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  • Disputation: 2025-01-20 09:00 room A1:107a, Uppsala
    Myers, Nadine E. M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Biokemi.
    Biochemical strategies for ligand discovery against cancer targets2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Cancer is a common disease and diagnosis frequency correlates with population age. Though many cancers can be cured today, numerous types remain difficult to treat. Treatments can evoke side effects and often don’t reach the clinic due to inefficacy. Thus, better targeted anti-cancer therapies and candidate drugs are required. This thesis focusses on initial stages of drug discovery where we sought to identify ligands specifically targeting SET and MYND domain containing protein 3 (SMYD3), and Cullin3 associated adaptor proteins: Kelch-like protein 12 (KLHL12) and 20 (KLHL20). These targets are all associated with cancer although their biological mechanisms remain elusive. The targets were challenging from a biochemical perspective, nevertheless via robust expression and purification methods, an amalgamation of biochemical techniques and computational methods were used to identify, characterize, and evolve fragment and peptide-based ligands. Sensitive multiplexed screening assays enabled selection of specific hits. A grating coupled interferometry-based biosensor assay implemented a kinetic criterion for fragment hit identification against SMYD3. Four fragments from a library containing 1056 fragments had their binding site and orientation established using X-ray crystallography. Fragment evolution based on the SMYD3 allosteric ligand diperodon encompassed a structure-affinity-relationship (SAR)-based approach, and a deconstruction-and-growth method wherein ligands with KD of 0.4-180 μM were attained. Structure prediction complemented a surface plasmon resonance (SPR) biosensor-driven approach to develop a stapled peptide ligand against the Kelch domain of KLHL20, derived from zinc finger translocation associated protein (ZFTA). This peptide had KD of 1.14 mM and alanine scanning revealed aspartate as vital for interaction. Multiplexed fragment-based SPR biosensor screening assays against the Kelch domains of KLHL12 and 20 identified 237 and 266 hits from a library containing 3000+ fragments. Hit selection was based on preference for folded protein and dose-response analysis was conducted for validation and hit reduction to 24 and 21. Hit SAR was probed using modelling and fragment analogues. NMR confirmed fragment-protein binding. All targets studied herein were concluded as poorly druggable, however using multiple experimental approaches alongside computational methodologies permitted hit identification, validation, and a further understanding of poorly druggable targets. The validated hits presented are befitting for evolution by medicinal chemistry.

    Delarbeten
    1. Identification of fragments targeting SMYD3 using highly sensitive kinetic and multiplexed biosensor-based screening
    Öppna denna publikation i ny flik eller fönster >>Identification of fragments targeting SMYD3 using highly sensitive kinetic and multiplexed biosensor-based screening
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    2024 (Engelska)Ingår i: RSC Medicinal Chemistry, E-ISSN 2632-8682, Vol. 15, nr 6, s. 1982-1990Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A 1056-membered fragment library has been screened against SMYD3 using a novel multiplexed experimental design implemented in a grating coupled interferometry (GCI)-based biosensor. SMYD3 is a prospective target for anticancer drugs and the focus has initially been on discovery of inhibitors of its lysine methyl transferase activity. However, it has multiple protein interaction partners and several potential roles in carcinogenesis. It therefore remains unclear what mode of action ligands targeting the protein should have. Our goal was therefore to identify new ligands and discriminate hits that interact with the active site and those that interact with other sites. In addition, we were interested in selecting hits based on kinetic features rather than affinity. Screening was done in parallel against SMYD3 alone or SMYD3 with the active site blocked by a tight binding inhibitor. Hit selection was primarily based on dissociation rates. In total, 20 fragments were selected as hits, of which half apparently targeted the active site and half targeted other sites. Twelve of the hits were selected for structural analysis using X-ray crystallography in order to identify binding sites and modes of binding. Four of the hits were successfully identified in crystal structures with SMYD3; the others did not show any electron densities for ligands in the crystals. Although it might be possible to optimize the crystallography approach for a better success rate, it was clear that the sensitivity and time resolution of the biosensor assay was exceptional and enabled kinetic rate constants to be estimated for fragments. Fragments are typically considered to interact too rapidly for such quantification to be possible. This approach consequently represents a paradigm shift. In addition, the multiplexed approach allows ligands targeting different sites to be rationally selected already in the fragment library screening stage.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2024
    Nationell ämneskategori
    Biokemi och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-542730 (URN)10.1039/d4md00093e (DOI)001207835200001 ()38911161 (PubMedID)2-s2.0-85191342276 (Scopus ID)
    Forskningsfinansiär
    Norges forskningsråd, 262695Norges forskningsråd, 274858EU, Horisont 2020, 675899EU, Horisont 2020, 860517
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2025-01-14Bibliografiskt granskad
    2. Integrated computational and biosensor-based strategies for the discovery of allosteric SMYD3 ligands using diperodon as a starting point
    Öppna denna publikation i ny flik eller fönster >>Integrated computational and biosensor-based strategies for the discovery of allosteric SMYD3 ligands using diperodon as a starting point
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Biokemi och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-543012 (URN)
    Forskningsfinansiär
    EU, Horisont 2020, 675899EU, Horisont 2020, 860517
    Tillgänglig från: 2024-11-18 Skapad: 2024-11-18 Senast uppdaterad: 2024-12-10
    3. Design of a Stapled Peptide Targeting KLHL20Kelch: A Computational and Biosensor-based Approach
    Öppna denna publikation i ny flik eller fönster >>Design of a Stapled Peptide Targeting KLHL20Kelch: A Computational and Biosensor-based Approach
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Biokemi och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-542740 (URN)
    Forskningsfinansiär
    EU, Horisont 2020, 860517Novo Nordisk fonden, NNF14CC0001
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2024-12-10
    4. Multiplexed biosensor-based screening and structural assessment of fragments targeting KLHL12 and KLHL20
    Öppna denna publikation i ny flik eller fönster >>Multiplexed biosensor-based screening and structural assessment of fragments targeting KLHL12 and KLHL20
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Biokemi och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-542912 (URN)
    Forskningsfinansiär
    EU, Horisont 2020, 860517
    Tillgänglig från: 2024-11-15 Skapad: 2024-11-15 Senast uppdaterad: 2024-12-10
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    UUThesis_N-E-M-Myers-2024
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  • Disputation: 2025-01-23 09:15 Heinz-Otto Kreiss, Uppsala
    Beháňová, Andrea
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen Vi3.
    Image and data analysis for understanding spatial transcriptomics and tissue architecture2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The human body is a complicated system, with its complex functions interpreted through interactions that scale from tissues down to individual genes. To unravel this complexity, we must look at the smallest functional compartments, specifically, the spatial organization of gene expression within tissues. This thesis focuses on computational methods in spatial transcriptomics, to precisely map gene expression patterns, providing insights into how cellular neighborhoods and protein interactions drive tissue functionality. Central to this research are computational tools and methodologies that tackle the spatial transcriptomics pipeline from start to finish, addressing data acquisition, pre-processing, decoding, classification, and spatial statistics. The contributions are presented across two perspectives: the technical advancements in the pipeline and their application to real-world biological scenarios.

    On the technical side, this thesis introduces two novel classification methods. The first is a graph-based segmentation algorithm that groups molecular signals into cells without relying on nuclear stains, overcoming common imaging limitations. The second is a fast and interactive clustering method for imaging-based spatial omics data. Additionally, the thesis includes work on TissUUmaps 3, an interactive visualization tool designed for high-resolution exploration and quality assessment of large-scale spatial data, along with plugins to enhance the detailed analysis of spatial patterns in gene expression across tissue types. A comprehensive review of spatial statistics methods applicable to spatial omics data complements these technical contributions. 

    The biological application side demonstrates the utility of these tools in uncovering insights from real-world datasets. In the mouse olfactory epithelium, spatial gene expression mapping reveals cellular patterns critical for sensory processing. In bladder cancer, spatial transcriptomics illuminates immune cell behavior and interactions within the tumor microenvironment, showcasing how these methods bridge computational advancements with biological discovery.

    Together, these contributions highlight the power of computational spatial transcriptomics to reveal critical insights into tissue architecture, gene co-expression, and cellular functionality. By refining and scaling analytical techniques, this thesis advances our understanding of tissue complexity and paves the way for discoveries in developmental biology, oncology, and precision medicine, demonstrating the transformative potential of spatial omics for both fundamental research and clinical applications.

    Delarbeten
    1. Decoding and spatial analysis of ISS data for understanding the mouse olfactory epithelium organization
    Öppna denna publikation i ny flik eller fönster >>Decoding and spatial analysis of ISS data for understanding the mouse olfactory epithelium organization
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Bioinformatik (beräkningsbiologi)
    Forskningsämne
    Bioinformatik
    Identifikatorer
    urn:nbn:se:uu:diva-543104 (URN)
    Tillgänglig från: 2024-11-19 Skapad: 2024-11-19 Senast uppdaterad: 2024-11-20
    2. TissUUmaps 3: Improvements in interactive visualization, exploration, and quality assessment of large-scale spatial omics data
    Öppna denna publikation i ny flik eller fönster >>TissUUmaps 3: Improvements in interactive visualization, exploration, and quality assessment of large-scale spatial omics data
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    2023 (Engelska)Ingår i: Heliyon, E-ISSN 2405-8440, Vol. 9, nr 5, artikel-id e15306Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Background and objectives: Spatially resolved techniques for exploring the molecular landscape of tissue samples, such as spatial transcriptomics, often result in millions of data points and images too large to view on a regular desktop computer, limiting the possibilities in visual interactive data exploration. TissUUmaps is a free, open-source browser-based tool for GPU-accelerated visualization and interactive exploration of 107+ data points overlaying tissue samples.

    Methods: Herein we describe how TissUUmaps 3 provides instant multiresolution image viewing and can be customized, shared, and also integrated into Jupyter Notebooks. We introduce new modules where users can visualize markers and regions, explore spatial statistics, perform quantitative analyses of tissue morphology, and assess the quality of decoding in situ transcriptomics data.

    Results: We show that thanks to targeted optimizations the time and cost associated with interactive data exploration were reduced, enabling TissUUmaps 3 to handle the scale of today's spatial transcriptomics methods.

    Conclusion: TissUUmaps 3 provides significantly improved performance for large multiplex datasets as compared to previous versions. We envision TissUUmaps to contribute to broader dissemination and flexible sharing of largescale spatial omics data.

    Ort, förlag, år, upplaga, sidor
    ElsevierElsevier BV, 2023
    Nyckelord
    Interactive visualization, Spatial omics, Spatial transcriptomics
    Nationell ämneskategori
    Bioinformatik och systembiologi
    Identifikatorer
    urn:nbn:se:uu:diva-508867 (URN)10.1016/j.heliyon.2023.e15306 (DOI)001029211200001 ()37131430 (PubMedID)
    Forskningsfinansiär
    Stiftelsen för strategisk forskning (SSF), BD150008Stiftelsen för strategisk forskning (SSF), SB160046EU, Europeiska forskningsrådet, CoG682810
    Tillgänglig från: 2023-08-11 Skapad: 2023-08-11 Senast uppdaterad: 2024-12-03Bibliografiskt granskad
    3. Cell Segmentation of in situ Transcriptomics Data using Signed Graph Partitioning
    Öppna denna publikation i ny flik eller fönster >>Cell Segmentation of in situ Transcriptomics Data using Signed Graph Partitioning
    2023 (Engelska)Ingår i: Graph-Based Representations in Pattern Recognition / [ed] Mario Vento; Pasquale Foggia; Donatello Conte; Vincenzo Carletti, Cham: Springer, 2023, s. 139-148Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The locations of different mRNA molecules can be revealed by multiplexed in situ RNA detection. By assigning detected mRNA molecules to individual cells, it is possible to identify many different cell types in parallel. This in turn enables investigation of the spatial cellular architecture in tissue, which is crucial for furthering our understanding of biological processes and diseases. However, cell typing typically depends on the segmentation of cell nuclei, which is often done based on images of a DNA stain, such as DAPI. Limiting cell definition to a nuclear stain makes it fundamentally difficult to determine accurate cell borders, and thereby also difficult to assign mRNA molecules to the correct cell. As such, we have developed a computational tool that segments cells solely based on the local composition of mRNA molecules. First, a small neural network is trained to compute attractive and repulsive edges between pairs of mRNA molecules. The signed graph is then partitioned by a mutex watershed into components corresponding to different cells. We evaluated our method on two publicly available datasets and compared it against the current state-of-the-art and older baselines. We conclude that combining neural networks with combinatorial optimization is a promising approach for cell segmentation of in situ transcriptomics data. The tool is open-source and publicly available for use at https://github.com/wahlby-lab/IS3G.

    Ort, förlag, år, upplaga, sidor
    Cham: Springer, 2023
    Serie
    Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 14121
    Nyckelord
    Cell segmentation, in situ transcriptomics, tissue analysis, mutex watershed
    Nationell ämneskategori
    Bioinformatik (beräkningsbiologi)
    Forskningsämne
    Datoriserad bildbehandling; Maskininlärning
    Identifikatorer
    urn:nbn:se:uu:diva-523993 (URN)10.1007/978-3-031-42795-4_13 (DOI)978-3-031-42794-7 (ISBN)978-3-031-42795-4 (ISBN)
    Konferens
    13th IAPR-TC-15 International Workshop, GbRPR 2023, Vietri sul Mare, Italy, September 6–8, 2023
    Tillgänglig från: 2024-02-27 Skapad: 2024-02-27 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
    4. Points2Regions: Fast, interactive clustering of imaging-based spatial transcriptomics data
    Öppna denna publikation i ny flik eller fönster >>Points2Regions: Fast, interactive clustering of imaging-based spatial transcriptomics data
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    2024 (Engelska)Ingår i: Cytometry Part A, ISSN 1552-4922, E-ISSN 1552-4930, Vol. 105, nr 9Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Imaging-based spatial transcriptomics techniques generate image data that, once processed, results in a set of spatial points with categorical labels for different mRNA species. A crucial part of analyzing downstream data involves the analysis of these point patterns. Here, biologically interesting patterns can be explored at different spatial scales. Molecular patterns on a cellular level would correspond to cell types, whereas patterns on a millimeter scale would correspond to tissue-level structures. Often, clustering methods are employed to identify and segment regions with distinct point-patterns. Traditional clustering techniques for such data are constrained by reliance on complementary data or extensive machine learning, limiting their applicability to tasks on a particular scale. This paper introduces 'Points2Regions', a practical tool for clustering spatial points with categorical labels. Its flexible and computationally efficient clustering approach enables pattern discovery across multiple scales, making it a powerful tool for exploratory analysis. Points2Regions has demonstrated efficient performance in various datasets, adeptly defining biologically relevant regions similar to those found by scale-specific methods. As a Python package integrated into TissUUmaps and a Napari plugin, it offers interactive clustering and visualization, significantly enhancing user experience in data exploration. In essence, Points2Regions presents a user-friendly and simple tool for exploratory analysis of spatial points with categorical labels. 

    Ort, förlag, år, upplaga, sidor
    John Wiley & Sons, 2024
    Nationell ämneskategori
    Bioinformatik (beräkningsbiologi)
    Forskningsämne
    Bioinformatik; Immunologi; Datoriserad bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-523994 (URN)10.1002/cyto.a.24884 (DOI)001261513900001 ()
    Forskningsfinansiär
    EU, Europeiska forskningsrådet, 682810Science for Life Laboratory, SciLifeLab
    Tillgänglig från: 2024-02-27 Skapad: 2024-02-27 Senast uppdaterad: 2025-01-16Bibliografiskt granskad
    5. Visualization and quality control tools for large-scale multiplex tissue analysis in TissUUmaps3
    Öppna denna publikation i ny flik eller fönster >>Visualization and quality control tools for large-scale multiplex tissue analysis in TissUUmaps3
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    2023 (Engelska)Ingår i: Biological Imaging, E-ISSN 2633-903X, Vol. 3, artikel-id e6Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-509452 (URN)10.1017/s2633903x23000053 (DOI)
    Tillgänglig från: 2023-08-18 Skapad: 2023-08-18 Senast uppdaterad: 2024-11-20
    6. The tumour microenvironment across tumour evolution in bladder cancer profiled by single-cell RNA-sequencing analysis and spatial transcriptomics
    Öppna denna publikation i ny flik eller fönster >>The tumour microenvironment across tumour evolution in bladder cancer profiled by single-cell RNA-sequencing analysis and spatial transcriptomics
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Cancer och onkologi
    Identifikatorer
    urn:nbn:se:uu:diva-543350 (URN)
    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2024-11-20
    7. Spatial Statistics for Understanding Tissue Organization
    Öppna denna publikation i ny flik eller fönster >>Spatial Statistics for Understanding Tissue Organization
    2022 (Engelska)Ingår i: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 13, artikel-id 832417Artikel, forskningsöversikt (Refereegranskat) Published
    Abstract [en]

    Interpreting tissue architecture plays an important role in gaining a better understanding of healthy tissue development and disease. Novel molecular detection and imaging techniques make it possible to locate many different types of objects, such as cells and/or mRNAs, and map their location across the tissue space. In this review, we present several methods that provide quantification and statistical verification of observed patterns in the tissue architecture. We categorize these methods into three main groups: Spatial statistics on a single type of object, two types of objects, and multiple types of objects. We discuss the methods in relation to four hypotheses regarding the methods' capability to distinguish random and non-random distributions of objects across a tissue sample, and present a number of openly available tools where these methods are provided. We also discuss other spatial statistics methods compatible with other types of input data.

    Ort, förlag, år, upplaga, sidor
    Frontiers Media S.A.Frontiers Media SA, 2022
    Nyckelord
    transcriptomics, spatial statistics, gene expression, tissue analysis, tissue organization, niches
    Nationell ämneskategori
    Fysiologi
    Identifikatorer
    urn:nbn:se:uu:diva-469678 (URN)10.3389/fphys.2022.832417 (DOI)000759335800001 ()35153840 (PubMedID)
    Forskningsfinansiär
    EU, Europeiska forskningsrådet, CoG 682810
    Tillgänglig från: 2022-03-21 Skapad: 2022-03-21 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
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    UUThesis_A-Beháňová-2024
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  • Disputation: 2025-01-24 09:00 A1:107, Uppsala
    Björnwall, Amanda
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Eating alone or eating in loneliness: Food routines, health, and social relations in later life2025Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The overall aim of this thesis was to study eating alone or together with others among community-living older adults, focusing on how eating alone is experienced and how it is associated with aspects related to food routines, health, and social relations in Sweden. In Paper I, a scoping review was used to map and summarize existing scientific articles, while Paper II explored experiences and perceptions of eating alone through qualitative interviews. Papers III and IV are based on a national cross-sectional survey of 70- to 75-year-old adults, examining both the objective frequency and subjective experience of eating alone, and their associations with food-related outcomes, loneliness, and self-rated health. 

    Research across various research fields has examined eating alone as a potential risk factor for different food- and health-related outcomes, often using cross-sectional designs to assess the frequency, but not the subjective experience, of eating alone or with others (Paper I). Perceptions of eating alone ranged from being a symbol of loss to an unproblematic routine or a sign of independence (Paper II). One-quarter of the 695 survey participants were categorised as eating alone, while three-quarters were eating together with someone daily. Eating alone seemed to be related to the organisation of food routines (e.g., lower number of main meals per day, and more frequent consumption of ready-made meals) but not to the healthiness of food intake (food index scores) or BMI (Paper III). A small share reported being bothered when eating alone; however, one-third of those eating alone reported not having the opportunity to eat together with someone if desired. Both eating alone and lower engagement in social activities were associated with loneliness. Lower engagement in social activities was also associated with lower self-rated health, though eating alone was not (Paper IV). 

    In conclusion, eating alone, in the early phase of retirement age, is experienced in various ways and appears to be more closely related to food routines and social relations than to aspects of health. This thesis provides valuable insights for the development of future health policies and research on the implications of eating alone among older adults.

    Delarbeten
    1. Eating Alone or Together among Community-Living Older People: A Scoping Review
    Öppna denna publikation i ny flik eller fönster >>Eating Alone or Together among Community-Living Older People: A Scoping Review
    2021 (Engelska)Ingår i: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 18, nr 7, artikel-id 3495Artikel, forskningsöversikt (Refereegranskat) Published
    Abstract [en]

    Research on healthy aging commonly concerns problems related to loneliness and food intake. These are not independent aspects of health since eating, beyond its biological necessity, is a central part of social life. This scoping review aimed to map scientific articles on eating alone or together among community-living older people, and to identify relevant research gaps. Four databases were searched, 989 articles were identified and 98 fulfilled the inclusion criteria. In the first theme, eating alone or together are treated as central topics of interest, isolated from adjoining, broader concepts such as social participation. In the second, eating alone or together are one aspect of the findings, e.g., one of several risk factors for malnutrition. Findings confirm the significance of commensality in older peoples’ life. We recommend future research designs allowing identification of causal relationships, using refined ways of measuring meals alone or together, and qualitative methods adding complexity.

    Ort, förlag, år, upplaga, sidor
    MDPI, 2021
    Nyckelord
    commensality, eating alone, older people, food intake, loneliness
    Nationell ämneskategori
    Tvärvetenskapliga studier inom samhällsvetenskap
    Forskningsämne
    Kostvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-439446 (URN)10.3390/ijerph18073495 (DOI)000638524300001 ()33801775 (PubMedID)
    Tillgänglig från: 2021-04-06 Skapad: 2021-04-06 Senast uppdaterad: 2024-11-22Bibliografiskt granskad
    2. Perceptions and experiences of eating alone among community-living retired Swedes: Loss, routine and independence
    Öppna denna publikation i ny flik eller fönster >>Perceptions and experiences of eating alone among community-living retired Swedes: Loss, routine and independence
    2023 (Engelska)Ingår i: Appetite, ISSN 0195-6663, E-ISSN 1095-8304, Vol. 186, artikel-id 106570Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The practice of eating together, commensality, is often considered as something positive in later life, particularly regarding peoples' nutritional status and psychosocial well-being. Eating alone, in contrast, is treated as a risk factor, although literature indicates that it is not necessarily something negative. Still, analyses that specifically target older peoples' varied experiences and notions of eating alone are scarce. This study has explored perceptions and experiences of eating alone among older people in Sweden, a country considered highly individualistic, yet with relatively low levels of loneliness in the older population. Semi-structured interviews were conducted with 20 community-living and retired Swedes, 70-90 years of age. A thematic analysis identified three themes: i) 'Eating alone as a manifestation of loss'; ii) 'Eating alone as an everyday routine'; and iii) 'Eating alone as independence and contentment'. General perceptions of eating alone were often related to the current living situation (e.g., cohabiting or single-living). One key finding was an identified tension between the idea of eating alone as something problematic among those living and eating with a partner and the practical experience of an uncomplicated routine among those living and eating alone. Eating together is discussed as a possible social need for many, but perhaps not for all. Some can feel content with eating alone or even enjoy it. Future studies should approach potential disadvantages of eating alone among older people as an open empirical question that is likely to depend on both the individual and the cultural context.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2023
    Nyckelord
    Aging, Commensality, Eating alone, Food, Loneliness, Meals
    Nationell ämneskategori
    Tvärvetenskapliga studier inom samhällsvetenskap
    Forskningsämne
    Kostvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-501440 (URN)10.1016/j.appet.2023.106570 (DOI)000984159800001 ()37068550 (PubMedID)
    Tillgänglig från: 2023-05-08 Skapad: 2023-05-08 Senast uppdaterad: 2024-11-22Bibliografiskt granskad
    3. The impact of eating alone on food intake and everyday eating routines: A cross-sectional study of community-living 70- to 75-year-olds in Sweden
    Öppna denna publikation i ny flik eller fönster >>The impact of eating alone on food intake and everyday eating routines: A cross-sectional study of community-living 70- to 75-year-olds in Sweden
    2024 (Engelska)Ingår i: BMC Public Health, E-ISSN 1471-2458, Vol. 24, nr 1, artikel-id 2214Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Background

    Eating is fundamental not only to survival and health, but also to how humans organise their social lives. Eating together with others is often seen as the healthy ideal, while eating alone is highlighted as a risk factor for negative health outcomes, especially among older adults. This paper, therefore, investigates the relationship between the frequency and subjective experience of eating alone and food-related outcomes among 70- to 75-year-olds in Sweden.

    Methods

    A survey was distributed to a nationally representative random sample of 1500 community-living in Sweden, aged 70–75 years. Two different constructs of eating alone (objective and subjective) were measured, along with the following food-related outcomes: a food index, intake of food groups, consumption of ready-made meals, number of main meals per day, and body mass index (BMI).

    Results

    In total, 695 respondents were included in the final sample. A quarter of the respondents were categorised as eating alone, of which a small proportion reported that doing so bothered them. There were no associations between eating alone and food index scores, BMI, or intake frequencies of fruits and berries, or fish and shellfish. However, people eating alone were less likely to report eating three meals per day (OR: 0.53, CI: 0.37–0.76, p = 0.006), less likely to report higher intake frequencies of vegetables and snacks, sugary foods, and sweet drinks (adjusted OR: 0.68, CI: 0.48–0.95, p = 0.023 resp. OR: 0.59, CI: 0.43–0.81, p = 0.001), and more likely to report higher intake frequencies of ready-made meals (adjusted OR: 3.71, CI: 2.02–6.84, p < 0.001) compared to those eating together with others. The subjective experience of eating alone did not have an impact on food-related outcomes.

    Conclusion

    Eating alone or with others played a role in participants’ food intake, and seemed to influence aspects of the organisation of everyday eating routines rather than overall dietary healthiness or weight status. Our findings add to the previous body of research on commensality, eating alone, and health among the older population, providing insights into the development of future health policies and research.

    Ort, förlag, år, upplaga, sidor
    BioMed Central (BMC), 2024
    Nyckelord
    Eating alone, Older people, Food-related outcomes, Food intake, Everyday eating routines, Eating pattern
    Nationell ämneskategori
    Tvärvetenskapliga studier inom samhällsvetenskap Annan hälsovetenskap Näringslära
    Forskningsämne
    Kostvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-537150 (URN)10.1186/s12889-024-19560-0 (DOI)001291754200005 ()39143537 (PubMedID)
    Forskningsfinansiär
    Uppsala universitetKronprinsessan Margaretas Minnesfond
    Tillgänglig från: 2024-08-28 Skapad: 2024-08-28 Senast uppdaterad: 2024-11-22Bibliografiskt granskad
    4. Eating Alone and its Associations with Loneliness and Self-Rated Health: Insights from a Cross-Sectional Study of 70- to 75-year-olds in Sweden
    Öppna denna publikation i ny flik eller fönster >>Eating Alone and its Associations with Loneliness and Self-Rated Health: Insights from a Cross-Sectional Study of 70- to 75-year-olds in Sweden
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    (Engelska)Ingår i: Artikel i tidskrift (Refereegranskat) Submitted
    Abstract [en]

    Objectives: To investigate whether eating alone (measured objectively and subjectively) and engagement in social activities are associated with loneliness and self-rated health, independently or through interaction effects among community-living adults in Sweden. Methods: Data from a national cross-sectional survey of 695 adults aged 70 to 75 years were used to assess both the subjective experience and frequency of eating alone and engagement in social activities and their associations with loneliness, and self-rated health using logistic regression and interaction analysis. Results: Eating alone and being bothered by eating alone were both associated with loneliness, but no interaction between the two was identified, meaning that the association between eating alone and loneliness was not dependent on whether eating alone was perceived as bothersome or not. Lower engagement in social activities was also associated with loneliness. However, no interaction effect was identified between eating alone and social activities. Lower engagement in social activities was associated with lower self-rated health, but no associations between eating alone or being bothered by eating alone and self-rated health were observed. Discussion: In this sample, eating alone was associated with loneliness but not lower self-rated health. The proportion of loneliness was high in groups that were bothered by eating alone, indicating specific subgroups for whom eating alone can be problematic. More research is needed to understand the issue of eating alone – and who it affects. This will allow effective policies to be developed and implemented among groups vulnerable to loneliness and poor health.

    Nationell ämneskategori
    Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi Övrig annan samhällsvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-543634 (URN)
    Tillgänglig från: 2024-11-22 Skapad: 2024-11-22 Senast uppdaterad: 2024-11-22
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  • Disputation: 2025-01-24 09:15 room A1:111a, Uppsala
    Swartling, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaci.
    Model-informed antibiotic dose individualisation in clinical practice2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Antibiotics are life-saving medications, and optimal dosing for each individual is critical to effective and safe treatment. Dose individualisation is needed when routine dosing results in concentrations that vary more than accepted between individuals from an efficacy or safety point of view. A tool for individualisation is model-informed precision dosing (MIPD), which uses software with integrated population pharmacokinetic (PK) models to interpret measured antibiotic concentrations and to optimise dosing.

    This thesis aimed to improve antibiotic treatment by evaluating pharmacokinetic/pharmacodynamic (PK/PD) target attainment for alternative dosing strategies, assessing PK variability between individuals, and developing processes for MIPD in clinical practice.

    One way to improve target attainment for beta-lactams without increasing the daily dose is to prolong the infusions. Different beta-lactam infusion durations were evaluated for adult intensive care patients. The predicted attainment of PK/PD targets recommended for critically ill was high for primary pathogen scenarios regardless of infusion strategy, indicating that short infusions (15 min) can be used. In situations when worst-case scenario pathogens are suspected, e.g., hospital-acquired infection, short infusions were insufficient, and 3h extended or continuous infusions improved target attainment. However, when evaluating the implemented routine use of extended infusions in critically ill, a large proportion of individuals was still below target. The large PK variability between individuals suggests a need for early monitoring to identify under and over-treated patients. In patients with sub-optimal exposure, MIPD can provide an added value.

    This thesis has brought MIPD closer to clinical implementation and the benefit of patients. Barriers to implementation were addressed, including an assessment of how documentation errors can impact dosing decisions based on concentration monitoring. For vancomycin, simulations indicate that target attainment evaluations are robust with respect to locally observed errors in dose administration time. For meropenem, the impact of errors was evident already at normal renal function and pronounced in augmented renal clearance. Extra measures to promote correct documentation are needed when monitoring beta-lactams like meropenem, particularly in intensive care. Further, a novel MIPD workflow and an implementation plan for vancomycin dosing were developed. This work defined a new role for physicians or pharmacists as MIPD consultants and new tasks for clinical pharmacists. The pragmatic development process can guide other institutions aiming to initiate MIPD, and the developed workflow provides an opportunity to expand MIPD to other treatments.

    Delarbeten
    1. Population pharmacokinetics of cefotaxime in intensive care patients
    Öppna denna publikation i ny flik eller fönster >>Population pharmacokinetics of cefotaxime in intensive care patients
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    2022 (Engelska)Ingår i: European Journal of Clinical Pharmacology, ISSN 0031-6970, E-ISSN 1432-1041, Vol. 78, nr 2, s. 251-258Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    PURPOSE: To characterise the pharmacokinetics and associated variability of cefotaxime in adult intensive care unit (ICU) patients and to assess the impact of patient covariates.

    METHODS: This work was based on data from cefotaxime-treated patients included in the ACCIS (Antibiotic Concentrations in Critical Ill ICU Patients in Sweden) study. Clinical data from 51 patients at seven different ICUs in Sweden, given cefotaxime (1000-3000 mg given 2-6 times daily), were collected from the first day of treatment for up to three consecutive days. In total, 263 cefotaxime samples were included in the population pharmacokinetic analysis.

    RESULTS: A two-compartment model with linear elimination, proportional residual error and inter-individual variability (IIV) on clearance and central volume of distribution best described the data. The typical individual was 64 years, with body weight at ICU admission of 92 kg and estimated creatinine clearance of 94 mL/min. The resulting typical value of clearance was 11.1 L/h, central volume of distribution 5.1 L, peripheral volume of distribution 18.2 L and inter-compartmental clearance 14.5 L/h. The estimated creatinine clearance proved to be a significant covariate on clearance (p < 0.001), reducing IIV from 68 to 49%.

    CONCLUSION: A population pharmacokinetic model was developed to describe cefotaxime pharmacokinetics and associated variability in adult ICU patients. The estimated creatinine clearance partly explained the IIV in cefotaxime clearance. However, the remaining unexplained IIV is high and suggests a need for dose individualisation using therapeutic drug monitoring where the developed model, after evaluation of predictive performance, may provide support.

    Nyckelord
    Cefotaxime, Critically ill, Modelling, Population pharmacokinetics
    Nationell ämneskategori
    Medicin och hälsovetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-459348 (URN)10.1007/s00228-021-03218-6 (DOI)000702582700001 ()34596726 (PubMedID)
    Forskningsfinansiär
    Vinnova, 2018-03340Stiftelsen Familjen Olinder-Nielsens fond för infektionsmedicinsk forskning
    Tillgänglig från: 2021-11-23 Skapad: 2021-11-23 Senast uppdaterad: 2024-11-19Bibliografiskt granskad
    2. Short, extended, and continuous infusion of β-lactams: predicted impact on target attainment and risk for toxicity in an ICU patient cohort
    Öppna denna publikation i ny flik eller fönster >>Short, extended, and continuous infusion of β-lactams: predicted impact on target attainment and risk for toxicity in an ICU patient cohort
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Infektionsmedicin
    Identifikatorer
    urn:nbn:se:uu:diva-543015 (URN)
    Tillgänglig från: 2024-11-18 Skapad: 2024-11-18 Senast uppdaterad: 2024-11-19
    3. First-dose target attainment with extended infusion regimens of piperacillin and meropenem
    Öppna denna publikation i ny flik eller fönster >>First-dose target attainment with extended infusion regimens of piperacillin and meropenem
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Infektionsmedicin
    Identifikatorer
    urn:nbn:se:uu:diva-543025 (URN)
    Tillgänglig från: 2024-11-18 Skapad: 2024-11-18 Senast uppdaterad: 2024-11-19
    4. Therapeutic drug monitoring of vancomycin and meropenem: Illustration of the impact of inaccurate information in dose administration time
    Öppna denna publikation i ny flik eller fönster >>Therapeutic drug monitoring of vancomycin and meropenem: Illustration of the impact of inaccurate information in dose administration time
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    2023 (Engelska)Ingår i: International Journal of Antimicrobial Agents, ISSN 0924-8579, E-ISSN 1872-7913, Vol. 63, nr 1, artikel-id 107032Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Objectives: To illustrate the impact of errors in documented dose administration time on therapeutic drug monitoring (TDM)-based target attainment evaluation for vancomycin and meropenem, and to explore the influence of drug and patient characteristics, and TDM sampling strategies.

    Methods: Bedside observations of errors in documented dose administration times were collected. Population pharmacokinetic simulations were performed for vancomycin and meropenem, evaluating different one- and two-sampling strategies for populations with estimated creatinine clearance (CLcr) of 30, 80 or 130 mL/min. The impact of errors was evaluated as the proportion of individuals incorrectly considered to have reached the target.

    Results: Of 143 observed dose administrations, 97% of doses were given within ±30 min of the documented time. For vancomycin, a +30 min error was predicted to result in a 0.1-3.9 percentage point increase of cases incorrectly evaluated as reaching area under the concentration-time curve during a 24-hour period (AUC24)/minimum inhibitory concentration (MIC) >400, with the largest increase for patients with augmented renal clearance and peak and trough sampling. For meropenem, a +30 min error resulted in a 1.3-6.4 and 0-20 percentage point increase of cases incorrectly evaluated as reaching 100% T>MIC, and 50% T>MIC, respectively. Overall, mid-dose and trough sampling was most favourable for both antibiotics.

    Conclusions: For vancomycin, simulations indicate that TDM-based target attainment evaluation is robust with respect to the observed errors in dose administration time of ±30 min; however, the errors had a potentially clinically important impact in patients with augmented renal clearance. For meropenem, extra measures to promote correct documentation are warranted when using TDM, as the impact of errors was evident even in patients with normal renal function.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2023
    Nyckelord
    Documentation, Meropenem, Model-informed precision dosing, Therapeutic drug monitoring, Vancomycin
    Nationell ämneskategori
    Samhällsfarmaci och klinisk farmaci
    Forskningsämne
    Farmakologi
    Identifikatorer
    urn:nbn:se:uu:diva-519941 (URN)10.1016/j.ijantimicag.2023.107032 (DOI)001151170700001 ()37956952 (PubMedID)
    Forskningsfinansiär
    Vinnova, 2018-03340Vinnova, 2021-02699Vetenskapsrådet, 2019-05911Vetenskapsrådet, 2020-02320
    Tillgänglig från: 2024-01-10 Skapad: 2024-01-10 Senast uppdaterad: 2024-11-19Bibliografiskt granskad
    5. Model-informed precision dosing of vancomycin in clinical practice: an intervention development study.
    Öppna denna publikation i ny flik eller fönster >>Model-informed precision dosing of vancomycin in clinical practice: an intervention development study.
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    2024 (Engelska)Ingår i: International Journal of Clinical Pharmacy, ISSN 2210-7703, E-ISSN 2210-7711Artikel i tidskrift (Refereegranskat) Epub ahead of print
    Abstract [en]

    BACKGROUND: Current guidelines recommend dosing vancomycin based on the area under the concentration time curve (AUC) to maximise efficacy and minimise the risk of nephrotoxicity. The preferred approach to AUC-guided therapy is to apply model-informed precision dosing (MIPD). However, the adoption in clinical practice has been slow.

    AIM: We aimed to develop an intervention, including a standardised MIPD workflow and an implementation plan for vancomycin AUC-guided dosing, in a Swedish tertiary hospital.

    METHOD: The intervention was developed in a framework-guided process. The design phase included stakeholder feedback (nurses, pharmacists, physicians), local data collection and feasibility testing of intervention components with parallel consideration of implementation aspects. The hypothesised relationships between the different components, implementation strategies and the mechanism of action resulting in expected outcomes were represented by a logic model.

    RESULTS: The final intervention consisted of a workflow for MIPD, with defined roles and responsibilities, as well as processes for data and information transfer. Details were provided in supportive documents; an instruction on therapeutic drug monitoring (TDM) sampling and documentation for nurses, and a detailed dosing software instruction for MIPD consultants and clinical pharmacists. Activities to facilitate implementation included the development of a local clinical routine for vancomycin dosing, staff training and recurring MIPD rounds.

    CONCLUSION: An intervention for MIPD, with an implementation plan for AUC-guided dosing of vancomycin, was developed for a tertiary hospital setting. The process can be used as guidance for other institutions with similar context wishing to initiate MIPD.

    Nyckelord
    Health plan implementation, Precision dosing, Precision medicine, Therapeutic drug monitoring, Vancomycin
    Nationell ämneskategori
    Samhällsfarmaci och klinisk farmaci
    Identifikatorer
    urn:nbn:se:uu:diva-543008 (URN)10.1007/s11096-024-01822-x (DOI)39514047 (PubMedID)
    Tillgänglig från: 2024-11-18 Skapad: 2024-11-18 Senast uppdaterad: 2024-11-19
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    UUThesis_Swartling,M-2024
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  • Disputation: 2025-01-24 09:15 Siegbahnsalen, Uppsala
    Chelebian, Eduard
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen Vi3.
    Representation Learning for Computational Pathology and Spatial Omics2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Artificial intelligence (AI) advancements have enhanced the analysis and interpretation of computational pathology. Through representation learning, deep learning models can automatically identify complex patterns and extract meaningful features from raw data, revealing subtle spatial relationships. Spatial omics, which captures spatially resolved molecular data, naturally aligns with these approaches, enabling a deeper examination of tissue architecture and cellular heterogeneity. However, early spatial omics methods often overlooked the morphological and spatial context inherent in tissues.

    The integration of spatial omics with imaging AI and representation learning provides a comprehensive view for understanding complex tissue environments, providing deeper insights into disease mechanisms and molecular landscapes. This thesis investigates how deep learning-derived representations from biological images can be utilized in the context of spatial omics and disease processes.

    Key contributions of this work include: (i) investigating the correlation between representations learned from models trained on hematoxylin-eosin (H&E)-stained images and underlying gene expression profiles; (ii) applying self-supervised learning to identify genetically relevant patterns across H&E and DAPI staining; and (iii) developing a framework that leverages self-supervised representations to refine cell-type assignments obtained from spatial transcriptomics deconvolution methods. As a culmination of this part of the thesis, this research introduces (iv) a conceptual framework for understanding representations within spatial omics and provides a survey of the current literature through this lens.

    The thesis further includes practical applications such as (v) developing a tool for annotation of whole-slide images (WSI) using self-supervised representations and (vi) exploring the use of weakly-supervised learning to identify early tumor-indicating morphological changes in benign prostate biopsies.

    Delarbeten
    1. Morphological Features Extracted by AI Associated with Spatial Transcriptomics in Prostate Cancer
    Öppna denna publikation i ny flik eller fönster >>Morphological Features Extracted by AI Associated with Spatial Transcriptomics in Prostate Cancer
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    2021 (Engelska)Ingår i: Cancers, ISSN 2072-6694, ISSN 2072-6694, Vol. 13, nr 19, artikel-id 4837Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Prostate cancer is a common cancer type in men, yet some of its traits are still under-explored. One reason for this is high molecular and morphological heterogeneity. The purpose of this study was to develop a method to gain new insights into the connection between morphological changes and underlying molecular patterns. We used artificial intelligence (AI) to analyze the morphology of seven hematoxylin and eosin (H & E)-stained prostatectomy slides from a patient with multi-focal prostate cancer. We also paired the slides with spatially resolved expression for thousands of genes obtained by a novel spatial transcriptomics (ST) technique. As both spaces are highly dimensional, we focused on dimensionality reduction before seeking associations between them. Consequently, we extracted morphological features from H & E images using an ensemble of pre-trained convolutional neural networks and proposed a workflow for dimensionality reduction. To summarize the ST data into genetic profiles, we used a previously proposed factor analysis. We found that the regions were automatically defined, outlined by unsupervised clustering, associated with independent manual annotations, in some cases, finding further relevant subdivisions. The morphological patterns were also correlated with molecular profiles and could predict the spatial variation of individual genes. This novel approach enables flexible unsupervised studies relating morphological and genetic heterogeneity using AI to be carried out.

    Ort, förlag, år, upplaga, sidor
    MDPIMDPI AG, 2021
    Nyckelord
    Cancer Research, Oncology
    Nationell ämneskategori
    Cancer och onkologi Medicinsk bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-458304 (URN)10.3390/cancers13194837 (DOI)000707769300001 ()34638322 (PubMedID)
    Forskningsfinansiär
    EU, Europeiska forskningsrådetStiftelsen för strategisk forskning (SSF)Cancerfonden
    Tillgänglig från: 2021-11-08 Skapad: 2021-11-08 Senast uppdaterad: 2024-11-18Bibliografiskt granskad
    2. Self-Supervised Learning for Genetically Relevant Domain Identification in Morphological Images
    Öppna denna publikation i ny flik eller fönster >>Self-Supervised Learning for Genetically Relevant Domain Identification in Morphological Images
    2024 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Nationell ämneskategori
    Datorseende och robotik (autonoma system) Medicinsk bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-542764 (URN)10.1109/isbi56570.2024.10635503 (DOI)
    Konferens
    2024 IEEE International Symposium on Biomedical Imaging (ISBI)
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2024-11-18
    3. Learned morphological features guide cell type assignment of deconvolved spatial transcriptomics
    Öppna denna publikation i ny flik eller fönster >>Learned morphological features guide cell type assignment of deconvolved spatial transcriptomics
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    2024 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Nationell ämneskategori
    Medicinsk bildbehandling Datorseende och robotik (autonoma system)
    Identifikatorer
    urn:nbn:se:uu:diva-542767 (URN)
    Konferens
    2024 Medical Imaging with Deep Learning (MIDL)
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2024-11-18
    4. What makes for good morphology representations for spatial omics?
    Öppna denna publikation i ny flik eller fönster >>What makes for good morphology representations for spatial omics?
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Datorseende och robotik (autonoma system) Medicinsk bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-542768 (URN)10.48550/arXiv.2407.20660 (DOI)
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2024-11-18
    5. DEPICTER: Deep representation clustering for histology annotation
    Öppna denna publikation i ny flik eller fönster >>DEPICTER: Deep representation clustering for histology annotation
    2024 (Engelska)Ingår i: Computers in Biology and Medicine, ISSN 0010-4825, E-ISSN 1879-0534, Vol. 170, artikel-id 108026Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Automatic segmentation of histopathology whole -slide images (WSI) usually involves supervised training of deep learning models with pixel -level labels to classify each pixel of the WSI into tissue regions such as benign or cancerous. However, fully supervised segmentation requires large-scale data manually annotated by experts, which can be expensive and time-consuming to obtain. Non -fully supervised methods, ranging from semi -supervised to unsupervised, have been proposed to address this issue and have been successful in WSI segmentation tasks. But these methods have mainly been focused on technical advancements in algorithmic performance rather than on the development of practical tools that could be used by pathologists or researchers in real -world scenarios. In contrast, we present DEPICTER (Deep rEPresentatIon ClusTERing), an interactive segmentation tool for histopathology annotation that produces a patch -wise dense segmentation map at WSI level. The interactive nature of DEPICTER leverages self- and semi -supervised learning approaches to allow the user to participate in the segmentation producing reliable results while reducing the workload. DEPICTER consists of three steps: first, a pretrained model is used to compute embeddings from image patches. Next, the user selects a number of benign and cancerous patches from the multi -resolution image. Finally, guided by the deep representations, label propagation is achieved using our novel seeded iterative clustering method or by directly interacting with the embedding space via feature space gating. We report both real-time interaction results with three pathologists and evaluate the performance on three public cancer classification dataset benchmarks through simulations. The code and demos of DEPICTER are publicly available at https://github.com/eduardchelebian/depicter.

    Ort, förlag, år, upplaga, sidor
    Elsevier, 2024
    Nyckelord
    Interactive annotation, Histology, Self-supervised learning, Clustering
    Nationell ämneskategori
    Datorseende och robotik (autonoma system) Datavetenskap (datalogi) Medicinsk bildbehandling
    Identifikatorer
    urn:nbn:se:uu:diva-528262 (URN)10.1016/j.compbiomed.2024.108026 (DOI)001179010100001 ()38308865 (PubMedID)
    Forskningsfinansiär
    EU, Europeiska forskningsrådet, CoG 682810
    Tillgänglig från: 2024-05-20 Skapad: 2024-05-20 Senast uppdaterad: 2024-11-18Bibliografiskt granskad
    6. Discovery of tumour indicating morphological changes in benign prostate biopsies through AI
    Öppna denna publikation i ny flik eller fönster >>Discovery of tumour indicating morphological changes in benign prostate biopsies through AI
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Medicinsk bildbehandling Datorseende och robotik (autonoma system)
    Identifikatorer
    urn:nbn:se:uu:diva-542769 (URN)10.1101/2024.06.18.24309064 (DOI)
    Tillgänglig från: 2024-11-13 Skapad: 2024-11-13 Senast uppdaterad: 2024-11-18
    Ladda ner fulltext (pdf)
    UUThesis_E-Chelebian-2024
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    preview image
  • Disputation: 2025-01-24 09:15 Å 10132 Häggsalen, Uppsala
    Chen, Heyin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Towards sustainable Ni-rich layered oxide cathodes: A synchrotron-based study2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Rechargeable Li-ion batteries (LIBs) are essential for portable electronic devices, electric vehicles and the development of large-scale energy storage for renewable sources. Among various cathode materials in LIBs, layered Ni-rich transition metal oxides are widely used due to their high energy density. Conventionally, the toxic N-methyl-2-pyrrolidone (NMP) solvent and fluorine-containing polyvinylidene fluoride (PVdF) binder are utilized during electrode manufacturing. However, it is desirable to replace NMP with an environmentally friendly solvent and also to aim for a fluorine-free binder. Thus, this thesis aims to develop the aqueous-processing methodology for LiNi0.8Mn0.1Co0.1O2 (NMC811) electrode production.

    This thesis identifies the formation of carboxylate species as a product of the irreversible reaction between the NMC811 surface and H2O vapor. Furthermore, results show that aqueous processing generates a reactive electrode surface, with subsequent electrolyte decomposition. In addition, a NiO-like rock-salt phase forms in the near-surface regions, most likely due to Li-ion leaching and Li/Ni disorder. Also, increased charge transfer resistance is observed, which likely correlate to the rock-salt phase. Building on insights into H2O’s effects on the NMC811 surface, two aqueous-processing methods for producing NMC811 electrodes are studied. To mitigate these challenges, firstly H3PO4 is added to the aqueous slurry, primarily to lower the pH and limit Al current collector corrosion. This modification to some extent stabilizes the reactive electrode surface and alleviates Li/Ni disorder, leading to improved capacity retention and enhanced reversibility of the phase transition. Secondly, with the aim to stabilize the NMC811 surface during aqueous processing, Ti is incorporated within the structure. This effectively hinders rock-salt phase formation and reduce the Li-ion transfer resistance. With inspiration from a reaction heterogeneity detected in the aqueous-processed NMC811 electrode, the study further investigates particle-scale Li-ion heterogeneity in the commercially aged LixNi0.9Co0.05Al0.05 secondary particles, suggesting a significant Li-ion heterogeneity within the particles cycled to a high state of charge.

    In conclusion, this thesis elucidates the degradation mechanisms of aqueous-processed NMC811 material and demonstrates the roles of material modifications in enhancing cycling performance, offering valuable insights into the manufacturing of sustainable batteries. Furthermore, it highlights the importance of employing X-ray-based techniques for in-depth studies of battery materials.

    Delarbeten
    1. Investigating Surface Reactivity of a Ni-Rich Cathode Material toward CO2, H2O, and O2 Using Ambient Pressure X-ray Photoelectron Spectroscopy
    Öppna denna publikation i ny flik eller fönster >>Investigating Surface Reactivity of a Ni-Rich Cathode Material toward CO2, H2O, and O2 Using Ambient Pressure X-ray Photoelectron Spectroscopy
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    2023 (Engelska)Ingår i: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 6, nr 22, s. 11458-11467Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Layered Ni-rich transition metal oxide materials are considered the most promising cathodes for use in commercial Li-ion batteries. Due to their instability in air, an impurity layer forms during storage under ambient conditions, and this layer increases electrochemical polarization during charging and discharging, which ultimately leads to a lower cycling capacity. In this work, we found that storage of the LiNi0.8Mn0.1Co0.1O2 (NMC 811) material in ultrahigh vacuum (UHV) can restore the surface by reducing the amount of native carbonate species in the impurity layer. In this work, in situ soft X-ray ambient pressure photoelectron spectroscopy is used to directly follow the interaction between common gases found in air and the NMC 811 surface. During gas exposure of the NMC 811 surface to pure CO2, O2, and a mixture of both pure gases, surface-adsorbed CO2 or/and O2 were detected; however, permanent changes could not be identified under UHV after the gas exposure. In contrast, a permanent increase in metal hydroxide species was observed on the sample surface following H2O vapor exposure, and an increased intensity in the carboxylate peak was observed after exposure to a mixture of CO2/O2/H2O. Thus, the irreversible degradation reaction with CO2 is triggered in the presence of H2O (on relevant time scales defined by the experiment). Additional measurements revealed that X-ray irradiation induces the formation of metal carbonate species on the NMC 811 surface under CO2 and H2O vapor pressure.

    Ort, förlag, år, upplaga, sidor
    American Chemical Society (ACS), 2023
    Nyckelord
    Ni-rich NMC materials, Li-ion batteries, gas exposure, ambient pressure PES, beam effect, surface degradation
    Nationell ämneskategori
    Annan elektroteknik och elektronik Materialkemi Annan materialteknik
    Forskningsämne
    Kemi med inriktning mot oorganisk kemi; Kemi; Materialvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-517422 (URN)10.1021/acsaem.3c01621 (DOI)001142942300001 ()
    Forskningsfinansiär
    Forskningsrådet Formas, 2019-02496Vetenskapsrådet, 2018-07152Vetenskapsrådet, 2020-04512Vetenskapsrådet, 2018-06465Energimyndigheten, 40495-1Energimyndigheten, 48678-1Vinnova, 2018-04969StandUp
    Tillgänglig från: 2023-12-07 Skapad: 2023-12-07 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
    2. Study of degradation mechanisms in aqueous-processed Ni-rich cathodes for enhanced sustainability of batteries
    Öppna denna publikation i ny flik eller fönster >>Study of degradation mechanisms in aqueous-processed Ni-rich cathodes for enhanced sustainability of batteries
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    2024 (Engelska)Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 12, nr 37, s. 25393-25406Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Traditionally, Ni-rich-layered oxide cathodes for lithium-ion batteries are produced utilizing N-methyl-2-pyrrolidone (NMP)-processed casting. However, to avoid using the reprotoxic solvent NMP, aqueous processing becomes one of the options. In this study, H2O-processed LiNi0.8Mn0.1Co0.1O2 (NMC811) electrodes have been prepared to compare with the NMP-processed counterparts to investigate the degradation mechanism. The thick cathode-electrolyte interphase (CEI), NiO-like phase formation, and the growth of electrochemically inactive NMC particles after long-term cycling lead to capacity decay. In addition, phosphoric acid (H3PO4) was utilized to lower the pH value during the water-processed electrode preparation, to avoid corrosion of the aluminium current collector. The use of H3PO4 enhanced the capacity retention of NMC811 electrodes, likely owing to the formation of a LiF-rich CEI layer in the initial cycle(s) and the alleviated formation of electrochemically inactive NMC particles. Additionally, reaction inhomogeneity is present in H3PO4-modified electrodes, which is attributed to various Li-ion reinsertion resistances throughout the porous electrode during long-term cycling. Although the performance of the water-processed NMC811 electrode is not reaching the level of NMP-processed electrodes, this study provides key insights into the involved degradation mechanisms and demonstrates a viable pathway for the development of sustainable battery manufacturing processes. A slightly thinner CEI layer and lower charge transfer resistance were achieved by H3OP4 modification during the water processing of Ni-rich cathodes, compared to non-treated counterparts.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2024
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:uu:diva-540056 (URN)10.1039/d4ta03592e (DOI)001301865300001 ()
    Forskningsfinansiär
    Energimyndigheten, 48678-1Energimyndigheten, P2020-90112Energimyndigheten, P2022-00055Vetenskapsrådet, 2021-04987StandUpEU, Horisont 2020, 875527Stiftelsen för strategisk forskning (SSF), GSn15-0008Vetenskapsrådet, 2018-07152Vinnova, 2018-04969Forskningsrådet Formas, 2019-02496VetenskapsrådetEU, Horisont 2020
    Tillgänglig från: 2024-10-11 Skapad: 2024-10-11 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
    3. Ti-induced surface stabilization for Enhanced capacity of Aqueous-Processed Ni-Rich Cathodes
    Öppna denna publikation i ny flik eller fönster >>Ti-induced surface stabilization for Enhanced capacity of Aqueous-Processed Ni-Rich Cathodes
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Naturvetenskap Materialkemi
    Identifikatorer
    urn:nbn:se:uu:diva-543365 (URN)
    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2024-11-20
    4. Surface Engineering of Aqueous-Processed Ni-Rich Cathodes for Enhanced Long-Term Capacity Retention
    Öppna denna publikation i ny flik eller fönster >>Surface Engineering of Aqueous-Processed Ni-Rich Cathodes for Enhanced Long-Term Capacity Retention
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:uu:diva-543381 (URN)
    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2024-11-20
    5. Revealing Secondary Particle Heterogeneity in Ni-rich NCA Secondary Particles in Electric Car Battery Material using nano-resolved Scanning X-ray Diffraction Microscopy
    Öppna denna publikation i ny flik eller fönster >>Revealing Secondary Particle Heterogeneity in Ni-rich NCA Secondary Particles in Electric Car Battery Material using nano-resolved Scanning X-ray Diffraction Microscopy
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Materialkemi
    Identifikatorer
    urn:nbn:se:uu:diva-514586 (URN)
    Tillgänglig från: 2023-10-18 Skapad: 2023-10-18 Senast uppdaterad: 2024-11-20
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    UUThesis_Chen,H-2024
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    presentationsbild
  • Disputation: 2025-01-24 09:15 Room 101121, Sonja Lyttkens, Uppsala
    Talebian Gevari, Moein
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för elektroteknik, Fasta tillståndets elektronik.
    Design and optimization of a microchip biosensor utilizing streaming current2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Biosensors are devices used for detecting biomolecules. They have wide applications including clinical diagnosis, drug discovery, fundamental biological investigation, and personalized medicine. This thesis introduces a novel biosensing platform leveraging streaming current for detecting small extracellular vesicles (sEVs) and single-stranded DNA (ss-DNA). First, fundamental electrokinetic theories are outlined to establish the relationship between streaming current and key parameters influencing the sensing performance. A silicon-based microfluidic device and a robust experimental setup are designed to enable multiplexed detection. The microchip achieves an improved limit of detection (LoD) of 1 × 104 sEVs/mL. Using this LoD, clinically relevant biomarkers for early-stage lung cancer are detected, demonstrating the platform’s diagnostic potential. Additionally, two novel labeling techniques are introduced to address sEV heterogeneity and amplify streaming current for improved detection sensitivity and specificity. The former uses secondary antibodies tagged with charged molecules to engineer surface charges and profile sEV surface proteins. Results demonstrate the capability of the microchips in multimarker profiling of sEVs. The latter uses an innovative nanoparticle-mediated sandwich assay to introduce new charges on the interface and amplify streaming current signal, enabling ss-DNA detection at picomolar concentrations. This method, benefiting from analyte size and charge, improves the LoD by four orders of magnitude over prior reports. Finally, the thesis advances toward a standalone EV analyzer by developing two modules. The first is a microfluidic system for sEV isolation and enrichment based on surface protein expression levels, pre-selecting and enriching sEVs before membrane protein profiling. The second is a picoammeter designed on a printed circuit board (PCB) to replace bulky and costly measurement units. Together, these innovations contribute to the creation of a highly sensitive and versatile biosensing platform.

    Delarbeten
    1. Multi-marker profiling of extracellular vesicles using streaming current and sequential electrostatic labeling
    Öppna denna publikation i ny flik eller fönster >>Multi-marker profiling of extracellular vesicles using streaming current and sequential electrostatic labeling
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    2023 (Engelska)Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 227, artikel-id 115142Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    High heterogeneity in the membrane protein expression of small extracellular vesicles (sEVs) means that bulk methods relying on antibody-based capture for expression analysis have a drawback that each type of antibody may capture a different sub-population. An improved approach is to capture a representative sEV population, without any bias, and then perform a multiplexed protein expression analysis on this population. However, such a possibility has been largely limited to fluorescence-based methods. Here, we present a novel electrostatic labelling strategy and a microchip-based all-electric method for membrane protein analysis of sEVs. The method allows us to profile multiple surface proteins on the captured sEVs using alternating charge labels. It also permits the comparison of expression levels in different sEV-subtypes. The proof of concept was tested by capturing sEVs both non-specifically (unbiased) as well as via anti-CD9 capture probes (biased), and then profiling the expression levels of various surface proteins using the charge labelled antibodies. The method is the first of its kind, demonstrating an all-electrical and microchip based method that allows for unbiased analysis of sEV membrane protein expression, comparison of expression levels in different sEV subsets, and fractional estimation of different sEV sub-populations. These results were also validated in parallel using a single-sEV fluorescence technique.

    Ort, förlag, år, upplaga, sidor
    ElsevierElsevier BV, 2023
    Nyckelord
    Biosensors, Extracellular vesicles, Streaming current, Electrostatic labels, Microfluidics
    Nationell ämneskategori
    Cell- och molekylärbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-500017 (URN)10.1016/j.bios.2023.115142 (DOI)000946918000001 ()36805937 (PubMedID)
    Forskningsfinansiär
    Vetenskapsrådet, 2016-05051Vetenskapsrådet, 2018-06228Cancerfonden, CAN 2018/597Cancerfonden, CAN 2021/1469
    Tillgänglig från: 2023-04-19 Skapad: 2023-04-19 Senast uppdaterad: 2024-11-21Bibliografiskt granskad
    2. Design and Optimization of a Silicon-Based Electrokinetic Microchip for Sensitive Detection of Small Extracellular Vesicles
    Öppna denna publikation i ny flik eller fönster >>Design and Optimization of a Silicon-Based Electrokinetic Microchip for Sensitive Detection of Small Extracellular Vesicles
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    2024 (Engelska)Ingår i: ACS Sensors, E-ISSN 2379-3694, Vol. 9, nr 6, s. 2935-2945Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Detection of analytes using streaming current has previously been explored using both experimental approaches and theoretical analyses of such data. However, further developments are needed for establishing a viable microchip that can be exploited to deliver a sensitive, robust, and scalable biosensor device. In this study, we demonstrated the fabrication of such a device on silicon wafer using a scalable silicon microfabrication technology followed by characterization and optimization of this sensor for detection of small extracellular vesicles (sEVs) with sizes in the range of 30 to 200 nm, as determined by nanoparticle tracking analyses. We showed that the sensitivity of the devices, assessed by a common protein–ligand pair and sEVs, significantly outperforms previous approaches using the same principle. Two versions of the microchips, denoted as enclosed and removable-top microchips, were developed and compared, aiming to discern the importance of high-pressure measurement versus easier and better surface preparation capacity. A custom-built chip manifold allowing easy interfacing with standard microfluidic connections was also constructed. By investigating different electrical, fluidic, morphological, and fluorescence measurements, we show that while the enclosed microchip with its robust glass-silicon bonding can withstand higher pressure and thus generate higher streaming current, the removable-top configuration offers several practical benefits, including easy surface preparation, uniform probe conjugation, and improvement in the limit of detection (LoD). We further compared two common surface functionalization strategies and showed that the developed microchip can achieve both high sensitivity for membrane protein profiling and low LoD for detection of sEV detection. At the optimum working condition, we demonstrated that the microchip could detect sEVs reaching an LoD of 104 sEVs/mL (when captured by membrane-sensing peptide (MSP) probes), which is among the lowest in the so far reported microchip-based methods.

    Ort, förlag, år, upplaga, sidor
    American Chemical Society (ACS), 2024
    Nyckelord
    microchip biosensor, extracellular vesicles, microfluidics, streaming current, electrokinetic effects
    Nationell ämneskategori
    Diagnostisk bioteknologi
    Identifikatorer
    urn:nbn:se:uu:diva-543571 (URN)10.1021/acssensors.4c00110 (DOI)001242705600001 ()38848141 (PubMedID)2-s2.0-85195801360 (Scopus ID)
    Forskningsfinansiär
    Vetenskapsrådet, 2016-05051Vetenskapsrådet, 2018-06228Familjen Erling-Perssons StiftelseCancerföreningen i Stockholm, 201202Cancerföreningen i Stockholm, 191293Cancerföreningen i Stockholm, 221212Cancerföreningen i Stockholm, 221383Cancerfonden, 21 1469 PjSjöbergstiftelsenStiftelsen för strategisk forskning (SSF), SIP21-0106Vetenskapsrådet, 2019-00207EU, Horisont 2020, 951768
    Tillgänglig från: 2024-11-21 Skapad: 2024-11-21 Senast uppdaterad: 2025-01-07Bibliografiskt granskad
    3. Single stranded DNA detection on chip utilizing streaming current–a novel approach for signal amplification
    Öppna denna publikation i ny flik eller fönster >>Single stranded DNA detection on chip utilizing streaming current–a novel approach for signal amplification
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Diagnostisk bioteknologi
    Identifikatorer
    urn:nbn:se:uu:diva-543572 (URN)
    Tillgänglig från: 2024-11-21 Skapad: 2024-11-21 Senast uppdaterad: 2024-11-21
    4. Flow-mediated extracellular vesicles selective capture based on their surface protein expression
    Öppna denna publikation i ny flik eller fönster >>Flow-mediated extracellular vesicles selective capture based on their surface protein expression
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Diagnostisk bioteknologi
    Identifikatorer
    urn:nbn:se:uu:diva-543574 (URN)
    Tillgänglig från: 2024-11-21 Skapad: 2024-11-21 Senast uppdaterad: 2024-11-22
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    UUThesis_Talebian,M-2024
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  • Disputation: 2025-01-24 09:25 Polhemsalen, Uppsala
    Hartwig-Nair, Marie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Tillämpad mekanik.
    Structure and hygroelastic properties of conifer branch wood: A multiscale approach2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Studies of  structure-property relationship of compression (CW) and opposite wood (OW) formed in conifer branches are rare, mostly due to their lack of application in construction. Instead most branch wood is today being used as fuel. However, utilising branches as material can contribute to a more efficient and sustainable use of forest biomass and reduce the demand of stem wood for engineered wood products. Furthermore, deeper insight in compression and opposite wood might inspire toward new engineering solutions by using principles prevalent in the tree branch.

    This thesis investigates hygroelastic properties of compression and opposite wood in branches by modelling and experimental techniques at several hierarchical material levels.

    First, mechanical optimisation of tree branches for bending by using compression and opposite wood in a beam model is analysed. One weakness of the analytical model is the lack of elastic properties of compression and opposite wood of branches. Hence, hygroelastic properties for these are determined by mechanical testing and micro-computed tomography.

    Following that, swelling behaviour of CW and OW lignin is studied by Molecular Dynamics (MD) simulations and wide-angle X-ray scattering to understand the effect of their chemically distinct structure.

    Lastly, a hierarchical multiscale model is established to study the effect of previously determined lignin swelling coefficient, as well as lignin content and microfibril angle on swelling properties of cell walls. Swelling coefficients and elastic properties obtained by MD simulations are used as an input for Finite Element modelling.

    The branches composition of compression wood and a opposite wood indicates that it is optimised for bending resistance. The hygroelastic properties of the comprising tissues are obtained. The swelling of CW is much less anisotropic than CW. The structural differences in lignin of compression and opposite wood and their resulting different swelling coefficient do not lead to different swelling of the compression and opposite wood cell walls.

    The experimental and modelling approaches in this thesis are not specific to branch wood and can be of interest in wood science in general to gain more insight into the effect of structural changes on moisture-wood interaction and hygroelastic properties.

    Delarbeten
    1. Softwood branches modelled as a composite beam of compression and opposite wood: investigation of bending resistance
    Öppna denna publikation i ny flik eller fönster >>Softwood branches modelled as a composite beam of compression and opposite wood: investigation of bending resistance
    2024 (Engelska)Ingår i: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 19, nr 4, s. 979-986Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Wood branches subjected to bending develop reaction wood to accommodate both tensile and compressive stresses. For softwood, such as Norway spruce and Scots pine, compression wood (CW) develops in the lower parts, while opposite wood (OW) develops on the upper parts of the branch. It is likely that the ratio of CW to OW is optimised for mechanical load bearing by nature. This hypothesis was tested with an analytical beam model using experimental data of stiffness and strength of CW and OW at CW fractions from 0 to 100%. It was found that there is indeed a maximum bending moment capacity around 35% CW, like literature values of CW content in softwood branches. For all compositions, compressive or tensile strength of OW was governing the behaviour.

    Ort, förlag, år, upplaga, sidor
    Taylor & Francis, 2024
    Nyckelord
    Analytical beam model, Euler-Bernoulli beam, branch wood, bending moment capacity
    Nationell ämneskategori
    Kompositmaterial och -teknik Trävetenskap Annan maskinteknik
    Identifikatorer
    urn:nbn:se:uu:diva-541370 (URN)10.1080/17480272.2024.2365784 (DOI)001249814800001 ()
    Tillgänglig från: 2024-11-05 Skapad: 2024-11-05 Senast uppdaterad: 2024-11-22Bibliografiskt granskad
    2. Characterisation of hygroelastic properties of compression and opposite wood found in branches of Norway spruce
    Öppna denna publikation i ny flik eller fönster >>Characterisation of hygroelastic properties of compression and opposite wood found in branches of Norway spruce
    2024 (Engelska)Ingår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 58, nr 3, s. 887-906Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The differential swelling seen between softwood opposite wood (OW) and its neighbouring compression wood (CW) developed in branches prompts several engineering issues such as dimensional instability and cracking. For a more efficient use of resources, the inevitable CW and OW should not be discarded or used as fuel, but incorporated into engineered wood products. Swelling is a hygroelastic phenomenon, where both the swelling and elastic properties of CW and OW are needed in order to make proper structural predictions. In this paper, swelling coefficients and moisture dependent elastic moduli for both CW and OW in the three principal material directions are provided along with measurements of moisture content, density, and microfibril angle. The small deformations necessitate the use of precise X-ray micro-computed tomography for measurements. The results indicate that CW and OW from Norway spruce branches differ in swelling, especially in longitudinal direction at low moisture content. It is noted that CW is a wood type with less pronounced anisotropic behaviour than both OW and normal wood from the stem, with the elastic moduli less sensitive to moisture changes in both longitudinal and transverse directions.

    Ort, förlag, år, upplaga, sidor
    Springer, 2024
    Nationell ämneskategori
    Trävetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-534088 (URN)10.1007/s00226-024-01548-z (DOI)001248076900017 ()
    Forskningsfinansiär
    Vetenskapsrådet
    Tillgänglig från: 2024-07-02 Skapad: 2024-07-02 Senast uppdaterad: 2024-11-22Bibliografiskt granskad
    3. Lignin Hygroexpansion in Compression and Opposite Wood: a Molecular Dynamics study
    Öppna denna publikation i ny flik eller fönster >>Lignin Hygroexpansion in Compression and Opposite Wood: a Molecular Dynamics study
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    2025 (Engelska)Ingår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 59, artikel-id 21Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Softwood branches develop compression wood (CW) in the lower parts of thebranch, while opposite wood (OW) develops on the upper. These wood typesdiffer in structure at several length scales, among others in the chemical composition of their lignin matrix. While OW mostly contains guaiacyl (G) units, CW is known to contain a substantial fraction of 4-hydroxyphenyl (H) lignin.In this study, the impact this difference has on lignin hygroexpansion and inter-action with water is studied by the means of atomistic models and moleculardynamics computer simulations of lignin systems at different levels of hydration. It was found that, despite the minor difference in chemical composition, thereare differences in swelling, structure and water dynamics. CW lignin is found tohave a higher uniaxial swelling coefficient, since the phase separation between lignin and water is more pronounced. This behavior is linked to structural differ-ences, where intermolecular π−π stacking is more common in CW lignin andhydrogen bonding to water more pronounced in OW lignin. These findings are of interest for understanding the role of lignin in CW, and general understanding of moisture interaction with lignin inside wood cell walls.

    Ort, förlag, år, upplaga, sidor
    Springer Nature, 2025
    Nyckelord
    lignin, molecular modelling, hygroexpansion, swelling coefficient
    Nationell ämneskategori
    Pappers-, massa- och fiberteknik Trävetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-543257 (URN)10.1007/s00226-024-01624-4 (DOI)001381405200002 ()
    Forskningsfinansiär
    Uppsala universitet
    Anmärkning

    De två första författarna delar förstaförfattarskapet.

    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2025-01-13Bibliografiskt granskad
    4. Structural analysis of compression and opposite wood lignin by X-ray scattering and molecular dynamics simulations
    Öppna denna publikation i ny flik eller fönster >>Structural analysis of compression and opposite wood lignin by X-ray scattering and molecular dynamics simulations
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Trävetenskap Pappers-, massa- och fiberteknik
    Identifikatorer
    urn:nbn:se:uu:diva-543253 (URN)
    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
    5. Modelling Hygroexpansion of Compression and Opposite Wood of Conifer Branches: Bridging the Gap between Molecular and Cell Wall Level
    Öppna denna publikation i ny flik eller fönster >>Modelling Hygroexpansion of Compression and Opposite Wood of Conifer Branches: Bridging the Gap between Molecular and Cell Wall Level
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The use of branch wood as a raw material in refined wood products has been limited. Compared with normal wood, this is due to the difference in structure from the tissue to molecular level, especially for compression wood found in conifers, resulting in different material behavior. To provide more insight into the underlying reasons for the difference in moisture induced swelling of compression and opposite wood, a simplified finite element model of the predominant S2 layer has been used to estimate the cell wall swelling based on previous and more recent findings of the composition and properties of the cell wall bio-polymers. Parametric investigations were carried out to determine the overall cell wall swelling of the three-phase composite, composed of cellulose, hemicellulose and lignin. Within reasonable bounds, it was found that the microfibril angle plays a significantly larger role in the swelling behavior of opposite and compression wood, than the relative composition of the cell wall bio-polymers and the hygroexpansion coefficient of lignin, of which the latter is known to be chemically different between compression and opposite wood.

    Nyckelord
    Finite Element Method, Molecular Dynamics, Hierarchical, Multi-scale
    Nationell ämneskategori
    Trävetenskap Kompositmaterial och -teknik Pappers-, massa- och fiberteknik
    Identifikatorer
    urn:nbn:se:uu:diva-543258 (URN)
    Tillgänglig från: 2024-11-20 Skapad: 2024-11-20 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
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    UUThesis_M-Hartwig-Nair-2024
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  • Disputation: 2025-01-24 10:15 Brusewitzsalen, Uppsala
    Umuhoza, Naomi
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Juridiska fakulteten, Juridiska institutionen.
    The Application of the Principle of the Best Interests of the Child in Custody Determination in Rwanda2024Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    This thesis analyses the application of the principle of the child’s best interests in custody determination in Rwanda. Rwanda is undergoing different economic and social transformation stages. Divorce is at its peak at the moment and increasing. Policies and legislation designed to keep the sanctity of the marriage and family are in place but they have not been able to halt divorce. Divorce leads to the question of child custody. Rwandan law majorly provides for sole physical custody while the other parent retains visitation rights. Child custody invites the children’s rights and in particular the consideration of the best interests of the child in all matters concerning them. Thus, child custody as a matter concerning children requires that the decision-maker in a custody dispute considers their best interests in choosing a custodian and other custodial related decisions. The study conducts a comprehensive normative and institutional review to analyse the foundation of the application of the best interests. Empirical research is also done through case law analysis and face-to face interviews with the judges with an aim of acquiring insights of practical application of the best interests of the child in custody determination. Apparently, child custody determination happens in the divorce process, which divorce is only granted after proving the ground or fault as provided for in the Family Act. Divorce can be denied if the fault is not proven. The parents (parties) or even the court do not engage in the discussion on the best interests of the child before they are sure divorce will be granted. At the time of pronouncement of divorce, custody is also decided, at which point the best interests has not been assessed or considered. Thus, whereas the consideration of the best interests of the child has a firm basis in Rwanda’s legislation and policies, the procedure to effect it in custody proceedings is absent. As a result, its application remains questionable.

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    UUThesis_N-Umuhoza-2024
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  • Disputation: 2025-01-24 13:15 Lecture hall 2, Uppsala
    Castañeda Garza, Diego
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Samhällsvetenskapliga fakulteten, Ekonomisk-historiska institutionen.
    Wealth, War and Modernization: Essays on Mexican Economic History2024Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [sv]

    Denna avhandling undersöker det komplicerade förhållandet mellan krig, välståndsackumulering och ekonomisk modernisering i Mexiko från självständigheten 1810 till mitten av 1900-talet. Den utmanar uppfattningen om det mexikanska 1800-talet som ett "censurerat århundrade", okänt på grund av brist på data, genom att använda en ny databas med testamenten för att rekonstruera trender i förmögenhetsojämlikhet. I sin tur kan dessa uppskattningar användas för att belysa den föränderliga politisk-ekonomiska dynamiken. Studien avslöjar konsekvent höga nivåer av förmögenhetsojämlikhet, med variationer som drivs av politiska och ekonomiska krafter.

    Ojämlikhet, krig och ekonomisk modernisering hänger oupplösligt samman. Tidigare forskning har sett krig som en stor utjämnare. Krig i 1800-talets Mexiko minskade dock inte ojämlikheten på ett enhetligt sätt. Vissa konflikter, som Självständighetskriget, förstörde välstånd, medan andra, som konflikterna under Första republiken, möjliggjorde elitens extraktion och välståndsackumulering. Utvecklingen av ojämlikhet klargör den politisk-ekonomiska dynamik som formade den mexikanska statens bildande och dess ackumulering av statskapacitet. Konstant krigföring blev ett hinder för strukturomvandlingen av landets ekonomi.

    I motsats till vad man skulle kunna tro stärktes den mexikanska staten av att förlora territorium till USA efter det Mexikansk-amerikanska kriget 1848. Den mindre och mer lätthanterliga gräns som blev resultatet förbättrade säkerheten och kontrollen över territoriet. Det underlättade demografiska förändringar som skulle leda till större statskapacitet. Konsolideringen och stärkandet av staten efter nästan 60 år av krigföring ledde till en modernisering av ekonomin under Porfiriatet (1877-1910). I slutet av 1800-talet inleddes industrialiseringen i ett sammanhang där ekonomiska eliter tog över staten och konsoliderade kontrollen över naturresurser, banker och infrastruktur.

    Den mexikanska revolutionen (1910-1940), en reaktion mot den porfirianska eliten, medförde betydande förändringar, men dess påverkan på ojämlikheten var blandad. De första reformerna ledde till minskad inkomstojämlikhet, men den efterföljande industrialiseringspolitiken, särskilt importsubstitutionsindustrialiseringen (ISI), bidrog till att öka den igen. Trots att ISI främjade ekonomisk tillväxt skapade den en "mesokratisk fördelning" som gynnade en växande medelklass samtidigt som ojämlikheten mellan stad och landsbygd förvärrades.

    Denna avhandling betonar den avgörande roll som politiska beslut och institutioner spelar för ojämlikhet och visar att ekonomiska krafter inte ensamma avgör resursfördelningen. Genom att analysera vinnare och förlorare under olika historiska perioder ger avhandlingen insikter i den komplexa dynamiken bakom ojämlikhet i ett utvecklingsland och ger lärdomar för dagens politiska beslutsfattande för att uppnå en rättvis och hållbar utveckling.

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  • Disputation: 2025-01-24 13:30 Ekmansalen, Uppsala
    Zhou, Qiujie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Drivers and Components of Genetic Diversity in Boreal Forest Trees: The Role of Hybridization and Gene Copy Number Variation in the Evolution of Norway and Siberian Spruce2024Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The genetic diversity that underpins biodiversity is shaped by a combination of evolutionary forces, including mutation, migration, genetic drift, and natural selection. The advent of sequencing technologies has enabled genetic studies to be scaled up, both in terms of the number of individuals and the number and types of genetic markers considered. In particular it has shown that structural variation captures more genetic diversity than single nucleotide polymorphisms. Extensive population genomics studies across species ranges have also revealed much more permissive boundaries between species than previously thought. A comprehensive understanding of the origins of genetic diversity and the factors that shape it would therefore require large-scale studies spanning a range of biological levels and scales, from individual genomes to whole populations, and from point mutations to large structural variations. We have addressed these questions in the case of Norway spruce (Picea abies) and Siberian spruce (Picea obovata), two boreal forest tree species with continental ranges.

    In Paper I, we used genome-wide SNPs to show that extensive gene flow exists between Norway spruce and Siberian spruce, and we used coalescent simulations to reveal the occurrence of repeated hybridization events between the two species across glacial cycles. These events had a profound impact on the evolutionary trajectories of both species, and a large hybrid zone now extends from northwestern Europe to the southern Urals. Paper II is an eco-evolutionary study in which we demonstrated the role of hybridization in expanding both the species' ecological niche breadth and their resilience to climate change. In Paper III, we investigated patterns of adaptation at two different geographical scales (a latitudinal cline across Sweden and a longitudinal cline across both species' ranges), focusing on the role of gene copy number variations (gCNVs). We showed that a significant proportion of genes have copy number variations and that they are distributed across the genome. These gCNVs are associated with responses to abiotic and biotic stresses, including drought tolerance, temperature regulation and immune responses. Genotype-environment association also revealed that gCNVs play an important role in adaptation along environmental gradients, probably because of the quantitative response they allow. Importantly, we did not detect these candidate genes with conventional methods using SNP data. This work on gCNVs was made possible by the development of a comprehensive framework for detecting CNVs from single nucleotide polymorphism (SNP) data, presented in Paper IV. Paper V further extends the method under a composite likelihood ratio framework to be used with whole genome resequencing data.

    Delarbeten
    1. Recurrent hybridization and gene flow shaped Norway and Siberian spruce evolutionary history over multiple glacial cycles
    Öppna denna publikation i ny flik eller fönster >>Recurrent hybridization and gene flow shaped Norway and Siberian spruce evolutionary history over multiple glacial cycles
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    2024 (Engelska)Ingår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 33, nr 17, artikel-id e17495Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Most tree species underwent cycles of contraction and expansion during the Quaternary. These cycles led to an ancient and complex genetic structure that has since been affected by extensive gene flow and by strong local adaptation. The extent to which hybridization played a role in this multi-layered genetic structure is important to be investigated. To study the effect of hybridization on the joint population genetic structure of two dominant species of the Eurasian boreal forest, Picea abies and P. obovata, we used targeted resequencing and obtained around 480 K nuclear SNPs and 87 chloroplast SNPs in 542 individuals sampled across most of their distribution ranges. Despite extensive gene flow and a clear pattern of Isolation-by-Distance, distinct genetic clusters emerged, indicating the presence of barriers and corridors to migration. Two cryptic refugia located in the large hybrid zone between the two species played a critical role in shaping their current distributions. The two species repeatedly hybridized during the Pleistocene and the direction of introgression depended on latitude. Our study suggests that hybridization helped both species to overcome main shifts in their distribution ranges during glacial cycles and highlights the importance of considering whole species complex instead of separate entities to retrieve complex demographic histories.

    Ort, förlag, år, upplaga, sidor
    John Wiley & Sons, 2024
    Nyckelord
    conifers, demographic inference, Eurasia, glacial cycles, recurrent hybridization
    Nationell ämneskategori
    Evolutionsbiologi Genetik
    Identifikatorer
    urn:nbn:se:uu:diva-541970 (URN)10.1111/mec.17495 (DOI)001291190100001 ()39148357 (PubMedID)
    Forskningsfinansiär
    Svenska Växtgeografiska SällskapetStiftelsen Akademiens Nilsson-Ehle medalj, 43255
    Tillgänglig från: 2024-11-06 Skapad: 2024-11-06 Senast uppdaterad: 2024-11-19Bibliografiskt granskad
    2. Hybridization mediated range expansion and climate change resilience in two keystone tree species of boreal forests
    Öppna denna publikation i ny flik eller fönster >>Hybridization mediated range expansion and climate change resilience in two keystone tree species of boreal forests
    2024 (Engelska)Ingår i: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 30, nr 4, artikel-id e17262Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Current global climate change is expected to affect biodiversity negatively at all scales leading to mass biodiversity loss. Many studies have shown that the distribution of allele frequencies across a species' range is often influenced by specific genetic loci associated with local environmental variables. This association reflects local adaptation and allele changes at those loci could thereby contribute to the evolutionary response to climate change. However, predicting how species will adapt to climate change from this type of data alone remains challenging. In the present study, we combined exome capture sequences and environmental niche reconstruction, to test multiple methods for assessing local adaptation and climate resilience in two widely distributed conifers, Norway spruce and Siberian spruce. Both species are keystone species of the boreal forest and share a vast hybrid zone. We show that local adaptation in conifers can be detected through allele frequency variation, population-level ecological preferences, and historical niche movement. Moreover, we integrated genetic and ecological information into genetic offset predictive models to show that hybridization plays a central role in expanding the niche breadth of the two conifer species and may help both species to cope better with future changing climates. This joint genetic and ecological analysis also identified spruce populations that are at risk under current climate change. Cycles of glaciation have induced phases of species expansion and contraction, occasionally occurring at continental scales. Our study, employing both ecological and genetic approaches, indicates that hybridization between Norway and Siberian spruce aided both species in adapting to climate change.

    Ort, förlag, år, upplaga, sidor
    John Wiley & Sons, 2024
    Nyckelord
    climate change, eco-evolution, forest trees, hybridization, landscape genomics, macrogenetics
    Nationell ämneskategori
    Ekologi Skogsvetenskap Klimatforskning
    Identifikatorer
    urn:nbn:se:uu:diva-526193 (URN)10.1111/gcb.17262 (DOI)001192377700001 ()38546370 (PubMedID)
    Forskningsfinansiär
    Swedish National Infrastructure for Computing (SNIC), 2021/6-313Swedish National Infrastructure for Computing (SNIC), 2021/5-540Stiftelsen Akademiens Nilsson-Ehle medalj, 43255Kungliga Fysiografiska Sällskapet i Lund, 42191Svenska Växtgeografiska Sällskapet
    Tillgänglig från: 2024-04-05 Skapad: 2024-04-05 Senast uppdaterad: 2024-11-19Bibliografiskt granskad
    3. Gene copy number variations are untaped key players in adaptation along environmental gradient
    Öppna denna publikation i ny flik eller fönster >>Gene copy number variations are untaped key players in adaptation along environmental gradient
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Gene copy number variations (gCNVs) are structural genomic alterations involving duplications or deletions that influence gene dosage and represent a significant source of genetic variation. While single nucleotide polymorphisms (SNPs) have constituted the primary focus of population genomics, recent studies indicate that gCNVs play an equally pivotal role in adaptation. In this study, we examine the contribution of gCNVs to local adaptation along environmental gradients in Norway spruce (Picea abies) and Siberian spruce (Picea obovata), utilizing comprehensive genomic datasets derived from exome capture sequencing. A robust pipeline for the detection and quantifying of gCNVs from short-read data is developed, employing haploid samples for validation purposes. The results of our analysis demonstrate that gCNVs are pervasive, representing approximately 12% of targeted genes, with enrichment of functional genes, particularly associated with environmental stress, such as temperature tolerance, immune response, and metal ion regulation. Furthermore, they exhibit a correlation with the population structure identified through the analysis of SNPs, while also displaying distinctive adaptive signatures. Genome scans and genotype-environment association (GEA) analyses demonstrate that gCNVs contribute disproportionately to local adaptation in comparison to SNPs. These findings emphasize the multiallelic and quantitative nature of gCNVs as a crucial factor in adaptive evolution. By integrating SNPs and gCNVs, we demonstrate that gCNVs are capable of capturing patterns of selection that are not evident when using SNPs alone. This highlights the necessity of incorporating structural variation into evolutionary genomics. This study demonstrates the feasibility and importance of studying gCNVs in non-model species and provides a framework for their integration into population and quantitative genomics.

    Nyckelord
    Gene copy number variation, local adaptation, Norway spruce, Siberian spruce, GEA.
    Nationell ämneskategori
    Genetik Evolutionsbiologi
    Identifikatorer
    urn:nbn:se:uu:diva-543179 (URN)
    Tillgänglig från: 2024-11-19 Skapad: 2024-11-19 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
    4. A comprehensive framework for detecting copy number variants from single nucleotide polymorphism data: ‘rCNV’, a versatile r package for paralogue and CNV detection
    Öppna denna publikation i ny flik eller fönster >>A comprehensive framework for detecting copy number variants from single nucleotide polymorphism data: ‘rCNV’, a versatile r package for paralogue and CNV detection
    2023 (Engelska)Ingår i: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 23, nr 8, s. 1772-1789Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Recent studies have highlighted the significant role of copy number variants (CNVs) in phenotypic diversity, environmental adaptation and species divergence across eukaryotes. The presence of CNVs also has the potential to introduce genotyping biases, which can pose challenges to accurate population and quantitative genetic analyses. However, detecting CNVs in genomes, particularly in non-model organisms, presents a formidable challenge. To address this issue, we have developed a statistical framework and an accompanying r software package that leverage allelic-read depth from single nucleotide polymorphism (SNP) data for accurate CNV detection. Our framework capitalises on two key principles. First, it exploits the distribution of allelic-read depth ratios in heterozygotes for individual SNPs by comparing it against an expected distribution based on binomial sampling. Second, it identifies SNPs exhibiting an apparent excess of heterozygotes under Hardy–Weinberg equilibrium. By employing multiple statistical tests, our method not only enhances sensitivity to sampling effects but also effectively addresses reference biases, resulting in optimised SNP classification. Our framework is compatible with various NGS technologies (e.g. RADseq, Exome-capture). This versatility enables CNV calling from genomes of diverse complexities. To streamline the analysis process, we have implemented our framework in the user-friendly r package ‘rCNV’, which automates the entire workflow seamlessly. We trained our models using simulated data and validated their performance on four datasets derived from different sequencing technologies, including RADseq (Chinook salmon—Oncorhynchus tshawytscha), Rapture (American lobster—Homarus americanus), Exome-capture (Norway spruce—Picea abies) and WGS (Malaria mosquito—Anopheles gambiae).

    Ort, förlag, år, upplaga, sidor
    John Wiley & Sons, 2023
    Nationell ämneskategori
    Evolutionsbiologi Genetik Bioinformatik och systembiologi
    Identifikatorer
    urn:nbn:se:uu:diva-516987 (URN)10.1111/1755-0998.13843 (DOI)001038240700001 ()
    Tillgänglig från: 2023-12-01 Skapad: 2023-12-01 Senast uppdaterad: 2024-11-19Bibliografiskt granskad
    5. rCNV2: A composite-likelihood ratio method for robust detection of CNVs from SNPs data
    Öppna denna publikation i ny flik eller fönster >>rCNV2: A composite-likelihood ratio method for robust detection of CNVs from SNPs data
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Copy number variations (CNVs) have been revealed prevalent in natural populations. CNVs show significant potential to contribute to phenotypic variation and local adaptation, but can introduce bias in single nucleotide polymorphism (SNP)-based analyses if not properly accounted for. However, the limitations of using existing next-generation sequencing (NGS) data to identify CNVs hinder exploring the evolutionary significance of CNVs in population and quantitative genomic studies. Traditional CNV detection methods often rely on single features such as coverage depth, making them prone to false positives due to confounding factors. In this study, we present a flexible composite likelihood ratio (CLR) method that integrates multiple signatures, including depth of coverage, allele depth ratio deviations, and excess of observed heterozygosity, to improve the accuracy of CNV detection from SNP data. Our approach enables both SNP- and window-based CNV detection at the individual and population level, and is designed to be versatile across sequencing technologies, including whole-genome and exome capture data. Simulations and validation on real-world datasets demonstrated improved sensitivity and accuracy of CNV detection. This approach will be implemented in the rCNV R package, which we are benchmarking against established CNV detection tools across different datasets. 

    Nyckelord
    Copy number variation, Composite likelihood ratio, Next-generation sequencing
    Nationell ämneskategori
    Bioinformatik (beräkningsbiologi) Bioinformatik och systembiologi
    Forskningsämne
    Bioinformatik
    Identifikatorer
    urn:nbn:se:uu:diva-543161 (URN)
    Tillgänglig från: 2024-11-19 Skapad: 2024-11-19 Senast uppdaterad: 2024-11-20Bibliografiskt granskad
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  • Disputation: 2025-01-29 09:15 Sal IX, Uppsala
    Muli, Irene
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kvinnors och barns hälsa, E-hälsa och hälsodata.
    eHealth: An Exploration of Adoption and Implementation in Swedish Primary Care from Patients’ and Healthcare Professionals’ Perspectives2025Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The World Health Organization (WHO) resolution on eHealth, adopted in 2005, served as a catalyst for global eHealth development. eHealth refers to the use of Information and Communication Technology  (ICT) to support health. In line with this, Sweden, in its current strategy, aims to become a world leader in eHealth by 2025. While Sweden is arguably at the forefront of digitalisation, the use and optimism of eHealth services among citizens remains low.

    This research aimed to describe how Swedish primary care patients have adopted two eHealth services and to deepen our understanding of the influence of implementation on this process. The two eHealth services were: 1) video consultations (VCs) through the Alltid Öppet application and 2) the Swedish Patient Accessible Electronic Health Record (PAEHR) 1177 Journal.

    Six Studies were conducted. Studies I-IV, investigating patients’ adoption of VCs and PAEHR, using a quantitative approach, a cross-sectional design, surveying primary care patients. Descriptive and comparative analyses, as well as logistic regressions, were conducted. Studies V and VI, investigating the implementation of VCs and PAEHR, used a qualitative approach, collecting data using individual and focus group interviews.

    The studies found inequalities in eHealth adoption, which may worsen in the future. Patients' older age, negative perceptions, and low digital and information literacy were among the identified adoption barriers. Additionally, the low usability of eHealth services further discourages use. Healthcare professionals (HCPs) facilitate patients’ adoption, but they may also contribute to the digital divide. A lack of comprehensive implementation strategies, particularly for patients, is a major barrier to adoption, and infrastructure issues exclude certain populations. Lastly, the COVID-19 pandemic accelerated eHealth implementation and adoption, but it also contributed to the challenges with the need for a rushed and unprepared implementation.

    In conclusion, this research underscores the urgent need to address these barriers and reshape the development of eHealth to mitigate growing health disparities. Patients should be better supported and their literacy levels improved. HCPs should also be provided with comprehensive training and ongoing support.  Developers must ensure high-quality eHealth services, implementers should adopt more comprehensive strategies, and policymakers must enhance the current infrastructure. Future research should not only delve deeper into these issues but also identify effective strategies to remove barriers and promote widespread adoption.

    Delarbeten
    1. To connect or not connect: long-term adoption of video consultations, and reasons for discontinuing use
    Öppna denna publikation i ny flik eller fönster >>To connect or not connect: long-term adoption of video consultations, and reasons for discontinuing use
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    2023 (Engelska)Ingår i: Journal of Telemedicine and Telecare, ISSN 1357-633X, E-ISSN 1758-1109Artikel i tidskrift (Refereegranskat) Epub ahead of print
    Abstract [en]

    IntroductionThis study investigates factors related to long-term and short-term adoption of video consultations (VCs) and reasons for discontinuing use among primary care patients.MethodsA sample of primary care patients using VCs with healthcare providers were invited to take a survey in a cross-sectional study. Participants were asked about their intention to continue to have video consultations in the future, and those indicating no intention to use VCs in the future (short-term adopters) were asked about their reasons for this. Prevalence and statistical differences between long-term and short-term adopters were investigated.ResultsThere were several statistically significant differences between long-term and short-term adopters (76% vs. 24%). Long-term adopters consisted of more middle-aged individuals (35?54 years) and the majority worked full-time (56%). They had more positive opinions of VCs and used VCs and video meetings for other purposes to a larger extent. They chose VCs because of the lack of time to go to the healthcare centre and because their provider offered them. The most common reason for discontinuing use was a preference for face-to-face consultations, with the youngest age group (16?34 years) reporting this to a larger extent.DiscussionYounger and older age groups may be less likely to continue the use of VCs, potentially preserving the digital divide. Additionally, disparities in using similar technologies might contribute to the digital divide. Moreover, convenience, positive opinions of VCs, and experience with VCs were related to long-term adoption. Further studies are needed to explore non-use, age?s influence, and address usability issues.

    Ort, förlag, år, upplaga, sidor
    SAGE Publications, 2023
    Nationell ämneskategori
    Medicin och hälsovetenskap
    Forskningsämne
    Medicinsk informatik
    Identifikatorer
    urn:nbn:se:uu:diva-513182 (URN)10.1177/1357633X231203267 (DOI)
    Konferens
    2023/10/03
    Forskningsfinansiär
    AFA Försäkring, 190210
    Tillgänglig från: 2023-10-03 Skapad: 2023-10-03 Senast uppdaterad: 2024-11-27
    2. Video Consultations and Environmental Sustainability - Usability's Impact on Long-Term Use.
    Öppna denna publikation i ny flik eller fönster >>Video Consultations and Environmental Sustainability - Usability's Impact on Long-Term Use.
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    2024 (Engelska)Ingår i: Studies in Health Technology and Informatics, ISSN 0926-9630, E-ISSN 1879-8365, Vol. 316, s. 291-295Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The rapid shift to digital healthcare, accelerated by the COVID-19 pandemic, holds promise for sustainable healthcare delivery and climate change mitigation. This study evaluates the Alltid öppet application through the lens of usability and patient satisfaction and their correlation with the intention for continued use. A cross-sectional analysis of primary care patients revealed that alignment with user needs significantly predicts long-term adoption, while frustration during use discourages it. Ease of use did not significantly affect the intention to continue, suggesting that usability alone is insufficient to drive sustained engagement. These findings highlight user-centred design's importance in digital healthcare solutions, suggesting that enduring adoption hinges on value perception and reducing user frustration. As the healthcare sector navigates its digital future, this study offers crucial insights into the design and implementation strategies that could underpin the environmental sustainability and resilience of healthcare systems.

    Nyckelord
    Environmental Sustainability, Primary Care, Resilience, Survey, Sweden, Usability, Video Consultations
    Nationell ämneskategori
    Människa-datorinteraktion (interaktionsdesign) Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi
    Forskningsämne
    Medicinsk informatik
    Identifikatorer
    urn:nbn:se:uu:diva-536912 (URN)10.3233/SHTI240401 (DOI)39176730 (PubMedID)
    Forskningsfinansiär
    AFA Försäkring, 190210
    Tillgänglig från: 2024-08-25 Skapad: 2024-08-25 Senast uppdaterad: 2024-11-27
    3. Patients' Experiences of Initiating Video Consultations.
    Öppna denna publikation i ny flik eller fönster >>Patients' Experiences of Initiating Video Consultations.
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    2023 (Engelska)Ingår i: Studies in Health Technology and Informatics, ISSN 0926-9630, E-ISSN 1879-8365, Vol. 309, s. 204-209Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Implementation and adoption of video consultations (VCs) in healthcare are not straightforward. Experiences of initiating a VC could increase our understanding of adoption by patients. This study aims to report patients' experiences of installing and booking a VC in primary care. Most people found it easy to find and install the VC application. Those with a higher self-reported ability and habit of using digital services and the internet found it easier than those reporting lower ability and habit. About half of our respondents had booked their recent VC themselves, most of whom had done so through a telephone call or the application "Alltid Öppet". The booking process was perceived to be easy by most but more difficult compared to installation. The easy installation process might have led to higher adoption by older people. Nevertheless, during implementation more support should be provided to people with lower digital service and internet use abilities and habits as they might find VC set-up more difficult. More attention should be given to the booking process as it may be a barrier potentially influencing adoption.

    Nyckelord
    Primary Care, Survey, Sweden, Video consultations
    Nationell ämneskategori
    Omvårdnad Systemvetenskap, informationssystem och informatik
    Forskningsämne
    Medicinsk informatik
    Identifikatorer
    urn:nbn:se:uu:diva-514966 (URN)10.3233/SHTI230779 (DOI)37869843 (PubMedID)
    Tillgänglig från: 2023-10-24 Skapad: 2023-10-24 Senast uppdaterad: 2024-11-27
    4. To read or not to read - A cross-sectional study of Swedish primary care patients' adoption of patient accessible electronic health records
    Öppna denna publikation i ny flik eller fönster >>To read or not to read - A cross-sectional study of Swedish primary care patients' adoption of patient accessible electronic health records
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    2024 (Engelska)Ingår i: Digital Health, E-ISSN 2055-2076, Vol. 10Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    ObjectivePatient-accessible electronic health records (PAEHR) were implemented in the Stockholm region of Sweden seven years ago. This study examines socio-demographic and psychographic factors associated with reading/not reading these records, as well as the common reasons for such behaviours.MethodsPatients or guardians of minors seeking face-to-face or digital primary healthcare in the Stockholm region responded to a questionnaire about whether they were aware that they could read their PAEHR, and if so, if they had read it and reasons for reading or not reading. We conducted a comparative analysis of readers and non-readers and a stepwise multiple logistic regression.ResultsThe majority of participants were aware that they could read the PAEHR (86%) and among those aware, 77% had read it. The odds of reading decreased with increased age, unfavourable opinion of PAEHR, low information literacy and being single. Access to a smartphone increased the probability of reading. Participants who had read their PAEHR had commonly read it to get an overview of their health and care (65%) and to follow up on a healthcare visit (55%). Participants who had not read their PAEHR stated generally that they did not need to (63%) and/or had received sufficient information from their providers (38%).ConclusionsWhile most people were aware they could read the PAEHR and many had read it, a digital divide and several barriers to reading the PAEHR were identified. Efforts to increase PAEHR reading may be targeted at older people, people needing more informal support, those who may be excluded due to limited information literacy, and towards improving the patient portals’ usability.

    Ort, förlag, år, upplaga, sidor
    Sage Publications, 2024
    Nationell ämneskategori
    Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi
    Forskningsämne
    Medicinsk informatik
    Identifikatorer
    urn:nbn:se:uu:diva-539932 (URN)10.1177/20552076241287636 (DOI)001328772000001 ()39381824 (PubMedID)
    Forskningsfinansiär
    Vetenskapsrådet, 2021-006426
    Tillgänglig från: 2024-10-07 Skapad: 2024-10-07 Senast uppdaterad: 2024-11-27Bibliografiskt granskad
    5. Who uses video consultations, and why?: A qualitative study of patients' and healthcare professionals' perceptions and experiences
    Öppna denna publikation i ny flik eller fönster >>Who uses video consultations, and why?: A qualitative study of patients' and healthcare professionals' perceptions and experiences
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: Video consultations (VCs) are effective and beneficial, yet there is a noticeable discontinuation of their use and a preference for face-to-face consultations. This study investigates the dual perspectives of patients and healthcare professionals (HCPs) on patients’ introduction to VCs, perceptions of who the users of VCs are, and the drivers of VC use in the Swedish healthcare context.

    Methods: Six focus group interviews with HCPs and 13 individual interviews with patients in primary care were conducted. The interviews examined VC implementation and use, and were analyzed using rapid assessment procedures.

    Results: Patients’ introductions were described as challenging, and both HCPs and patients as unprepared. Use or non-use was perceived to be related to patients’ different characteristics, needs and circumstances. The drivers of use were related to patients’ preferences and opportunities; HCPs’ choice, judgement, type of care; and societal and organizational factors.

    Conclusion: The challenging introduction of VCs could have been avoided and might explain the observed discontinuation of VC use and preference for face-to-face consultations. Additionally, the perception of users’ characteristics may have negatively impacted VC use. Preference also emerged as a key driver of VC use, which was positively and negatively influenced by a range of different factors. Another significant driver of VC use was the judgement of suitability, which was greatly influenced by preferences. Furthermore, infrastructure, organisation, sociodemographics, the service’s usability and the application’s owner, in addition to the pandemic, may have further negatively influenced VC use.

    Nyckelord
    Video Consultations, Primary Care, Introduction, Perceptions, Drivers, Sweden
    Nationell ämneskategori
    Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi
    Identifikatorer
    urn:nbn:se:uu:diva-542843 (URN)
    Anmärkning

    De två sista författarna delar sistaförfattarskapet

    Tillgänglig från: 2024-11-27 Skapad: 2024-11-27 Senast uppdaterad: 2024-11-27Bibliografiskt granskad
    6. Implementing Patient Accessible Electronic Health Records in Primary Care: Potential Barriers and Facilitators from Healthcare Professionals' Perspective
    Öppna denna publikation i ny flik eller fönster >>Implementing Patient Accessible Electronic Health Records in Primary Care: Potential Barriers and Facilitators from Healthcare Professionals' Perspective
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: Patients are increasingly being offered online record access (ORA) through Patient Accessible Electronic Health Records (PAEHR), yet implementation is often met with resistance from healthcare professionals (HCPs). Experiences from previous implementations may provide important insights into potential barriers and facilitators.  

    Objective: To investigate factors influencing implementation of the Swedish PAEHR in primary care from HCPs’ perspective.

    Methods: We conducted 14 semi-structured interviews with a diverse group of HCPs shortly after the implementation of the Swedish PAEHR. The interviews were analysed using the Consolidated Framework for Implementation Research (CFIR) and content analysis, identifying key themes related to PAEHR implementation.

    Results: Several potential barriers and facilitators were identified. According to HCPs, the PAEHR had shortcomings but offered some flexibility. HCPs described working in a complex and challenging organisation, which nonetheless had an existing structure, support, and established communication with patients. They also described using EHR system for other purposes than documentation. Moreover, they reported dealing with a complicated patient group with varying needs and high expectations. HCPs expressed that they worked in a patient-centred way and with patient engagement. The HCPs could see both advantages and disadvantages with PAEHR and had some concerns. There were mixed views of the extent of the change, where some felt patient ORA would not affect their work at all and others expected a substantial impact. Some had experiences using PAEHR themselves, while some lacked knowledge or interest. Furthermore, the implementation process was perceived as long and uneventful, with fragmented communication, where existing communication activities were utilized. They also reported receiving some information and education about PAEHR outside the organisation. HCPs had limited awareness of how patients were introduced to the PAEHR.

    Conclusions: Shortcomings with the EHR system and within the organisation must be addressed for optimal implementation where patients’ and HCPs’ benefits and risks are mitigated. Moreover, improved information and education for patients and HCPs is a potential solution to address many concerns and perceived disadvantages of PAEHR.

    Nyckelord
    Patient Accessible Electronic Health Record (PAEHR), Implementation, Consolidated Framework for Implementation Research (CFIR), Primary Care
    Nationell ämneskategori
    Hälso- och sjukvårdsorganisation, hälsopolitik och hälsoekonomi
    Identifikatorer
    urn:nbn:se:uu:diva-542844 (URN)
    Tillgänglig från: 2024-11-27 Skapad: 2024-11-27 Senast uppdaterad: 2024-11-27Bibliografiskt granskad
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    UUThesis_Muli,I-2025
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  • Disputation: 2025-02-06 13:00 Polhemsalen, Room 10134, Uppsala
    Johnson, Catherine E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Ferrous and Ferric N-Heterocyclic Carbene Complexes: Characterization and Applications in Photoredox Catalysis2025Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Iron complexes are emerging as favourable substitutes to noble metal complexes as photocatalysts due to iron being earth-abundant and inexpensive. Much of the recent progress has been enabled by the strong electron-donating character of N-heterocyclic carbene (NHC) ligands that strongly destabilizes metal-centred (MC) states of FeNHC complexes and thereby greatly extends the lifetimes of their charge transfer (CT) states that are otherwise rapidly deactivated via low-lying MC states.

    The first part of this thesis successfully employed FeNHC complexes in different photoredox catalysis (PRC) reactions and an example of high-turnover catalytic hydrogen production. The latter was accomplished with the benchmark ferric bis-tridentate scorpionate complex [FeIII(phtmeimb)2]+ (phtmeimb = phenyl(tris(3-methylimidazol-1-ylidene))borate) which has a 2LMCT state lifetime of two nanoseconds and excellent photostability. It was further employed in two PRC reactions that yielded synthetically-useful organic compounds, where fast and efficient reductive quenching of the 2LMCT state by various amine donors with cage escape yields between 2 and 22 % were observed. A tris-bidentate complex with favourable excited-state (ES) redox properties and lifetimes in both oxidation states, [FeII,III(btz)3]2+,3+ (btz = 3,3’-dimethyl-1,1’-bis(p-tolyl)-4,4’-bis(1,2,3-triazol-5-ylidene)), was employed in a two-photon PRC reaction utilizing both oxidative and reductive quenching steps, making the PRC reaction overall more efficient. 

    The second part of this thesis describes the electrochemical and photophysical characterization of novel FeNHC complexes with three different motifs in view of their potential suitability as photocatalysts. (i) For a series of ferric bis-tridentate complexes with cyclometalating ligands, not only were their emissive 2LMCT states with lifetimes of hundreds of picoseconds approaching values previously obtained with the [FeIII(phtmeimb)2]+ motif, their electrochemical and ES properties were more tunable by substituent effects. (ii) For the (NHC)4(bpy)2 bis-tridentate complexes [Fe(btz)2bpy]2+,3+ (bpy = 2,2'-bipyridyl) and [Fe(btz)2mbpy]2+,3+ (mbpy = 4,4'-dimethyl-2,2'-bipyridyl), both ferrous and ferric analogues offered insufficient ES lifetimes on the order of ten ps. The ferrous mbpy variant featured however a more long-lived, presumably MC state that deserves further characterization, also in regard to its potential reactivity. (iii) For the ferrous analogue of [FeIII(phtmeimb)2]+, the strikingly-short picosecond 3MLCT state lifetime concludes that even the phtmeimb- ligand with superior σ-donating ability cannot sufficiently prevent the relatively high-energy 3MLCT state from rapid deactivation. 

    Delarbeten
    1. High turnover photocatalytic hydrogen formation with an Fe(iii) N-heterocyclic carbene photosensitiser
    Öppna denna publikation i ny flik eller fönster >>High turnover photocatalytic hydrogen formation with an Fe(iii) N-heterocyclic carbene photosensitiser
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    2022 (Engelska)Ingår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 58, nr 35, s. 5351-5354Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Herein we report the first high turnover photocatalytic hydrogen formation reaction based on an earth-abundant Fe-III-NHC photosensitiser. The reaction occurs via reductive quenching of the (LMCT)-L-2 excited state that can be directly excited with green light and employs either Pt-colloids or [Co(dmgH)(2)pyCl] as proton reduction catalysts and [HNEt3][BF4] and triethanolamine/triethylamine as proton and electron donors. The outstanding photostability of the Fe-III-NHC complex enables turnover numbers >1000 without degradation.

    Ort, förlag, år, upplaga, sidor
    Royal Society of ChemistryRoyal Society of Chemistry (RSC), 2022
    Nationell ämneskategori
    Fysikalisk kemi Teoretisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-483680 (URN)10.1039/d2cc01016j (DOI)000777682500001 ()35373799 (PubMedID)
    Forskningsfinansiär
    Stiftelsen för strategisk forskning (SSF)Knut och Alice Wallenbergs StiftelseVetenskapsrådetEnergimyndigheten
    Tillgänglig från: 2022-09-05 Skapad: 2022-09-05 Senast uppdaterad: 2024-12-07Bibliografiskt granskad
    2. Base-promoted homolytic aromatic substitution (BHAS) reactions and hydrodehalogenations driven by green light and an iron(III)-NHC photoredox catalyst
    Öppna denna publikation i ny flik eller fönster >>Base-promoted homolytic aromatic substitution (BHAS) reactions and hydrodehalogenations driven by green light and an iron(III)-NHC photoredox catalyst
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-544433 (URN)
    Tillgänglig från: 2024-12-04 Skapad: 2024-12-04 Senast uppdaterad: 2024-12-07
    3. Aminomethylations of electron-deficient compounds: bringing iron photoredox catalysis into play
    Öppna denna publikation i ny flik eller fönster >>Aminomethylations of electron-deficient compounds: bringing iron photoredox catalysis into play
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    2024 (Engelska)Ingår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 15, nr 30, s. 12077-12085Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The α-functionalisation of N-containing compounds is an area of broad interest in synthetic chemistry due to their presence in biologically active substances among others. Visible light-induced generation of nucleophilic α-aminoalkyl radicals as reactive intermediates that can be trapped by electron-deficient alkenes presents an attractive and mild approach to achieve said functionalisation. In this work, [Fe(III)(phtmeimb)2]PF6 (phtmeimb = phenyl(tris(3-methylimidazol-2-ylidene))borate), an N-heterocyclic carbene (NHC) complex based on Earth-abundant iron, was used as photoredox catalyst to efficiently drive the formation of α-aminoalkyl radicals from a range of different α-trimethylsilylamines and their subsequent addition to a number of electron-deficient alkenes under green light irradiation. Mechanistic investigations elucidated the different reaction steps of the complete photocatalytic cycle. In terms of yields and substrate scope, we show that [Fe(III)(phtmeimb)2]PF6 can compete with noble metal photoredox catalysts, for instance outcompeting archetypal [Ru(bpy)3]Cl2 under comparable reaction conditions, illustrating that iron photocatalysts can efficiently facilitate photoredox reactions of synthetic value.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2024
    Nationell ämneskategori
    Organisk kemi Atom- och molekylfysik och optik
    Identifikatorer
    urn:nbn:se:uu:diva-540961 (URN)10.1039/d4sc02612h (DOI)001261895400001 ()39092117 (PubMedID)
    Forskningsfinansiär
    Stiftelsen för strategisk forskning (SSF), EM16-0067Knut och Alice Wallenbergs Stiftelse, 2018.0074Vetenskapsrådet, 2020-05058Vetenskapsrådet, 2020-03207Energimyndigheten, P48747-1LMK StiftelsenSten K Johnsons Stiftelse
    Tillgänglig från: 2024-10-25 Skapad: 2024-10-25 Senast uppdaterad: 2024-12-07Bibliografiskt granskad
    4. Photoredox catalysis via consecutive 2LMCT- and 3MLCT-excitation of an Fe(iii/ii)–N-heterocyclic carbene complex
    Öppna denna publikation i ny flik eller fönster >>Photoredox catalysis via consecutive 2LMCT- and 3MLCT-excitation of an Fe(iii/ii)–N-heterocyclic carbene complex
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    2022 (Engelska)Ingår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 13, nr 32, s. 9165-9175Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Fe-N-heterocyclic carbene (NHC) complexes attract increasing attention as photosensitisers and photoredox catalysts. Such applications generally rely on sufficiently long excited state lifetimes and efficient bimolecular quenching, which leads to there being few examples of successful usage of Fe-NHC complexes to date. Here, we have employed [Fe(iii)(btz)(3)](3+) (btz = (3,3 '-dimethyl-1,1 '-bis(p-tolyl)-4,4 '-bis(1,2,3-triazol-5-ylidene))) in the addition of alkyl halides to alkenes and alkynes via visible light-mediated atom transfer radical addition (ATRA). Unlike other Fe-NHC complexes, [Fe(iii/ii)(btz)(3)](3+/2+) benefits from sizable charge transfer excited state lifetimes >= 0.1 ns in both oxidation states, and the Fe(iii) (LMCT)-L-2 and Fe(ii) (MLCT)-M-3 states are strong oxidants and reductants, respectively. The combined reactivity of both excited states enables efficient one-electron reduction of the alkyl halide substrate under green light irradiation. The two-photon mechanism proceeds via reductive quenching of the Fe(iii) (LMCT)-L-2 state by a sacrificial electron donor and subsequent excitation of the Fe(ii) product to its highly reducing (MLCT)-M-3 state. This route is shown to be more efficient than the alternative, where oxidative quenching of the less reducing Fe(iii) (LMCT)-L-2 state by the alkyl halide drives the reaction, in the absence of a sacrificial electron donor.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2022
    Nationell ämneskategori
    Teoretisk kemi Fysikalisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-483786 (URN)10.1039/d2sc02122f (DOI)000834974500001 ()
    Forskningsfinansiär
    Stiftelsen för strategisk forskning (SSF), EM16-0067Knut och Alice Wallenbergs Stiftelse, 2018.0074Vetenskapsrådet, 2020-03207Vetenskapsrådet, 2020-05058EnergimyndighetenWenner-Gren Stiftelserna
    Anmärkning

    Title in Web in Science: Photoredox catalysis via consecutive (LMCT)-L-2- and (MLCT)-M-3-excitation of an Fe(iii/ii)-N-heterocyclic carbene complex

    Tillgänglig från: 2022-09-06 Skapad: 2022-09-06 Senast uppdaterad: 2024-12-07Bibliografiskt granskad
    5. Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited
    Öppna denna publikation i ny flik eller fönster >>Ferrous and ferric complexes with cyclometalating N-heterocyclic carbene ligands: a case of dual emission revisited
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    2023 (Engelska)Ingår i: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 14, nr 37, s. 10129-10139Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Iron N-heterocyclic carbene (FeNHC) complexes with long-lived charge transfer states are emerging as a promising class of photoactive materials. We have synthesized [Fe-II(ImP)(2)] (ImP = bis(2,6-bis(3-methylimidazol-2-ylidene-1-yl)phenylene)) that combines carbene ligands with cyclometalation for additionally improved ligand field strength. The 9 ps lifetime of its (MLCT)-M-3 (metal-to-ligand charge transfer) state however reveals no benefit from cyclometalation compared to Fe(II) complexes with NHC/pyridine or pure NHC ligand sets. In acetonitrile solution, the Fe(II) complex forms a photoproduct that features emission characteristics (450 nm, 5.1 ns) that were previously attributed to a higher ((MLCT)-M-2) state of its Fe(III) analogue [Fe-III(ImP)(2)](+), which led to a claim of dual (MLCT and LMCT) emission. Revisiting the photophysics of [Fe-III(ImP)(2)](+), we confirmed however that higher ((MLCT)-M-2) states of [Fe-III(ImP)(2)](+) are short-lived (<10 ps) and therefore, in contrast to the previous interpretation, cannot give rise to emission on the nanosecond timescale. Accordingly, pristine [Fe-III(ImP)(2)](+) prepared by us only shows red emission from its lower (LMCT)-L-2 state (740 nm, 240 ps). The long-lived, higher energy emission previously reported for [Fe-III(ImP)(2)](+) is instead attributed to an impurity, most probably a photoproduct of the Fe(II) precursor. The previously reported emission quenching on the nanosecond time scale hence does not support any excited state reactivity of [Fe-III(ImP)(2)](+) itself.

    Ort, förlag, år, upplaga, sidor
    Royal Society of Chemistry, 2023
    Nationell ämneskategori
    Fysikalisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-514757 (URN)10.1039/d3sc02806b (DOI)001062236300001 ()37772113 (PubMedID)
    Forskningsfinansiär
    Stiftelsen för strategisk forskning (SSF), EM16- 0067Knut och Alice Wallenbergs Stiftelse, KAW, 2018.0074Vetenskapsrådet, VR, 2020-03207Energimyndigheten, P48747-1Sten K Johnsons StiftelseKungliga Fysiografiska Sällskapet i LundVetenskapsrådet, VR, 2020-05058
    Tillgänglig från: 2023-10-24 Skapad: 2023-10-24 Senast uppdaterad: 2024-12-07Bibliografiskt granskad
    6. Homo- and Heteroleptic Iron N-Heterocyclic Carbene Complexes with Cyclometalating Ligands
    Öppna denna publikation i ny flik eller fönster >>Homo- and Heteroleptic Iron N-Heterocyclic Carbene Complexes with Cyclometalating Ligands
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-544628 (URN)
    Tillgänglig från: 2024-12-06 Skapad: 2024-12-06 Senast uppdaterad: 2024-12-16
    7. Electron withdrawing groups with opposing influence on excited state properties of iron cyclometalated carbene complexes
    Öppna denna publikation i ny flik eller fönster >>Electron withdrawing groups with opposing influence on excited state properties of iron cyclometalated carbene complexes
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-544534 (URN)
    Tillgänglig från: 2024-12-05 Skapad: 2024-12-05 Senast uppdaterad: 2024-12-07
    8. Heteroleptic Ferrous and Ferric Tetra-N-Heterocyclic Carbene Complexes - A Comparative Study
    Öppna denna publikation i ny flik eller fönster >>Heteroleptic Ferrous and Ferric Tetra-N-Heterocyclic Carbene Complexes - A Comparative Study
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-544533 (URN)
    Tillgänglig från: 2024-12-05 Skapad: 2024-12-05 Senast uppdaterad: 2024-12-07
    9. Shining light on the ferrous analogue: Excited state dynamics of an Fe(II) hexa-carbene scorpionate complex
    Öppna denna publikation i ny flik eller fönster >>Shining light on the ferrous analogue: Excited state dynamics of an Fe(II) hexa-carbene scorpionate complex
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    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Nationell ämneskategori
    Fysikalisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-544429 (URN)
    Tillgänglig från: 2024-12-04 Skapad: 2024-12-04 Senast uppdaterad: 2024-12-07
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    UUThesis_C-E-Johnson-2025
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  • Disputation: 2025-02-06 13:15 Humanistiska teatern, Engelska Parken, Uppsala
    Folland, Anna
    Uppsala universitet, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Historisk-filosofiska fakulteten, Filosofiska institutionen, Avdelningen för praktisk filosofi.
    Harm: Essays on Its Nature and Normative Significance2025Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis examines how we should understand the concept of harm, and its moral and prudential importance. It discusses various analyses of harm and normative principles that appeal to harm. In broad terms, it offers a defense of the view that harm is normatively important and useful for philosophical theorizing. Further it proposes a novel analysis of harm, which aligns with that view.

    The first paper, "The Harm Principle and the Nature of Harm", defends John Stuart Mill’s Harm Principle against the criticism that the principle has unacceptable implications regardless of which analysis of harm we plug into it. I argue that the criticism is built on mistaken assumptions – most importantly, the assumption that the Harm Principle is plausible only if there exists an unproblematic analysis of harm.

    The second paper, "Feit on the Normative Importance of Harm", criticizes Neil Feit’s suggested solution to the so-called Failing to Benefit Problem for the Counterfactual Comparative Account (CCA). Feit argues that CCA’s inability to align with some commonsense views about harm’s moral importance is no flaw since those views are false. I object to that argument, in part by showing that the cases that Feit appeals to are not genuine counterexamples.

    The third paper, "Doing Away with Skepticism about Harm", scrutinizes the elimination thesis, which states that we should do away with the concept of harm in philosophical theorizing. I examine various claims in support of that thesis – for instance that the concept is defective – but conclude that we lack good reasons to accept it.  

    The fourth paper, "Misfortune and Missing Out", focuses on Kaila Draper’s famous challenge for deprivationism – the view that death harms a subject in so far as it deprives her of life’s goods. Since not winning the lottery is also a deprivation, the challenge is to explain why only death is a misfortune in the sense that it merits negative emotional responses. I argue that the challenge is serious, in part by criticizing some prominent suggested solutions, and identify a parallel challenge for CCA.

    The fifth paper, "A Fitting Attitudes Analysis of Harm", puts forward a novel analysis of harm. Roughly, this analysis says that an event harms me if, and only if, it is fitting for me to disfavor the event for my own sake.

    Delarbeten