| 1. |
- Steding-Ehrenborg, Katarina, et al.
(författare)
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Hydraulic force is a novel mechanism of diastolic function which may contribute to decreased diastolic filling in HFpEF and facilitate filling in HFrEF
- 2021
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Ingår i: Journal of Applied Physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 130:4, s. 993-1000
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A hydraulic force generated by blood moving the atrio-ventricular plane is a novel mechanism of diastolic function. The direction and magnitude of the force is dependent on the geometrical relationship between the left atrium and ventricle and is measured as the short-axis atrio-ventricular area difference (AVAD). In short, the net hydraulic force acts from a larger area towards a smaller. It is currently unknown how cardiac remodeling affects this mechanism. The aim of the study was therefore to investigate this diastolic mechanism in patients with pathological or physiological remodeling.METHODS: 70 subjects (n=11 heart failure with preserved ejection fraction (HFpEF), n=10 heart failure with reduced ejection fraction (HFrEF), n=7 signs of isolated diastolic dysfunction, n=10 hypertrophic cardiomyopathy (HCM), n=10 cardiac amyloidosis, n=18 triathletes and n=14 controls) were included. Subjects underwent Cardiac MR and short-axis images of the left atrium and ventricle were delineated. AVAD was calculated as ventricular area minus atrial area and used as an indicator of net hydraulic force.RESULTS: At the onset of diastole, AVAD in HFpEF was median -9.2 cm2 versus -4.4 cm2 in controls, p=0.02). The net hydraulic force was directed towards the ventricle for both, but larger in HFpEF. HFrEF was the only group with a positive median value 11.6 cm2 and net hydraulic force was throughout diastole directed towards the atrium.CONCLUSION: The net hydraulic force may impede cardiac filling throughout diastole in HFpEF, worsening diastolic dysfunction. In contrast, it may work favorably in patients with dilated ventricles and aid ventricular filling.
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| 2. |
- Arvidsson, Martin, 1990-
(författare)
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Beyond Generative Sufficiency : On Interactions, Heterogeneity & Middle-Range Dynamics
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Explaining how properties at the level of individuals translate into properties at the level of collectives is a core objective of sociology. Because the social world is characterized by complex webs of social interdependencies, establishing how micro and macro are related to one another requires a detailed understanding of how individuals are influenced by their social environments and the consequences that such influences have for the dynamics of the social process. However, until very recently, it has been difficult to conduct detailed empirical investigations of micro-macro linkages due to the lack of large-scale data containing information on how individuals interact with one another. In the absence of such data, substantive research has tended to (a) focus its attention elsewhere: studying how social factors influence individual outcomes, rather than how actors in interaction with one another bring about collective outcomes, or (b) propose models of micro-macro linkages that—for reasons of parsimony and tractability—often assume artificially high levels of homogeneity. Against this background, this thesis sets out to investigate, first, how the data and tools that have emerged from the digital and computational revolution can help sociologists construct empirically well-founded mappings from the micro to the macro level, and second, how the conclusions about the role of social interdependencies and networks change when the analysis is informed by real-world heterogeneities.In the introductory chapter, a conceptual and analytical framework for studying micro-macro processes is proposed that integrates the theoretical principles of analytical sociology with the data and methods of computational social science. This framework constitutes the foundation of the thesis. It is used in Essays I-III, and it is methodologically built upon in Essay IV.In Essay I, the role of social networks in labor-market segregation processes is examined. Scholarship on labor-market segregation commonly assume that social networks have a segregating effect because of homophilous selection tendencies in network-based recruitment. Using large-scale register data and focusing attention on individuals’ heterogenous opportunities to form same-category ties in different workplaces, Essay I finds that opportunity structures often dominate homophilic preferences. In particular, a mechanism is identified which shows—in contradiction with the main tenet of previous research—that networks often reduce rather than increase segregation by triggering mobility events that counteract the impact of segregating mobility events.Essay II examines the conditions under which social influence can decouple adoption behaviour from individual preferences and thereby bring about unexpected collective outcomes. Prior research has shown that such decoupling can occur, but conflicting evidence and implicit assumptions of strong homogeneity mean that we still know little about the conditions under which this is likely to occur in the real world. Addressing these limitations, this study uses fine-grained, real-world behavioural data from Spotify to estimate heterogeneous social influence effects conditional on properties of individuals’ social environments, and then examine their macro-implications in empirically calibrated simulations. It is found that partial overlap in preferences and strong social ties between the senders and receivers of social influence is needed for social influence to produce decoupling.Essay III centers on the phenomenon of urban scaling and examines the relationship between within-city and between-city inequality. Previous urban scaling research has documented how cities’ total outputs increase more than proportionally with city size and has proposed theoretical models which demonstrate impressive predictive accuracy at aggregate levels. However, this research has overlooked the stark inequalities that exist within cities. Using microdata from multiple countries, it is found that between 36–80% of the previously reported scaling effects can be explained by differences in the distributional tails of cities. Providing explanatory depth to these findings, a cumulative advantage mechanism is identified which elucidates one important channel through which differences in the size of cities’ tails emerge.In Essay IV, a method is proposed for inferring theoretically meaningful dimensions from complex high-dimensional data such as text. The results show that the method captures latent semantic concepts better than or on-par with the current state of the art. For the study of social interactions, the method constitutes a new and potentially important tool for inferring theoretically meaningful dimensions about individuals and their social environments, and in so doing, improves our ability to adjust for specific types of homophily and enables richer and more precise measures of heterogeneity in social interaction processes.
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| 3. |
- Arvidsson, Martin, et al.
(författare)
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The Trojan-horse mechanism : How networks reduce gender segregation
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 7:16
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Tidskriftsartikel (refereegranskat)abstract
- The segregation of labor markets along ethnic and gender lines is socially highly consequential, and the social science literature has long viewed homophily and network-based job recruitments as some of its most crucial drivers. Here, we focus on a previously unidentified mechanism, the Trojan-horse mechanism, which, in contradiction to the main tenet of previous research, suggests that network-based recruitment reduce rather than increase segregation levels. We identify the conditions under which networks are desegregating, and using unique data on all individuals and all workplaces located in the Stockholm region during the years 2000-2017, we find strong empirical evidence for the Trojan-horse mechanism and its role in the gender segregation of labor markets.
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| 4. |
- Goswami, Sreetosh, et al.
(författare)
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Charge disproportionate molecular redox for discrete memristive and memcapacitive switching
- 2020
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Ingår i: Nature Nanotechnology. - : Springer Science and Business Media LLC. - 1748-3387 .- 1748-3395. ; 15:5, s. 380-389
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Tidskriftsartikel (refereegranskat)abstract
- Electronic symmetry breaking by charge disproportionation results in multifaceted changes in the electronic, magnetic and optical properties of a material, triggering ferroelectricity, metal/insulator transition and colossal magnetoresistance. Yet, charge disproportionation lacks technological relevance because it occurs only under specific physical conditions of high or low temperature or high pressure. Here we demonstrate a voltage-triggered charge disproportionation in thin molecular films of a metal-organic complex occurring in ambient conditions. This provides a technologically relevant molecular route for simultaneous realization of a ternary memristor and a binary memcapacitor, scalable down to a device area of 60 nm(2). Supported by mathematical modelling, our results establish that multiple memristive states can be functionally non-volatile, yet discrete-a combination perceived as theoretically prohibited. Our device could be used as a binary or ternary memristor, a binary memcapacitor or both concomitantly, and unlike the existing 'continuous state' memristors, its discrete states are optimal for high-density, ultra-low-energy digital computing. Charge disproportionation in thin molecular films of a metal-organic complex enables the realization of a ternary memristor and binary memcapacitor.
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| 5. |
- Hedström, Ulf, et al.
(författare)
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Impaired differentiation of chronic obstructive pulmonary disease bronchial epithelial cells grown on bronchial scaffolds
- 2021
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Ingår i: American Journal of Respiratory Cell and Molecular Biology. - 1044-1549. ; 65:2, s. 201-213
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Tidskriftsartikel (refereegranskat)abstract
- Chronic obstructive pulmonary disease (COPD) is characterized by airway inflammation, small airway remodeling, and emphysema. Airway remodeling in patients with COPD involves both the airway epithelium and the subepithelial extracellular matrix (ECM). However, it is currently unknown how epithelial remodeling in COPD airways depends on the relative influence from inherent defects in the epithelial cells and alterations in the ECM. To address this, we analyzed global gene expression in COPD human bronchial epithelial cells (HBEC) and normal HBEC after repopulation on decellularized bronchial scaffolds derived from patients with COPD or donors without COPD. COPD HBEC grown on bronchial scaffolds showed an impaired ability to initiate ciliated-cell differentiation, which was evident on all scaffolds regardless of their origin. In addition, although normal HBEC were less affected by the disease state of the bronchial scaffolds, COPD HBEC showed a gene expression pattern indicating increased proliferation and a retained basal-cell phenotype when grown on COPD bronchial scaffolds compared with normal bronchial scaffolds. By using mass spectrometry, we identified 13 matrisome proteins as being differentially abundant between COPD bronchial scaffolds and normal bronchial scaffolds. These observations are consistent with COPD pathology and suggest that both epithelial cells and the ECM contribute to epithelial-cell remodeling in COPD airways.
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| 6. |
- Jantra, Jongjit, et al.
(författare)
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Development of an automated flow-based spectrophotometric immunoassay for continuous detection of zearalenone
- 2020
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Ingår i: Biotechnology and Applied Biochemistry. - : Wiley. - 0885-4513 .- 1470-8744. ; 67:3, s. 375-382
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Tidskriftsartikel (refereegranskat)abstract
- Considering the widespread contaminations of food products with mycotoxins, it is important to develop, robust, time- and cost-effective detection methods. We developed and optimized an immunoassay using a continuous flow system for the detection of zearalenone (ZEN). The assay was performed in a flow mode using an automated sequential injection system. Time for an assay cycle was 18 Min. Under optimal conditions, the limit for quantification for ZEN was 0.40 µg L−1 with a linear dependency between concentration and signal amplitude between 0.10 and 10 µg L−1. The assay proved to be robust and reliable with 13% relative standard deviation between measurements. By dissociating the antigen–antibody complex using a regeneration solution, we showed 50 times reusability of the immobilized antibodies without affecting the antigen-binding properties.
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| 7. |
- Johansson, Martin, et al.
(författare)
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Atrioventricular Area Difference Aids Diastolic Filling in Patients with Repaired Tetralogy of Fallot
- 2024
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Ingår i: Pediatric Cardiology. - 0172-0643.
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Tidskriftsartikel (refereegranskat)abstract
- A hydraulic force aids diastolic filling of the left ventricle (LV) and is proportional to the difference in short-axis area between the left ventricle and atrium; the atrioventricular area difference (AVAD). Patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) have reduced LV filling which could lead to a negative AVAD and a hydraulic force impeding diastolic filling. The aim was to assess AVAD and to determine whether the hydraulic force aids or impedes diastolic filling in patients with rToF and PR, compared to controls. Twelve children with rToF (11.5 [9–13] years), 12 pediatric controls (10.5 [9–13] years), 12 adults with rToF (21.5 [19–27] years) and 12 adult controls (24 [21–29] years) were retrospectively included. Cine short-axis images were acquired using cardiac magnetic resonance imaging. Atrioventricular area difference was calculated as the largest left ventricular short-axis area minus the largest left atrial short-axis area at beginning of diastole and end diastole and indexed to height (AVADi). Children and adults with rToF and PR had higher AVADi (0.3 cm2/m [− 1.3 to 0.8] and − 0.6 [− 1.5 to − 0.2]) at beginning of diastole compared to controls (− 2.7 cm2/m [− 4.9 to − 1.7], p = 0.015) and − 3.3 cm2/m [− 3.8 to − 2.8], p = 0.017). At end diastole AVADi did not differ between patients and controls. Children and adults with rToF and pulmonary regurgitation have an atrioventricular area difference that do not differ from controls and thus a net hydraulic force that contributes to left ventricular diastolic filling, despite a small underfilled left ventricle due to pulmonary regurgitation.
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| 8. |
- Johansson, Martin, et al.
(författare)
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Right ventricular longitudinal function is linked to left ventricular filling pressure in patients with repaired tetralogy of fallot
- 2023
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Ingår i: International Journal of Cardiovascular Imaging. - : Springer Science and Business Media LLC. - 1875-8312. ; 39:2, s. 401-409
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Tidskriftsartikel (refereegranskat)abstract
- Experimental data on pulmonary regurgitation has linked right ventricular longitudinal function to left ventricular filling pressure in animals with induced and treated pulmonary regurgitation but this relationship has not been investigated in patients with repaired Tetralogy of Fallot (rToF). The aim of this study was to determine if right ventricular longitudinal function assessed using cardiovascular magnetic resonance (CMR) is associated with left ventricular filling pressure in patients with rToF. A second objective of this study was to determine if direction of septal movement is related to right ventricular pressure load in rToF. Eighteen patients with rToF undergoing CMR and heart catheterization prior to pulmonary valve replacement were retrospectively included and catheter-based pressure measurements were compared with CMR-derived RV regional function. Left ventricular filling pressure was measured as precapillary wedge pressure (PCWP). Longitudinal contribution to RV stroke volume correlated with PCWP (r = 0.48; p = 0.046) but not with RV EF or pulmonary regurgitation. Neither RV longitudinal strain nor TAPSE showed correlation with PCWP. Longitudinal contribution to stroke volume was lower for the RV compared to the LV (49 vs 54%; p = 0.039). Direction of septal movement did not show a correlation with RV end-systolic pressure. Right ventricular longitudinal pumping is associated with left ventricular filling pressure in rToF-patients and this inter-ventricular coupling may explain LV underfilling in patients with pulmonary regurgitation and rToF and may be of value to determine right ventricular dysfunction. RV systolic pressure, however, cannot be assessed from the direction of septal movement, in these patients.
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| 9. |
- König, Hans-Henrik, et al.
(författare)
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MiniMelt : An instrument for real-time tracking of electron beam additive manufacturing using synchrotron x-ray techniques
- 2023
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 94:12
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Tidskriftsartikel (refereegranskat)abstract
- The development of a sample environment for in situ x-ray characterization during metal Electron Beam Powder Bed Fusion (PBF-EB), called MiniMelt, is presented. The design considerations, the features of the equipment, and its implementation at the synchrotron facility PETRA III at Deutsches Elektronen-Synchrotron, Hamburg, Germany, are described. The equipment is based on the commercially available Freemelt ONE PBF-EB system but has been customized with a unique process chamber to enable real-time synchrotron measurements during the additive manufacturing process. Furthermore, a new unconfined powder bed design to replicate the conditions of the full-scale PBF-EB process is introduced. The first radiography (15 kHz) and diffraction (1 kHz) measurements of PBF-EB with a hot-work tool steel and a Ni-base superalloy, as well as bulk metal melting with the CMSX-4 alloy, using the sample environment are presented. MiniMelt enables time-resolved investigations of the dynamic phenomena taking place during multi-layer PBF-EB, facilitating process understanding and development of advanced process strategies and materials for PBF-EB.
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| 10. |
- Mahadhy, Ally, et al.
(författare)
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Evaluation of polytyramine film and 6-mercaptohexanol self-assembled monolayers as the immobilization layers for a capacitive dna sensor chip : A comparison
- 2021
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 21:23
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Tidskriftsartikel (refereegranskat)abstract
- The performance of a biosensor is associated with the properties of an immobilization layer on a sensor chip. In this study, gold sensor chips were modified with two different immobilization layers, polytyramine film and 6-mercaptohexanol self-assembled monolayer. The physical, electrochemical and analytical properties of polytyramine film and mercaptohexanol self-assembled monolayer modified gold sensor chips were studied and compared. The study was conducted using atomic force microscopy, cyclic voltammetry and a capacitive DNA-sensor system (CapSenze™ Biosystem). The results obtained by atomic force microscopy and cyclic voltammetry indicate that polytyramine film on the sensor chip surface possesses better insulating properties and provides more spaces for the immobilization of the capture probe than a mercaptohexanol self-assembled monolayer. A capacitive DNA sensor hosting a polytyramine single-stranded DNA-modified sensor chip displayed higher sensitivity and larger signal amplitude than that of a mercaptohexanol singlestranded DNA-modified sensor chip. The linearity responses for polytyramine single-stranded DNAand mercaptohexanol single-stranded DNA-modified sensor chips were obtained at log concentration ranges, equivalent to 10−12 to 10−8 M and 10−10 to 10−8 M, with detection limits of 4.0 × 10−13 M and 7.0 × 10−11 M of target complementary single-stranded DNA, respectively. Mercaptohexanol single-stranded DNA-and polytyramine single-stranded DNA-modified sensor chips exhibited a notable selectivity at an elevated hybridization temperature of 50◦C, albeit the signal amplitudes due to the hybridization of the target complementary single-stranded DNA were reduced by almost 20% and less than 5%, respectively.
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| 11. |
- Mahadhy, Ally, et al.
(författare)
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Rapid detection of mecA gene of methicillin-resistant Staphylococcus aureus by a novel, label-free real-time capacitive biosensor
- 2020
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Ingår i: Biotechnology Reports. - : Elsevier BV. - 2215-017X. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- This work presents a rapid, selective and sensitive automated sequential injection flow system with a capacitive biosensor for detection of the mecA gene (the model chosen for this study), which emerges from methicillin-resistant Staphylococcus aureus. A DNA-based 25-mer capture probe was immobilized on the surface of a gold electrode which was integrated in the capacitive sensor system. A constant current pulse was applied and the resulting capacitance was measured. Injection of the target DNA sample to the sensor surface induced hybridization to occur between the target and the complementary sequence, which resulted in a shift in the measured capacitance (ΔC). The ΔC was directly proportional to the concentrations of the applied target probe with linearity ranging from 10−12 to 10−7 M. The biosensor had a detection limit of 6.0 × 10−13 M and a recovery of 95 % of the mecA gene when spiked in human saliva. The biosensor showed a promising selectivity. It could clearly discriminate single-base, two-base and twelve-base mismatch probes with a decrease in the signal strength by 13 %, 26 %, and 89 %, respectively relative to the signal strength of the complementary target probe. There was no significant signal observed for the non-complementary probe. The biosensor-chip could be re-used for more than 12 cycles with residual capacity of 94.5 ± 4.3 % and a RSD of 4.6 % by regenerating the biosensor-chip with a solution of 50 mM NaOH.
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| 12. |
- Mohammadi, Milad, et al.
(författare)
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Xylanases and high-degree wet milling improve soluble dietary fibre content in liquid oat base
- 2024
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Ingår i: Food Chemistry. - 0308-8146. ; 442
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Tidskriftsartikel (refereegranskat)abstract
- The growth of plant-based food and drink substitutes has led to increased interest in oat-based milk substitute as a dairy milk alternative. Conventional liquid oat base (LOB) production results in a fibre-rich insoluble by-product and loss of valuable macronutrients. This study investigates the use of xylanase enzymes to release insoluble arabinoxylan (AX) fibre and employs different degrees of milling in the LOB manufacturing process, with the aim to reduce insoluble waste and simultaneously increase soluble dietary fibre in oat-based milk substitutes. The combination of decreased mill gap space from 1 to 0.05 mm and addition of GH10 xylanase, resulted in a homogenous LOB product and solubilization of all available AX. Potential prebiotic arabinoxylooligosaccharides of DP3-7 from GH10 hydrolysis were identified using HPAEC-PAD and MS analysis. These findings demonstrate the value of utilizing xylanases and fine-milling in LOB manufacturing, offering a sustainable approach to maximize health benefits of oat-based beverages.
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| 13. |
- Moreno, Maiara, 1993-, et al.
(författare)
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Strain and phase evolution in TiAlN coatings during high-speed metal cutting : An in operando high-energy x-ray diffraction study
- 2024
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Ingår i: Acta Materialia. - : Elsevier. - 1359-6454 .- 1873-2453. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- We report on phase and strain changes in Ti1-xAlxN (0 ≤ x ≤ 0.61) coatings on cutting tools during turning recorded in operando by high-energy x-ray diffractometry. Orthogonal cutting of AISI 4140 steel was performed with cutting speeds of 360–370 m/min. Four positions along the tool rake face were investigated as a function of time in cut. Formation of γ-Fe in the chip reveals that the temperature exceeds 727 °C between the tool edge and the middle of the contact area when the feed rate is 0.06 mm/rev. Spinodal decomposition and formation of wurtzite AlN occurs at the positions of the tool with the highest temperature for the x ≥ 0.48 coatings. The strain evolution in the chip reveals that the mechanical stress is largest closest to the tool edge and that it decreases with time in cut for all analyzed positions on the rake face. The strain evolution in the coating varies between coatings and position on the rake face of the tool and is affected by thermal stress as well as the applied mechanical stress. Amongst others, the strain evolution is influenced by defect annihilation and, for the coatings with highest Al-content (x ≥ 0.48), phase changes.
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| 14. |
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| 15. |
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| 16. |
- Teeparuksapun, Kosin, et al.
(författare)
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A sensitive capacitive biosensor for protein a detection using human igg immobilized on an electrode using layer-by-layer applied gold nanoparticles
- 2022
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- A capacitive biosensor for the detection of protein A was developed. Gold electrodes were fabricated by thermal evaporation and patterned by photoresist photolithography. A layer-by-layer (LbL) assembly of thiourea (TU) and HAuCl4 and chemical reduction was utilized to prepare a probe with a different number of layers of TU and gold nanoparticles (AuNPs). The LbL-modified electrodes were used for the immobilization of human IgG. The binding interaction between human IgG and protein A was detected as a decrease in capacitance signal, and that change was used to investigate the correlation between the height of the LbL probe and the sensitivity of the capacitive measurement. The results showed that the initial increase in length of the LbL probe can enhance the amount of immobilized human IgG, leading to a more sensitive assay. However, with thicker LbL layers, a reduction of the sensitivity of the measurement was registered. The performance of the developed system under optimum set-up showed a linearity in response from 1 × 10−16 to 1 × 10−13 M, with the limit detection of 9.1 × 10−17 M, which could be interesting for the detection of trace amounts of protein A from affinity isolation of therapeutic monoclonal antibodies.
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