Publikationer från Linköpings universitet
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Protein-capped mesoporous silica SBA-15 enables protease-responsive and controlled antimicrobial peptide delivery
No full textMesoporous silica materials are promising carriers for antimicrobial peptides (AMPs), offering a versatile platform for combating bacterial infections. However, achieving high loading efficiency and controlled AMP release under physiological conditions remains a challenge. This study introduces a protein-capped mesoporous silicabased delivery system for treating topical bacterial infections. The system leverages elevated protease activity at infection sites to trigger the release of the sequence-optimized antimicrobial lipopeptide L-6-C5 (SOAP), facilitating efficient bacterial killing. SOAP was loaded into aminopropyl-functionalized SBA-15 mesoporous silica (amino-SBA-15) and capped with bovine serum albumin (BSA) or casein, forming amino-SBA-15SOAP@protein. Protein adsorption prevented premature SOAP release while enabling protease-triggered delivery. BSA capping achieved 92.6 +/- 0.2 % loading efficiency and enhanced peptide retention by 4.5-fold compared to non-capped particles, while casein yielded only a 1.25-fold increase. In the absence of proteases, SOAP release followed first-order kinetics, resulting in sustained release over 6 days. When exposed to trypsin, the release mechanism changed from diffusion-based to anomalous non-Fickian transport with zero-order kinetics, enabling rapid and efficient SOAP release. Proteolytic degradation of the protein cap also accelerated particle degradation and aggregation, offering insights into release dynamics under physiological conditions. The BSA-capped systems (amino-SBA-15-SOAP@BSA) showed effective bacteriostatic activity against Staphylococcus aureus (S. aureus), low hemolytic activity, and high cytocompatibility toward human dermal fibroblasts, outperforming free SOAP. Additionally, BSA capping reduced nonspecific protein binding in serum-rich media. By integrating sustained SOAP delivery with protease-triggered release, the amino-SBA-15-SOAP@BSA system addresses key limitations in AMP delivery, providing a promising strategy for controlled and localized AMP delivery in the treatment of topical bacterial infections.Funding Agencies|Swedish Research Council (VR) [2021-04427]; Swedish Foundation for Strategic Research (SSF) within the HEALiX project [RMX18-0039]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Centre in Nanoscience and Technology at LiTH, CeNano</p
Circular economy in the extractive frontier : Tensions and pathways for transformative change in mining
No full textThe mining sector, like other sectors of the economy, is under increasing pressure to adopt circular economy (CE) principles across its value chains and core operations. This paper offers a critical and conceptually grounded contribution to understanding how CE can support systemic transformation in one of the most resource-intensive and path-dependent sectors of the global economy. It examines the structural and institutional conditions that shape the adoption of CE in mining and identifies key tensions that constrain or enable transformative change. In parallel, the paper explores emerging pathways informed by technological innovation, shifts in production routines, and the rise of new circular business models. These insights are synthesised into a multi-level framework that captures the dynamic interactions between micro-, meso-, and macro-level processes shaping CE transitions. In addition to offering a diagnostic perspective, the framework outlines concrete action points for advancing systemic change. Funding Agencies|Marianne and Marcus Wallenberg Foundation [MMW 2023.0056]; Swedish Energy Agency (Energimyndigheten) [P2022-01062]</p
Neighborhood social structure in Sweden: A latent transition analysis using registry data from 1991 to 2020
No full textBackground: Neighborhoods shape daily life through physical and social structures, such as socioeconomic conditions, population density, and resident turnover. Decades of research link neighborhood characteristics to health and behavioral outcomes. However, these factors are often studied independently, neglecting their interrelated nature. Methods: Using Swedish population registry data, we employed latent class analyses to identify neighborhood typologies across six timepoints spanning 1991-2020. Neighborhoods, defined by Demographic Statistical Areas, were characterized by socioeconomic conditions, ethnic heterogeneity, residential instability, and urbanicity. Latent transition analyses examined changes over time. Results: Four neighborhood types emerged in the early period (1991-2000): Rural Low-Diversity (45 %), Urban Professional (27 %), Urban Affluent (21 %), and Resource-Limited (7 %). From 2001 onwards, five types were identified, with the addition of Urban High-Diversity (9 %) and Rural Resource-Limited (3 %). Three types, Rural Low-Diversity, Urban Professional, and Urban Affluent, persisted across 30 years, representing 87-93 % of neighborhoods, with over 90 % of neighborhoods retaining their classification over time. Conclusions: This multidimensional framework offers a foundation for future research, urban planning, and policy development.Funding Agencies|Swedish Research Council (Vetenskapsradet) [2021-02105]; Swedish Research Council [2021-02105] Funding Source: Swedish Research Council</p
Pediatric brain tumor classification using digital pathology and deep learning : Evaluation of SOTA methods on a multi-center Swedish cohort
No full textBrain tumors are the most common solid tumors in children and young adults, but the scarcity of large histopathology datasets has limited the application of computational pathology in this group. This study implements two weakly supervised multiple-instance learning (MIL) approaches on patch features obtained from state-of-the-art histology-specific foundation models to classify pediatric brain tumors in hematoxylin and eosin whole slide images (WSIs) from a multi-center Swedish cohort. WSIs from 540 subjects (age 8.5 ± 4.9 years) diagnosed with brain tumors were gathered from the six Swedish university hospitals. Instance (patch)-level features were obtained from WSIs using three pre-trained feature extractors: ResNet50, UNI, and CONCH. Instances were aggregated using attention-based MIL (ABMIL) or clustering-constrained attention MIL (CLAM) for patient-level classification. Models were evaluated on three classification tasks based on the hierarchical classification of pediatric brain tumors: tumor category, family, and type. Model generalization was assessed by training on data from two of the centers and testing on data from four other centers. Model interpretability was evaluated through attention mapping. The highest classification performance was achieved using UNI features and ABMIL aggregation, with Matthew's correlation coefficient of 0.76 ± 0.04, 0.63 ± 0.04, and 0.60 ± 0.05 for tumor category, family, and type classification, respectively. When evaluating generalization, models utilizing UNI and CONCH features outperformed those using ResNet50. However, the drop in performance from the in-site to out-of-site testing was similar across feature extractors. These results show the potential of state-of-the-art computational pathology methods in diagnosing pediatric brain tumors at different hierarchical levels with fair generalizability on a multi-center national dataset.Funding Agencies|Linkoeping University's Cancer Strength Area; ALF Grants, Region Ostergoetland [974566]; Vinnova via Medtech4Health and Analytic Imaging Diagnostics Arena [2222]; Swedish Childhood Cancer Fund [MT2021-0011, MT2022-0013]; Joanna Cocozza's Foundation for Children's Medical Research</p
Childhood Functional Constipation : Clinical outcomes and lived experiences of Children and their Families
No full textBackground This thesis investigates the multifaceted experiences and outcomes associated with childhood functional constipation, a condition that significantly affects children’s health and family life. Drawing on one quantitative and three qualitative studies, the research provides an increased understanding of how children and families navigate the challenges of diagnosis, treatment, and daily life with a child suffering from functional constipation. Aim The overall aim was to inform a more child- and family-centred perspective to functional constipation care by exploring the experiences of parents and children, and to evaluate a clinical treatment programme. Methods Study I is a retrospective cohort review of medical records with pre-post intervention measurements. Children participating in a structured bowel management programme in a secondary outpatient clinic between 2015 and 2022 were recruited. Clinical variables were compared between the recovered and the unrecovered groups to identify predisposing characteristics and predictive factors for recovery. Studies II and III have a qualitative design, presents interviews with parents about their experiences of having a child with constipation and of giving treatment at home. The same data set of 15 parents were used for both studies. The Reflective Lifeworld Research approach originating from phenomenology was used during analysis. Study IV, also qualitative, presents interviews with 20 children aged between 6 and 14 about their experiences of having constipation and receiving treatment. Reflexive thematic analysis was used during analysis. Findings The first study demonstrates significant improvements in bowel function and symptom relief among children following the intervention. Structured care helped 44% of therapy-resistant children to reach cure or self-management abilities within six months. The study underscores the value of integrating clinical protocols with family education and support. The second study reveals how childhood constipation disrupts family routines, emotional well-being, and social interactions as treatment support requires considerable attention and strength. Parents report feelings of frustration, helplessness, and isolation, often compounded by limited support from healthcare professionals. The findings highlight the need for more empathetic child and family-centred care strategies. The third study uncovers the emotional and practical challenges involved in managing medication routines, feelings of abuse and inadequacy, while trying to maintain adherence. The study emphasises the importance of clear communication and sustained support to empower parents in their caregiving roles because they might question their parental identity. The fourth study presents the child’s perspectives on functional constipation with associated treatments. It presents a close and realistic narrative of procrastination of toilet visits, fear of exposure of leakage in social situations, rectal enemas as both awful and relieving, and hope, while striving for control. Conclusions Together these studies offer a holistic understanding of childhood functional constipation, bridging the gap between clinical outcomes and family experiences. Families deal with physical symptoms, psychological defences, fear of social judgment, and struggles with treatment. This thesis offers actionable insights for children, parents, clinicians, and researchers to improve the quality of constipation care for children and their caregivers
Rapid and scalable combustion synthesis of (Mo2/3Y1/3)2AlC i-MAX as the precursor for vacancy-ordered MXene
No full textFor MXenes to be viable in commercial and industrial applications, their production must rely on processes that are energy-efficient, environmentally sustainable, and scalable. A critical factor influencing this viability is the synthesis route of the parent MAX phase. In this study, we report a novel and rapid approach for synthesizing a chemically ordered MAX phase (i-MAX), specifically the in-plane ordered (Mo2/3Y1/3)2AlC, using self-propagating high-temperature synthesis (SHS) completed in one minute. The target MAX phase yield was estimated using Rietveld refinement to be 73.6% with the main impurity phases identified as Mo3Al2C and YF3. Thermodynamic calculations combined with experimental characterizations indicate that the use of an aluminum-yttrium master alloy played a pivotal role in achieving high synthesis yield by facilitating a sequence of intermediate phase transformations that enhance reaction kinetics and i-MAX formation. This method involves the utilization of Poly(tetrafluoroethylene)- (C2F4)nas a promoter, which enables the formation of volatile fluorides and fluorine-containing intermediates, making the reaction self-sustaining. Etching and delamination of the SHS-produced i-MAX phase, resulted in a vacancy-ordered MXene with the formula Mo4/3CTx, with a yield value twice that obtained using the conventional MAX-phase parent material preparation route. This work demonstrates the method's effectiveness in achieving rapid, straightforward, and energy-efficient synthesis of a diverse range of MAX and i-MAX phases, thereby paving the way for scalable and efficient MXene production. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Funding Agencies|Science Ministry of Education, Science, Culture and Sports of the Republic of Armenia [23LCG-2F001, 24FP-2B026]; Swedish Research Council; Swedish Foundation for Strategic Research for access to ARTEMI [2021-00171, RIF21-0026]; PLANSEE Composite Materials GmbH [AlY2.3, 2025, DALLE]</p
4D Flow MRI Velocity and Turbulence Mapping in Mild Valvular Heart Disease
No full textBackground: Valvular heart disease (VHD) commonly leads to the development of turbulent blood flow. Turbulent kinetic energy (TKE), measured with 4D flow MRI, may be a complement to current metrics for early identification of VHD. Purpose: To investigate TKE as a marker of VHD in relation to flow velocity and cardiovascular geometry. Study Type: Retrospective observational cross-sectional. Population: Twenty controls and 106 subjects with VHDs, including mitral regurgitation, aortic regurgitation, pulmonary regurgitation, tricuspid regurgitation, and aortic stenosis. Field Strength/Sequences: Four-dimensional flow MRI using a spoiled gradient-echo phase-contrast sequence with asymmetric 4-point motion encoding at 1.5 or 3 T. Assessment: Time-resolved segmentations of the left and right ventricles (LV, RV), atria (LA, RA), and aorta were performed. Total and maximum TKE, maximum and average velocity, and diameters were evaluated in each. Correlations between TKE, velocity, and diameter were assessed, along with group differences between VHD subjects and controls. Statistical Tests: Student's t-test, Wilcoxon rank-sum test, chi-squared test, Pearson's correlation, two-way analysis of covariance. A p value &lt; 0.05 was considered significant. Results: Total and maximum TKE correlated significantly with maximum velocity (r = 0.45-0.76) and averaged velocity (r = 0.22-0.44) and less strongly with diameters for aorta, LV, LA, and RV (r = 0.18-0.37). Compared to controls, total and maximum aortic TKE were significantly higher in aortic stenosis (3.8 vs. 1.6 mJ; 291.7 vs. 133.7 J/m(3)). Maximum LV TKE was significantly elevated in aortic regurgitation (106.6 vs. 91.8 J/m(3)). Total TKE was significantly elevated in LA for mitral regurgitation (1.1 vs. 0.6 mJ), in RA for tricuspid regurgitation (1.6 vs. 0.7 mJ), and in RV for pulmonary regurgitation (1.7 vs. 1.0 mJ). Data Conclusion: TKE is elevated in mild VHD. When evaluated alongside velocity as a marker for VHD, TKE may be more discriminative. Consequently, it has potential to be a hemodynamic marker of early VHD conveying complementary information to velocity.Funding Agencies|Medical Faculty at Linkping University</p
The Safety Belt estimator under multivariate linear models with inequality constraints
No full textThe main goal of this paper is to determine maximum likelihood estimators under a multivariate linear model with prior information introduced via inequality restrictions on the mean parameters. The restrictions are in the form of quadratic inequalities. Methods from convex optimization theory play a fundamental role in determining the estimators. A characteristic of the new estimators, called Safety Belt estimators, is that depending on the observed data, there are two alternative solutions to the likelihood equations.Funding Agencies|Poznan University of Technology, Poland [0213/SBAD/0119]; Polish National Science Center [NCN UMO-2018/31/B/ST1/00253]</p
Optimization of interfacial bonding between graphene-enhanced polyethylene liners and CFRP composites using plasma treatment for hydrogen storage applications
No full textAs the need for sustainable hydrogen storage solutions increases, enhancing the bonding interface between polymer liners and carbon fiber-reinforced polymer (CFRP) in Type IV hydrogen tanks is essential to ensure tank integrity and safety. This study investigates the effect of plasma treatment on polyethylene (PE) and PE/graphene nanoplatelets (GNP) composites to optimize bonding with CFRP, simulating the liner-CFRP interface in hydrogen tanks. Initially, plasma treatment effects on PE surfaces were assessed, focusing on plasma energy and exposure time, with key surface modifications characterized and bonding performance being evaluated. Plasma treatment on PE/GNP composites, with increasing GNP content, was then examined, comparing the bonding effectiveness of untreated and plasma-treated samples. Wedge peel tests revealed that plasma treatment significantly enhanced PE-CFRP bonding, with optimal conditions at 510 W and 180 s resulting in 212 % and 165 % increases in the wedge peel strength and fracture energy, respectively. Plasma-treated PE/GNP composites with 0.75 wt.% GNP achieved a notable bonding enhancement with CFRP, showing 528 % and 269 % improvements in strength and fracture energy over untreated neat PE-CFRP samples. These findings offer practical implications for improving the mechanical performance of hydrogen storage tanks, contributing to safer and more efficient hydrogen storage systems for a sustainable energy future.Funding Agencies|Directed Research Projects Program of the Research and Innovation Center for Graphene and 2D Materials (RIC2D) , Khalifa University [8434000546]</p
Digital transformation as a multi-phase process: a longitudinal study of corporate strategy and business unit adaptation
No full textThis study investigates how digital transformation unfolds over time within a multi-business manufacturing firm. Drawing on a longitudinal case study of SweX—a global industrial firm—we trace the dynamics of digital transformation across three empirically derived phases: experimentation, consolidation, and acceleration. Five interrelated patterns shape the process: (1) digital transformation unfolds recursively rather than linearly; (2) tensions arise between corporate strategy and business unit adaptation; (3) monetizing digital innovation remains challenging; (4) structural adjustments are needed to balance stability and change; and (5) temporal asymmetry—misalignments between technology deployment and customer readiness—can hinder digital transformation. We organize these insights around three overarching themes—organizational tension, structural adjustment, and organizational adaptation—developed through iterative analysis across corporate and business unit levels. The study advances process-oriented perspectives on strategy by showing how recursive patterns of tension, structural change, and organizational adaptation drive digital transformation in complex, multi-level firms. Funding Agencies|Vinnova - Sweden's Innovation Agency [2022-00301, 2024-03735]</p