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Chronic wounds have a detrimental impact on patient quality of life, a significant economic cost, and often lead to severe outcomes such as amputation, sepsis or death. The elaborate interplay between bacteria, cutaneous cells, immune cells, growth factors, and proteases in chronic wounds has complicated the development of new therapies that could improve outcomes for chronic wound patients. Existing in vitro models of chronic wounds do not appreciably mimic the complexity of the wound environment. In this work, tissue-engineered skin was developed with the goal of creating an in vitro platform appropriate for testing potential clinical therapies for chronic wounds. The Lumen-X, a digital light processing bioprinter, was used to create tissue-engineered skin from a 7.5% (w/v) gelatin methacryloyl hydrogel laden with primary dermal fibroblasts. This dermal layer was developed with an emphasis on providing a favourable microenvironment for the fibroblasts in order to mimic their in vivo phenotype. An epidermal layer of human keratinocytes was formed on the hydrogel surface and stratified through culture at the air-liquid-interface. The maturation of the epidermis was thoroughly characterized with histology, immunohistochemistry, and trans-epithelial electrical resistance analyses which showed a degree of maturation suitable for wound healing studies. To verify the suitability of this tissue-engineered skin for studying healing in vitro, sharp tweezers were used to create physical wounds in the epidermis which were then infected with Pseudomonas aeruginosa. Reepithelialisation, the production of the pro- inflammatory cytokine TNF-α, and the presence of bacteria were monitored over time, showing healing in wounds without infection and those treated with antibiotics, and potential biofilm formation in infected wounds. The tissue-engineered skin developed here is suitable for use as an in vitro model of the infected chronic wound environment. Future work includes developing better methods for creating the physical wound and characterizing the bacterial biofilm in order to improve the reproducibility and clarity of results. Such a model will then be well-poised to begin testing potential chronic wound therapies in vitro. / Graduate / 2023-07-26

Identifying people in historical photographs is an important task in many fields, including history, journalism, genealogy, and collecting. A wide variety of different methods, such as manual analysis, facial recognition, and crowdsourcing, have been used to identify the unknown photos. However, because of the large numbers of candidates and the poor quality or lack of source evidence, accurate historical person identification still remains challenging. Researchers especially struggle with the ``last mile problem" of historical person identification, where they must make a selection among a small number of highly similar candidates. Collaboration, including both human-AI collaboration and collaboration within human teams, has shown the advantages of improving data accuracy, but there is lack of research about how we can design a collaborative workspace to support the historical person identification. In this work, we present SleuthTalk, a web-based collaboration tool integrated into the public website Civil War Photo Sleuth which addresses the last-mile problem in historical person identification by providing support for shortlisting potential candidates from face recognition results, private collaborative workspaces, and structured feedback interfaces. We evaluated this feature in a mixed-method study involving 6 participants, who spent one week each using SleuthTalk and a comparable social media platform to identify an unknown photo. The results of this study show how our design helps with identifying historical photos in a collaborative way and suggests directions for improvement in future work. / Master of Science / Identifying people in historical photographs is an important task in many fields, including history, journalism, genealogy, and collecting. A wide variety of different methods, such as manual analysis, facial recognition, and crowdsourcing, have been used to identify the unknown photos. However, because of the large numbers of candidates and the poor quality or lack of source evidence, accurate historical person identification still remains challenging. Researchers especially struggle with the ``last mile problem" of historical person identification, where they must make a selection among a small number of highly similar candidates. Collaboration, including both human-AI collaboration and collaboration within human teams, has shown the advantages of improving data accuracy, but there is lack of research about how we can design a collaborative workspace to support the historical person identification. In this work, we present SleuthTalk, a web-based collaboration tool integrated into the public website Civil War Photo Sleuth which addresses the last-mile problem in historical person identification by providing support for shortlisting potential candidates from face recognition results, private collaborative workspaces, and structured feedback interfaces. We evaluated this feature in a mixed-method study involving 6 participants, who spent one week each using SleuthTalk and a comparable social media platform to identify an unknown photo. The results of this study show how our design helps with identifying historical photos in a collaborative way and suggests directions for improvement in future work.

It was decided to determine whether or not 2,2,3-trimethylbutane could be formed by the photochemical reaction of isobutane and propane in the presence of mercury vapor energized by ultraviolet radiation from a mercury vapor lamp.

Existing cancer treatments, while perhaps proving effective in being destructive of tumours, can also cause significant damage to surrounding healthy tissue. This can cause severe side effects which one would wish to avoid. In order to improve the localisation of the inflicted damage in the tumours, as well as increase the actual damage itself when using X-rays as therapy, the potential effect of attaching a high Z atom into the DNA of the cancer cells as markers or antenna for the X-rays is investigated. The larger size and higher absorption cross section of the iodine makes it favourable for this purpose, as it becomes more sensitive to the X-rays. This has been studied for a single stranded DNA molecule which is three bases long, loaded with iodine, using quantum mechanical/molecular dynamical simulations in SIESTA. The purpose was to study in what way the presence of the iodine affected and possibly increased the fragmentation of the molecule due to ionisation of the 2p orbital and the following Auger cascade, as well as use the results to better interpret mass over charge spectra from experiments. If the molecule fragments more, it becomes more difficult for the cell to repair it and thus perform effective DNA replication. It has been found that by matching the X-rays to above the 2p orbital of the iodine, the parent molecule fragments into much more and smaller remains, than when matching the X-rays to below this edge, meaning an increased damage when using the high Z atom. In addition to this, the results in this thesis provide a complement to existing experimental data, contributing with detailed information about specific fragmentation pathways of the molecule, facilitating the interpretation of mass over charge spectra from experiments.

Yes / Biological hydrogels have been increasingly sought after as wound dressings or scaffolds for regenerative medicine, owing to their inherent biofunctionality in biological environments. Especially in moist wound healing, the ideal material should absorb large amounts of wound exudate while remaining mechanically competent in situ. Despite their large hydration, however, current biological hydrogels still leave much to be desired in terms of mechanical properties in physiological conditions. To address this challenge, a multi-scale approach is presented for the synthetic design of cyto-compatible collagen hydrogels with tunable mechanical properties (from the nano- up to the macro-scale), uniquely high swelling ratios and retained (more than 70%) triple helical features. Type I collagen was covalently functionalized with three different monomers, i.e. 4-vinylbenzyl chloride, glycidyl methacrylate and methacrylic anhydride, respectively. Backbone rigidity, hydrogen-bonding capability and degree of functionalization (F: 16 ± 12–91 ± 7 mol%) of introduced moieties governed the structure–property relationships in resulting collagen networks, so that the swelling ratio (SR: 707 ± 51–1996 ± 182 wt%), bulk compressive modulus (Ec: 30 ± 7–168 ± 40 kPa) and atomic force microscopy elastic modulus (EAFM: 16 ± 2–387 ± 66 kPa) were readily adjusted. Because of their remarkably high swelling and mechanical properties, these tunable collagen hydrogels may be further exploited for the design of advanced dressings for chronic wound care.