| 190251. |
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| 190252. |
- Svensson, Astrid, et al.
(författare)
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Effects of size and sodium dodecyl sulfate on mass transfer for liquid-liquid two-phase flow in non-circular glass microchannels
- 2018
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Ingår i: ASME 2018 16th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2018. - 9780791851197
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Konferensbidrag (refereegranskat)abstract
- This study concerns effects of two main variables on hydrodynamics and mass transfer in the liquid-liquid two-phase slug flow regime. The influence of size of square and rectangular microchannels and presence of sodium dodecyl sulfate (SDS) are investigated. Three microchannels with dimensions 600x600 (MC600), 400x400 (MC400) and 600x300 (MC300) µm were used with hydraulic diameters of 600, 400 and 400 µm respectively. The results revealed that decreasing the hydraulic diameter improved the interfacial area due to slug length enlargement in both phases. Furthermore, mass transfer resistance was reduced because of enhanced internal circulations, leading to considerable enhancement of the overall mass transfer coefficient KL. It was also found that the enhancement of KL was greater in the square MC400 microchannel than in the rectangular MC300, as compared to the MC600. The enhancing benefit from internal circulations in organic slugs in rectangular microchannels decreased at higher aqueous flow rates due to enlarged stagnant liquid film flow between the organic slug and the microchannel wall. The presence of SDS slightly increased the interfacial area by reducing the slug length in both phases. However, there was a significant decrement in KL, due to a greater mass transfer resistance.
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| 190253. |
- Svensson, Andreas, et al.
(författare)
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Endogenous brain pericytes are widely activated and contribute to mouse glioma microvasculature.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma multiforme (GBM) is the most common brain tumor in adults. It presents an extremely challenging clinical problem, and treatment very frequently fails due to the infiltrative growth, facilitated by extensive angiogenesis and neovascularization. Pericytes constitute an important part of the GBM microvasculature. The contribution of endogenous brain pericytes to the tumor vasculature in GBM is, however, unclear. In this study, we determine the site of activation and the extent of contribution of endogenous brain pericytes to the GBM vasculature. GL261 mouse glioma was orthotopically implanted in mice expressing green fluorescent protein (GFP) under the pericyte marker regulator of G protein signaling 5 (RGS5). Host pericytes were not only activated within the glioma, but also in cortical areas overlying the tumor, the ipsilateral subventricular zone and within the hemisphere contralateral to the tumor. The host-derived activated pericytes that infiltrated the glioma were mainly localized to the tumor vessel wall. Infiltrating GFP positive pericytes co-expressed the pericyte markers platelet-derived growth factor receptor-β (PDGFR-β) and neuron-glial antigen 2. Interestingly, more than half of all PDGFR-β positive pericytes within the tumor were contributed by the host brain. We did not find any evidence that RGS5 positive pericytes adopt another phenotype within glioma in this paradigm. We conclude that endogenous pericytes become activated in widespread areas of the brain in response to an orthotopic mouse glioma. Host pericytes are recruited into the tumor and constitute a major part of the tumor pericyte population.
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| 190254. |
- Svensson, Anders
(författare)
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Event Prediction and Bootstrap in Time Series
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Alarm systems are used in many situations, and should be as efficient as possible. In this thesis optimal predictive alarm systems, event predictors, are presented for general linear time series models with external signals. This family of process models include e.g. AR, ARMA, ARMAX and Box-Jenkins-type models. An optimal alarm system is characterized by having the least number of false alarms, for a specified probability of detecting the events, the catastrophes. The family of events treated is based on the time series and very general. When the process parameters are known and the noise distribution is Gaussian, the resulting optimal event predictor is based on predictions of future process values, and the alarm regions can be calculated in advance. Thus the event predictor can be used also in processes with a high sampling rate. It is also possible to construct an event predictor where a major part of the calculations can be made in real-time, which may be of advantage if the process parameters change. The peformance of the event predictors is examined using simulated as well as real data, and they are compared to simpler and more conventional alarm systems. When the noise distribution is unknown or the process parameters are unknown or time-varying, it is not possible to use the explicit event predictor above. However, statistical bootstrap techniques for calculating the distribution of the future process values can be applied to the problem. The presented bootstrap based event predictor demands large amounts of calculations for AR processes and even more so for ARX processes, but it is much more flexible than the event predictor discussed above, and the performance of the event predictors are comparable. Simulations are used to assess the performance. The bootstrap technique for ARX processes is also possible to apply to control problems, resulting in a new predictive control algorithm, the bootstrap control, which takes care of arbitrary loss functions and unknown noise distributions, even for small estimation sets. The bootstrap control algorithm has been tested through simulations and was found to work well for complicated loss functions and also for processes with slowly time-varying parameters.
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| 190255. |
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| 190256. |
- Svensson, Anneli, 1972-, et al.
(författare)
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Genetic Variant Score and Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Plakophilin-2 Mutation Carriers
- 2021
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Ingår i: Cardiology. - : S. Karger. - 0008-6312 .- 1421-9751. ; 146:6, s. 763-771
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Whether detailed genetic information contributes to risk stratification of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains uncertain. Pathogenic genetic variants in some genes seem to carry a higher risk for arrhythmia and earlier disease onset than others, but comparisons between variants in the same gene have not been done. Combined Annotation Dependent Depletion (CADD) score is a bioinformatics tool that measures the pathogenicity of each genetic variant. We hypothesized that a higher CADD score is associated with arrhythmic events and earlier age at ARVC manifestations in individuals carrying pathogenic or likely pathogenic genetic variants in plakophilin-2 (PKP2).METHODS: CADD scores were calculated using the data from pooled Scandinavian and North American ARVC cohorts, and their association with cardiac events defined as ventricular tachycardia/ventricular fibrillation (VT/VF) or syncope and age at definite ARVC diagnosis were assessed.RESULTS: In total, 33 unique genetic variants were reported in 179 patients (90 males, 71 probands, 96 with definite ARVC diagnosis at a median age of 35 years). Cardiac events were reported in 76 individuals (43%), of whom 53 had sustained VT/VF (35%). The CADD score was neither associated with age at cardiac events (HR 1.002, 95% CI: 0.953-1.054, p = 0.933) nor with age at definite ARVC diagnosis (HR 0.992, 95% CI: 0.947-1.039, p = 0.731).CONCLUSION: No correlation was found between CADD scores and clinical manifestations of ARVC, indicating that the score has no additional risk stratification value among carriers of pathogenic or likely pathogenic PKP2 genetic variants.
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| 190257. |
- Svensson, Anders, et al.
(författare)
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Hepatic contrast medium enhancement at computed tomography and its correlation with various body size measures
- 2012
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Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 53:6, s. 601-606
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Tidskriftsartikel (refereegranskat)abstract
- Background: When the same dose of iodine is given to all patients when performing abdominal computed tomography (CT) there may be a wide inter-individual variation in contrast medium (CM) enhancement of the liver. Purpose: To evaluate if any of the measures body height (BH), body mass index (BMI), lean body mass (LBM), ideal body weight (IBW), and body surface area (BSA) correlated better than body weight (BW) with hepatic enhancement, and to compare the enhancement when using iodixanol and iomeprol. Material and Methods: One hundred patients referred for standard three-phase CT examination of abdomen were enrolled. Body weight and height were measured at the time of the CT examination. Forty grams of iodine (iodixanol 320 mg l/mL or iomeprol 400 mg l/mL) was injected at a rate of 1.6 g-l/s, followed by a 50 mL saline flush. The late arterial phase was determined by using a semi-automatic smart prep technique with a scan delay of 20 s. The hepatic parenchymal phase started automatically 25 s after the late arterial phase. CM concentration was estimated by placement of regions of interest in aorta (native and late arterial phase) and in liver (native and parenchymal phase). Results: BW (r = -0.51 and -0.64), LBM (r = -0.54 and -0.59), and BSA (r = -0.54 and -0.65) showed the best correlation coefficients with aortic and hepatic parenchymal enhancement, respectively, without any significant differences between the measures. Comparing iodixanol and iomeprol there was no significant difference in aortic enhancement. The liver enhancement was significantly higher (P < 0.05) using iodixanol than iomeprol. Conclusion: To achieve a consistent hepatic enhancement, CM dose may simply be adjusted to body weight instead of using more complicated calculated parameters based on both weight and height.
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| 190258. |
- Svensson, Anna, et al.
(författare)
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Hydration of an amphiphilic excipient, Gelucire (R) 44/14
- 2004
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 1873-3476 .- 0378-5173. ; 281:1-2, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- The incorporation of drugs into Gelucires has been reported to increase the dissolution rate of poorly soluble drugs, often leading to improved drug bioavailability. In pharmaceutical applications, it is important to know how the excipient interacts with the drug, and how the mixture behaves during manufacturing, storage as well as during administration. The uptake of water by an amphiphilic excipient, Gelucire(R) 44/14, has been investigated in two ways: storage in humid air and addition of liquid water. During exposure to humid air, the uptake goes in stages that correspond to the dissolution of the components of the excipient, starting with the most hydrophilic ones: glycerol, then polyethylene glycol (PEG), PEG esters (PEG monolaurate and PEG dilaurate), and finally glycerides (trilaurin). At each stage, the remaining: crystals are in equilibrium with an interstitial solution made of water and the dissolved components. In this range of hydrations, the total uptake is close to the sum of the equilibrium hydrations of the components. In the pharmaceutical formulation, the active ingredient could dissolve in the liquid phase. At larger hydrations obtained through addition of liquid water, the state of Gelucire(R) 44/14 differs from those of its components. Gelucire(R) 44/14 forms a lamellar phase and this phase melts at 30degreesC whereas the pure PEG esters form hexagonal and cubic mesophases. The cubic mesophases do not melt until the temperature exceeds 40degreesC. At body temperature, all crystals in Gelucire(R) 44/14 melt to an isotropic fluid as soon as the total water content exceeds 5%. Therefore the formulation of amphiphilic excipients can be optimized to avoid the formation of mesophases that impede dissolution of the excipient at body temperature. (C) 2004 Elsevier B.V. All rights reserved.
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| 190259. |
- Svensson, Andreas, et al.
(författare)
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Identification of two distinct mesenchymal stromal cell populations in human malignant glioma
- 2017
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Ingår i: Journal of Neuro-Oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 131:2, s. 245-254
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Tidskriftsartikel (refereegranskat)abstract
- Gene profiling has revealed that malignant gliomas can be divided into four distinct molecular subtypes, where tumors with a mesenchymal gene expression are correlated with short survival. The present investigation was undertaken to clarify whether human malignant gliomas contain endogenous mesenchymal stromal cells (MSC), fulfilling consensus criteria defined by The International Society for Cellular Therapy, recruited from the host. We found that MSC-like cells can be isolated from primary human malignant gliomas. Two distinct MSC-like cell populations, differing in their expression of the CD90 surface marker, were discovered after cell sorting. RNA sequencing revealed further genetic differences between these two cell populations and MSC-like cells lacking CD90 produced higher amounts of VEGF and PGE2 compared to cells with the true MSC phenotype, implying that the CD90− MSC-like cells most probably are more active in tumor vascularization and immunosuppression than their CD90+ counterpart. The results highlight the CD90− subpopulation as an important tumor component, however, its functional effects in glioma remains to be resolved. Using the protocols presented here, it will be possible to isolate, characterize and analyze brain tumor-derived MSC-like cells in more detail and to further test their functions in vitro and in in vivo xenograft models of glioma.
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| 190260. |
- Svensson, Anton, et al.
(författare)
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Income inequality in an industrial city during the great levelling: micro level evidence from malmö, 1900–1950
- 2022
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Ingår i: Scandinavian Economic History Review. - : Informa UK Limited. - 1750-2837 .- 0358-5522. ; 71:1
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Tidskriftsartikel (refereegranskat)abstract
- This paper contributes to the debate on historical income inequality, and especially on the decrease in inequality found in industrialised countries during the first half of the twentieth century. We use new archival individual – and household-level data for taxpayers in Sweden’s third- largest city, Malmö, from 1900 to 1950. Previous research has established that Sweden had a distinctive downturn in income inequality during the first half of the twentieth century, and explanations have not the least focused on capital incomes and taxes. With our original data we shed light on what happened to working- class and middle-class incomes, and show the importance of job upgrading of the working-class, the decline of domestic service and women’s enhanced position on the labour market, and declining market incomes for top income earners in changing Malmö’s income distribution. We compare pre-tax and post-tax distributions, and the distribution on the individual level and the household level. With the new micro data, a richer account of income growth and income distribution in twentieth century Sweden is provided.
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