| 1. |
- Berntsson, Thore, 1947, et al.
(författare)
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Towards Sustainabel Oil Refinery - Pre-study for larger co-operation project
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report, the Chalmers EnergiCentrum (CEC) presents the results of a pre-study commissioned by Preem relating to the effective production of future vehicle fuels.This pre-study was made up of three studies focusing on energy streamlining, the utilisation of waste heat and carbon-dioxide separation and biorefinement relating to the gasification and hydration of vegetable oils. One of the common starting points for these studies was the current situation at the Preem refineries in Göteborg and Lysekil from where the measurement data were obtained and analysed. The report summarises the knowledge situation based on current research in the individual technical fields. The results present some interesting future opportunities for developing the sustainable production of future vehicle fuels. The sections vary, as the areas that have been examined differ and the sections have been written by different people. The reports ends with some joint conclusions and a number of questions which could be included and answered in a more extensive future main study, as part of a developed research partnership between Preem and the Chalmers University of Technology. The preliminary results of this work were analysed with the client at workshops on 1 October and 29 November 2007. The report is written in English combined with an extensive summary in Swedish including a proposal on a future main study. The study was conducted by the Chalmers EnergiCentrum (CEC), in collaboration with a number of researchers in the CEC’s network. They included Thore Berntsson, Jessica Algehed, Erik Hektor and Lennart Persson Elmeroth, all from Heat and Power Technology, Börje Gevert, Chemical and Biological Engineering, Tobias Richards, Forest Products and Chemical Engineering, Filip Johnsson and Anders Lyngfelt, Energy Technology, and Per-Åke Franck and Anders Åsblad, CIT Industriell Energianalys AB. The client, Preem, was represented by Bengt Ahlén, Sören Eriksson, Johan Jervehed, Bertil Karlsson, Gunnar Olsson, Ulf Kuylenstierna, Stefan Nyström, Martin Sjöberg and Thomas Ögren. Tobias Richards was responsible for compiling the report and Bertil Pettersson was the project manager.
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| 2. |
- Semb, Gunvor, et al.
(författare)
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A Scandcleft randomised trials of primary surgery for unilateral cleft lip and palate: 1. Planning and management.
- 2017
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - : Taylor & Francis. - 2000-656X .- 2000-6764. ; 51:1, s. 2-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Longstanding uncertainty surrounds the selection of surgical protocols for the closure of unilateral cleft lip and palate, and randomised trials have only rarely been performed. This paper is an introduction to three randomised trials of primary surgery for children born with complete unilateral cleft lip and palate (UCLP). It presents the protocol developed for the trials in CONSORT format, and describes the management structure that was developed to achieve the long-term engagement and commitment required to complete the project.METHOD: Ten established national or regional cleft centres participated. Lip and soft palate closure at 3-4 months, and hard palate closure at 12 months served as a common method in each trial. Trial 1 compared this with hard palate closure at 36 months. Trial 2 compared it with lip closure at 3-4 months and hard and soft palate closure at 12 months. Trial 3 compared it with lip and hard palate closure at 3-4 months and soft palate closure at 12 months. The primary outcomes were speech and dentofacial development, with a series of perioperative and longer-term secondary outcomes.RESULTS: Recruitment of 448 infants took place over a 9-year period, with 99.8% subsequent retention at 5 years.CONCLUSION: The series of reports that follow this introductory paper include comparisons at age 5 of surgical outcomes, speech outcomes, measures of dentofacial development and appearance, and parental satisfaction. The outcomes recorded and the numbers analysed for each outcome and time point are described in the series.TRIAL REGISTRATION: ISRCTN29932826.
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| 3. |
- Ahmad, Irma, et al.
(författare)
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High prevalence of persistent symptoms and reduced health-related quality of life 6 months after COVID-19
- 2023
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Ingår i: Frontiers in Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The long-term sequelae after COVID-19 constitute a challenge to public health and increased knowledge is needed. We investigated the prevalence of self-reported persistent symptoms and reduced health-related quality of life (HRQoL) in relation to functional exercise capacity, 6 months after infection, and explored risk factors for COVID-19 sequalae.METHODS: This was a prospective, multicenter, cohort study including 434 patients. At 6 months, physical exercise capacity was assessed by a 1-minute sit-to-stand test (1MSTST) and persistent symptoms were reported and HRQoL was evaluated through the EuroQol 5-level 5-dimension (EQ-5D-5L) questionnaire. Patients with both persistent symptoms and reduced HRQoL were classified into a new definition of post-acute COVID syndrome, PACS+. Risk factors for developing persistent symptoms, reduced HRQoL and PACS+ were identified by multivariable Poisson regression.RESULTS: Persistent symptoms were experienced by 79% of hospitalized, and 59% of non-hospitalized patients at 6 months. Hospitalized patients had a higher prevalence of self-assessed reduced overall health (28 vs. 12%) and PACS+ (31 vs. 11%). PACS+ was associated with reduced exercise capacity but not with abnormal pulse/desaturation during 1MSTST. Hospitalization was the most important independent risk factor for developing persistent symptoms, reduced overall health and PACS+.CONCLUSION: Persistent symptoms and reduced HRQoL are common among COVID-19 survivors, but abnormal pulse and peripheral saturation during exercise could not distinguish patients with PACS+. Patients with severe infection requiring hospitalization were more likely to develop PACS+, hence these patients should be prioritized for clinical follow-up after COVID-19.
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| 4. |
- Björkegren, Sanna, 1984, et al.
(författare)
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Surface activity and flocculation behavior of polyethylene glycol-functionalized silica nanoparticles
- 2015
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 452, s. 215-223
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal silica nanoparticles have been functionalized with methyl polyethylene glycol silane (mPEG silane) and the PEGylated particles have been characterized with focus on exploring their surface chemical properties. The degree of surface functionalization was quantified using NMR diffusometry, and the measurements showed that the silane binds covalently to the silica surface. Samples with surface coverages ranging from 0.068 to 0.315 gmol silane/m(2) have been analyzed. The functionalized particles proved to be surface active and showed a significant reduction in surface charge and zeta potential with increasing degree of PEG functionalization. All samples showed colloidal stability at neutral pH and above within the range studied. At lower pH, the samples with low surface coverage displayed a reversible flocculation behavior, while samples with a high surface coverage and samples without functionalization remained stable. This suggests that steric stabilization is effective at low pH when the surface coverage is high enough; electrostatic stabilization is effective for samples without functionalization; and that inter-particle PEG-silica interactions cause flocculation of particles with too low degrees of PEG functionalization.
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| 5. |
- Persson, Marta, 1979, et al.
(författare)
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Clinically significant copy number alterations and complex rearrangements of MYB and NFIB in head and neck adenoid cystic carcinoma.
- 2012
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Ingår i: Genes, chromosomes & cancer. - : Wiley. - 1098-2264 .- 1045-2257. ; 51:8, s. 805-17
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Tidskriftsartikel (refereegranskat)abstract
- Adenoid cystic carcinoma (ACC) of the head and neck is a malignant tumor with poor long-term prognosis. Besides the recently identified MYB-NFIB fusion oncogene generated by a t(6;9) translocation, little is known about other genetic alterations in ACC. Using high-resolution, array-based comparative genomic hybridization, and massively paired-end sequencing, we explored genomic alterations in 40 frozen ACCs. Eighty-six percent of the tumors expressed MYB-NFIB fusion transcripts and 97% overexpressed MYB mRNA, indicating that MYB activation is a hallmark of ACC. Thirty-five recurrent copy number alterations (CNAs) were detected, including losses involving 12q, 6q, 9p, 11q, 14q, 1p, and 5q and gains involving 1q, 9p, and 22q. Grade III tumors had on average a significantly higher number of CNAs/tumor compared to Grade I and II tumors (P = 0.007). Losses of 1p, 6q, and 15q were associated with high-grade tumors, whereas losses of 14q were exclusively seen in Grade I tumors. The t(6;9) rearrangements were associated with a complex pattern of breakpoints, deletions, insertions, inversions, and for 9p also gains. Analyses of fusion-negative ACCs using high-resolution arrays and massively paired-end sequencing revealed that MYB may also be deregulated by other mechanisms in addition to gene fusion. Our studies also identified several down-regulated candidate tumor suppressor genes (CTNNBIP1, CASP9, PRDM2, and SFN) in 1p36.33-p35.3 that may be of clinical significance in high-grade tumors. Further, studies of these and other potential target genes may lead to the identification of novel driver genes in ACC.
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| 6. |
- Wang, Chunliang, 1980-, et al.
(författare)
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Can segmented 3D images be used for stenosis evaluation in coronary CT angiography?
- 2012
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Ingår i: Acta Radiologica. - : Sage Publications. - 0284-1851 .- 1600-0455. ; 53:8, s. 845-851
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Tidskriftsartikel (refereegranskat)abstract
- Background: Thanks to the development of computed tomography (CT) scanners and computer software, accurate coronary artery segmentation can be achieved with minimum user interaction. However, the question remains whether we can use these segmented images for reliable diagnosis. Purpose: To retrospectively evaluate the diagnostic accuracy of coronary CT angiography (CCTA) using segmented 3D data for the detection of significant stenosis. Material and Methods: CCTA data-sets from 30 patients were acquired with a 64-slice CT scanner and segmented using the region growing (RG) method and the "virtual contrast injection" (VC) method. Three types of images of each patient were reviewed by different reviewers for the presence of stenosis with diameter reduction of 50% or more. The evaluation was performed on four main arteries of each patient (120 arteries in total). For the original series, the reviewer was allowed to use all the 2D and 3D visualization tools available (conventional method). For the segmented results from RG and VC, only maximum intensity projection was used. Evaluation results were compared with catheter angiography (CA) for each artery in a blinded fashion. Results: Overall, 34 arteries with significant stenosis were identified by CA. The percentage of evaluable arteries, accuracy and negative predictive value for detecting stenosis were, respectively, 86%, 74%, and 93% for the conventional method, 83%, 71%, and 92% for VC, and 64%, 56%, and 93% for RG. Accuracy was significantly lower for the RG method than for the other two methods (P < 0.01), whereas there was no significant difference in accuracy between the VC method and the conventional method (P = 0.22). Conclusion: The diagnostic accuracy for the RG-segmented 3D data is lower than those with access to 2D images, whereas the VC method shows diagnostic accuracy similar to the conventional method.
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| 7. |
- Arnqvist, Anders, et al.
(författare)
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En kunskapsbas : Sätt att organisera för att individanpassa skolgången
- 2010
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Ingår i: I rättan tid. - Stockholm : Fritzes. - 9789138234471 ; , s. 67-87
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- De överväganden och förslag som redovisas i detta betänkande har tagits fram med utgångspunkt i en kunskapsbas. Kunskapsbasen består av dels översikter över aktuella forskningsresultat inom ett antal områden som har bäring på frågan om flexibel skolstart i grundskolan, dels några internationella utblickar. Vetenskapligt förankrade kunskapsöversikter har för utredningens räkning sammanställts av fyra forskare, nämligen professor Anders Arnqvist, Karlstads universitet, professor Sven Persson, Malmö högskola, fil dr Monika Vinterek, Umeå universitet och fil lic Helena Ackesjö, Linnéuniversitetet. Var och en har haft i uppdrag att inom respektive område redogöra för resultat inom svensk och internationell forskning från mitten av 1990-talet och senare. I uppdraget har ingått att uppmärksamma eventuella skillnader mellan olika elevgrupper samt effekter på både elevers kunskapsutveckling och sociala utveckling. I detta kapitel redovisas forskarnas egna sammanfattningar av forskningsöversikterna. Dessa återges i sin helhet i bilagorna 2–5. Av dem framgår också de frågeställningar och områden med bäring på flexibel skolstart som forskarna finner behov av att följa upp, utvärdera och beforska. Kunskapsbasen innehåller även en internationell utblick. I den återges hur barn på Nya Zeeland börjar skolan successivt på sin födelsedag och hur barn i England kan börja skolan vid fler tillfällen under läsåret. Lite mer utförligt redovisas dessutom diskussionen inför och införandet av rullande skolstart i Danmark och flexibel skolstart i Norge.
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| 10. |
- Contreras, Mariela, 1979-, et al.
(författare)
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Socio-economic resources, young child feeding practices, consumption of highly processed snacks and sugar-sweetened beverages : a population-based survey in rural northwestern Nicaragua
- 2015
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Socio-economic resources may be associated with infant feeding in complex patterns in societies undergoing a nutrition transition. This study evaluates associations of housing quality, food security and maternal education to the World Health Organization (WHO) feeding recommendations and to consumption of highly processed snacks (HP snacks) and sugar-sweetened beverages (SSBs) in rural Nicaragua. Methods: Data were collected from May to November 2009, with mothers of 0- to 35-month-olds being asked about young child feeding using a food frequency questionnaire. A validated questionnaire was used to assess household food insecurity and data were collected on maternal education and housing quality. Pearson's chi-squared test was used to compare proportions and determine associations between the resources and young child feeding. The three socio-economic resources and other confounders were introduced to multivariate logistic regression analyses to assess the independent contribution of the resources to the feeding practices and consumption of HP snacks and SSBs. Results: Mothers with the lowest education level were more likely to be exclusively breastfeeding (EBF) their infants (OR not EBF: 0.19; 95% CI: 0.07, 0.51), whilst mothers of 6- to 35-month-olds in the lowest education category had more inadequate dietary diversity (DD) (OR for not meet DD: 2.04; 95% CI: 1.36, 3.08), were less likely to consume HP snacks (OR for HP snacks: 0.47; 95% CI: 0.32, 0.68) and SSBs (OR for SSBs: 0.68; 95% CI: 0.46, 0.98), compared to mothers with the highest level of education. Similarly, children residing in households with the highest food insecurity were also more prone to have inadequate dietary diversity (OR for not meet DD: 1.47; 95% CI: 1.05, 2.05). The odds for double burden of suboptimal feeding (concurrent inadequate diet and consumption of HP snacks/SSBs) were significantly lower in children of least educated mothers (OR: 0.64; 95% CI: 0.44, 0.92). Conclusions: Higher level of education was associated with both more and less adherence to the WHO recommended feeding practices as well as with more consumption of HP snacks and SSBs. Regardless of educational strata, the children in the community were exposed to suboptimal feeding practices conducive to both under-as well as overnutrition.
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