| 1. |
- Brolin, Gustav, et al.
(author)
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The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography : a national audit based on virtual image data
- 2016
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In: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 36:2, s. 146-154
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Journal article (peer-reviewed)abstract
- Assessment of image analysis methods and computer software used in Tc-99m-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in Tc-99m-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T-max) were reported by 21 of the 28 Swedish departments performing Tc-99m-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T-max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic Tc-99m-MAG3 renography, especially for patients with impaired renal function.
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| 2. |
- Carrington, Thomas, 1974-, et al.
(author)
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Exploring Compliance and Convergence of Auditor Commitments to Professional Values : A Contextual Analysis
- 2015
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Conference paper (peer-reviewed)abstract
- By emphasising the work context of auditing in terms of clients served, and by disentangling conformity into compliance and convergence this article extends the institutional analysis of conformity and variation in value commitments in the auditing profession. We find that type of client is a factor that results in differences in compliance and convergence to professional value commitments in the complete sample of 1,646 Swedish Big 4 and non-Big 4 auditors. By analysing not only compliance to value commitments, but also how closely sub-groups within the profession resemble each other (i.e., convergence), we contribute by showing that the type of client served is both a source of conformity and destabilizing factor within the auditing profession, and that Big 4 firms are less homogenous than typically portrayed in previous research.
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| 3. |
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| 4. |
- Carrington, Thomas, et al.
(author)
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The Client as a Source of Institutional Conformity for Commitments to Core Values in the Auditing Profession
- 2019
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In: Contemporary Accounting Research. - : John Wiley & Sons. - 0823-9150 .- 1911-3846. ; 36:2, s. 1077-1097
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Journal article (peer-reviewed)abstract
- Based on an analysis of questionnaire data from a large sample of certified auditors, this study examines how the main type of client being served influences auditor conformity to the core values of their profession. We contrast auditors of (primarily) listed companies with auditors of (primarily) single member companies, that is, limited liability companies with a single owner who typically is also the only employee of the company. We show that these two groups of auditors differ in the extent to which they hold certain values important (i.e., show compliance) and in the closeness with which these values are held within each group of auditors (i.e., show convergence). Our results also demonstrate that the type of client predominately served by an auditor is relevant for explaining variation in professional values both within and between organizational contexts. In addition, we offer a new theoretical approach to classifying auditors, and analyzing their commitment to core values of the profession. We analyze commitment to values via both compliance and convergence, two often overlooked aspects of conformity to value commitments in professions.
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| 5. |
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| 6. |
- Chen, Zhe, et al.
(author)
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Nano-scale characterization of white layer in broached Inconel 718
- 2017
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In: Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing. - Amsterdam : Elsevier BV. - 0921-5093 .- 1873-4936. ; 684, s. 373-384
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Journal article (peer-reviewed)abstract
- The formation mechanism of white layers during broaching and their mechanical properties are not well investigated and understood to date. In the present study, multiple advanced characterization techniques with nano-scale resolution, including transmission electron microscopy (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT) as well as nano-indentation, have been used to systematically examine the microstructural evolution and corresponding mechanical properties of a surface white layer formed when broaching the nickel-based superalloy Inconel 718.TEM observations showed that the broached white layer consists of nano-sized grains, mostly in the range of 20–50 nm. The crystallographic texture detected by TKD further revealed that the refined microstructure is primarily caused by strong shear deformation. Co-located Al-rich and Nb-rich fine clusters have been identified by APT, which are most likely to be γ′ and γ′′ clusters in a form of co-precipitates, where the clusters showed elongated and aligned appearance associated with the severe shearing history. The microstructural characteristics and crystallography of the broached white layer suggest that it was essentially formed by adiabatic shear localization in which the dominant metallurgical process is rotational dynamic recrystallization based on mechanically-driven subgrain rotations. The grain refinement within the white layer led to an increase of the surface nano-hardness by 14% and a reduction in elastic modulus by nearly 10% compared to that of the bulk material. This is primarily due to the greatly increased volume fraction of grain boundaries, when the grain size was reduced down to the nanoscale.
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| 7. |
- Duhr, Claude, et al.
(author)
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Full-Color Two-Loop Four-Gluon Amplitude in N=2 Supersymmetric QCD
- 2019
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In: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 123:24
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Journal article (peer-reviewed)abstract
- We present the fully integrated form of the two-loop four-gluon amplitude in N = 2 supersymmetric quantum chromodynamics with gauge group SU(N-c) and with N-f massless supersymmetric quarks (hypermultiplets) in the fundamental representation. Our result maintains full dependence on N-c and N-f, and relies on the existence of a compact integrand representation that exhibits the duality between color and kinematics. Specializing to the N = 2 superconformal theory, where N-f = 2N
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| 8. |
- Ek, Gustav, et al.
(author)
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Hydrogen induced structure and property changes in Eu3Si4
- 2019
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In: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596 .- 1095-726X. ; 277, s. 37-45
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Journal article (peer-reviewed)abstract
- Hydrides Eu3Si4H2-X were obtained by exposing the Zintl phase Eu3Si4 to a hydrogen atmosphere at a pressure of 30 bar and temperatures from 25 to 300 degrees C. Structural analysis using powder X-ray diffraction (PXRD) data suggested that hydrogenations in a temperature range 25-200 degrees C afford a uniform hydride phase with an orthorhombic structure (Immm, a approximate to 4.40 angstrom, b approximate to 3.97 angstrom, c approximate to 19.8 angstrom), whereas at 300 degrees C mixtures of two orthorhombic phases with c approximate to 19.86 and approximate to 19.58 angstrom were obtained. The assignment of a composition Eu3Si4H2+x is based on first principles DFT calculations, which indicated a distinct crystallographic site for H in the Eu3Si4 structure. In this position, H atoms are coordinated in a tetrahedral fashion by Eu atoms. The resulting hydride Eu3Si4H2 is stable by -0.46 eV/H atom with respect to Eu3Si4 and gaseous H-2. Deviations between the lattice parameters of the DFT optimized Eu3Si4H2 structure and the ones extracted from PXRD patterns pointed to the presence of additional H in interstitials also involving Si atoms. Subsequent DFT modeling of compositions Eu3Si4H3 and Eu3Si4H4 showed considerably better agreement to the experimental unit cell volumes. It was then concluded that the hydrides of Eu3Si4 have a composition Eu3Si4H2+x (x
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| 9. |
- Ekback, Gunnar, et al.
(author)
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Reporting dental caries disease in longitudinal studies : a suggestion
- 2016
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In: Swedish Dental Journal. - : Swedish Dental Association. - 0347-9994. ; 40:2, s. 173-179
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Journal article (peer-reviewed)abstract
- Sjukdomar och medicinska tillstånd definieras vanligen genom att ett antal kriterier uppfylls och en individ bedöms som frisk från sjukdom när dessa kriterier inte längre föreligger, ofta efter en definierad tidsperiod. Incidens och prevalens mellan olika sjukdomar kan därför ofta jämföras. I longitudinella studier definieras dental karies ofta som förändringar i medeltal av ett index, vanligen DMFT/S. Karies är en livsstilssjukdom som går att bota, men symtomen på kariessjukdom är oftast persisterande vilket innebär att ett sådant index inte redovisar hur många individer som är sjuka under en viss period eller hur många som är botade från själva kariessjukdomen under samma tid utan istället redovisar en livstidsprevalens. Syftet med denna studie var att beräkna karies incidens och karies prevalens utgående från begreppen årsprevalens, kumulativ incidens och incidenstalet (incidensraten). Definition på karies hämtades från ICD-10 (KO2.1) som beskriver diagnosen för karies in i dentin. Som definition på att vara frisk (botad) från kariessjukdom användes en definierad tidsperiod på tre år utan att ny dentinkaries registrerats. Studiepopulationen var 423 individer och bestod av alla 12-åringar i Örebro län, år 1990, och som under sex år deltog i samtliga årliga recall-undersökningar (1990–1995). Av dessa hade 210 dentinkaries (definierat som ICD K02.1) någon gång under de tre åren 1990–1992 medan 213 inte uppvisade dentinkaries någon gång under samma tidsperiod. Under den efterföljande perioden 1993–1995 blev 17 % av de sjuka barnen friska från karies. Av de friska barnen insjuknade 38 individer vilket ger en årlig prevalens av 12 %. Karies hade en incidens rate av 134 fall per 1000 manår (13 %) och en kumulativ incidens på 15 % för ett år, 17 % för två år och slutligen 18% för tre år. Vår definition av den tid som krävs (3 år) för att kunna avgöra om en tidigare sjuk individ kan bedömas som frisk från karies kan i framtiden behöva justeras och fler studier i olika åldrar och populationer behövs för att ytterligare belysa problemställningen. Studien visar på relativt dåligt resultat när det gäller att bota kariessjukdom då endast 17 % av de sjuka blev friskförklarade under en period på tre år. Likaledes är resultaten av preventionen nedslående då hela 12 % av individerna i den friska gruppen blev sjuka. Resultatet bör dock tolkas med försiktighet med tanke på det begränsade antal barn som ingick i studien och risker för selektionsbias mellan grupperna. Under dessa år hade dock individuella kallelseintervall utifrån ett riskperspektiv inte införts hos Folktandvården Örebro utan orsaken till att barn inte kallades årligen berodde vanligtvis på resursbrist hos vårdgivaren. Denna metod att rapportera karies i longitudinella material och därmed definiera karies på individnivå ersätter inte traditionella metoder för att mäta kariesincidens och kariesprevalens. Metoden ger dock en ökad information avseende det antal individer som faktiskt är sjuka i karies. Ett sådant förfaringssätt medför stora fördelar ur planeringssynpunkt för tandvården då fokus blir individer och inte medeltal av ytor eller tänder, och möjliggör dessutom jämförelser mellan dem som faktiskt är sjuka i karies med dem som diagnostiserats med andra sjukdomar.
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| 10. |
- Ekbäck, Gunnar, 1954-, et al.
(author)
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Reporting dental caries disease in longitudinal studies - a suggestion
- 2016
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In: Swedish Dental Journal. - Stockholm, Sweden : Swedish Dental Journal. - 0347-9994. ; 40:2, s. 173-179
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Journal article (peer-reviewed)abstract
- In general, most infectious and/or lifestyle-related diseases are defined as being present when sufficient signs or symptoms occurs in an individual. The term "sufficient" is a relative concept and a disease can therefore be measured with different degrees of certainty. These symptoms are commonly defined in such a way that it is possible to determine the incidence and prevalence of the disease and also the proportion of individuals that are cured from the disease. If dental caries is an individual disease which can be compared to other diseases regarding incidence and prevalence, it is important to determine for how long an individual must be free from new signs of the disease before being considered cured or free from the disease and to define the "sufficient" signs or symptoms needed for a diagnose. Based on these thoughts, the purpose of this study was to calculate caries incidence and prevalence in a group of adolescents from a definition of dental caries based on ICD-10. This study included all 12 year olds in 1990 who attended a clinical dental examination in 1990-1995 in Orebro County, Orebro, Sweden, yearly during these six years. Dental caries disease at the individual level was defined as Ko2.1 (dentinal caries) according to ICD-bo while freedom of caries was defined as the absence of Ko2.1 during a three-year period. In this study the yearly prevalence was 12%, the three year cumulative incidence was 18% and the incidence rate 13%. Results of this study highlight the poor outcomes in curing caries disease in this age-group, according to the criteria in this study, as only 17% of the children with caries at the outset of the study were free from the disease three years later. Defining both a practical level to measure signs of dental caries, and the period an individual must be free from them to be classified as cured from the disease create new opportunities to compare and communicate the disease of dental caries with other diseases. This way of registration is also of advantage for planning purposes as there the centre of interest must be the individual patient and not the tooth or surface.
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