration as well as plastic reorganization. Objective: The purpose of the present investigation of six cases was to identify auditory, cognitive and neuroimaging long-term sequelae of closed head injury (CHI) with particular focus on environmental sound recognition and moving sound sources. Subjects and methods: Six subjects who had experienced CHI were investigated with auditory tests. Four subjects also completed cognitive testing. CT and MRI were performed. Results: There was a large individual variability of the test results with respect to morphological findings. In five cases with central auditory processing disorders morphological brain damage was demonstrated. Two cases with shortcomings on cognitive testing and with frontal brain lesions demonstrated problems in determining the direction of movement of a sound source. The results may indicate that basal frontal lobe structures play a role in following and determining the direction of movement of a sound source. Two cases had problems with environmental sound recognition; in one left temporal brain lesions were demonstrated.
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| 44. |
- Bergh, Anne-Louise, et al.
(författare)
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Psychometric properties of the Swedish version of the Well-Being Questionnaire in a sample of patients with diabetes type 1.
- 2000
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Ingår i: Scandinavian journal of public health. - : Sage Publications Ltd.. - 1403-4948 .- 1651-1905. ; 28:2, s. 137-45
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The aim of the present investigation was to further test the psychometric properties of a Swedish version of the Well-Being Questionnaire (WBQ) in order to determine whether it could be suitable for measuring health-related quality of life among type 1 diabetic patients. METHODS: In total, 94 patients who fulfilled the inclusion criteria were selected for the study and of these 85% participated. Reliability was tested with Cronbach's alpha coefficient and the internal validity by means of principal component analysis and multitrait analysis. To test the external validity, comparisons were made with two other questionnaires, the Short form-36 and a Swedish Mood Adjective Check List. RESULTS: The results show that, above all, the Swedish version of the WBQ measures psychological well-being, and thus must also be complemented with scales that measure other consequences of the illness and/or treatment, i.e. physical symptoms. The questionnaire has low discriminatory validity between subscales, which casts doubt on the appropriateness of using the four subscales as separate measures. The two scales measuring anxiety and depression are not sensitive enough for use among type 1 diabetics without complications and high or normal levels of psychological well-being. CONCLUSIONS: The Well-Being Questionnaire alone does not give any more information about subjective health status among type 1 diabetic patients than, for example, the generic SF-36.
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| 45. |
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| 46. |
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| 47. |
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| 48. |
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| 49. |
- Björk, Glenn, et al.
(författare)
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A conserved modified wobble nucleoside (mcm5s2U) in lysyl-tRNA is required for viability in yeast.
- 2007
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Ingår i: RNA. - : Cold Spring Harbor Laboratory. - 1355-8382 .- 1469-9001. ; 13:8, s. 1245-55
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Tidskriftsartikel (refereegranskat)abstract
- Transfer RNAs specific for Gln, Lys, and Glu from all organisms (except Mycoplasma) and organelles have a 2-thiouridine derivative (xm(5)s(2)U) as wobble nucleoside. These tRNAs read the A- and G-ending codons in the split codon boxes His/Gln, Asn/Lys, and Asp/Glu. In eukaryotic cytoplasmic tRNAs the conserved constituent (xm(5)-) in position 5 of uridine is 5-methoxycarbonylmethyl (mcm(5)). A protein (Tuc1p) from yeast resembling the bacterial protein TtcA, which is required for the synthesis of 2-thiocytidine in position 32 of the tRNA, was shown instead to be required for the synthesis of 2-thiouridine in the wobble position (position 34). Apparently, an ancient member of the TtcA family has evolved to thiolate U34 in tRNAs of organisms from the domains Eukarya and Archaea. Deletion of the TUC1 gene together with a deletion of the ELP3 gene, which results in the lack of the mcm(5) side chain, removes all modifications from the wobble uridine derivatives of the cytoplasmic tRNAs specific for Gln, Lys, and Glu, and is lethal to the cell. Since excess of the unmodified form of these three tRNAs rescued the double mutant elp3 tuc1, the primary function of mcm(5)s(2)U34 seems to be to improve the efficiency to read the cognate codons rather than to prevent mis-sense errors. Surprisingly, overexpression of the mcm(5)s(2)U-lacking tRNA(Lys) alone was sufficient to restore viability of the double mutant.
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| 50. |
- Björk, Glenn R, et al.
(författare)
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A primordial tRNA modification required for the evolution of life?
- 2001
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Ingår i: EMBO Journal. - : Wiley. - 0261-4189 .- 1460-2075. ; 20:1-2, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of reading frame maintenance must have been an early event, and presumably preceded the emergence of the three domains Archaea, Bacteria and Eukarya. Features evolved early in reading frame maintenance may still exist in present-day organisms. We show that one such feature may be the modified nucleoside 1-methylguanosine (m(1)G37), which prevents frameshifting and is present adjacent to and 3' of the anticodon (position 37) in the same subset of tRNAs from all organisms, including that with the smallest sequenced genome (Mycoplasma genitalium), and organelles. We have identified the genes encoding the enzyme tRNA(m(1)G37)methyltransferase from all three domains. We also show that they are orthologues, and suggest that they originated from a primordial gene. Lack of m(1)G37 severely impairs the growth of a bacterium and a eukaryote to a similar degree. Yeast tRNA(m(1)G37)methyltransferase also synthesizes 1-methylinosine and participates in the formation of the Y-base (yW). Our results suggest that m(1)G37 existed in tRNA before the divergence of the three domains, and that a tRNA(m(1)G37)methyltrans ferase is part of the minimal set of gene products required for life.
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