| 1. |
- Andrén, Niclas, et al.
(författare)
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Finansiering
- 2003
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Bok (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Börvik, Tore, et al.
(författare)
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Experimental and numerical study on the perforation of AA6005-T6 panels
- 2005
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 32:1-4, s. 35-64
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Tidskriftsartikel (refereegranskat)abstract
- Extruded aluminium panels find their use in many different structures such as offshore platforms, bridge decks, train and ship components and lightweight protection systems. Impacts or other types of high-speed loading conditions are thus a relevant issue for several of these applications. There are, however, not many investigations published on the perforation of extruded aluminium panels covering experiments in combination with numerical analyses. This paper presents an experimental and numerical study on the perforation of AA6005-T6 aluminium panels impacted by ogival-nosed steel projectiles. The chosen panel has three triangular-shaped cells with a total depth of 130 mm. The wall thickness is 6 mm in the front and rear side plate, and 3 mm in the slanting webs. A rather comprehensive material test programme has been carried out in order to determine the material's response to dynamic loading. The experimental results were used to calibrate slightly modified versions of the Johnson-Cook constitutive relation and fracture criterion. 3D numerical simulations of the perforation process were then performed on a high-performance computer using the MPP version of the explicit finite element code LS-DYNA. In the simulations, the typical dimension of the elements was less than 1 mm. The numerical model is able to capture the main trends in the experiments in an adequate manner, and excellent agreement between numerical and experimental results is obtained.
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| 3. |
- Derkert, Jacob
(författare)
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Tonalitet och harmonisk artikulation i Claude Debussys verk : Om reception, harmonikteori och analys
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation is a study of ways to analyze some harmonic features of the music of Claude Debussy. It begins with a critical survey of the discussion of tonality and dissolution of tonality in Debussy's works, as it did manifest itself in contemporary French criticism and in the Germanspeaking countries after World War I. It tries to clarify the notion of 'tonality' involved in this discussion. It comes to a critical conclusion concerning the characterization of Debussy's music as embodying dissolution of tonality, which is found to be either rather trivial or speculative, i.e. unproven and difficult to test. A conceptual clarification is suggested, which gives a slightly different, at once more general and more precise, meaning to the trivial version of the discussed characterization.Next we turn to a discussion of the use of different scale-forms found in Debussy's music. We show that, in spite of the absence of tonality at the chord level, and in spite of the presence of a wide variety of different scale-forms, a scale-based conception of keys can be used to analyze at least some works of Debussy as embodying an articulation of keys. We then turn to ways to analyze the scale-form variation in itself. Lastly, we note that key-articulation in Debussy's music is due to two factors: transposition and scale-form variation. We present a simple method to single out the contributions of these two factors.
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| 4. |
- Erdtman, Edvin, 1981-
(författare)
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5-Aminolevulinic acid and derivatives thereof : properties, lipid permeability and enzymatic reactions
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 5-aminolevulinic acid (5-ALA) and derivatives thereof are widely usedprodrugs in treatment of pre-malignant skin diseases of the cancer treatmentmethod photodynamic therapy (PDT). The target molecule in 5-ALAPDTis protoporphyrin IX (PpIX), which is synthesized endogenously from5-ALA via the heme pathway in the cell. This thesis is focused on 5-ALA,which is studied in different perspectives and with a variety of computationalmethods. The structural and energetic properties of 5-ALA, itsmethyl-, ethyl- and hexyl esters, four different 5-ALA enols, and hydrated5-ALA have been investigated using Quantum Mechanical (QM) first principlesdensity functional theory (DFT) calculations. 5-ALA is found to bemore stable than its isomers and the hydrolysations of the esters are morespontaneous for longer 5-ALA ester chains than shorter. The keto-enoltautomerization mechanism of 5-ALA has been studied, and a self-catalysismechanism has been proposed to be the most probable. Molecular Dynamics(MD) simulations of a lipid bilayer have been performed to study themembrane permeability of 5-ALA and its esters. The methyl ester of 5-ALAwas found to have the highest permeability constant (PMe-5-ALA = 52.8 cm/s).The mechanism of the two heme pathway enzymes; Porphobilinogen synthase(PBGS) and Uroporphyrinogen III decarboxylase (UROD), have beenstudied by DFT calculations and QM/MM methodology. The rate-limitingstep is found to have a barrier of 19.4 kcal/mol for PBGS and 13.7kcal/mol for the first decarboxylation step in UROD. Generally, the resultsare in good agreement with experimental results available to date.
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| 5. |
- Eriksson, Anna, 1977-
(författare)
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Studies of New Signal Transduction Modulators in Acute Myeloid Leukemia
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute myeloid leukemia (AML) is a life-threatening malignant disorder with dismal prognosis. AML is characterized by frequent genetic changes involving tyrosine kinases, normally acting as important mediators in many basic cellular processes. Due to the overexpression and frequent mutations of the FMS-like receptor tyrosine kinase 3 (FLT3) in AML, this tyrosine kinase receptor has become one of the most sought after targets in AML drug development.In this thesis, we have used a combination of high-throughput screens, direct target interaction assays and sequential cellular screens, including primary patient samples, as an approach to discover new targeted therapies. Gefitinib, a previously known inhibitor of epidermal growth factor receptor and the two novel tyrosine kinase inhibitors AKN-032 and AKN-028, have been identified as compounds with cytotoxic activity in AML.AKN-028 is a potent inhibitor of FLT3 with an IC50 value of 6 nM in an enzyme assay, but also displaying in vitro activity in a variety of primary AML samples, irrespective of FLT3 mutation status or quantitative FLT3 expression. AKN-028 shows a sequence dependent in vitro synergy when combined with standard cytotoxic agents cytarabine or daunorubicin, with better efficacy when cells are exposed to standard chemotherapy simultaneously or for 24 hours prior to adding AKN-028. Antagonism is observed when cells are pre-treated with AKN-028, possibly explained by the cell cycle arrest induced by the compound. In vivo cytotoxic activity and good oral bioavailability have made AKN-028 a candidate drug for clinical studies and the compound is presently investigated in an international two-part multicenter phase I/II study.Results from microarray studies performed to further elucidate the mechanism of action of AKN-028, revealed significantly altered gene expression induced by AKN-028 in both AML cell lines and in primary AML cells, with an enrichment of the Myc pathway among the downregulated genes.Furthermore, tyrosine kinase activity profiling shows a dose-dependent kinase inhibition by AKN-028 in all AML samples tested. Interestingly, cells with a high overall kinase activity were more sensitive to AKN-028. Provided conformation in a larger set of samples, kinase activity profiling may give useful information in individualizing treatment of patients with AML.
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| 6. |
- Eriksson, Daniel, 1987-, et al.
(författare)
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Laboratory measurement method for the mechanical interaction between a tactile sensor and a cartonboard package – presentation and evaluation
- 2021
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Ingår i: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter. - 0283-2631 .- 2000-0669. ; 36:1, s. 91-99
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Tidskriftsartikel (refereegranskat)abstract
- The importance of sensory information in product purchasing decisions has gained increasing attention in recent years. Tactile properties of packaging are usually measured with the help of trained evaluators. An objective, fast and repeatable method that describes the mechanical interaction and does not rely on a panel would have many benefits. We propose and evaluate such a method for measuring the mechanical interaction between a deformable finger-like shaped sensor and a package. Evaluation of the method shows good repeatability, the variability in the measurement result is within a few percent in most cases. The method captures indentation differences at contact between sensor and package due to measurement position and package design.
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| 7. |
- Eriksson, Tore, et al.
(författare)
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Measurement method for finding gas adsorption equilibrium isotherms by employing a gas chromatograph and using its integrator in a new way
- 2005
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 76:4, s. 044102-
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Tidskriftsartikel (refereegranskat)abstract
- A method for measuring the adsorption ability of zeolites has been developed. The adsorption can be accurately measured over a wide range of pressures and temperatures. The range usually covered is partial pressures ranging from 0.2 to 20 bar (a) and temperatures from 10 to 50 degrees C. However, it may be extended to 0.1-25 bar (a) and -40-80 degrees C. When a partial pressure below 2 bar (a) is to be used, the gas is diluted with helium. The method is built around a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD) and having a programming and peak integrating unit. It also has an option using liquid nitrogen to allow work below ambient temperature. The GC has been modified with two special columns to be used alternately for purging with helium and as test chamber for the measurements. It is also equipped with a separate external flow and pressure-handling unit. The GC is used, not as a chromatograph, but instead to integrate suitably interrupted breakthrough curves. The primary measured data are evaluated using a program written in BASIC, which separates the part of the primary measured results that originates from the adsorption from the part that is induced by the measuring equipment. Using a calibration file that can easily be updated from within the program, this separation has achieved a high degree of accuracy. Using the adsorption data from these measurements, Langmuir-type isotherm equations are fitted, which accurately represent the adsorption of the tested gas both with respect to pressure and to temperature. It has been found that adsorption data measured in this way can achieve a standard deviation between measured and calculated data that typically varies around 1% over the whole measured range. In order to do this, however, in the case of nitrogen adsorption the sum of two Langmuir isotherms has to be used. This is not needed with oxygen or argon adsorption.
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| 8. |
- Eriksson, Tore, et al.
(författare)
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Temperature swing adsorption device for oxygen-enriched air
- 2014
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 76, s. 174-179
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Tidskriftsartikel (refereegranskat)abstract
- In connection with a project aimed at producing oxygen-enriched air from ambient air using temperature differences in the so-called temperature swing adsorption (TSA), a device was designed and constructed that took into consideration most of the conceivable parameters governing such a process. While designing the device, care was taken so that it was adaptable to different operating modes, fulfilling high versatility and extending to more processes than producing oxygen-enriched air. The device was small-scale, mounted on a movable table. It was equipped with a total of 54 individually controllable on/off valves. The valves could be controlled at a resolution of 1 s using a programmable logic controller, controlled by a personal computer, so the time program for the valves could be easily exchanged for a readymade program. The device had six cylinders, with removable lids filled with zeolite and easily maintained plastic tubing, which could therefore be changed or replaced without much difficulty. The results show that 15 L of oxygen could be produced at a concentration of 30% in the oxygen-enriched air per kg zeolite and hour. Equipping the device in the future with valves that close and open securely in both directions would vastly extend the possibility of using this technology to other applications, in addition to this method of TSA process for air separation.
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| 9. |
- Eriksson, Tina, et al.
(författare)
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The ethics of risk communication in lifestyle interventions: Consequences of patient centredness
- 2007
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Ingår i: Health, Risk and Society. - : Informa UK Limited. - 1469-8331 .- 1369-8575. ; 9:1, s. 19-36
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Tidskriftsartikel (refereegranskat)abstract
- Background: Broader patient access to information, expanding clinical options and greater accommodation of patients' personal values makes clinical decision-processes increasingly complex. Given the challenges and implications of risk communication, it is important to explore what is happening when clinicians adopt different approaches to consultations. Aim: To perform an ethical analysis of personal risk communication based around a scenario of cardiovascular risk reduction by exploring how different consultation models raise different ethical implications. Method: We based our analysis on the triangle of autonomy, utility and justice. Because ethical questions arise during consultations, consultation approach is a basic context for interpretations. We chose four distinct approaches; paternalistic, shared decision-making, mandatory autonomist and narrative. Results: The ethical principles of autonomy, utility and justice proved ambiguous. Tradeoffs exist between principles to balance the rights of individual patients (autonomy and protection of personal rights and the patient's personal view on utility), with medical utility seen from the perspective of the health care system (with limited resources), equity and solidarity. Patient centredness is believed to enhance trust in the doctor -patient relationship, but the decisional authority given to patients in such approaches may hazard biomedical utility in the individual consultation and make prioritizing between tasks in the health care sector difficult. Conclusion: The consultation style of the GP has implications for the individual patient, for population health and for the cost of health care. This debate is unavoidable.
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| 10. |
- Flygare, Lennart, et al.
(författare)
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Cartilage matrix macromolecules in lavage fluid of temporomandibular joints before and 6 months after diskectomy
- 1997
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Ingår i: European Journal of Oral Sciences. - : Wiley-Blackwell. - 0909-8836 .- 1600-0722. ; 105:4, s. 369-372
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Tidskriftsartikel (refereegranskat)abstract
- The purpose was to investigate if antigenic fragments of aggrecan and cartilage oligomeric matrix protein (COMP) are detectable by enzyme-linked immunosorbent assay in lavage fluids from the temporomandibular joint (TMJ) and to examine if the relative content of these cartilage markers changes during development of osteoarthrosis (OA) after diskectomy. Lavage fluid was obtained at surgery and 6 months postoperatively in 13 patients. Computed tomography or magnetic resonance imaging was without evidence of hard-tissue changes prior to surgery in all patients. In 9 of the patients, sufficient material for analysis was obtained at both examinations. Aggrecan and COMP were detectable in all but 2 fluids, in which the COMP levels were below detection limit. The aggrecan/COMP ratio increased in all 9 patients during the 6-month period, indicating increased release of aggrecan relative to COMP fragments. The changed aggrecan/COMP ratio possibly reflects increased cartilage turnover during development of OA. Changes compatible with OA were present on computed tomography in all cases at the 6-month follow-up. This study shows that the lavage procedure is feasible for obtaining synovial fluid from the TMJ for immunochemical analyses of tissue-derived macromolecules.
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| 11. |
- Flygt, Hjalmar, et al.
(författare)
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Long-term tolerability and efficacy after initial PegIFN-alpha addition to dasatinib in CML-CP : Five-year follow-up of the NordCML007 study
- 2021
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Ingår i: European Journal of Haematology. - : Wiley-Blackwell. - 0902-4441 .- 1600-0609. ; 107:6, s. 617-623
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Treatment-free remission (TFR) has emerged as a treatment goal in chronic myeloid leukemia in the chronic phase (CML-CP). Attempts to increase proportion of patients achieving TFR include combination of tyrosine kinase inhibitors (TKI) and other drugs. Interferon-alpha in addition to TKI has shown promising efficacy but with dose-dependent toxicity and discontinuations. NordCML007 was initiated to study the efficacy and safety of low dose pegylated IFN-alpha (PegIFN-alpha) in combination with dasatinib (DAS) in CML-CP. Methods Forty patients with newly diagnosed CML-CP were given DAS upfront. After month 3 (M3) 15 mu g/wk of PegIFN-alpha was added and increased to 25 mu g/wk from M7 until M15. DAS treatment was continued and adverse events and BCR-ABL1 qRT-PCR values were reported yearly after M24. Results from M1 to M18 have previously been published, and here we present long-term data. Results After 5 years of follow-up, there were no suspected unexpected serious adverse reactions, no increase in serosal effusions, no disease progressions and no CML-related deaths. Rates of MR3.0 (MMR), MR4.0 and MR4.5 were 84.6%, 64.1% and 51.3% respectively at M60, and 95% of patients reached MMR at some point during the study. Conclusion Initial addition of PegIFN-alpha to DAS shows good long-term efficacy without increased toxicity.
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| 12. |
- Flygt, Hjalmar, et al.
(författare)
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Long-term tolerability and efficacy after initial PegIFN-α addition to dasatinib in CML-CP : Five-year follow-up of the NordCML007 study
- 2021
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Ingår i: European Journal of Haematology. - : John Wiley & Sons. - 0902-4441 .- 1600-0609. ; 107:6, s. 617-623
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTreatment-free remission (TFR) has emerged as a treatment goal in chronic myeloid leukemia in the chronic phase (CML-CP). Attempts to increase proportion of patients achieving TFR include combination of tyrosine kinase inhibitors (TKI) and other drugs. Interferon-α in addition to TKI has shown promising efficacy but with dose-dependent toxicity and discontinuations. NordCML007 was initiated to study the efficacy and safety of low dose pegylated IFN-α (PegIFN-α) in combination with dasatinib (DAS) in CML-CP.MethodsForty patients with newly diagnosed CML-CP were given DAS upfront. After month 3 (M3) 15 μg/wk of PegIFN-α was added and increased to 25 μg/wk from M7 until M15. DAS treatment was continued and adverse events and BCR-ABL1 qRT-PCR values were reported yearly after M24. Results from M1 to M18 have previously been published, and here we present long-term data.ResultsAfter 5 years of follow-up, there were no suspected unexpected serious adverse reactions, no increase in serosal effusions, no disease progressions and no CML-related deaths. Rates of MR3.0 (MMR), MR4.0 and MR4.5 were 84.6%, 64.1% and 51.3% respectively at M60, and 95% of patients reached MMR at some point during the study.ConclusionInitial addition of PegIFN-α to DAS shows good long-term efficacy without increased toxicity.
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| 13. |
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| 14. |
- Gariani, Talal, et al.
(författare)
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Conformational variability of the GTPase domain of the signal recognition particle receptor FtsY.
- 2006
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Ingår i: Journal of structural biology. - : Elsevier BV. - 1047-8477. ; 153:1, s. 85-96
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Tidskriftsartikel (refereegranskat)abstract
- The prokaryotic signal recognition particle Ffh and its receptor FtsY allow targeting of proteins into or across the plasma membrane. The targeting process is GTP dependent and the two proteins constitute a distinct GTPase family. The receptor FtsY is composed of A and NG domains where the NG's GTPase domain plays a critical role in the targeting process. In this study, we describe two X-ray structures determined independently of each other of the NG domain of FtsY from Mycoplasma mycoides (MmFtsY). The two structures are markedly different in three of the nucleotide-binding segments, GI (P-loop), GII, and GIII, making only one of the structures compatible with nucleotide binding. Interestingly, the two distinct conformations of the nucleotide-binding segments of MmFtsY are similar to the apo- and ADP-loaded forms of certain ATPases. The structure of the extended interface between the A and NG domains of MmFtsY provides new insights into the role of the A domain for phospholipid interaction.
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| 15. |
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| 16. |
- Ghorai, Sagar, et al.
(författare)
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Site-specific atomic substitution in a giant magnetocaloric Fe2P-type system
- 2023
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 107:10
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Tidskriftsartikel (refereegranskat)abstract
- Giant magnetocaloric (GMC) materials constitute a requirement for near room temperature magnetic refrigeration. (Fe,Mn)2(P,Si) is a GMC compound with strong magnetoelastic coupling. The main hindrance towards application of this material is a comparably large temperature hysteresis, which can be reduced by metal site substitution with a nonmagnetic element. However, the (Fe,Mn)2(P,Si) compound has two equally populated metal sites, the tetrahedrally coordinated 3f and the pyramidally coordinated 3g sites. The magnetic and magnetocaloric properties of such compounds are highly sensitive to the site specific occupancy of the magnetic atoms. Here we have attempted to study separately the effect of 3f and 3g site substitution with equal amounts of vanadium. Using formation energy calculations, the site preference of vanadium and its influence on the magnetic phase formation are described. A large difference in the isothermal entropy change (as high as 44\%) with substitution in the 3f and 3g sites is observed. The role of the lattice parameter change with temperature and the strength of the magnetoelastic coupling on the magnetic properties are highlighted.
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| 17. |
- Gröndal, Staffan, et al.
(författare)
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Steroid profile in urine : a useful tool in the diagnosis and follow-up of adrenocortical carcinoma
- 1990
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Ingår i: Acta Endocrinologica. - : Oxford University Press (OUP). - 0001-5598 .- 0804-4643 .- 1479-683X. ; 122:5, s. 656-663
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Tidskriftsartikel (refereegranskat)abstract
- The urinary steroid profile was determined in 24 patients with adrenocortical carcinoma. Seventeen of the patients had Cushing's syndrome, virilization or feminization, and 7 had no signs of endocrine disease. Seven of the 11 patients still alive are free of disease, after a follow-up period of 5-75 months. The steroid profile varied widely between the patients with adrenocortical carcinoma. Patients with Cushing's syndrome had increased levels of cortisol metabolites and those with virilism had raised excretion of androgen metabolites. Six of the patients with adrenocortical carcinoma showed normal values of these metabolites. In 23 of the 24 patients the excretion of 3 beta-hydroxy-5-ene steroids and/or metabolites of cortisol precursors, such as tetrahydro-11-deoxycortisol, were significantly increased, compared with healthy controls or patients with adrenal adenomas. These findings suggest a relative deficit or low activity of 3 beta-hydroxysteroid dehydrogenase/delta isomerase and/or 11 beta-hydroxylase in tumour tissue. In the single patient where the steroid profile failed to indicate malignancy, hypercortisolism was seen and the tumour mass was small. The steroid excretion normalized after radical surgery and decreased in patients responding to chemotherapy. During recurred disease the metabolites of 3 beta-hydroxy-5-ene steroids and/or cortisol precursors increased, but in some patients the excretory pattern then was different from that seen before treatment
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| 18. |
- Iqbal, Muhammad Naeem, 1985-
(författare)
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Mesoporous Silica Particles for a Potential Therapeutic Application
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mesoporous silica particles (MSPs) have a high surface area, pore volume, and tunable pore size and surface properties, which makes them ideal for advanced therapeutic, biocatalytic, separation, and drug delivery applications. The work in this thesis shows that MSPs can be employed for therapeutic applications with minimal risk of adverse consequences. The MSPs in the study are of the SBA-15 type.Obesity is a serious health problem caused by an excess of adipose tissue (body fat) as a result of inadequate energy expenditure. Both in developed and developing countries, the prevalence is increasing rapidly. Type 2 diabetes (T2D) mellitus is going to be one of the most destructive consequences of the global obesity pandemic. Obesity and diabetes are anticipated to affect 783 million people by 2045, with diabetes being the leading cause of death for an estimated 6.7 million people in 2021 (according to International Diabetes Federation, IDF Diabetes Atlas 10th edition, 2021). People who are overweight or have diabetes are more likely to trigger other physiological conditions such as the development of dyslipidemia. Dyslipidemia is defined by a combination of risk factors for cardiovascular disease, including excessive plasma free fatty acids, cholesterol, and triglycerides; low levels of high density lipoprotein (HDL); and aberrant low-density lipoprotein (LDL). Public health expenditures and initiatives are under severe strain as a result of these situations. Researching therapies that are both safe and effective is in dire need.MSPs were produced at bench scale, and scaled to pilot (100L) and then at a relatively large demonstration scale (100-1000L) and tested in vitro, in vivo, ex vivo, and clinically. The results from these studies have shown that when administered orally, MSPs adsorb enzymes that break down carbohydrates and lipids (amylase and lipase), physically separating them from their large substrates. When administered orally, this consequently reduces the breakdown of carbohydrates and fats, leading to a lowering of the total energy intake in animals and humans. This occurs when the MSP has pore sizes which is typically in the range of 8–13 nm that are slightly larger than the food-digesting enzymes. The research carried out as part of this thesis showed that when the MSPs are in the micron size range, they operate locally in the gastrointestinal tract (GIT) and exit in the fecal mass without being absorbed by the body. The adsorbed enzymes aid in the safe transit of MSPs through the gastrointestinal system. Furthermore, the presence of these digestive enzymes within the pores was shown to have no effect on enzymatic function. It was also observed that when a large substrate (starch) was used to measure the activity of α-amylase adsorbed in the pores of MSPs, the activity appeared reduced. However, this was not related to an inactivation of α-amylase but to the fact that starch was molecularly too large to enter the pores of the MSPs.
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| 19. |
- Iqbal, Muhammad Naeem, et al.
(författare)
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Surface Effect of Nano-Roughened Yttria-Doped Zirconia on Salivary Protein Adhesion
- 2021
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 14:21
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Tidskriftsartikel (refereegranskat)abstract
- Biocompatibility of yttria (3 mol%) stabilized zirconia ceramics, 3Y-TZP, was affected to a large degree as a result of protein adsorption from human saliva that in turn depends on materials surface properties. Variable nano-roughness levels in 3Y-TZP discs were characterized and tested for specificity and selectivity with respect to size and uptake for human salivary protein.
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| 20. |
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| 21. |
- Krantz, Ingela, et al.
(författare)
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Screening for postpartum depression with the Edinburgh Postnatal Depression Scale (EPDS) : An ethical analysis
- 2008
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Ingår i: Scandinavian Journal of Public Health. - London : SAGE Publications. - 1403-4948 .- 1651-1905. ; 36:2, s. 211-216
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To assess the Edinburgh Postnatal Depression Scale (EPDS), a self-administered questionnaire created to screen for symptoms of postpartum depression in the community, from an epidemiological and ethical perspective. Screening, as the practice of investigating apparently healthy individuals to detect unrecognised disease or its precursors, has interpretation problems and is complicated by deliberations on probabilities for something to occur, on which the scientific community is unanimous. Methods: Our ethical analysis is made using a framework with two different dimensions, the ethical principles autonomy and beneficence and the affected persons. To balance the ethical costs and the ethical benefits of EPDS an analogy with the assessment of pharmaceutics is used. Results: In this article we argue that routine EPDS screening of Swedish postpartum women would lead to considerable ethical problems due to the weak scientific foundation of the screening instrument. Despite a multitude of published studies, the side-effects in terms of misclassifications have not been considered carefully. The EPDS does not function very well as a routine screening instrument. The dualism created is too reductive and fails to recognize the plurality of difference that exists in the social word. Conclusions: Public health authorities should not advocate screening of unproved value. Screening is not just a medical issue but also an ethical one.
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| 22. |
- Liljenberg, Magnus, 1962-
(författare)
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Quantum Chemical Studies of Aromatic Substitution Reactions
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, density functional theory (DFT) is used to investigate the mechanisms and reactivities of electrophilic and nucleophilic aromatic substitution reactions (SEAr and SNAr respectively). For SEAr, the σ-complex intermediate is preceded by one (halogenation) or two (nitration) π-complex intermediates. Whereas the rate-determining transition state (TS) for nitration resembles the second π-complex, the corresponding chlorination TS is much closer to the σ-complex. The last step, the expulsion of the proton, is modeled with an explicit solvent molecule in combination with PCM and confirmed to be a nearly barrierless process for nitration/chlorination and involves a substantial energy barrier for iodination. It is also shown for nitration that the gas phase structures and energetics are very different from those in polar solvent. The potential energy surface for SNAr reactions differs greatly depending on leaving group; the σ-complex intermediate exist for F-/HF, but for Cl-/HCl or Br-/HBr the calculations indicate a concerted mechanism. These mechanistic results form a basis for the investigations of predictive reactivity models for aromatic substitution reactions. For SEAr reactions, the free energy of the rate-determining TS reproduces both local (regioselectivity) and global reactivity (substrate selectivity) with good to excellent accuracy. For SNAr reactions good accuracies are obtained for Cl-/HCl or Br-/HBr as leaving group, using TS structures representing a one-step concerted mechanism. The σ-complex intermediate can be used as a reactivity indicator for the TS energy, and for SEAr the accuracy of this method varies in a way that can be rationalized with the Hammond postulate. It is more accurate the later the rate-determining TS, that is the more deactivated the reaction. For SNAr reactions with F-/HF as leaving group, the same method gives excellent accuracy for both local and global reactivity irrespective of the degree of activation.
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| 23. |
- Odd-Geir, Lademo, et al.
(författare)
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A model for process-based crash simulation
- 2008
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 35:5, s. 376-388
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturing of a bumper system from aluminium extrusions often involves series of forming operations performed in the soft W-temper condition, and then artificially age-hardening of the components to the material's peak hardness T6 condition. It is probable that proper finite element (FE) modelling of the crash performance of the resulting systems must rely upon a geometry obtained from an FE model following the process route, i.e., including simulation of all major forming operations. The forming operations also result in an inhomogeneous evolution of some internal variables (among others the effective plastic strain) within the shaped components. Results from tensile tests reveal that plastic straining in W-temper leads to a significant change of the T6 work-hardening curves. In addition, the tests show that the plastic pre-deformation causes a reduction of the elongation of the T6 specimens. In the present work, these process effects have been included in a user-defined elastoplastic constitutive model in LS-DYNA incorporating a state-of-the-art anisotropic yield criterion, the associated flow rule and a non-linear isotropic work hardening rule as well as some ductile fracture criteria. A first demonstration and assessment of the modelling methodology is shown by ‘through-process analysis' of two uniaxial tensile test series. The industrial use and relevance of the modelling technique is subsequently demonstrated by a case study on an industrial bumper beam system.
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| 24. |
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| 25. |
- Wahlström, Johan, 1978-
(författare)
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Control of EGR and VGT for emission control and pumping work minimization in diesel engines
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Legislators steadily increase the demands on lowered emissions from heavy duty vehicles. To meet these demands it is necessary to integrate technologies like Exhaust Gas Recirculation (EGR) and Variable Geometry Turbochargers (VGT) together with advanced control systems. A control structure with PID controllers and selectors is proposed and investigated for coordinated control of EGR valve and VGT position in heavy duty diesel engines. Main control goals are to fulfill the legislated emission levels, to reduce the fuel consumption, and to fulfill safe operation of the turbocharger. These goals are achieved through regulation of normalized oxygen/fuel ratio and intake manifold EGR-fraction. These are chosen as main performance variables since they are strongly coupled to the emissions, compared to manifold pressure or air mass flow, which makes it easy to adjust set-points depending on e.g. measured emissions during an emission calibration process. In addition a mechanism for fuel efficient operation is incorporated in the structure, this is achieved by minimizing the pumping work. To design a successful control structure, a mean value model of a diesel engine is developed and validated. The intended applications of the model are system analysis, simulation, and development of model-based control systems. Model equations and tuning methods for the model parameters are described for each subsystem in the model. Static and dynamic validations of the entire model show mean relative errors that are less than 12%. Based on a system analysis of the model, a key characteristic behind the control structure is that oxygen/fuel ratio is controlled by the EGR-valve and EGR-fraction by the VGT-position, in order to handle a sign reversal in the system from VGT to oxygen/fuel ratio. For efficient calibration an automatic controller tuning method is developed. The controller objectives are captured in a cost function, that is evaluated utilizing a method choosing representative transients. The performance is evaluated on the European Transient Cycle. It is demonstrated how the weights in the cost function influence behavior, and that the tuning method is important in order to improve the control performance compared to if only a standard method is used. It is also demonstrated that the controller structure performs well regarding all control objectives. In combination with its efficient tuning, the controller structure thus fulfills all requirements for successful application.
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| 26. |
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