| 1. |
- Agnarsson, Björn, 1977, et al.
(author)
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Rutile TiO 2 thin films grown by reactive high power impulse magnetron sputtering
- 2013
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In: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 545, s. 445-450
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Journal article (peer-reviewed)abstract
- Thin TiO 2 films were grown on Si(001) substrates by reactive dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS) at temperatures ranging from 300 to 700 C.Optical and structural properties of films were compared both before and after post-annealing using scanning electron microscopy, low angle X-ray reflection (XRR), grazing inc idence X-ray diffractometry and spectroscopic ellipsometry.Both dcMS- and HiPIMS-grown films reveal polycrystalline rutile TiO 2 , even prior to post-annealing.The HiPIMS-grown films exhibit significantly larger grains compared to that of dcMC-grown films, approaching 100% of the film thickness for films grown at 700 C.In addition, the XRR surface roughness of HiPIMS-grown films was significantly lower than that of dcMS-grown films over the whole temperature range 300-700 C.Dispersion curves could only be obtained for the HiPIMS-grown films, which were shown to have a refractive index in the range of 2.7-2.85 at 500 nm.The results show that thin, rutile TiO 2 films, with high refractive index, can be obtained by HiPIMS at relatively low growth temperatures, without post-annealing.Furthermore, these films are smoother and show better optical characteristics than their dcMS-grown counterparts.© 2013 Elsevier B.V.All rights reserved.
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| 2. |
- Alsafi, Zahraa, et al.
(author)
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Myocardial performance index in female athletes.
- 2017
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In: Cardiovascular Ultrasound. - : BioMed Central. - 1476-7120. ; 15
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Journal article (peer-reviewed)abstract
- Background: Long-term intensive training leads to morphological and mechanical changes in the heart generally known as “athlete’s heart”. Previous studies have suggested that the diastolic and systolic function of the ventricles is unaltered in athletes compared to sedentary. The purpose of this study was to investigate myocardial performance index (MPI) by pulsed wave Doppler (PWD) and by tissue Doppler imaging (TDI) in female elite athletes compared to sedentary controls. Methods: The study consisted of 32 athletes (mean age 20 ± 2 years) and 34 sedentary controls (mean age 23 ± 2 years). MPI by PWD and TDI were measured in the left (LV) and right ventricle (RV) in both groups. Moreover, comparisons of MPI by the two methods and between the LV and RV within the two groups were made. Results: There were no significant differences in MPI between athletes and controls (p > 0.05), whereas the LV had significantly higher MPI compared to RV (p < 0.001, in athletes and controls). The agreement and the correlation between the two methods measuring MPI showed low agreement and no correlation (athletes RV r = −0.027, LV r = 0.12; controls RV r = 0.20, LV r = 0.30). Conclusion: The global function of the LV and RV measured by MPI with PWD and TDI is similar in female athletes compared to sedentary controls. Conversely, both MPI by PWD and by TDI shows a significant difference between the LV and RV. However, the agreement and correlation between conventional methods of measuring MPI by PWD compared to MPI by TDI is very poor in both these populations.
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| 3. |
- Broberg, Martin, et al.
(author)
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Comparative genomics highlights the importance of drug efflux transporters during evolution of mycoparasitism in Clonostachys subgenus Bionectria (Fungi, Ascomycota, Hypocreales)
- 2021
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In: Evolutionary applications. - : Wiley. - 1752-4571. ; 14, s. 476-497
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Journal article (peer-reviewed)abstract
- Various strains of the mycoparasitic fungal speciesClonostachys roseaare used commercially as biological control agents for the control of fungal plant diseases in agricultural crop production. Further improvements of the use and efficacy ofC. roseain biocontrol require a mechanistic understanding of the factors that determines the outcome of the interaction betweenC. roseaand plant pathogenic fungi. Here, we determined the genome sequences of 11Clonostachysstrains, representing five species inClonostachyssubgenusBionectria, and performed a comparative genomic analysis with the aim to identify gene families evolving under selection for gene gains or losses. Several gene families predicted to encode proteins involved in biosynthesis of secondary metabolites, including polyketide synthases, nonribosomal peptide syntethases and cytochrome P450s, evolved under selection for gene gains (p <= .05) in theBionectriasubgenus lineage. This was accompanied with gene copy number increases (p <= .05) in ATP-binding cassette (ABC) transporters and major facilitator superfamily (MFS) transporters predicted to contribute to drug efflux. MostClonostachysspecies were also characterized by high numbers of auxiliary activity (AA) family 9 lytic polysaccharide monooxygenases, AA3 glucose-methanol-choline oxidoreductases and additional carbohydrate-active enzyme gene families with putative activity (or binding) towards xylan and rhamnose/pectin substrates. Particular features of theC. roseagenome included expansions (p <= .05) of the ABC-B4 multidrug resistance transporters, the ABC-C5 multidrug resistance-related transporters and the 2.A.1.3 drug:H + antiporter-2 MFS drug resistance transporters. The ABC-G1 pleiotropic drug resistance transporter geneabcG6inC. roseawas induced (p <= .009) by exposure to the antifungalFusariummycotoxin zearalenone (1121-fold) and various fungicides. Deletion ofabcG6resulted in mutants with reduced (p < .001) growth rates on media containing the fungicides boscalid, fenhexamid and iprodione. Our results emphasize the role of biosynthesis of, and protection against, secondary metabolites inClonostachyssubgenusBionectria.
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| 4. |
- Carlson, Elisabeth, et al.
(author)
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Students´ Experiences of Participation in a Research Team : Evaluation of a Research-based Teaching Activity in HigherEducation
- 2022
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In: International Journal for the Scholarship of Teaching & Learning. - : Faculty Center at Georgia Southern University. - 1931-4744. ; 16:3
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Journal article (peer-reviewed)abstract
- AbstractIn Sweden as well as internationally the teaching and research nexus has been described as the defining charac-teristics of higher education promoting generic skills such as information analysis and critical reflection. Vertically Integrated Projects has been proposed as one educational strategy where research and teaching are linked by in-viting students to take active part in actual research projects. The strategy is well aligned to Scholarship of teaching and learning enabling the transition from a teacher-centred accepted knowledge to a student-centred perspective where students are invited as producers of knowledge. The aim of the current study was to explore students’ experiences of participation in a research-based learning activity with academia and industrial partners, designed as a qualitative explorative study using focus group interviews. Findings describe not only factors students find motivating for learning, but also their experience of being part of professional life with its benefits and challenges.
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| 5. |
- Cirovic, Stefan, et al.
(author)
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Vortex formation time in female athletes
- 2024
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In: The International Journal of Cardiovascular Imaging. - : Springer Nature. - 1569-5794 .- 1875-8312. ; 40:2, s. 373-384
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Journal article (peer-reviewed)abstract
- Regular, vigorous physical activity can have a significant impact on cardiac function, leading to cardiac morphological alterations that may be challenging to distinguish from pathological changes. Therefore, new screening methods are needed to accurately differentiate between adaptive changes and pathological alterations in athletes. Vortex formation time (VFT) is an emerging method that shows potential in this regard, as it involves the formation of a rotating vortex ring in the left ventricle during the early filling phase of diastole. In this study, we investigated the difference in VFT between two groups of women: professional handball players and healthy middle-aged female athletes, along with their corresponding control groups. By using echocardiography-Doppler analysis of the heart, VFT was calculated based on the left ventricular ejection fraction, the ratio between the end-diastolic volume and the diameter of the mitral annulus, and the ratio of the atrial contraction volume to the total inflow via the mitral valve. The study reveals a significant increase in VFT in both professional handball players and middle-aged female athletes compared to their respective control groups. Moreover, statistically significant differences between handball players and middle-aged female athletes were observed, indicating that the level of physical activity may affect the VFT. These results suggest that VFT could be a promising screening tool for identifying cardiac adaptations due to long-term vigorous training, potentially enabling more accurate diagnoses of cardiac morphological alterations in athletes. Representation of the graphical abstract of the conducted research.
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| 6. |
- Dubey, Mukesh, et al.
(author)
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Evolution and functional characterization of pectate lyase PEL12, a member of a highly expanded Clonostachys rosea polysaccharide lyase 1 family
- 2018
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In: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 18
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Journal article (peer-reviewed)abstract
- BackgroundPectin is one of the major and most complex plant cell wall components that needs to be overcome by microorganisms as part of their strategies for plant invasion or nutrition. Microbial pectinolytic enzymes therefore play a significant role for plant-associated microorganisms and for the decomposition and recycling of plant organic matter. Recently, comparative studies revealed significant gene copy number expansion of the polysaccharide lyase 1 (PL1) pectin/pectate lyase gene family in the Clonostachys rosea genome, while only low numbers were found in Trichoderma species. Both of these fungal genera are widely known for their ability to parasitize and kill other fungi (mycoparasitism) and certain species are thus used for biocontrol of plant pathogenic fungi.ResultsIn order to understand the role of the high number of pectin degrading enzymes in Clonostachys, we studied diversity and evolution of the PL1 gene family in C. rosea compared with other Sordariomycetes with varying nutritional life styles. Out of 17 members of C. rosea PL1, we could only detect two to be secreted at acidic pH. One of them, the pectate lyase pel12 gene was found to be strongly induced by pectin and, to a lower degree, by polygalacturonic acid. Heterologous expression of the PEL12 in a PL1-free background of T. reesei revealed direct enzymatic involvement of this protein in utilization of pectin at pH5 without a requirement for Ca2+. The mutants showed increased utilization of pectin compounds, but did not increase biocontrol ability in detached leaf assay against the plant pathogen Botrytis cinerea compared to the wild type.ConclusionsIn this study, we aimed to gain insight into diversity and evolution of the PL1 gene family in C. rosea and other Sordariomycete species in relation to their nutritional modes. We show that C. rosea PL1 expansion does not correlate with its mycoparasitic nutritional mode and resembles those of strong plant pathogenic fungi. We further investigated regulation, specificity and function of the C. rosea PEL12 and show that this enzyme is directly involved in degradation of pectin and pectin-related compounds, but not in C. rosea biocontrol.
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| 7. |
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| 8. |
- Fischer, D., et al.
(author)
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Importance of Thomas single-electron transfer in fast p-He collisions
- 2010
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 81:1, s. 12714-
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Journal article (peer-reviewed)abstract
- We report experimental angular differential cross sections for nonradiative single-electron capture in p-He collisions (p + He -> H + He+) with a separate peak at the 0.47 mrad Thomas scattering angle for energies in the 1.3-12.5 MeV range. We find that the intensity of this peak scales with the projectile velocity as v(P)(-11). This constitutes the first experimental test of the prediction from 1927 by L. H. Thomas [Proc. R. Soc. 114, 561 (1927)]. At our highest energy, the peak at the Thomas angle contributes with 13.5% to the total integrated nonradiative single-electron capture cross section.
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| 9. |
- Gillblad, Daniel, et al.
(author)
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Approximating process simulators with learning systems
- 2005. - 1
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Reports (other academic/artistic)abstract
- We explore the possibility of replacing a first principles process simulator with a learning system. This is motivated in the presented test case setting by a need to speed up a simulator that is to be used in conjunction with an optimisation algorithm to find near optimal process parameters. Here we will discuss the potential problems and difficulties in this application, how to solve them and present the results from a paper mill test case.
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| 10. |
- Gudmundsson, Magnus, et al.
(author)
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Angular scattering in fast ion-atom electron transfer collisions : projectile wave diffraction and Thomas mechanisms
- 2010
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In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 43:18, s. 185209-
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Journal article (peer-reviewed)abstract
- We report experimental angular differential cross sections for double-electron capture in He2+ + He collisions and single-electron capture in H+ + He collisions for the 1.3-12.5 MeV kinetic energy range. In all cases, the total cross sections are dominated by forward scattering peaks in d sigma/d Omega. The shapes and widths (but not the magnitudes) of these peaks are very similar for all energies and for capture of one or two electrons corresponding also to our measured linear increases in the transverse momentum transfers with increasing projectile velocities. These observations may be ascribed to diffraction limitations which are connected to electron transfer probabilities P(b) which are significant in limited regions of b only. For the H+ + He single-electron capture we observe two additional maxima in the angular differential cross sections. We conclude that while the secondary maxima at similar to 0.5 mrad probably have large contributions from the Thomas proton-electron-nucleus scattering mechanism, the third maxima at similar to 0.75 mrad are most likely mainly due to projectile de Broglie wave diffraction.
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| 11. |
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| 12. |
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| 13. |
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| 14. |
- Gudmundsson, Magnus, 1979-
(author)
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Heavy particle interference and diffraction in fast electron transfer collisions
- 2011
-
Doctoral thesis (other academic/artistic)abstract
- This thesis presents experimental results from the synchrotron cooler and storage ring CRYRING on charge transfer processes in fast electron transfer collisions using high-resolution cold target recoil-ion momentum spectroscopy. The main focus of these studies was to investigate a key concept of quantum mechanics: the wave-particle duality. One series of experiments has been dedicated to the study of heavy particle de Broglie wave interference due to scattering on a molecular ’double slit’. This is a fundamental manifestation of the wave properties of matter. Quantum interference oscillations were observed in the target orientation dependent cross section of single- and double-electron capture from H2 to 1.3 MeV protons and to 1.2 and 2.0 MeV He2+ ions. Another study, included in this work, is a series of angular differential cross section measurements for single-electron capture to 1.3-12.5 MeV kinetic energy protons from He that enabled us to systematically investigate the classically allowed non-radiative electron capture process in fast collisions predicted by L. H. Thomas in 1927. The cross section for this process is expected to have a nonrelativistic, asymptotic dependence on the projectile velocity, vp, of vp−11. This prediction (from 1927) was verified experimentally for the first time through the present measurements. Using the above mentioned experimental data in addition to measurements of double electron capture by 6.0 MeV He2+ from He, we have also studied the dominating, central part of the angular differential cross section, dσ/dΩ, where the peak shapes and widths surprisingly are very similar regardless of projectile energy and the number of captured electrons. We explain this with a diffraction model for the electron capture and calculate the corresponding diffracting electron capture ‘apertures’ from the shapes and widths of the measured cross sections and the projectile de Broglie wavelengths. We have on one hand established very strong experimental support for the picture suggested by Thomas in 1927 in which electrons and protons are described as classical particles. On the other hand, the diffraction picture describes the shapes of the central peaks in dσ/dΩ quite well, and nicely explains appearances of second and a third maxima in the angular differential cross section. It is hard to see how these seemingly contradicting results can be explained through complementary classical and quantum descriptions of the same underlying physical processes.
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| 15. |
- Gudmundsson, Magnus, et al.
(author)
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How to analyse Practice in the New Age Movement
- 2001
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In: Pathways : Approaches to the Study and Teaching of Folklore - Approaches to the Study and Teaching of Folklore. - 1455-9129. - 9521208473 ; 9
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Book chapter (peer-reviewed)
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| 16. |
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| 17. |
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| 18. |
- Gudmundsson, Magnus
(author)
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Tarot : New age i bild och berättelse
- 2001
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Doctoral thesis (other academic/artistic)abstract
- In the course of my dissertation work, I have sought knowledge about what New Age is, contains, and conveys by looking at practice and rhetoric, how the participants act and reason regarding their commitment, as well as how the contents of the field is discussed. I have put an emphasis on the small details: the objects, the rituals, and the narrating. Using the tarot cards as a starting point, the purpose is to analyse and disclose practices and structures within New Age with the help of theories about cultural reserves, text, and discourse. The dissertation starts from one sole New Age practice: tarot. Tarot cards are used and interpreted according to a particular ritual and manual. The cards can be bought in New Age shops and in ordinary bookshops. They are used privately, in groups, and professionally. In the right situation the cards form the basis of discussions, give rise to reflections, and are also seen as a link to an occult reality. The reading of the tarot cards inspires to reflect upon everyday issues as health, money, and relations. The tarot readers interpret symbols and pictures as well as mediate imaginary worlds. Tarot is one example of practice within New Age. Tarot is said to be an ancient practice dating back to Old Egypt and the Middle or Far East. There exist a great many sources and references aiming at legitimising the authenticity of the cards. Today, the practice of reading cards can be found in New Age. A hundred years ago the reading was performed by poor or outcast women. Rider Waite Tarot and Thoth Tarot are examples of how tarot cards have been designed differently. The tarot card Death illustrates a central theme within New Age: changes in man and society. A meeting between a professional tarot reader and her/his client will end up in a dialogue regarding life, death, love, money, and work. The conversation primarily turns on the present and the past. The reader talks about earlier lives that are said to have influenced the client’s present situation. The Tarot reading demands a special setting, e.g. incense, rituals, or evocative music. The set-up of the tarot reading differs depending on who is participating, their actions, and the actual narrating. The tarot readers vary their linguistic behaviour to achieve certain purposes. What is central to the practisers is the individual experience. It is based on the latter that beliefs are put together. They refer to energies, holism, conscious outsiderness, reincarnation, and extraterrestial beings/deities/forces. These themes are in one way or another common to most people who act within the New Age field. Despite its disparate composition, New Age contains some dogmatic themes. Within society there is an order of discourse that is governed by and influence the way we act, talk, and think. Discussions about and within New Age is thusly governed and influenced by this order of discourse. New Age receives, or at least has received, a good deal of attention in media, which may be due to the marginal but challenging role of the field. This has, among other things, lead to practisers feeling obliged to clarify and legitimise their actions. New Age illustrates the conflict in our time between the rational and the irrational, between science and faith.
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| 19. |
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| 20. |
- Gudmundsson, Magnus, et al.
(author)
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Two-site double-core-hole states formed when fast protons capture electrons from aligned N2
- 2011
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In: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 44:17, s. 175201-
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Journal article (peer-reviewed)abstract
- We report on an experimental investigation of 1.04 MeV H++N2 electron transfer collisions. The fast protons were stored in the electron-cooler ion-storage ring, CRYRING and the molecular nitrogen target was provided with a supersonic gas jet. We report momentum distributions of atomic nitrogen dissociation products Nq+ with charge states q+ (q=1, 2, 3) which are detected in coincidence with neutralized projectiles. Further, we investigate the influence of the angle between the direction of the incoming projectile beam and the target molecular axis. The orientation of the latter is determined a posteriorly from the momentum vector of one emitted atomic nitrogen fragment ion. We find signicantly higher total yields, dominated by N+, of charged atomic dissociation products when the N2 molecular axis is perpendicular to the incoming H+-beam. The relative contributions from N2+- and N3+- fragments, however, are strongest when the N2 axis is aligned -or close to aligned- with the ion beam. This, we suggest, is due to increased probabilities for formation of two-site double-core-hole states.
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| 21. |
- Gudmundsson, Petri, et al.
(author)
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Head to head comparisons of two modalities of perfusion adenosine stress echocardiography with simultaneous SPECT
- 2009
-
In: Cardiovascular Ultrasound. - : BioMed Central. - 1476-7120. ; 7:19
-
Journal article (peer-reviewed)abstract
- Background: Real-time perfusion (RTP) contrast echocardiography can be used during adenosine stress echocardiography (ASE) to evaluate myocardial ischemia. We compared two different types of RTP power modulation techniques, angiomode (AM) and high-resolution grayscale (HR), with 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia. Methods: Patients with known or suspected coronary artery disease (CAD), admitted to SPECT, were prospectively invited to participate. Patients underwent RTP imaging (SONOS 5500) using AM and HR during Sonovue® infusion, before and throughout the adenosine stress, also used for SPECT. Analysis of myocardial perfusion and wall motion by RTP-ASE were done for AM and HR at different time points, blinded to one another and to SPECT. Each segment was attributed to one of the three main coronary vessel areas of interest. Results: In 50 patients, 150 coronary areas were analyzed by SPECT and RTP-ASE AM and HR. SPECT showed evidence of ischemia in 13 out of 50 patients. There was no significant difference between AM and HR in detecting ischemia (p = 0.08). The agreement for AM and HR, compared to SPECT, was 93% and 96%, with Kappa values of 0.67 and 0.75, respectively (p < 0.001). Conclusion: There was no significant difference between AM and HR in correctly detecting myocardial ischemia as judged by SPECT. This suggests that different types of RTP modalities give comparable data during RTP-ASE in patients with known or suspected CAD.
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| 22. |
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| 23. |
- Gudmundsson, Pia, 1978, et al.
(author)
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Longitudinal associations between physical activity and depression scores in Swedish women followed 32 years
- 2015
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In: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 132:6, s. 451-458
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Journal article (peer-reviewed)abstract
- Objective: Physical activity is negatively associated with depressive symptoms. However, few studies consider dynamic associations of changes in physical activity and reciprocal relationships. This study aimed to perform comprehensive evaluations of relationships between physical activity and depression scores in women followed from mid- to late life. Method: The Prospective Population Study of Women in Gothenburg, Sweden, provided repeated measures of self-reported physical activity and depressive symptoms between 1974 and 2005 (baseline N = 676, 84.5% response rate). Depressive symptoms were assessed using the Montgomery–Åsberg Depression Rating Scale, and physical activity was evaluated by the Saltin–Grimby Physical Activity Level Scale. Latent growth curve analyses were used to evaluate associations of change, and cross-lagged models were used to study the reciprocal relationship between physical activity and depression scores. Results: At baseline, lower levels of physical activity were related to higher depression scores. Individuals with decreasing physical activity over time evidenced higher depression scores at 32-year follow-up. Higher average baseline depression score was related to declining levels of physical activity at subsequent examinations. Conclusion: Reduced physical activity may be a long-term consequence of depression. It is important to address individual changes in physical activity and not merely absolute levels of physical activity in relationship to depression.
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| 24. |
- Gudmundsson, Petri, et al.
(author)
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Parametric quantification of myocardial ischaemia using real-time perfusion adenosine stress echocardiography images, with SPECT as reference method
- 2010
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In: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 30:1, s. 30-42
-
Journal article (peer-reviewed)abstract
- SUMMARY BACKGROUND: Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique, provides images for off-line parametric perfusion quantification using Qontrast software. From replenishment curves, this generates parametric images of peak signal intensity (A), myocardial blood flow velocity (beta) and myocardial blood flow (Axbeta) at rest and stress. This may be a tool for objective myocardial ischaemia evaluation. We assessed myocardial ischaemia by RTP-ASE Qontrast((R))-generated images, using 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) as reference. METHODS: Sixty-seven patients admitted to SPECT underwent RTP-ASE (SONOS 5500) during Sonovue infusion, before and throughout adenosine stress, also used for SPECT. Quantitative off-line analyses of myocardial perfusion by RTP-ASE Qontrast-generated A, beta and Axbeta images, at different time points during rest and stress, were blindly compared to SPECT. RESULTS: We analysed 201 coronary territories [corresponding to the left anterior descendent (LAD), left circumflex (LCx) and right coronary (RCA) arteries] from 67 patients. SPECT showed ischaemia in 18 patients. Receiver operator characteristics and kappa values showed that A, beta and Axbeta image interpretation significantly identified ischaemia in all territories (area under the curve 0.66-0.80, P = 0.001-0.05). Combined A, beta and Axbeta image interpretation gave the best results and the closest agreement was seen in the LAD territory: 89% accuracy; kappa 0.63; P<0.001. CONCLUSION: Myocardial isachemia can be evaluated in the LAD territory using RTP-ASE Qontrast-generated images, especially by combined A, beta and Axbeta image interpretation. However, the technique needs improvements regarding the LCx and RCA territories.
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| 25. |
- Gudmundsson, P, et al.
(author)
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Parametric quantification of myocardial ischaemia using real-time perfusion adenosine stress echocardiography images, with SPECT as reference method.
- 2010
-
In: Clinical Physiology and Functional Imaging. - 1475-0961. ; 30:1, s. 30-42
-
Journal article (peer-reviewed)abstract
- Summary Background: Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique, provides images for off-line parametric perfusion quantification using Qontrast((R)) software. From replenishment curves, this generates parametric images of peak signal intensity (A), myocardial blood flow velocity (beta) and myocardial blood flow (Axbeta) at rest and stress. This may be a tool for objective myocardial ischaemia evaluation. We assessed myocardial ischaemia by RTP-ASE Qontrast((R))-generated images, using 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) as reference. Methods: Sixty-seven patients admitted to SPECT underwent RTP-ASE (SONOS 5500) during Sonovue((R)) infusion, before and throughout adenosine stress, also used for SPECT. Quantitative off-line analyses of myocardial perfusion by RTP-ASE Qontrast((R))-generated A, beta and Axbeta images, at different time points during rest and stress, were blindly compared to SPECT. Results: We analysed 201 coronary territories [corresponding to the left anterior descendent (LAD), left circumflex (LCx) and right coronary (RCA) arteries] from 67 patients. SPECT showed ischaemia in 18 patients. Receiver operator characteristics and kappa values showed that A, beta and Axbeta image interpretation significantly identified ischaemia in all territories (area under the curve 0.66-0.80, P = 0.001-0.05). Combined A, beta and Axbeta image interpretation gave the best results and the closest agreement was seen in the LAD territory: 89% accuracy; kappa 0.63; P<0.001. Conclusion: Myocardial isachemia can be evaluated in the LAD territory using RTP-ASE Qontrast((R))-generated images, especially by combined A, beta and Axbeta image interpretation. However, the technique needs improvements regarding the LCx and RCA territories.
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| 26. |
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| 27. |
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| 28. |
- Gudmundsson, Petri, et al.
(author)
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Quantitative detection of myocardial ischaemia by stress echocardiography; a comparison with SPECT
- 2009
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In: Cardiovascular Ultrasound. - : BioMed Central. - 1476-7120. ; 7:28
-
Journal article (peer-reviewed)abstract
- Aims: Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique angio-mode (AM), provides images for off-line perfusion quantification using Qontrast® software, generating values of peak signal intensity (A), myocardial blood flow velocity (β) and myocardial blood flow (Axβ). By comparing rest and stress values, their respective reserve values (A-r, β-r, Axβ-r) are generated. We evaluated myocardial ischaemia by RTP-ASE Qontrast® quantification, compared to visual perfusion evaluation with 99mTc-tetrofosmin singlephoton emission computed tomography (SPECT). Methods and Results: Patients admitted to SPECT underwent RTP-ASE (SONOS 5500) using AM during Sonovue® infusion, before and throughout adenosine stress, also used for SPECT. Visual myocardial perfusion and wall motion analysis, and Qontrast® quantification, were blindly compared to one another and to SPECT, at different time points off-line. We analyzed 201 coronary territories (left anterior descendent [LAD], left circumflex [LCx] and right coronary [RCA] artery territories) in 67 patients. SPECT showed ischaemia in 18 patients and 19 territories. Receiver operator characteristics and kappa values showed significant agreement with SPECT only for β-r and Axβ-r in all segments: area under the curve 0.678 and 0.665; P < 0.001 and < 0.01, respectively. The closest agreements were seen in the LAD territory: kappa 0.442 for both β-r and Axβ- r; P < 0.01. Visual evaluation of ischaemia showed good agreement with SPECT: accuracy 93%; kappa 0.67; P < 0.001; without non-interpretable territories. Conclusion: In this agreement study with SPECT, RTP-ASE Qontrast® quantification of myocardial ischaemia was less accurate and less feasible than visual evaluation and needs further development to be clinically useful.
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| 29. |
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| 30. |
- Iqbal, Mudassir, et al.
(author)
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Comparative evolutionary histories of fungal proteases reveal gene gains in the mycoparasitic and nematode-parasitic fungus Clonostachys rosea
- 2018
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In: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 18
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Journal article (peer-reviewed)abstract
- Background: The ascomycete fungus Clonostachys rosea (order Hypocreales) can control several important plant diseases caused by plant pathogenic fungi and nematodes. Subtilisin-like serine proteases are considered to play an important role in pathogenesis in entomopathogenic, mycoparasitic, and nematophagous fungi used for biological control. In this study, we analysed the evolutionary histories of protease gene families, and investigated sequence divergence and regulation of serine protease genes in C. rosea.Results: Proteases of selected hypocrealean fungal species were classified into families based on the MEROPS peptidase database. The highest number of protease genes (590) was found in Fusarium solani, followed by C. rosea with 576 genes. Analysis of gene family evolution identified non-random changes in gene copy numbers in the five serine protease gene families S1A, S8A, S9X, S12 and S33. Four families, S1A, S8A, S9X, and S33, displayed gene gains in C. rosea. A gene-tree / species-tree reconciliation analysis of the S8A family revealed that the gene copy number increase in C. rosea was primarily associated with the S08.054 (proteinase K) subgroup. In addition, regulatory and predicted structural differences, including twelve sites evolving under positive selection, among eighteen C. rosea S8A serine protease paralog genes were also observed. The C. rosea S8A serine protease gene prs6 was induced during interaction with the plant pathogenic species F. graminearum.Conclusions: Non-random increases in S8A, S9X and S33 serine protease gene numbers in the mycoparasitic species C. rosea, Trichoderma atroviride and T. virens suggests an involvement in fungal-fungal interactions. Regulatory and predicted structural differences between C. rosea S8A paralogs indicate that functional diversification is driving the observed increase in gene copy numbers. The induction of prs6 expression in C. rosea during confrontation with F. graminearum suggests an involvement of the corresponding protease in fungal-fungal interactions. The results pinpoint the importance of serine proteases for ecological niche adaptation in C. rosea, including a potential role in the mycoparasitic attack on fungal prey.
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| 31. |
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| 32. |
- Knudsen, Jenny Dahl, et al.
(author)
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Selection of Resistant Streptococcus pneumoniae during Penicillin Treatment In Vitro and in Three Animal Models.
- 2003
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In: Antimicrobial Agents and Chemotherapy. - 1098-6596. ; 47:8, s. 2499-2506
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Journal article (peer-reviewed)abstract
- Pharmacokinetic (PK) and pharmacodynamic (PD) properties for the selection of resistant pneumococci were studied by using three strains of the same serotype (6B) for mixed-culture infection in time-kill experiments in vitro and in three different animal models, the mouse peritonitis, the mouse thigh, and the rabbit tissue cage models. Treatment regimens with penicillin were designed to give a wide range of T>MICs, the amounts of time for which the drug concentrations in serum were above the MIC. The mixed culture of the three pneumococcal strains, 107 CFU of strain A (MIC of penicillin, 0.016 µg/ml; erythromycin resistant)/ml, 106 CFU of strain B (MIC of penicillin, 0.25 µg/ml)/ml, and 105 CFU of strain C (MIC of penicillin, 4 µg/ml)/ml, was used in the two mouse models, and a mixture of 105 CFU of strain A/ml, 104 CFU of strain B/ml, and 103 CFU of strain C/ml was used in the rabbit tissue cage model. During the different treatment regimens, the differences in numbers of CFU between treated and control animals were calculated to measure the efficacies of the regimens. Selective media with erythromycin or different penicillin concentrations were used to quantify the strains separately. The efficacies of penicillin in vitro were similar when individual strains or mixed cultures were studied. The eradication of the bacteria, independent of the susceptibility of the strain or strains or the presence of the strains in a mixture or on their own, followed the well-known PK and PD rules for treatment with ß-lactams: a maximum efficacy was seen when the T>MIC was >40 to 50% of the observation time and the ratio of the maximum concentration of the drug in serum to the MIC was >10. It was possible in all three models to select for the less-susceptible strains by using insufficient treatments. In the rabbit tissue cage model, a regrowth of pneumococci was observed; in the mouse thigh model, the ratio between the different strains changed in favor of the less-susceptible strains; and in the mouse peritonitis model, the susceptible strain disappeared and was overgrown by the less-susceptible strains. These findings with the experimental infection models confirm the importance of eradicating all the bacteria taking part in the infectious process in order to avoid selection of resistant clones.
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| 33. |
- Leosson, K., et al.
(author)
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Comparing resonant photon tunneling via cavity modes and Tamm plasmon polariton modes in metal-coated Bragg mirrors
- 2012
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In: Optics Letters. - 0146-9592 .- 1539-4794. ; 37:19, s. 4026-4028
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Journal article (peer-reviewed)abstract
- Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO2/SiO2) Bragg mirror capped with a semitransparent gold film. Transmission via a fundamental cavity resonance was compared with transmission via the Tamm plasmon polariton resonance that appears at the interface between a metal film and a one-dimensional photonic bandgap structure. The Tamm-plasmon-mediated transmission exhibits a smaller dependence on the angle and polarization of the incident light for similar values of peak transmission, resonance wavelength, and finesse. Implications for transparent electrical contacts based on resonant tunneling structures are discussed.
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| 34. |
- Magnus, Fridrik, et al.
(author)
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Current-voltage-time characteristics of the reactive Ar/N2 high power impulse magnetron sputtering discharge
- 2011
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In: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 110:8
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Journal article (peer-reviewed)abstract
- The discharge current and voltage waveforms have been measured in a reactive high power impulse magnetron sputtering (HiPIMS) Ar/N2" role="presentation">N2 discharge with a Ti target for 400 μs" role="presentation">μs long pulses. We observe that the current waveform in the reactive Ar/N2" role="presentation">N2 HiPIMS discharge is highly dependent on the pulse repetition frequency, unlike the non-reactive Ar discharge. The current is found to increase significantly as the frequency is lowered. This is attributed to an increase in the secondary electron emission yield during the self-sputtering phase, when the nitride forms on the target at low frequencies. In addition, self-sputtering runaway occurs at lower discharge voltages when nitrogen is added to the discharge. This illustrates the crucial role of self-sputtering in the behavior of the reactive HiPIMS discharge.
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| 35. |
- Magnus, Fridrik, et al.
(author)
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Current-voltage-time characteristics of the reactive Ar/O2 high power impulse magnetron sputtering discharge
- 2012
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In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Institute of Physics (AIP). - 0734-2101 .- 1520-8559. ; 30:5
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Journal article (peer-reviewed)abstract
- The discharge current–voltage–time waveforms are studied in the reactive Ar/O2 high power impulse magnetron sputtering discharge with a titanium target for 400 μs long pulses. The discharge current waveform is highly dependent on both the pulse repetition frequency and discharge voltage and the current increases with decreasing frequency or voltage. The authors attribute this to an increase in the secondary electron emission yield during the self-sputtering phase of the pulse, as an oxide forms on the target.
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| 36. |
- Magnus, Fridrik, et al.
(author)
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Digital Smoothing of the Langmuir Probe I-V Characteristic
- 2008
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In: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 79:7
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Journal article (peer-reviewed)abstract
- Electrostatic probes or Langmuir probes are the most common diagnostic tools in plasma discharges. The second derivative of the Langmuir probe I-V characteristic is proportional to the electron energy distribution function. Determining the second derivative accurately requires some method of noise suppression. We compare the Savitzky-Golay filter, the Gaussian filter, and polynomial fitting to the Blackman filter for digitally smoothing simulated and measured I-V characteristics. We find that the Blackman filter achieves the most smoothing with minimal distortion for noisy data.
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| 37. |
- Magnus, F, et al.
(author)
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Morphology of TiN thin films grown on SiO(2) by reactive high power impulse magnetron sputtering
- 2011
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In: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 520:5, s. 1621-1624
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Journal article (peer-reviewed)abstract
- Thin TiN films were grown on SiO(2) by reactive high power impulse magnetron sputtering (HiPIMS) at a range of temperatures from 45 to 600 degrees C. The film properties were compared to films grown by conventional dc magnetron sputtering (dcMS) at similar conditions. Structural characterization was carried out using X-ray diffraction and reflection methods. The HiPIMS process produces denser films at lower growth temperature than does dcMS. Furthermore, the surface is much smoother for films grown by the HiPIMS process. The [200] grain size increases monotonically with increased growth temperature, whereas the size of the [111] oriented grains decreases to a minimum for a growth temperature of 400 degrees C after which it starts to increase with growth temperature. The [200] crystallites are smaller than the [111] crystallites for all growth temperatures. The grain sizes of both orientations are smaller in HiPIMS grown films than in dcMS grown films.
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| 38. |
- Magnus, Fridrik, et al.
(author)
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Nucleation and resistivity of ultrathin TiN films grown by high power impulse magnetron sputtering
- 2012
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In: IEEE Electron Device Letters. - : IEEE. - 0741-3106 .- 1558-0563. ; 33:7, s. 1045-1047
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Journal article (peer-reviewed)abstract
- TiN films have been grown on SiO 2 by reactive high-power impulse magnetron sputtering (HiPIMS) at temperatures of 22°C-600°C. The film resistance is monitored in situ to determine the coalescence and continuity thicknesses that decrease with increasing growth temperature with a minimum of 0.38 ± 0.05 nm and 1.7 ± 0.2 nm, respectively, at 400°C. We find that HiPIMS-deposited films have significantly lower resistivity than dc magnetron sputtered (dcMS) films on SiO 2 at all growth temperatures due to reduced grain boundary scattering. Thus, ultrathin continuous TiN films with superior electrical characteristics can be obtained with HiPIMS at reduced temperatures compared to dcMS.
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| 39. |
- Malik, Azhar, et al.
(author)
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Methodology for Sampling and Characterizing Internally Mixed Soot-Tar Particles Suspended in the Product Gas from Biomass Gasification Processes
- 2011
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In: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 25:4, s. 1751-1758
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Journal article (peer-reviewed)abstract
- When biomass is used to produce fuels and green products by thermochemical conversion, the ability to handle or remove the fine particle phase in the product gas is crucial. The product gas from biomass gasification contains relatively volatile organic compounds (“tar”) condensed on nonvolatile cores of, for example, aggregated soot particles and char. The problems are, for example, that particles will poison catalysts used for upgrading of the gas and loss of thermal energy occurs when carbonaceous particles are being formed. The aim of the work is to design and use novel methodologies to characterize the particles in the product gas stream. A methodology has been developed to sample and characterize fine particles by a sampling probe connected to either a denuder or a packed bed device. The system was designed to avoid condensation of organic compounds when diluting the sample and decreasing the temperature. A flame soot generator connected to a condensation−evaporation unit was used to produce internally mixed model particles, i.e., particles consisting of a core of soot with an outer layer of condensed volatile compounds. A scanning mobility particle sizer (SMPS) and a differential mobility analyzer followed by an aerosol particle mass analyzer (APM) were used to characterize the particles. Because of the agglomerated structure of soot, the SMPS system was not adequate to fully characterize the mass of volatiles condensed onto the soot core, and therefore the DMA-heater-APM technique was used to determine the mass fraction of the condensed phase on the soot particles. The two different configurations were studied, and the sampling system was shown to work at a high load of organic mass. In both cases, the organic removal efficiency was >99.5%. Minor condensation of organics on the sampled soot was found for the denuder but not the packed bed. On the other hand, the particle losses were substantially higher for the packed bed compared to the denuder. The results showed that the tested sampling methodology can be used to get sufficient characterization of particles in the product gas and to evaluate the performance of biomass product gas cleaning systems at high temperature.
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| 40. |
- Malmgren, Andreas, et al.
(author)
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Cardiac dimensions and function in female handball players.
- 2015
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In: Journal of Sports Medicine and Physical Fitness. - : Minerva Medica. - 0022-4707 .- 1827-1928. ; 55:4, s. 320-328
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Journal article (peer-reviewed)abstract
- AIM: Long-term intensive endurance training leads to increased left ventricular mass and increased left ventricular end-diastolic and left atrial end-systolic diameters. Different types of sports tend to give rise to distinct morphological forms of the athlete's heart. However, the sport-specific aspects have not been fully investigated in female athletes. The purpose of the present study was to investigate differences in left and right cardiac dimensions, cardiac volumes, and systolic and diastolic function in elite female handball players compared to sedentary controls. METHODS: A cross-sectional study of 33 elite female handball players was compared to 33 matched sedentary controls. Mean age was 21.5±2 years. The subjects underwent echocardiography examinations, both 2-dimensional (2DE) and 3-dimensional (3DE). Cardiac dimensions and volumes were quantified using M-mode, 2DE and 3DE. Systolic and diastolic left ventricular functions were also evaluated. All cardiac dimensions and volumes were adjusted for body surface area (BSA). RESULTS: Left atrium and left ventricle volumes were significantly (P<0.001) larger in elite female handball players compared with sedentary controls. Even right atrium area as well as right ventricular end-diastolic and end-systolic area were significantly (P<0.001) larger in elite female handball players. Significant differences were observed in three out of five systolic parameters. Most diastolic function parameters did not differ between the two groups. CONCLUSION: The findings from the present study suggest that similar cardiac remodeling takes place in elite female handball players as it does in athletes pursuing endurance or team game sports.
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| 41. |
- Misra, Deepankar, et al.
(author)
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Two-Center Double-Capture Interference in Fast He2++H2 Collisions
- 2009
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:15, s. 153201-
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Journal article (peer-reviewed)abstract
- We report the first observation of Young-type interference effects in a two-electron transfer process. These effects change strongly as the projectile velocity changes in fast (1.2 and 2.0 MeV) He^{2+}-H_2 collisions as manifested in strong variations of the double-electron capture rates with the H_2 orientation. This is consistent with fully quantum mechanical calculations, which ignore sequential electron transfer, and a simple projectile de Broglie wave picture assuming that two-electron transfer probabilities are higher in collisions where the projectile passes close to either one of the H_2 nuclei.
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| 42. |
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| 43. |
- Nilsson, Patrik, et al.
(author)
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Laboratory evaluation of a gasifier particle sampling system using model compounds of different particle morphology
- 2011
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In: Biomass Conversion & Biorefinery. - : Springer Science and Business Media LLC. - 2190-6815 .- 2190-6823. ; 1:2
-
Journal article (peer-reviewed)abstract
- The objective of this work was to design and evaluate an experimental setup to be used for field studies of particle formation in biomass gasification processes. The setup includes a high-temperature dilution probe and a denuder to separate solid particles from condensable volatile material. The efficiency of the setup to remove volatile material from the sampled stream and the influence from condensation on particles with different morphologies is presented. In order to study the sampling setup model, aerosols were created with a nebulizer to produce compact and solid KCl particles and a diffusion flame burner to produce agglomerated and irregular soot particles. The nebulizer and soot generator was followed by an evaporation–condensation section where volatile material, dioctylsebacete (DOS), was added to the system as a tar model compound. The model aerosol particles were heated to 200°C to create a system containing both solid particles and volatile organic material in gas phase. The heated aerosol particles were sampled and diluted at the same temperature with the dilution probe. Downstream the probe, the DOS was adsorbed in the denuder. This was achieved by slowly decreasing the temperature of the diluted sample towards ambient level in the denuder. Thereby the supersaturation of organic vapors was reduced which decreased the probability for tar condensation and nucleation of new particles. Both the generation system and the sampling technique gave reproducible results. A DOS collection efficiency of >99% was achieved if the denuder inlet concentration was diluted to less than 1–6 mg/m3 depending on the denuder flow rate. Concentrations higher than that lead to significant impact on the resulting KCl size distribution. The choice of model compounds was done to study the effect from the particle morphology on the achieved particle characteristics after the sampling setup. When similar amounts of volatile material condensed on soot agglomerates and compact particles, a substantially smaller growth in mobility diameter was found for soot compared with compact KCl.
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| 44. |
- Nisen, Harry, et al.
(author)
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Contemporary treatment of renal tumors : a questionnaire survey in the Nordic countries (the NORENCA-I study)
- 2017
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In: Scandinavian journal of urology. - : Taylor & Francis. - 2168-1805 .- 2168-1813. ; 51:5, s. 360-366
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: The five Nordic countries comprise 25 million people, and have similar treatment traditions and healthcare systems. To take advantage of these similarities, a collaborative group (Nordic Renal Cancer Group, NORENCA) was founded in 2015.MATERIALS AND METHODS: A questionnaire of 17 questions on renal tumor management and surgical education was designed and sent to 91 institutions performing renal tumor surgery in 2015. The response rate was 68% (62 hospitals), including 28 academic, 25 central and nine district hospitals. Hospital volume was defined as low (LVH: < 20 operations), intermediate (IVH: 20-49 operations), high (HVH: 50-99) and very high (VHVH: ≥ 100). Descriptive statistics were performed.RESULTS: Fifteen centers were LVH, 16 IVH, 21 HVH and 10 VHVH. Of all 3828 kidney tumor treatments, 55% were radical nephrectomies (RNs), 37% partial nephrectomies (PNs) and 8% thermoablations. For RN and PN, the percentages of open, laparoscopic and robotic approaches were 47%, 40%, 13% and 47%, 20%, 33%, respectively. The mean complication rate (Clavien-Dindo 3-5) was 4.9%, and 30 day mortality (TDM) was 0.5%. The median length of hospital stay was 4 days. Training with a simulator, black box or animal laboratory was possible in 48%, 74% and 21% of institutions, respectively.CONCLUSIONS: Despite some differences between countries, the data suggest an overall general common Nordic treatment attitude for renal tumors. Furthermore, the data demonstrate high adherence to international standards, with a high proportion of PN and acceptable rates for major complications and TDM.
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| 45. |
- Olafsson, I, et al.
(author)
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The aminoterminal portion of cerebrospinal fluid cystatin C in hereditary cystatin C amyloid angiopathy is not truncated. Direct sequence analysis from agarose gel electropherograms
- 1990
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In: Scandinavian Journal of Clinical & Laboratory Investigation. - 1502-7686. ; 50:1, s. 85-93
-
Journal article (peer-reviewed)abstract
- The isolated amyloid substance in hereditary cystatin C amyloid angiopathy (HCCAA) is mainly composed of a cystatin C variant devoid of the 10 amino terminal amino acid residues of extracellular cystatin C from healthy individuals. We have developed a procedure for protein sequencing directly from agarose gel electropherograms and used this in conjunction with isoelectric focusing to investigate the amino terminal sequence of cerebrospinal fluid (CSF) cystatin C in HCCAA patients. The amino-terminal sequence determined for cystatin C from a HCCAA patient CSF sample, Xaa-Ser-Pro-Gly-Lys-Pro-Pro-Xaa-Leu-Val-Gly-Gly-Pro-Met-Xaa-Ala-Xaa-Val, showed that the protein was not amino-termi-nally truncated. CSF cystatin C from all nine HCCAA patients investigated was found to have an isoelectric point identical to that of native cystatin C, and the truncated form of cystatin C isolated from amyloid deposits was shown to contribute to less than 1 % of the total amount of cystatin C in CSF. The total cysteine proteinase inhibitory capacity of CSF from HCCAA patients was lower than that of CSF from other patients. This decreased CSF inhibitory capacity in HCCAA patients was caused by decreased levels of cystatin C, since the levels of the other two cysteine proteinase inhibitors found in CSF, oc2-macroglobulin and kininogen, were significantly higher than in CSF from non-HCCAA patients.
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| 46. |
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| 47. |
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| 48. |
- Psotta, Carolin, et al.
(author)
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Continuous ex vivo glucose sensing in human physiological fluids using an enzymatic sensor in a vein replica
- 2023
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In: Bioelectrochemistry. - : Elsevier. - 1567-5394 .- 1878-562X. ; 152
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Journal article (peer-reviewed)abstract
- Managing blood glucose can affect important clinical outcomes during the intraoperative phase of surgery. However, currently available instruments for glucose monitoring during surgery are few and not optimized for the specific application. Here we report an attempt to exploit an enzymatic sensor in a vein replica that could continuously monitor glucose level in an authentic human bloodstream. First, detailed investigations of the superficial venous systems of volunteers were carried out using ocular and palpating examinations, as well as advanced ultrasound measurements. Second, a tubular glucose-sensitive biosensor mimicking a venous system was designed and tested. Almost ideal linear dependence of current output on glucose concentration in phosphate buffer saline was obtained in the range 2.2-22.0 mM, whereas the dependence in human plasma was less linear. Finally, the developed biosensor was investigated in whole blood under homeostatic conditions. A specific correlation was found between the current output and glucose concentration at the initial stage of the biodevice operation. However, with time, blood coagulation during measurements negatively affected the performance of the biodevice. When the experimental results were remodeled to predict the response without the influence of blood coagulation, the sensor output closely followed the blood glucose level.
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| 49. |
- Rögnvaldsson, Kristjan Godsk, et al.
(author)
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Obstructive sleep apnea is an independent risk factor for severe COVID-19 : a population-based study
- 2022
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In: Sleep. - : Oxford University Press (OUP). - 0161-8105 .- 1550-9109. ; 45:3
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Journal article (peer-reviewed)abstract
- Study Objectives Obstructive sleep apnea (OSA) has been proposed as a risk factor for severe COVID-19. Confounding is an important consideration as OSA is associated with several known risk factors for severe COVID-19. Our aim was to assess the association of OSA with hospitalization due to COVID-19 using a population-based cohort with detailed information on OSA and comorbidities. Methods Included were all community-dwelling Icelandic citizens 18 years of age and older diagnosed with SARS-CoV-2 infection in 2020. Data on demographics, comorbidities, and outcomes of COVID-19 was obtained from centralized national registries. Diagnosis of OSA was retrieved from the centralized Sleep Department Registry at Landspitali - The National University Hospital. Severe COVID-19 was defined as the composite outcome of hospitalization and death. The associations between OSA and the outcome were expressed as odds ratios (OR) with 95% confidence intervals (95% CI), calculated using logistic regression models and inverse probability weighting. Results A total of 4,756 individuals diagnosed with SARS-CoV-2 infection in Iceland were included in the study (1.3% of the Icelandic population), of whom 185 had a diagnosis of OSA. In total, 238 were hospitalized or died, 38 of whom had OSA. Adjusted for age, sex, and BMI, OSA was associated with poor outcome (OR 2.2, 95% CI 1.4-3.5). This association was slightly attenuated (OR 2.0, 95% CI 2.0, 1.2-3.2) when adjusted for demographic characteristics and various comorbidities. Conclusions OSA was associated with twofold increase in risk of severe COVID-19, and the association was not explained by obesity or other comorbidities.
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