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- Alexandersson, Bjarki T., et al.
(författare)
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Diverticulosis is not associated with altered gut microbiota nor is it predictive of future diverticulitis : a population-based colonoscopy study
- 2023
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 58:10, s. 1131-1138
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Tidskriftsartikel (refereegranskat)abstract
- Background: The etiopathogenesis of diverticular disease is unknown.Objective: To compare the fecal and mucosa-associated microbiota between participants with and without diverticulosis and participants who later developed diverticulitis versus those that did not from a population-based study.Methods: The PopCol study, conducted in Stockholm, Sweden, invited a random sample of 3556 adults to participate, of which 745 underwent colonoscopy. Overall, 130 participants (17.5%) had diverticulosis. 16S rRNA gene sequencing was conducted on available sigmoid biopsy samples from 529 and fecal samples from 251 individuals. We identified individuals who subsequently developed acute diverticulitis up to 13 years after sample collection. In a case-control design matching for gender, age (+/−5 years), smoking and antibiotic exposure, we compared taxonomic composition, richness and diversity of the microbiota between participants with or without diverticulosis, and between participants who later developed acute diverticulitis versus those who did not.Results: No differences in microbiota richness or diversity were observed between participants with or without diverticulosis, nor for those who developed diverticulitis compared with those who did not. No bacterial taxa were significantly different between participants with diverticulosis compared with those without diverticulosis. Individuals who later developed acute diverticulitis (2.8%) had a higher abundance of genus Comamonas than those who did not (p = .027).Conclusions: In a population-based cohort study the only significant difference was that those who later develop diverticulitis had more abundance of genus Comamonas. The significance of Comamonas is unclear, suggesting a limited role for the gut microbiota in the etiopathogenesis of diverticular disease.
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| 4. |
- Aldi, Silvia, et al.
(författare)
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Dual roles of heparanase in human carotid plaque calcification
- 2019
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Ingår i: Atherosclerosis. - : ELSEVIER IRELAND LTD. - 0021-9150 .- 1879-1484. ; 283, s. 127-136
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Calcification is a hallmark of advanced atherosclerosis and an active process akin to bone remodeling. Heparanase (HPSE) is an endo-beta-glucuronidase, which cleaves glycosaminoglycan chains of heparan sulfate proteoglycans. The role of HPSE is controversial in osteogenesis and bone remodeling while it is unexplored in vascular calcification. Previously, we reported upregulation of HPSE in human carotid endarterectomies from symptomatic patients and showed correlation of HPSE expression with markers of inflammation and increased thrombogenicity. The present aim is to investigate HPSE expression in relation to genes associated with osteogenesis and osteolysis and the effect of elevated HPSE expression on calcification and osteolysis in vitro.Methods: Transcriptomic and immunohistochemical analyses were performed using the Biobank of Karolinska Endarterectomies (BiKE). In vitro calcification and osteolysis were analysed in human carotid smooth muscle cells overexpressing HPSE and bone marrow-derived osteoclasts from HPSE-transgenic mice respectively.Results: HPSE expression correlated primarily with genes coupled to osteoclast differentiation and function in human carotid atheromas. HPSE was expressed in osteoclast-like cells in atherosclerotic lesions, and HPSE-transgenic bone marrow-derived osteoclasts displayed a higher osteolytic activity compared to wild-type cells. Contrarily, human carotid SMCs with an elevated HPSE expression demonstrated markedly increased mineralization upon osteogenic differentiation.Conclusions: We suggest that HPSE may have dual functions in vascular calcification, depending on the stage of the disease and presence of inflammatory cells. While HPSE plausibly enhances mineralization and osteogenic differentiation of vascular smooth muscle cells, it is associated with inflammation-induced osteoclast differentiation and activity in advanced atherosclerotic plaques.
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| 6. |
- Almbladh, Carl-Olof, et al.
(författare)
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THEORY OF RESONANT EMISSION PROCESSES IN METALS
- 1984
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Ingår i: Annals of the Israel Physical Society. - 0309-8710. ; 6, s. 309-311
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Konferensbidrag (refereegranskat)abstract
- A simple and transparent formalism is presented to treat emission processes in general and resonant emission processes in metals in particular. As an example resonant photoemission in Cu metal is discussed.
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| 7. |
- Aryasetiawan, F., et al.
(författare)
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Multiple Plasmon Satellites in Na and Al Spectral Functions from Ab Initio Cumulant Expansion
- 1996
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 77:11, s. 2268-2271
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Tidskriftsartikel (refereegranskat)abstract
- The valence photoemission spectra of alkali metals exhibit multiple plasmon satellite structure. The calculated spectral functions within the GW approximation show only one plasmon satellite at too large binding energy. In this Letter we use the cumulant expansion approach to obtain the spectral functions of Na and Al from ab initio calculations including the effects of band structure. The GW spectral functions are dramatically improved and the positions of the multiple plasmon satellites are in very good agreement with experiment while their intensities cannot be explained from intrinsic effects only.
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| 8. |
- Bardyszewski, Witold, et al.
(författare)
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A New Approach to the Theory of Photoemission from Solids
- 1985
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Ingår i: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 32, s. 439-439
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Tidskriftsartikel (refereegranskat)abstract
- By neglecting certain terms in the Hamiltonian (of importance only in the immediate neighbourhood of the threshold energy) we are able to write an exact expression for the photoemission intensity which involves the standard time inverted LEED state and broadened hole-states. If inelastic extrinsic losses are neglected our expression is similar to the one used by e.g. Feibelman and Eastman [1], Pendry [2] and Spanjaard et al. [3]. Our theory also allows inelastic losses (including interference between intrinsic and extrinsic losses) to be evaluated. The expressions are similar to those obtained by Inglesfield [4], but the damping effect no longer has to be put in by hand. Our theory further can handle not only core electron but also valence electron photoemission and it is not restricted to metals but applies to all types of solids. We have also traced why and when Inglesfield's one step theory agrees with a semiclassical calculation.
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| 9. |
- Bardyszewski, Witold, et al.
(författare)
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EFFECTS OF MANY-BODY INTERACTIONS IN EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY (EXAFS)
- 1987
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Ingår i: Journal de Physique Colloques. - : EDP Sciences. - 0449-1947. ; 48 (C9), s. 1101-1104
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Konferensbidrag (refereegranskat)abstract
- Abstract : We present the first a priori derivation of a many-body theory for EXAFS with clearly defined approximations and with final expressions which are feasible for quantitative evaluations. We conclude that the conventional EXAFS expression should be complemented with a term that crudely is the main term, energy-shifted and scaled down by a factor of order 0.2-0.3. Further the f-factors depend significantly, not only on the scattering properties of the individual ions, but also on the electron energy-loss properties of the material itself.
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| 10. |
- Baron, Tomasz, et al.
(författare)
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Test-retest reliability of new and conventional echocardiographic parameters of left ventricular systolic function
- 2019
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Ingår i: Clinical Research in Cardiology. - : Springer Science and Business Media LLC. - 1861-0684 .- 1861-0692. ; 108:4, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reliability of left ventricular function measurements depends on actual biological conditions, repeated registrations and their analyses.Objective: To investigate test–retest reliability of speckle-tracking-derived strain measurements and its determinants compared to the conventional parameters, such as ejection fraction (EF), LV volumes and mitral annular plane systolic excursion (MAPSE).Methods: In 30 patients with a wide range of left ventricular function (mean EF 46.4 ± 16.4%, range 14–73%), standard echo views were acquired independently in a blinded fashion by two different echocardiographers in immediate sequence and analyzed off-line by two independent readers, creating 4 data sets per patient. Test–retest reliability of studied parameters was calculated using the smallest detectable change (SDC) and a total, inter-acquisition and inter-reader intra-class correlation coefficient (ICC).Results: The smallest detectable change normalized to the mean absolute value of the measured parameter (SDCrel) was lowest for MAPSE (10.7%). SDCrel for EF was similar to GLS (14.2 and 14.7%, respectively), while SDCrel for CS was much higher (35.6%). The intra-class correlation coefficient was excellent (> 0.9) for all measures of the left ventricular function. Intra-patient inter-acquisition reliability (ICCacq) was significantly better than inter-reader reliability (ICCread) (0.984 vs. 0.950, p = 0.03) only for EF, while no significant difference was observed for any other LV function parameter. Mean intra-subject standard deviations were significantly correlated to the mean values for CS and LV volumes, but not for the other studied parameters.Conclusions: In a test–retest setting, both with normal and impaired left ventricular function, the smallest relative detectable change of EF, GLS and MAPSE was similar (11–15%), but was much higher for CS (35%). Surprisingly, reliability of GLS was not superior to that of EF. Acquisition and reader to a similar extent influenced the reliability of measurements of all left ventricular function measures except for ejection fraction, where the reliability was more dependent on the reader than on the acquisition.
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