| 1. |
- Forssten, Maximilian Peter, 1996-, et al.
(författare)
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The Role of Glycerol-Containing Drugs in Cerebral Microdialysis : A Retrospective Study on the Effects of Intravenously Administered Glycerol
- 2019
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Ingår i: Neurocritical Care. - : Humana Press. - 1541-6933 .- 1556-0961. ; 30:3, s. 590-600
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cerebral microdialysis (CMD) is a valuable tool for monitoring compounds in the cerebral extracellular fluid (ECF). Glycerol is one such compound which is regarded as a marker of cell membrane decomposition. Notably, in some acutely brain-injured patients, CMD-glycerol levels rise without any other apparent indication of cerebral deterioration. The aim of this study was to investigate whether this could be due to an association between CMD-glycerol levels and the administration of glycerol-containing drugs.METHODS: Microdialysis data were retrospectively retrieved from the hospital's intensive care unit patient data management system (PDMS). All patients who were monitored with CMD for ≥ 96 h were included. Administered drug doses were retrieved from the PDMS and converted to exact doses of glycerol. Cross-correlation analyses were performed between the free, metabolized as well as total administered dose of glycerol and the detrended and differenced CMD-glycerol concentration. These analyses were repeated for two sets of subgroups based upon the individual catheter's graphical trend and its location in relation to the lesion.RESULTS: There was no significant correlation between the differenced CMD-glycerol levels and drug-administered glycerol. Furthermore, there was no significant correlation between CMD-glycerol and catheter location or graphical trend. However, if the CMD-glycerol levels were detrended, significant but clinically non-relevant correlations were identified (maximum correlation coefficient of 0.1 (0.04-0.15, 95% CI) at a lag of 7 h using the total administered dose of glycerol).CONCLUSIONS: Glycerol-containing drugs routinely administered intravenously in the clinical setting appear to have a minimal and clinically insignificant effect on levels of glycerol in the cerebral ECF.
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| 2. |
- Lindblad, Caroline, et al.
(författare)
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Fluid proteomics of CSF and serum reveal important neuroinflammatory proteins in blood-brain barrier disruption and outcome prediction following severe traumatic brain injury : a prospective, observational study
- 2021
-
Ingår i: Critical Care. - : Springer Nature. - 1364-8535 .- 1466-609X. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe traumatic brain injury (TBI) is associated with blood-brain barrier (BBB) disruption and a subsequent neuroinflammatory process. We aimed to perform a multiplex screening of brain enriched and inflammatory proteins in blood and cerebrospinal fluid (CSF) in order to study their role in BBB disruption, neuroinflammation and long-term functional outcome in TBI patients and healthy controls. Methods: We conducted a prospective, observational study on 90 severe TBI patients and 15 control subjects. Clinical outcome data, Glasgow Outcome Score, was collected after 6-12 months. We utilized a suspension bead antibody array analyzed on a FlexMap 3D Luminex platform to characterize 177 unique proteins in matched CSF and serum samples. In addition, we assessed BBB disruption using the CSF-serum albumin quotient (Q(A)), and performed Apolipoprotein E-genotyping as the latter has been linked to BBB function in the absence of trauma. We employed pathway-, cluster-, and proportional odds regression analyses. Key findings were validated in blood samples from an independent TBI cohort. Results: TBI patients had an upregulation of structural CNS and neuroinflammatory pathways in both CSF and serum. In total, 114 proteins correlated with Q(A), among which the top-correlated proteins were complement proteins. A cluster analysis revealed protein levels to be strongly associated with BBB integrity, but not carriage of the Apolipoprotein E4-variant. Among cluster-derived proteins, innate immune pathways were upregulated. Forty unique proteins emanated as novel independent predictors of clinical outcome, that individually explained similar to 10% additional model variance. Among proteins significantly different between TBI patients with intact or disrupted BBB, complement C9 in CSF (p = 0.014, Delta R-2 = 7.4%) and complement factor B in serum (p = 0.003, Delta R-2 = 9.2%) were independent outcome predictors also following step-down modelling. Conclusions: This represents the largest concomitant CSF and serum proteomic profiling study so far reported in TBI, providing substantial support to the notion that neuroinflammatory markers, including complement activation, predicts BBB disruption and long-term outcome. Individual proteins identified here could potentially serve to refine current biomarker modelling or represent novel treatment targets in severe TBI.
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| 3. |
- Thelin, Eric Peter, et al.
(författare)
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Protein profiling in serum after traumatic brain injury in rats reveals potential injury markers
- 2018
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Ingår i: Behavioural Brain Research. - : Elsevier. - 0166-4328 .- 1872-7549. ; 340, s. 71-80
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The serum proteome following traumatic brain injury (TBI) could provide information for outcome prediction and injury monitoring. The aim with this affinity proteomic study was to identify serum proteins over time and between normoxic and hypoxic conditions in focal TBI. Material and methods: Sprague Dawley rats (n = 73) received a 3 mm deep controlled cortical impact ("severe injury"). Following injury, the rats inhaled either a normoxic (22% O-2) or hypoxic (11% O-2) air mixture for 30 min before resuscitation. The rats were sacrificed at day 1, 3, 7, 14 and 28 after trauma. A total of 204 antibodies targeting 143 unique proteins of interest in TBI research, were selected. The sample proteome was analyzed in a suspension bead array set-up. Comparative statistics and factor analysis were used to detect differences as well as variance in the data. Results: We found that complement factor 9 (C9), complement factor B (CFB) and aldolase c (ALDOC) were detected at higher levels the first days after trauma. In contrast, hypoxia inducing factor (HIF)1 alpha, amyloid precursor protein (APP) and WBSCR17 increased over the subsequent weeks. S100A9 levels were higher in hypoxic-compared to normoxic rats, together with a majority of the analyzed proteins, albeit few reached statistical significance. The principal component analysis revealed a variance in the data, highlighting clusters of proteins. Conclusions: Protein profiling of serum following TBI using an antibody based microarray revealed temporal changes of several proteins over an extended period of up to four weeks. Further studies are warranted to confirm our findings.
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| 4. |
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| 5. |
- Thelin, Peter, et al.
(författare)
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Analytical Calculation of the Airgap Flux Density of PM Synchronous Motors with Buried Magnets Including Axial Leakage, Tooth and Yoke Saturations
- 2000
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Ingår i: Proc. of the International Conference on Power Electronics and Variable Speed Drives, London, September 2000.. - : IEE. ; , s. 218-223
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Konferensbidrag (refereegranskat)abstract
- It has been shown earlier that the airgap flux density of PM motors with buried magnets can be calculated with a satisfactory result, if saturated iron bridges, axial leakage flux (from 2D-FEM) and teeth saturation are taken into account. In this paper, instead of using 2D-FEM, an analytical expression for the axial reluctance is derived. By including the saturation of rotor and stator yokes, the model is even further improved. The result is a complete analytical model, which takes into account all phenomena mentioned above, and improves the agreement with experimental values.
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| 6. |
- Thelin, Peter, et al.
(författare)
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Calculation of the Airgap Flux Density of PM Synchronous Motors with Buried Magnets including Axial Leakage and Teeth Saturation
- 1999
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Ingår i: Proc. of the Electrical Machines and Drives Conference, Canterbury, UK, September 1999. - : Institution of Electrical Engineers (IEE). ; , s. 339-345
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Konferensbidrag (refereegranskat)abstract
- It has been shown earlier that the airgap flux density of unsaturated PM motors with buried magnets can be calculated analytically, with a satisfactory result, compared to 2D-FEM calculations. By taking axial leakage flux, and stator and rotor teeth saturation into account an improved expression for the airgap flux density, showing better agreement with experiments, is obtained.
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| 7. |
- Thelin, Peter, et al.
(författare)
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Comparison between Different Ways to Calculate the Induced No-Load Voltage of PM Synchronous Motors using Finite Element Methods
- 2001
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Ingår i: Proc. of the 4th IEEE International Conference on Power Electronics and Drive Systems (PEDS'01), Bali, Indonesia, October 2001, vol. 2.. ; , s. 468-474
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Konferensbidrag (refereegranskat)abstract
- In this paper two different ways of calculating the induced no-load voltage of permanent magnet synchronous motors (PMSM), by the use of a finite element method (FEM) program, have been compared. Neither of the two calculation methods require a FEM software package that can perform time-stepping. The number of required static FEM-calculations is limited to just a few, or even to one. The calculations are performed on five motor geometries. The results are compared to values obtained from time-stepping FEM-calculations, and to the measured induced no-load voltages of the five manufactured prototype motors. It can be seen that the least time-consuming method is accurate enough in most of these cases. The exceptions, in this study, are when there are relatively large airgaps and/or when the stator teeth are saturated.
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| 8. |
- Thelin, Peter, et al.
(författare)
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Development and Efficiency Measurements of a Compact 15 kW 1500 r/min Integral Permanent Magnet Synchronous Motor
- 2000
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Ingår i: Proc. of the IEEE Industry Applications Society Annual Meeting, Roma, Italy, October 2000.. ; , s. 155-162
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Konferensbidrag (refereegranskat)abstract
- This paper presents the development of a 15 kW, 1500 r/min integral motor, with the same outer dimensions as an equivalent standard induction motor, but with the possibility of operating with speed control and at a higher efficiency. To make a compact integral motor, a permanent magnet rotor is used, the coils of the line-filter and the coil of the DC-link have been integrated with the stator core, only a small DC-link capacitor is employed, and the motor is controlled without a shaft sensor. Temperature and efficiency measurements on the manufactured prototype machine are performed and the results are very promising.
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| 9. |
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| 10. |
- Thelin, Peter, et al.
(författare)
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Rotor Cage Losses of an Inverter-Fed PMSM investigated with FEM
- 2003
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Ingår i: Proceedings of the European Conference on Power Electronics and Applications, EPE´03.
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Konferensbidrag (refereegranskat)abstract
- In the design of a compact inverter-fed buried permanent magnet synchronous motor, the high-frequency losses of the sparse rotor cage - which are difficult to predict - were assumed to be small. To investigate these ohmic high-frequency losses of the rotor cage, fixed-speed time-stepping 2D-FEM calculations have been carried out. The losses due to only the magnets, magnets and sinusoidal currents, high-frequency currents etc., and the actual currents are presented. The actual current wave-forms were obtained from measurements on the manufactured prototype motor.
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| 11. |
- Thelin, Peter, et al.
(författare)
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Suggestions Regarding the Pole-Number of Inverter-Fed PM-Synchronous Motors with Buried Magnets
- 1998
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Ingår i: Proc. of the International Conference on Power Electronics and Variable Speed Drives 1998. - : Institution of Electrical Engineers (IEE). ; , s. 544-547
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Konferensbidrag (refereegranskat)abstract
- When designing an inverter-fed PM-motor, one is quite free to choose a number of poles which utilizes the machine in a good way. A common rule of thumb is to choose a high pole-number for low-speed motors and vice versa, but there are no sharp borderlines between the different areas. This paper gives a suggestion regarding the pole-number for a desired power and speed of the motor.
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| 12. |
- Wouters, Mira M., et al.
(författare)
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Genetic variants in CDC42 and NXPH1 as susceptibility factors for constipation and diarrhoea predominant irritable bowel syndrome
- 2014
-
Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 63:7, s. 1103-1111
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The complex genetic aetiology underlying irritable bowel syndrome (IBS) needs to be assessed in large-scale genetic studies. Two independent IBS cohorts were genotyped to assess whether genetic variability in immune, neuronal and barrier integrity genes is associated with IBS.Design: 384 single nucleotide polymorphisms (SNPs) covering 270 genes were genotyped in an exploratory cohort (935 IBS patients, 639 controls). 33 SNPs with P-uncorrected<0.05 were validated in an independent set of 497 patients and 887 controls. Genotype distributions of single SNPs were assessed using an additive genetic model in IBS and clinical subtypes, IBS-C and IBS-D, both in individual and combined cohorts. Trait anxiety (N=614 patients, 533 controls), lifetime depression (N=654 patients, 533 controls) and mRNA expression in rectal biopsies (N=22 patients, 29 controls) were correlated with SNP genotypes.Results: Two SNPs associated independently in the exploratory and validation cohort: rs17837965-CDC42 with IBS-C (ORexploratory=1.59 (1.05 to 1.76); ORvalidation=1.76 (1.03 to 3.01)) and rs2349775-NXPH1 with IBS-D (ORexploratory=1.28 (1.06 to 1.56); ORvalidation=1.42 (1.08 to 1.88)). When combining both cohorts, the association of rs2349775 withstood post hoc correction for multiple testing in the IBS-D subgroup. Additionally, three SNPs in immune-related genes (rs1464510-LPP, rs1881457-IL13, rs2104286-IL2RA), one SNP in a neuronal gene (rs2349775-NXPH1) and two SNPs in epithelial genes (rs245051-SLC26A2, rs17837965-CDC42) were weakly associated with total-IBS (P-uncorrected<0.05). At the functional level, rs1881457 increased IL13 mRNA levels, whereas anxiety and depression scores did not correlate with rs2349775-NXPH1.Conclusions: Rs2349775 (NXPH1) and rs17837965 (CDC42) were associated with IBS-D and IBS-C, respectively, in two independent cohorts. Further studies are warranted to validate our findings and to determine the mechanisms underlying IBS pathophysiology.
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| 13. |
- Ahl, Rebecka, 1987-, et al.
(författare)
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β-Blocker after severe traumatic brain injury is associated with better long-term functional outcome : a matched case control study
- 2017
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Ingår i: European Journal of Trauma and Emergency Surgery. - : Springer Berlin/Heidelberg. - 1863-9933 .- 1863-9941. ; 43:6, s. 783-789
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Severe traumatic brain injury (TBI) is the predominant cause of death and disability following trauma. Several studies have observed improved survival in TBI patients exposed to β-blockers, however, the effect on functional outcome is poorly documented.METHODS: Adult patients with severe TBI (head AIS ≥ 3) were identified from a prospectively collected TBI database over a 5-year period. Patients with neurosurgical ICU length of stay <48 h and those dying within 48 h of admission were excluded. Patients exposed to β-blockers ≤ 48 h after admission and who continued with treatment until discharge constituted β-blocked cases and were matched to non β-blocked controls using propensity score matching. The outcome of interest was Glasgow Outcome Scores (GOS), as a measure of functional outcome up to 12 months after injury. GOS ≤ 3 was considered a poor outcome. Bivariate analysis was deployed to determine differences between groups. Odds ratio and 95% CI were used to assess the effect of β-blockers on GOS.RESULTS: 362 patients met the inclusion criteria with 21% receiving β-blockers during admission. After propensity matching, 76 matched pairs were available for analysis. There were no statistical differences in any variables included in the analysis. Mean hospital length of stay was shorter in the β-blocked cases (18.0 vs. 26.8 days, p < 0.01). The risk of poor long-term functional outcome was more than doubled in non-β-blocked controls (OR 2.44, 95% CI 1.01-6.03, p = 0.03).CONCLUSION: Exposure to β-blockers in patients with severe TBI appears to improve functional outcome. Further prospective randomized trials are warranted.
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| 14. |
- Arshad, W. M., et al.
(författare)
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Analytical analysis and dimensioning of a low-leakage linear transverse-flux machine
- 2004
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Ingår i: IEE Conference Publication. ; , s. 414-419
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a two-dimensional analytical analysis and dimensioning procedure of a novel low-leakage linear transverse-flux machine (TFM). The two-dimensionalanalytical models approximate the complex three-dimensional fluxes of the TFM. Theanalysis is based upon how the different airgap permeances and the non-linear iron reluctances in the different machine sections vary, as the translator is traversed through the airgap. The reluctance networks for the magnetomotive force (MMF) of the magnets and for the current dependent armature-MMF are solved simultaneously. A 5-kW proof-of-concept machine is dimensioned and its performance predicted using the described procedure. The different performance defining parameters are derived as continuous functions of the translator position. The dependence of the machine power factor and the force capability upon the current loading, which is quite interesting when analysing TFMs, is also investigated.
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| 15. |
- Arshad, Waqas Mahmood, et al.
(författare)
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Modelling of complex flux paths in a new high-performance transverse-flux electrical machine
- 2004
-
Ingår i: SECOND SEEHEIM CONFERENCE ON MAGNETISM, PROCEEDINGS. - WEINHEIM : WILEY-V C H VERLAG GMBH. - 3527405771 ; , s. 3227-3234
-
Konferensbidrag (refereegranskat)abstract
- The complex three-dimensional fluxes in a newly introduced high-performance transverse-flux electrical machine are investigated. The magnet-flux, the armature-flux and the combined-flux in the machine are studied as a function of mover position. Separate non-linear reluctance networks for the magnets- and current- magneto-motive forces are developed and solved simultaneously in an iterative manner. The airgap is modelled by defining two/three-dimensional varying permeances. The iron is represented with three different non-linear reluctances. The analytical models are fine tuned and verified by employing a detailed three-dimensional finite element analysis. The role these fluxes play in the determination of the machine's performance is also described. Lastly, it is shown how these fluxes help explain the machines' measured performance when unexpected manufacturing defects occurred.
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| 16. |
- Arshad, Waqas M., et al.
(författare)
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Use of transverse-flux machines in a free-piston generator
- 2004
-
Ingår i: IEEE transactions on industry applications. - 0093-9994 .- 1939-9367. ; 40:4, s. 1092-1100
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the use of transverse-flux machines (TFMs) in a free-piston generator, an integration of a combustion engine and a linear electrical machine. For hybrid vehicles (the intended application), this integrated device has benefits in efficiency, emissions, reliability, etc. Conventional TFMs are dimensioned and their shortcomings illustrated. Several surface-mounted TFM designs are suggested. These designs, initially believed to be promising, are later discovered to be. poor during the three-dimensional finite-element method (3-D FEM) analysis. These designs suffered from a large axial pole-to-pole armature-flux leakage in the stator. This problem is solved in the proposed buried-magnets TFM variants, for which patents have been filed as well. A 5-kW proof-of-concept prototype of one such design is dimensioned that allowed the near fulfilment of 3-D FEM verifiable system demands. One phase. of this dimensioned three-phase prototype is built. Measurements on this,prototype showed that the use of short pole lengths in the machine had led to manufacturing defects. Nevertheless, the electromagnetic viability of the design could still be approximately verified.
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| 17. |
- Bednarska, Olga, et al.
(författare)
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The Effectiveness and Tolerability of a Very Low-Volume Bowel Preparation for Colonoscopy Compared to Low and High-Volume Polyethylene Glycol-Solutions in the Real-Life Setting
- 2022
-
Ingår i: Diagnostics. - Basel, Switzerland : MDPI. - 2075-4418. ; 12:5
-
Tidskriftsartikel (refereegranskat)abstract
- Adequate bowel cleansing is essential for high-quality colonoscopy. Recently, a new very low-volume 1 litre (1L) polyethylene glycol (PEG) plus ascorbate solution (ASC) has been introduced. Our aims were to assess the effectiveness and tolerability of this product compared to low-volume 2L PEG-ASC and high-volume 4L PEG solutions, in a real-life setting. In six endoscopy units in Sweden, outpatients undergoing colonoscopy were either prescribed solutions according to local routines, or the very low-volume solution in split dose regimen. Bowel cleansing effectiveness and patient experience was assessed using the Boston Bowel preparation scale (BBPS) and a patient questionnaire. A total of 1098 patients (mean age 58 years, 52% women) were included. All subsegment and the total BBPS scores were significantly greater for 1L PEG-ASC in comparison to other solutions (p < 0.05 for 1L PEG-ASC and 4L PEG for transverse and left colon, otherwise p < 0.001). Nausea was more frequent with 1L PEG-ASC compared to 2L PEG-ASC (p < 0.001) and vomiting were more often reported compared to both other solutions (p < 0.01 and p < 0.05 for 2L PEG-ASC and 4L PEG, respectively). Smell, taste, and total experience was better for 1L PEG-ASC compared to 4L PEG (p < 0.001), and similar compared to the 2L PEG-ASC. In conclusion, 1L PEG-ASC leads to better bowel cleansing compared to 2L PEG-ASC or 4L PEG products, with similar or greater patient satisfaction.
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| 18. |
- Bronner, Kerstin Birgitta Thelin, et al.
(författare)
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Alcohol habits in patients with long term musculoskeletal pain : comparison with a matched control group from the general population
- 2012
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Ingår i: International Journal of Rehabilitation Research. - 0342-5282 .- 1473-5660. ; 35:2, s. 130-137
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Tidskriftsartikel (refereegranskat)abstract
- This prospective study aimed to describe alcohol habits in patients with chronic pain compared with those in a matched control group from the general Swedish population. In total, 100 consecutive patients enrolled were matched against 100 individuals in a control group on the basis of age and sex. Alcohol habits were measured using the Alcohol Use Disorders Identification Test in both groups. The patients were recruited if they underwent a biopsychosocial pain analysis for possible participation in pain rehabilitation. The patients with chronic pain drank alcohol significantly less, less often, in smaller quantities, and became intoxicated less than the control group did. The study was rather small and at a single site, but its strengths were the comprehensive and simple design and the possibility to describe the sample's representativeness compared with other clinics on the basis of data from a national quality register.
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| 19. |
- Börjesson Axén, Jenny, et al.
(författare)
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Short-Term Impact of AC Harmonics on Aging of NiMH Batteries for Grid Storage Applications
- 2021
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 14:5
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Tidskriftsartikel (refereegranskat)abstract
- Batteries in energy storage systems are exposed to electrical noise, such as alternating current (AC) harmonics. While there have been many studies investigating whether Lithium-ion batteries are affected by AC harmonics, such studies on Nickel Metal Hydride (NiMH) batteries are scarce. In this study a 10 Ah, 12 V NiMH battery was tested with three different harmonic current frequency overlays during a single charge/discharge cycle: 50 Hz, 100 Hz, and 1000 Hz. No effect on battery internal temperature or gas pressure was found, indicating that NiMH battery aging is not affected by the tested harmonic AC frequencies. This can reduce the cost of energy storage systems, as no extra filters are needed to safeguard the batteries. Instead, the capacitive properties of the batteries give the possibility to use the battery bank itself as a high pass filter, further reducing system complexity and cost.
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| 20. |
- Cosic, Alija, 1977-, et al.
(författare)
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APPLICATION OF A FREE-PISTON GENERATOR IN A SERIES HYBRID VEHICLE
- 2003
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Ingår i: Proceedings of the 4th international Symposium on Linear Drives for Industry Applications. ; , s. 541-544
-
Konferensbidrag (refereegranskat)abstract
- This paper deals with an investigation of differentcontrol strategies for a series hybrid electric vehicle (SHEV).Another discussed issue is the application of a free-pistongenerator. By replacing a conventional combustion enginewith a free-piston generator it is possible to increase the totalefficiency of the system. The object of investigation is a12-ton truck, mainly used in urban areas. The drive systemhas been built up and simulated in a MATLAB Simulinkenvironment. It follows from the investigation that theapplication of a free-piston engine in a SEHV can increasethe efficiency by 25 percent compared to the conventionalengine.
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| 21. |
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| 22. |
- Edvinsson, Marie, et al.
(författare)
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Trace Element Changes in Thoracic Aortic Dissection
- 2016
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Ingår i: Biological Trace Element Research. - : Springer Science and Business Media LLC. - 0163-4984 .- 1559-0720. ; 169:2, s. 159-163
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Tidskriftsartikel (refereegranskat)abstract
- Thoracic aortic dissection is a life-threatening condition with an incompletely understood pathogenesis. Trace elements are essential for the functioning of different processes in the body, including the immune system and associated responses to infection/inflammation. Because inflammation may be part of the pathogenesis of thoracic aortic dissection, we investigated whether trace element changes associated with inflammation occur in serum and tissue samples during the disease. The study included 21 patients undergoing surgery for thoracic aortic dissection, 10 forensic autopsy specimens for tissue controls and 23 healthy blood donors for serum controls. Levels of magnesium (Mg), calcium (Ca), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd) and mercury (Hg) were measured in the aortic tissue and serum by inductively coupled plasma-mass spectrometry (ICP-MS). In the serum, Ca, V, Cu and Zn decreased, whereas Fe increased. In the tissue, Cu and Zn decreased and Fe tended to increase. The Cu/Zn ratio in the serum, a marker of infection/inflammation, did not change in the patients. Concerning trace element changes in the serum and tissue, our data do not support the hypothesis that inflammation is involved in the pathogenesis of thoracic aortic dissection.
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| 23. |
- Fletcher-Sandersjoo, Alexander, et al.
(författare)
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Stockholm score of lesion detection on computed tomography following mild traumatic brain injury (SELECT-TBI) : study protocol for a multicentre, retrospective, observational cohort study
- 2022
-
Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 12:9
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction Mild traumatic brain injury (mTBI) is one of the most common reasons for emergency department (ED) visits. A portion of patients with mTBI will develop an intracranial lesion that might require medical or surgical intervention. In these patients, swift diagnosis and management is paramount. Several guidelines have been developed to help direct patients with mTBI for head CT scanning, but they lack specificity, do not consider the interactions between risk factors and do not provide an individualised estimate of intracranial lesion risk. The aim of this study is to create a model that estimates individualised intracranial lesion risks in patients with mTBI who present to the ED. Methods and analysis This will be a retrospective cohort study conducted at ED hospitals in Stockholm, Sweden. Eligible patients are adults (>= 15 years) with mTBI who presented to the ED within 24 hours of injury and performed a CT scan. The primary outcome will be a traumatic lesion on head CT. The secondary outcomes will be any clinically significant lesion, defined as an intracranial finding that led to neurosurgical intervention, hospital admission >= 48 hours due to TBI or death due to TBI. Machine-learning models will be applied to create scores predicting the primary and secondary outcomes. An estimated 20 000 patients will be included. Ethics and dissemination The study has been approved by the Swedish Ethical Review Authority (Dnr: 2020-05728). The research findings will be disseminated through peer-reviewed scientific publications and presentations at international conferences.
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| 24. |
- Fletcher-Sandersjöö, Alexander, et al.
(författare)
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Absolute Contusion Expansion Is Superior to Relative Expansion in Predicting Traumatic Brain Injury Outcomes : A Multi-Center Observational Cohort Study
- 2024
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 41:5-6, s. 705-713
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Tidskriftsartikel (refereegranskat)abstract
- Contusion expansion (CE) is a potentially treatable outcome predictor in traumatic brain injury (TBI), and a suitable end-point for hemostatic therapy trials. However, there is no consensus on the definition of clinically relevant CE, both in terms of measurement criteria (absolute vs. relative volume increase) and cutoff values. In light of this, the aim of this study was to assess the predictive abilities of different CE definitions on outcome. We performed a multi-center observational cohort study of adults with moderate-to-severe TBI treated in an intensive care unit. The exposure of interest was CE, defined as the absolute and relative volume change between the first and second computed tomography scan. The primary outcome was the Glasgow Outcome Scale (GOS) at 6–12 months post-injury, dichotomized into unfavorable (GOS ≤3) or favorable (GOS ≥4). The secondary outcome was all-cause mortality. In total, 798 patients were included, with a median duration of 7.0 h between the first and second CT scan. The median absolute and relative CE was 1.5 mL (interquartile range [IQR] 0.1–8.3 mL) and 100% (IQR 10–530%), respectively. Both CE forms were independently associated with unfavorable GOS. Absolute CE outperformed relative CE in predicting both unfavorable GOS (area under the curve [AUC]: 0.65 vs. 0.60, p = 0.002) and all-cause mortality (AUC: 0.66 vs. 0.60, p = 0.003). For dichotomized CE, absolute cutoffs of 1–10 mL yielded the best results. We conclude that absolute CE demonstrates stronger outcome correlation than relative CE. In studies focusing on lesion progression in TBI, it may be advantageous to use absolute CE as the primary outcome metric. For dichotomized outcomes, cutoffs between 1 and 10 mL are suggested, depending on the desired sensitivity-specificity balance.
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| 25. |
- Hugerth, Luisa W., et al.
(författare)
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No distinct microbiome signature of irritable bowel syndrome found in a Swedish random population
- 2020
-
Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 69:6, s. 1076-1084
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Tidskriftsartikel (refereegranskat)abstract
- Objective The ethiopathogenesis of irritable bowel syndrome (IBS) is unknown. While a link to the gut microbiome is postulated, the heterogeneity of the healthy gut makes it difficult to draw definitive conclusions. We aimed to describe the faecal and mucosa-associated microbiome (MAM) and health correlates on a community cohort of healthy and IBS individuals with no colonoscopic findings.Design The PopCol study recruited a random sample of 3556 adults; 745 underwent colonoscopy. IBS was defined by Rome IV criteria and organic disease excluded. 16S rRNA gene sequencing was conducted on sigmoid biopsy samples from 376 representative individuals (63 IBS cases) and faecal samples from 185 individuals (32 IBS cases).Results While sigmoid MAM was dominated by Lachnospiraceae, faeces presented a higher relative abundance of Ruminococcaceae. Microbial richness in MAM was linearly correlated to that in faeces from the same individual (R-2=0.255, p<3E-11) as was diversity (R-2=0.06, p=0.0022). MAM diversity decreased with increasing body mass index (BMI; Pearson's r=-0.1, p=0.08) and poorer self-rated health (r=-0.15, p=0.007), but no other health correlates. Faecal microbiome diversity was correlated to stool consistency (r=-0.16, p=0.043). Several taxonomic groups were correlated to age, BMI, depression and self-reported health, including Coprococcus catus associated with lower levels of depression (r=-0.003, p=0.00017). The degree of heterogeneity observed between IBS patients is higher than that observed between healthy individuals.Conclusions No distinct microbial signature was observed in IBS. Individuals presenting with low self-rated health or high BMI have lower gut microbiome richness.
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| 26. |
- Kasparaviciute, Gabriele, 1990, et al.
(författare)
-
Online Encoder-decoder Anomaly Detection using Encoder-decoder Architecture with Novel Self-configuring Neural Networks & Pure Linear Genetic Programming for Embedded Systems
- 2019
-
Ingår i: Proceedings of the 11th International Joint Conference on Computational Intelligence - Volume 1: ECTA, 163-171, 2019 , Vienna, Austria. s. 163-171. - : SCITEPRESS - Science and Technology Publications. - 9789897583841
-
Konferensbidrag (refereegranskat)abstract
- Recent anomaly detection techniques locus on the use of neural networks and an encoder-decoder architecture. However, these techniques lead to trade offs if implemented in an embedded environment such as high heat management, power consumption and hardware costs. This paper presents two related new methods for anomaly detection within data sets gathered from an autonomous mini-vehicle with a CAN bus. The first method which to the best of our knowledge is the first use of encoder-decoder architecture for anomaly detection using linear genetic programming (LGP). Second method uses self-configuring neural network that is created using evolutionary algorithm paradigm learning both architecture and weights suitable for embedded systems. Both approaches have the following advantages: it is inexpensive regarding resource use, can be run on almost any embedded board due to linear register machine advantages in computation. The proposed methods are also faster by at least one order of magnitude, and it includes both inference and complete training.
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| 27. |
- Leifsdottir, K., et al.
(författare)
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Proteomic profiles in cerebrospinal fluid predicted death and disability in term infants with perinatal asphyxia : A pilot study
- 2022
-
Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 111:5, s. 961-970
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: Perinatal asphyxia, resulting in hypoxic-ischaemic encephalopathy (HIE), has been associated with high mortality rates and severe lifelong neurodevelopmental disabilities. Our aim was to study the association between the proteomic profile in cerebrospinal fluid (CSF) and the degree of HIE and long-term outcomes. Methods: We prospectively enrolled 18-term born infants with HIE and 10-term born controls between 2000 and 2004 from the Karolinska University Hospital. An antibody suspension bead array and FlexMap3D analysis was used to characterise 178 unique brain-derived and inflammation associated proteins in their CSF. Results: Increased CSF concentrations of several brain-specific proteins were observed in the proteome of HIE patients compared with the controls. An upregulation of neuroinflammatory pathways was also noted and this was confirmed by pathway analysis. Principal component analysis revealed a gradient from favourable to unfavourable HIE grades and outcomes. The proteins that provided strong predictors were structural proteins, including myelin basic protein and alpha-II spectrin. The functional proteins included energy-related proteins like neuron-specific enolase and synaptic regulatory proteins. Increased CSF levels of 51 proteins correlated with adverse outcomes in infants with HIE. Conclusion: Brain-specific proteins and neuroinflammatory mediators in CSF may predict HIE degrees and outcomes after perinatal asphyxia.
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| 28. |
- Leifsdottir, Kristin, et al.
(författare)
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The cerebrospinal fluid proteome of preterm infants predicts neurodevelopmental outcome
- 2022
-
Ingår i: Frontiers in Pediatrics. - : Frontiers Media SA. - 2296-2360. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundSurvival rate increases for preterm infants, but long-term neurodevelopmental outcome predictors are lacking. Our primary aim was to determine whether a specific proteomic profile in cerebrospinal fluid (CSF) of preterm infants differs from that of term infants and to identify novel biomarkers of neurodevelopmental outcome in preterm infants. MethodsTwenty-seven preterm infants with median gestational age 27 w + 4 d and ten full-term infants were enrolled prospectively. Protein profiling of CSF were performed utilizing an antibody suspension bead array. The relative levels of 178 unique brain derived proteins and inflammatory mediators, selected from the Human Protein Atlas, were measured. ResultsThe CSF protein profile of preterm infants differed from that of term infants. Increased levels of brain specific proteins that are associated with neurodevelopment and neuroinflammatory pathways made up a distinct protein profile in the preterm infants. The most significant differences were seen in proteins involved in neurodevelopmental regulation and synaptic plasticity, as well as components of the innate immune system. Several proteins correlated with favorable outcome in preterm infants at 18-24 months corrected age. Among the proteins that provided strong predictors of outcome were vascular endothelial growth factor C, Neurocan core protein and seizure protein 6, all highly important in normal brain development. ConclusionOur data suggest a vulnerability of the preterm brain to postnatal events and that alterations in protein levels may contribute to unfavorable neurodevelopmental outcome.
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| 29. |
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| 30. |
- Magnussen, Freddy, et al.
(författare)
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Performance evaluation of permanent magnet synchronous machines with concentrated and distributed windings including the effect of field-weakening
- 2004
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Ingår i: Power Electronics, Machines and Drives, 2004. (PEMD 2004). Second International Conference on (Conf. Publ. No. 498). - : IEE. ; , s. 679-685
-
Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to evaluate different concentrated fractional pitch winding designs in comparison to a distributed full pitch winding design with one slot per pole per phase as a reference. The rotor design is fixed and the permanent magnets are surface mounted, i.e. the rotor has negligible magnetic saliency. The studied parameters are power capability considering inverter capacity, field-weakening performance, torque ripple (including cogging), iron losses, winding losses and thermal behaviour. The results of the machine performance comparisons are based on a comprehensive use of finite element analysis tools. Measurement results from tests on a laboratory prototype are used to define heat coefficients.
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| 31. |
- Nee, Hans-Peter, et al.
(författare)
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Determination of d and q reactances of permanent-magnet synchronous motors without measurements of the rotor position
- 2000
-
Ingår i: IEEE transactions on industry applications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0093-9994 .- 1939-9367. ; 36:5, s. 1330-1335
-
Tidskriftsartikel (refereegranskat)abstract
- The interest in permanent-magnet synchronous motors:(PMSMs) is increasing in a wide area of applications. Since most PMSMs will operate without a shaft sensor in the future, valuable: information for experimental determination of machine parameters will be lost,In this paper, therefore, a method is presented where the induced EMF and the d-axis reactance are determined in a no-load test and the q-axis reactance is determined in a load test. The load angle delta is determined from the load test by means of a new analytical method. In this way, no separate measurement of the load angle is required. The method is especially suitable for line-start PMSMs which normally operate with negative d-axis current and, therefore, are not saturated in the d-axis flux paths. Moreover, the method is very simple to carry out for any laboratory technician, since the only tests that have to be made are standard tests which are made on standard induction motors on a regular basis.
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| 32. |
- Needham, Edward J, et al.
(författare)
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Complex Autoantibody Responses Occur following Moderate to Severe Traumatic Brain Injury.
- 2021
-
Ingår i: Journal of immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 207:1, s. 90-100
-
Tidskriftsartikel (refereegranskat)abstract
- Most of the variation in outcome following severe traumatic brain injury (TBI) remains unexplained by currently recognized prognostic factors. Neuroinflammation may account for some of this difference. We hypothesized that TBI generated variable autoantibody responses between individuals that would contribute to outcome. We developed a custom protein microarray to detect autoantibodies to both CNS and systemic Ags in serum from the acute-phase (the first 7 d), late (6-12 mo), and long-term (6-13 y) intervals after TBI in human patients. We identified two distinct patterns of immune response to TBI. The first was a broad response to the majority of Ags tested, predominantly IgM mediated in the acute phase, then IgG dominant at late and long-term time points. The second was responses to specific Ags, most frequently myelin-associated glycopeptide (MAG), which persisted for several months post-TBI but then subsequently resolved. Exploratory analyses suggested that patients with a greater acute IgM response experienced worse outcomes than predicted from current known risk factors, suggesting a direct or indirect role in worsening outcome. Furthermore, late persistence of anti-MAG IgM autoantibodies correlated with raised serum neurofilament light concentrations at these time points, suggesting an association with ongoing neurodegeneration over the first year postinjury. Our results show that autoantibody production occurs in some individuals following TBI, can persist for many years, and is associated with worse patient outcome. The complexity of responses means that conventional approaches based on measuring responses to single antigenic targets may be misleading.
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| 33. |
- Nilsson, Simon R O, et al.
(författare)
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A mouse model of the 15q13.3 microdeletion syndrome shows prefrontal neurophysiological dysfunctions and attentional impairment
- 2016
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Ingår i: Psychopharmacologia. - : Springer Science and Business Media LLC. - 0033-3158. ; 233:11, s. 2151-2163
-
Tidskriftsartikel (refereegranskat)abstract
- Rationale: A microdeletion at locus 15q13.3 is associated with high incidence rates of psychopathology, including schizophrenia. A mouse model of the 15q13.3 microdeletion syndrome has been generated (Df[h15q13]/+) with translational utility for modelling schizophrenia-like pathology. Among other deficits, schizophrenia is characterised by dysfunctions in prefrontal cortical (PFC) inhibitory circuitry and attention. Objectives: The objective of this study is to assess PFC-dependent functioning in the Df(h15q13)/+ mouse using electrophysiological, pharmacological, and behavioural assays. Method: Experiments 1–2 investigated baseline firing and auditory-evoked responses of PFC interneurons and pyramidal neurons. Experiment 3 measured pyramidal firing in response to intra-PFC GABAAreceptor antagonism. Experiments 4–6 assessed PFC-dependent attentional functioning through the touchscreen 5-choice serial reaction time task (5-CSRTT). Experiments 7–12 assessed reversal learning, paired-associate learning, extinction learning, progressive ratio, trial-unique non-match to sample, and object recognition. Results: In experiments 1–3, the Df(h15q13)/+ mouse showed reduced baseline firing rate of fast-spiking interneurons and in the ability of the GABAAreceptor antagonist gabazine to increase the firing rate of pyramidal neurons. In assays of auditory-evoked responses, PFC interneurons in the Df(h15q13)/+ mouse had reduced detection amplitudes and increased detection latencies, while pyramidal neurons showed increased detection latencies. In experiments 4–6, the Df(h15q13)/+ mouse showed a stimulus duration-dependent decrease in percent accuracy in the 5-CSRTT. The impairment was insensitive to treatment with the partial α7nAChR agonist EVP-6124. The Df(h15q13)/+ mouse showed no cognitive impairments in experiments 7–12. Conclusion: The Df(h15q13)/+ mouse has multiple dysfunctions converging on disrupted PFC processing as measured by several independent assays of inhibitory transmission and attentional function.
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| 34. |
- Nyström-Rosander, Christina, et al.
(författare)
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Thoracic aortic aneurysm patients with Chlamydophila pneumoniae infection showed a shift in trace element levels in serum and diseased aortic tissue
- 2009
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Ingår i: Journal of Trace Elements in Medicine and Biology. - : Elsevier BV. - 0946-672X .- 1878-3252. ; 23:2, s. 100-106
-
Tidskriftsartikel (refereegranskat)abstract
- Few studies have been performed on trace elements in tissues and serum in cardiovascular disease and none in aortic aneurysm. In this study the concentrations of 10 trace elements were determined in serum and aneurysmatic aortic tissue from 23 patients undergoing thoracic surgery. Macroscopically, normal thoracic aortic tissue specimens from 10 forensic autopsies and serum from 23 healthy blood donors served as controls. DNA from the intracellular respiratory pathogen Chlamydophila pneumoniae (C. pneumoniae), which may be involved in the pathogenesis of atherosclerosis, was found in 26% (6/23) of the patients but in none of the controls. The serum copper/zinc ratio, a well-known marker of ongoing infection and/or inflammation, was higher (26%, p<0.001) in aneurysm patients. C. pneumoniae requires iron for its growth. In our aneurysm patients iron was higher in serum (by 54%, p<0.001) and aneurysmal tissue (by 60%, p<0.001). Although calcium was lower in patient sera (by 8%, p<0.001), it tended to be higher (by 20%, ns) in aneurysmatic tissue. In addition, mercury concentrations in serum and aneurysmatic tissue were positively correlated (r=0.51, p<0.05). Moreover, C. pneumoniae-positive aneurysmatic tissues had lower concentrations of manganese (46%, p<0.05) and zinc (26%, ns) but a higher concentration of mercury (50%, p<0.05) than C. pneumoniae-negative aneurysmatic tissues. In conclusion, aneurysm patients showed a shift in trace element levels in serum and in the diseased part of the aorta, the pattern being partly different in C. pneumoniae-positive compared with C. pneumoniae-negative patients. The results are compatible with active infection and/or inflammation, possibly initiated by C. pneumoniae.
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| 35. |
- Rosengren, Evald, et al.
(författare)
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The macrophage migration inhibitory factor MIF is a phenylpyruvate tautomerase
- 1997
-
Ingår i: FEBS Letters. - 1873-3468. ; 417:1, s. 85-88
-
Tidskriftsartikel (refereegranskat)abstract
- A macrophage migration inhibitory factor (MIF), originally described as a product of activated lymphocytes, has been defined as a 12 kDa protein, expressed in a wide variety of tissues. Here MIF is identified as a phenylpyruvate tautomerase (EC 5.3.2.1) having p-hydroxyphenylpyruvate and phenylpyruvate as its natural substrates. The definition of MIF as an enzyme may yield insight into the mechanism of action of this proinflammatory and immunomodulating cytokine.
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| 36. |
- Schmidt, Peter Thelin, et al.
(författare)
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Methods to assess gastric motility and sensation
- 2008
-
Ingår i: Scandinavian Journal of Gastroenterology. - London : Informa Healthcare. - 0036-5521 .- 1502-7708. ; 43:11, s. 1285-1295
-
Tidskriftsartikel (refereegranskat)
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| 37. |
- Skoglund, Mattias
(författare)
-
Evaluation of test cycles for freight locomotives
- 2011
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diesel locomotives provide versatility to the railway system as they do not depend on electric feeding. Worldwide they constitute important parts of locomotive fleets used for various tasks such as mainline services, shunting and terminal operations. The main drawbacks are emissions of CO2, NOx and other pollutants. The emissions to air are in general controlled by legislation. The European testing and approval procedure for locomotive engines is performed with the ISO 8178-F test cycle. It is alone meant to resemble all European locomotives. Good correlation was found between mainline operations and the ISO 8178-F test cycle. A good correlation was furthermore found between shunting operations and North American shunting test cycles. However, this thesis has shown that this results in inadequate description of for instance shunting operations. Typical characteristics for shunting are relatively high ratio of transient loading, low mean power output and high amount of idling. Therefore important aspects of diesel locomotive usage are thereby disregarded in certifications. Deficient correlation between test cycle and intended operations may lead to locomotives that are not properly optimised for the type of operation they are intended for. Improperly dimensioned and optimised locomotives cause impaired fuel economy and more emissions emitted. Many Swedish diesel locomotives are to a large extent used in shunting-like conditions in yards and industries for instance. Therefore, it is recommended to supplement the present ISO test cycle with a test cycle that includes the characteristic of shunting. Knowledge about duty cycles for specific operations can be of importance in locomotive acquisition, dimensioning of new locomotives or when estimating emissions and/or fuel consumption. It is essential to make proper dimensioning of propulsion systems as it can imply lower life cycle costs as well as fewer emissions. Appropriate dimensioning of the propulsion system is particularly important for non-conventional propulsion systems. If the application range of a test cycle is narrow, its emulating capability ought to be better at describing and representing the indented application. Today's test cycles state fractional power or torque as a function of engine speed. This may result in misleading duty cycles when the same kind of operation is undertaken with different locomotives that have widespread power ratings. A more powerful locomotive used for the very same load as a less powerful locomotive will result in a different duty cycle. Non-conventional propulsion systems are gaining popularity also in the railway industry where implementation of new technology usually is slow. Dual mode and hybrid systems are two examples. Related to test and duty cycles the build-up of these new propulsion systems change the prerequisites of the propulsion systems. From a duty cycle perspective it is reasonable to implement an additional test cycle for non-conventional propulsion systems if the popularity rises.
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| 38. |
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| 39. |
- Thelin, Eric Peter, et al.
(författare)
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S100B Is an Important Outcome Predictor in Traumatic Brain Injury
- 2013
-
Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 30:7, s. 519-528
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to examine how S100B, a biomarker of traumatic brain injury (TBI), contributes to outcome prediction after adjusting for known parameters, including age, Glasgow Coma Scale (GCS), pupil reaction, and computed tomography (CT) variables; to examine which parameters have the best correlation to elevated serum levels of S100B; and to investigate when to sample S100B to achieve the strongest association to outcome. This retrospective study included 265 patients with TBI admitted to the neurointensive care unit, Karolinska University Hospital Solna, Stockholm, Sweden. Univariate and multivariate proportional odds regressions were performed to determine parameters most closely related to outcome, and how S100B adds to prediction accuracy. Age (p < 0.0001), pupil reaction (p < 0.0001), and levels of S100B (p < 0.0001) had the strongest statistical correlation to outcome. The area under curve of S100B, the first 48 h after trauma, yielded an additional explained variance of 6.6% in excess of known outcome parameters, including age, GCS, pupil reaction, and CT variables, themselves exhibiting an explained variance of 29.3%. S100B adds substantial information regarding patient outcome, in excess of that provided by known parameters. Only CT variables were found to be significant predictors of increased levels of S100B in uni- and multivariate analysis. Early samples of S100B, within 12 h after trauma, appear to have little prognostic value, and S100B should likely be sampled 12-36 h following trauma to best enhance TBI outcome prediction.
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| 40. |
- Thelin, Eric Peter, et al.
(författare)
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Serial sampling of serum protein biomarkers for monitoring human traumatic brain injury dynamics : A systematic review
- 2017
-
Ingår i: Frontiers in Neurology. - : Frontiers Media S.A.. - 1664-2295. ; 8
-
Forskningsöversikt (refereegranskat)abstract
- Background: The proteins S100B, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and neurofilament light (NF-L) have been serially sampled in serum of patients suffering from traumatic brain injury (TBI) in order to assess injury severity and tissue fate. We review the current literature of serum level dynamics of these proteins following TBI and used the term "effective half-life" (t1/2) in order to describe the "fall" rate in serum.Materials and methods: Through searches on EMBASE, Medline, and Scopus, we looked for articles where these proteins had been serially sampled in serum in human TBI. We excluded animal studies, studies with only one presented sample and studies without neuroradiological examinations.Results: Following screening (10,389 papers), n = 122 papers were included. The proteins S100B (n = 66) and NSE (n = 27) were the two most frequent biomarkers that were serially sampled. For S100B in severe TBI, a majority of studies indicate a t1/2 of about 24 h, even if very early sampling in these patients reveals rapid decreases (1-2 h) though possibly of non-cerebral origin. In contrast, the t1/2 for NSE is comparably longer, ranging from 48 to 72 h in severe TBI cases. The protein GFAP (n = 18) appears to have t1/2 of about 24-48 h in severe TBI. The protein UCH-L1 (n = 9) presents a t1/2 around 7 h in mild TBI and about 10 h in severe. Frequent sampling of these proteins revealed different trajectories with persisting high serum levels, or secondary peaks, in patients with unfavorable outcome or in patients developing secondary detrimental events. Finally, NF-L (n = 2) only increased in the few studies available, suggesting a serum availability of >10 days. To date, automated assays are available for S100B and NSE making them faster and more practical to use.Conclusion: Serial sampling of brain-specific proteins in serum reveals different temporal trajectories that should be acknowledged. Proteins with shorter serum availability, like S100B, may be superior to proteins such as NF-L in detection of secondary harmful events when monitoring patients with TBI.
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| 41. |
- Thelin, Peter, 1969-
(författare)
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Design and Evaluation of a Compact 15 kW PM Integral Motor
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis deals with the integral motor of tomorrow, and particularly with a variable speed, sensorless permanent magnet synchronous motor with an integrated converter. The rated power is 15 kW at 1500 r/min. The outer dimensions are approximately the same as for the equivalent standard induction motor.Control strategies for pumps and fans, i.e. suitable loads for variable speed motors, are briefly described. The huge energy savings that can be made by reducing the speed instead of throttling/choking the flow are pointed out. Compared to installing an induction motor with a separate converter, a PM integral motor will probably pay-off in less than a year.A totally analytical expression for calculating the airgap flux density of permanent magnet motors with buried magnets is derived. The analytical expression includes axial leakage, and iron saturation of the most narrow part of the magnetic circuit of the machine.A computer program for optimization of PM motors with buried magnets has been developed. It was used to design the manufactured prototype PM integral motor, and the parameters are investigated with analytical and/or FEM calculations. The optimization program is also used to suggest nearoptimum pole numbers for desired powers (4-37 kW) and speeds (750- 3000 r/min) of inverter-fed PM motors. Results show that compact buried PM motors should have relatively large airgaps and high NdFeB-magnet masses to improve the efficiency. Ferrite magnets are unsuitable.Measurements on the manufactured PM motor, the novel concept of stator integrated filter coils, and the complete PM integral motor are presented. Special attention was given to temperature and overall efficiency measurements.The rotor cage losses were investigated by time-stepping FEM. Four short circuit fault conditions were also examined in order to evaluate the risks of demagnetization of the buried magnets.
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| 42. |
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| 43. |
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| 44. |
- Westfelt, Petter, et al.
(författare)
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Training nonanesthetist administration of propofol for gastrointestinal endoscopy in scenario-based full-scale hybrid simulation - a pilot study
- 2013
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Informa Healthcare. - 0036-5521 .- 1502-7708. ; 48:11, s. 1354-1358
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. The use of nonanesthetist-administered propofol (NAAP) in GI endoscopy has long been controversial. In the setting of NAAP, acute situations can develop during endoscopy and thus training before starting with NAAPs is considered crucial. The aim was to evaluate a pilot study on crew resource management (CRM)-based training of teams of endoscopists and endoscopy nurses in NAAP in a full-scale hybrid simulation consisting of a full-scale human patient simulator and an endoscopy simulator. Our hypothesis was that the training would increase the self-efficacy of the participants. Material and methods. Four scenarios were created, each with typical side effects of propofol administration. All scenarios included the need for prompt decision-making and treatment. Colonoscopy, gastroscopy or endoscopic retrograde cholangiopancreatography (ERCP) cases were assigned to the course participants in coherence with their main clinical expertise in order to facilitate situated and contextualized training. Twenty-one participants (ten doctors and eleven nurses) completed a questionnaire on self-efficacy before and after the course. A questionnaire regarding the quality and yield of the course was also completed. Results. For all participants, the self-efficacy score was 26.0 (24.0-28.0; interquartile range) before training and 30.0 (27.0-30.5) after training (p = 0.0003). The ten doctors had a self-efficacy score before training of 26.5 (25.0-29.5) and 30.0 (29.0-33.0) after (p = 0.0078). The eleven nurses scored 24.0 (22.0-26.0) before and 28.0 (27.0-30.0) after training (p = 0.0098). Conclusions. Systematic target focused scenario-based training with hybrid simulation of NAAP in endoscopy resulted in increased self-efficacy in both nurses and physicians.
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| 45. |
- Witte, Anne-Barbara, et al.
(författare)
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Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion
- 2011
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 46:4, s. 428-435
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma concentrations of insulin, glucagon and glucose were measured during infusion of saline or the GLP-1 receptor antagonist exendin(9-39)amide (Ex(9-39)) at 300 pmol·kg−1·min−1. Results. Ex(9-39) infusion had no effect on the total gastric emptying curve, but changed the intra-gastric distribution of the meal. During infusion of Ex(9-39), more content stayed in the upper stomach (79.1 ± 2.5% of total during Ex(9-39) compared to 66.6 ± 5.7% during saline at 5 min). During Ex(9-39) infusion, higher concentrations of plasma glucagon were measured both before (after 40 min of Ex(9-39) infusion the glucagon level was 15.1 ± 0.7 pmol·L−1 compared to 5.4 ± 1.4 during saline) and after the meal, and postprandial GLP-1 levels increased. Basal insulin and glucose levels were not affected by Ex(9-39), but the postprandial rise of insulin and glucose enhanced during Ex(9-39). Conclusions. Endogenous GLP-1 is involved in the regulation of gastric motility in relation to meal intake and also in the regulation of postprandial insulin and glucose levels. Furthermore, endogenous GLP-1 seems to tonically restrain glucagon secretion.
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| 46. |
- Wood, Sara, et al.
(författare)
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Predictors of intracranial hemorrhage in neonatal patients on extracorporeal membrane oxygenation
- 2023
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Extracorporeal membrane oxygenation (ECMO) is a life-supportive treatment in neonatal patients with refractory lung and/or heart failure. Intracranial hemorrhage (ICH) is a severe complication and reliable predictors are warranted. The aims of this study were to explore the incidence and possible predictors of ICH in ECMO-treated neonatal patients. We performed a single-center retrospective observational cohort study. Patients aged <= 28 days treated with ECMO between 2010 and 2018 were included. Exclusion criteria were ICH, ischemic stroke, cerebrovascular malformation before ECMO initiation or detected within 12 h of admission, ECMO treatment < 12 h, or prior treatment with ECMO at another facility > 12 h. The primary outcome was a CT-verified ICH. Logistic regression models were employed to identify possible predictors of the primary outcome. Of the 223 patients included, 29 (13%) developed an ICH during ECMO treatment. Thirty-day mortality was 59% in the ICH group and 16% in the non-ICH group (p < 0.0001). Lower gestational age (p < 0.01, odds ratio (OR) 0.96; 95%CI 0.94-0.98), and higher pre-ECMO lactate levels (p = 0.017, OR 1.1; 95%CI 1.01-1.18) were independently associated with increased risk of ICH-development. In the clinical setting, identification of risk factors and multimodal neuromonitoring could help initiate steps that lower the risk of ICH in these patients.
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| 47. |
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| 48. |
- Zheng, P, et al.
(författare)
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Influence of saturation and saliency on the inductance of a four-quadrant transducer prototype machine
- 2006
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Ingår i: IEEE transactions on magnetics. - 0018-9464 .- 1941-0069. ; 42:4, s. 1319-1322
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Tidskriftsartikel (refereegranskat)abstract
- An inductance determination method that can be based on both experiments and calculations is discussed in this paper. The inductances of a four-quadrant transducer (4QT) prototype machine were measured and calculated with the two-dimensional time-stepping finite-element method (FEM), and the measured and calculated results are in good agreement. It is found that the d- and q-axis inductances are different, and the inductances obtained from the phase and line voltage are also different for both the two machines of the 4QT prototype machine. Analysis shows that the differences are caused by the saliency and d-axis saturation. Although there is little saliency for the double rotor machine (DRM), the two kinds of the inductance differences of the DRM are more serious than that of the stator machine (SM). This is because of the higher level of the d-axis saturation of the DRM. The inductances obtained from the phase voltage at very low frequency are recommended as final results for both experiments and calculations.
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| 49. |
- Zheng, P., et al.
(författare)
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Investigation of the winding current distribution in a 4-quadrant-transducer prototype machine
- 2005
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Ingår i: IEEE transactions on magnetics. - 0018-9464 .- 1941-0069. ; 41:5, s. 1972-1975
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Tidskriftsartikel (refereegranskat)abstract
- The 4-quadrant energy transducer (4QT) is a solution to realize both the torque and speed control of the internal combustion engine (ICE) for hybrid electric vehicles. Since the base frequency of the prototype 4QT is much higher than the industrial one, the effect of eddy current on winding current distribution is considered in this paper. A two-dimensional (2-D) eddy-current FEM model is established and used for analysis. Current density and strand current distribution are given. It is pointed out that owing to the effect of eddy current, the conductor currents are unevenly distributed within the strands of the same turn. According to the 2-D FEM analysis, when the uneven current distribution is considered, the average rms turn current is increased by 1.05 times for the stator and 1.65 times for the inner rotor, and the copper loss is increased by 1.1 times for the stator and 3.16 times for the inner rotor. Since the inner rotor slots are much deeper than the stator slots, the inner rotor current distribution is more uneven than the stator. It means that for high-frequency deep slot machine the eddy current effect should be considered seriously. Because of the increased current and copper loss, more ventilation will be needed for the 4QT, especially for the inner rotor. The average torques of stator machine and double rotor machine meet the requirements, and the torque ripples are small owing to the skewed slots.
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- Zheng, Ping, et al.
(författare)
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Research on a tubular longitudinal flux PM linear generator used for free-piston energy converter
- 2007
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Ingår i: IEEE transactions on magnetics. - 0018-9464 .- 1941-0069. ; 43:1, s. 447-449
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Tidskriftsartikel (refereegranskat)abstract
- The free-piston energy converter (FPEC) is used for a series hybrid electric vehicle scheme, which may have the advantages of high efficiency, compact structure, and reliable operation. The linear generator is an important part in the FPEC, and a tubular longitudinal flux permanent-magnet (PM) linear generator scheme is investigated in this paper. The electromagnetic and thermal properties of the generator are analyzed with commercial software Flux 2D. The generator is optimized from the aspects of material selection and structure optimization. Rare-earth PM material VACODYM 655HR is selected for the permanent magnets, and low-performance low-loss material M235-35A is chosen for the stator lamination. The pole number and machine size are optimized, and the optimum scheme with efficiency of 0.935 and specific power of 1.49 kW/kg is obtained, which meets the requirements of FPEC application.
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