Coming dissertations at Uppsala university
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Finding stroke with a blood test
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-536281
In contrast to many other diseases and conditions, there is no established blood-based biomarker to aid in the diagnosis, prognosis, or outcome prediction of stroke. The neurospecific proteins glial fibrillary acidic protein (GFAP), myelin basic protein, neurofilament light (NFL), tau, and ubiquitin carboxy-terminal hydrolase L1 are released into blood in response to injurious processes affecting the central nervous system. This thesis aims to enhance the understanding of if, how, and when these biomarkers can provide important information in stroke and stroke-related disorders and which should be the focus for further translation into a useful blood test for stroke.
Firstly, we determined how and at which concentrations these biomarkers are distributed in the human CNS. We found substantial variation between brain regions, indicating that these biomarkers' circulating levels are likely affected by both the size and location of a cerebral insult.
After that, we investigated how plasma levels of these biomarkers change during the first week after an ischemic stroke and determined the optimal time point for assessing infarct volume. Undoubtedly, GFAP was the most optimal biomarker to assess infarct volume in the acute phase, while NFL was better suited to evaluate infarct volume one week to three months after symptom onset.
The findings indicated that NFL holds information long after a cerebrovascular event, so we analyzed plasma NFL in patients undergoing the cardiac procedure transcatheter aortic valve implantation, which is associated with a high frequency of relatively small and covert brain infarcts. We found that NFL increased by 60% after the procedure, which in approximative numbers corresponds to 1 cm3 infarcted brain tissue, similar to the previously reported mean lesion size after the procedure, indicating that NFL may contribute to the detection of procedure-related insults.
Finally, we analyzed serum NFL in patients with atrial fibrillation (AF), a cardiac disease associated with both overt and covert brain infarcts, and in matched controls. We discovered that patients with AF had slightly elevated levels of NFL and that patients with ongoing AF rhythm had the highest levels, indicating that the cerebrovascular pathologies associated with AF may, at least in part, be reflected by NFL.
In summary, this thesis has contributed to the understanding of how and when these biomarkers provide information about stroke and stroke-related disorders. Future studies should aim to further NFL and GFAP into the clinical management of cerebrovascular disease.
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We Drank the Wine from His Hand : Studies on the time, life and poetry of the Kurdish Sufi poet Malā-yē Jazīrī
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-536508
This study is about the Kurdish Sufi poet Malā-yē Jazīrī (1570–1640), whose poems are considered to mark the beginning of classical Kurdish poetry.
To understand the poet’s time and poetry, the political, religious and cultural background is presented, which represents an important phase of Kurdistan’s history. Jazīrī lived in a period when several semi-independent Kurdish principalities were established and flourished as a result of the rivalry between the Safavids and the Ottomans. He lived in the city of Jazīra, the capital of Botan principality, and was close to the princely family of Azīzān, especially Prince Šaraf-Xān III, for whom he composed two panegyrics.
Two important philosophical and Sufi schools of thought were present and active during Jazīrī’s lifetime, and they had a great impact on his thought and poetry. These were the Naqšbandī order and Ibn ʿArabī’s doctrine of Waḥdat al-wujūd.
Manuscripts and printed editions of Malā-yē Jazīrī’s Dīwān are presented, and formal and linguistic aspects of Jazīrī’s poetry are studied, particularly how he applied the Arabic prosodic system to Kurdish poetry. Various aspects of Jazīrī’s poetry are also examined with a focus on his Sufi ideas and the aesthetic expression of his philosophical and spiritual experience.
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Lignocellulosic Biomass Components for Materials Applications
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-536293
This thesis presents a comprehensive study of the use of lignocellulosic biomass components in materials, targeting two distinct applications: conductive materials and additive manufacturing. The lignocellulosic biomass components -lignin, cellulose, and hemicellulose- have been identified as promising renewable feedstocks to replace fossil resources and contribute to the green transition. The first work presented focuses on the synthesis of conductive polymers, specifically polypyrroles. The synthesis of the monomers, N-functionalized pyrroles, was achieved by a modified Clauson-Kaas protocol, both performed in continuous flow and in batch. The substrates used, 2,5-dimethoxytetrahydrofuran and anilines, are promising candidates for biomass-based chemical production. The produced N-functionalised pyrroles were then deposited onto electrodes via electropolymerization to obtain thin films and their electrical properties were characterized. Next, the thesis delves into the isolation and valorisation of lignin, specifically into softwood lignin, modified and isolated via a phenol-assisted fractionation. This approach supresses the formation of condensed lignin while simultaneously introducing new functional groups that could be beneficial for a number of applications. Phenolated lignin was obtained with a high degree of functionalization, a well-defined structure and relatively low molecular weight. Detailed analysis of the fractionation conditions and of the corresponding lignin structures gave insights on how to tailor lignin on demand. The potential of the one-step phenolated lignin was investigated for materials applications.
Filaments of lignin and polylactic acid (PLA) were produced to be used in additive manufacturing. The study focused on high lignin incorporation to PLA at three different concentrations (30, 50, and 70 wt%). The lignin-PLA filaments were used for 3D printing of dog bone shaped specimens to examine their mechanical properties. Additionally, detailed thermal and chemical analysis were performed to get an in-depth understanding of the materials. The results were compared to the performance of technical lignins that were also included in the study. Importantly, recycling studies of the filaments indicated good printing performance up to three recycling cycles.
Another application explored was the production of conductive carbon materials, starting from the modified lignin. The carbonization was performed using a CO2 laser engraver and lignin was the main component in the wet film formulation. The optimized carbonization parameters afforded carbonized films with low sheet resistance (< 7 Ω sq-1). The structural analysis of the carbonized materials revealed the formation of few-layers graphene-like carbon structures. Further applications of these materials are under investigation.
These innovative applications showcase the potential for sustainable, biomass-based materials. The lignin fractionation method reported herein can contribute to further advancements in lignin research. A phenol modified lignin with defined structure offers more opportunities in comparison with bulk lignins, with the advantage of tailoring lignin properties to its end use in the same number steps. Biomass-based organic electronics will help paving the way for environmentally friendly advancements in the energy sector.