| 1. |
- Cid Gomes, Leandro, 1993-
(författare)
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Light-Induced Routes to Sustainable Biocrudes for Fuels and Lubricant Oils
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Fossil-based hydrocarbons are at present the ideal compounds for jet fuels and lubricant oils, so their replacement by novel technologies is not easy. Instead, sustainable routes to hydrocarbons, such as sunlight-driven processes, are desired to reduce the environmental impact by the transport sector. Photosynthetic microorganisms can convert water and CO2 into small hydrocarbons, yet, a second step is needed to convert them into jet fuels and lubricant oils. The aim of this thesis is to investigate photochemical routes for this second step.We first explore the triplet photosensitized dimerization of isoprene produced by cyanobacteria. We developed a combined photobiological-photochemical route from CO2 to C10 jet fuel via isoprene that has a climate change impact 80% lower than that of fossil jet fuel. The photosensitizer 1,1-dinaphthylmethanone absorbs in the near-UV light, so natural sunlight can be used with low photosensitizer loading (0.1 mol%). Later, other small conjugated dienes were investigated, providing a deeper understanding of the photodimerization. We concluded that isoprene is the ideal diene to be dimerized into jet fuel, as it has a suitable boiling point that facilitates its harvesting and as it dimerizes more efficiently than the other small volatile dienes.The photodimerization is then expanded to larger substrates to produce lubricant oils and diesel-like fuels. We found that α-phellandrene dimerizes very efficiently (>90%, 12h), and we utilize it in a cross-dimerization with less reactive monoterpenes and with isoprene. We also investigated the influence of light intensity in the reaction of α-phellandrene and the rates of triplet quenching of the photosensitizer by different monoterpenes.A final part of this thesis addresses the need of photochemical routes that can oligomerize unsaturated hydrocarbons other than conjugated dienes. The seminal idea is to use photoacids as catalysts. This journey started by designing a new photoacid based on the anilinium and dibenzotropylium cationic moieties. We found computationally a strong photoacidity, with pKa = -12. We discovered that the photoacidity is operating by a novel mechanism involving a reorganization of charge distribution within the dibenzotropylium moiety upon excitation, which interacts electrostatically with the anilinium moiety and makes the acidic proton of the anilinium unit more acidic.The work described in this thesis provides further understanding of the triplet photosensitized reactions first reported in the early 1960s, and it applies this important organic photoreaction in the context of renewable energy. Furthermore, the last part of this thesis contributes to new interpretations of photoacidity.
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| 2. |
- Ernst, Tomasz, et al.
(författare)
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Electromagnetic images of the deep structure of the Trans-European Suture Zone beneath Polish Pomerania
- 2008
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 35:15, s. L15307-
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Tidskriftsartikel (refereegranskat)abstract
- A large-scale international electromagnetic experiment has been carried out in northwest Poland and northeast Germany. The main goal was to study the deep conductivity structure across the Trans-European Suture Zone, which is the most prominent tectonic structure of Phanerozoic age in Europe. Electromagnetic measurements were carried out mainly along seismic profiles P2, LT-7, and LT-2 crossing the suture zone and running in the northeastern direction. Strike and dimensionality analyses indicate that a geoelectrical strike of N60 degrees W common to both profiles LT-7 and P2 can be estimated. This strike direction was used to project and rotate all transfer functions and both profiles were subjected to 2D inversion using three different approaches. The results show the presence of highly conductive Cenozoic-Mesozoic sedimentary cover reaching depths up to 3 km. A significant conductivity anomaly beneath the central part of the TESZ, called the Central Polish Anticlinorium, has been well resolved at midcrustal depths. The upper mantle of the Precambrian East European Craton is more resistive than, adjacent to the West, the younger Paleozoic Platform.
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| 3. |
- Hibar, Derrek P., et al.
(författare)
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Novel genetic loci associated with hippocampal volume
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 4. |
- Mátrai, Norbert, et al.
(författare)
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Do the European Great Reed Warblers (Acrocephalus arundinaceus) reach South Africa during wintering?
- 2012
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 153:2, s. 579-583
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Former studies have shown that the Great Reed Warbler (Acrocephalus arundinaceus) has two genetically distinguishable haplogroups (a ‘‘western’’ and an ‘‘eastern’’ clade). The species occurs in South Africa from January to late March, yet, in the whole database of EURING, there are no recoveries to the south of the Congo. There are at least three hypotheses concerning which birds are seen wintering in South Africa: (1) the European breeders reach South Africa, but there are no ringing recoveries; (2) a mixed population of birds originating from Turkey, Iran and Kazakhstan (Near and Middle East) winters in South Africa; and (3) birds from Europe and the Near and Middle Eastern populations both reach South Africa. We have sequenced a 492-bp part of the mtDNA control region II in 146 samples from five European breeding and one South African wintering population of Great Reed Warblers. The results show that over 60% of the wintering birds in South Africa carry European haplotypes, belonging to both ‘‘eastern’’ and ‘‘western’’ clades. Since the exact haplotypic constitution of the Near and Middle Eastern populations are not known to us, we cannot exclude that a mixed wintering population is formed from birds originating from these regions, but it seems more likely that the European breeders reach South Africa.
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| 5. |
- Satizabal, Claudia L., et al.
(författare)
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Genetic architecture of subcortical brain structures in 38,851 individuals
- 2019
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 51:11, s. 1624-
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Tidskriftsartikel (refereegranskat)abstract
- Subcortical brain structures are integral to motion, consciousness, emotions and learning. We identified common genetic variation related to the volumes of the nucleus accumbens, amygdala, brainstem, caudate nucleus, globus pallidus, putamen and thalamus, using genome-wide association analyses in almost 40,000 individuals from CHARGE, ENIGMA and UK Biobank. We show that variability in subcortical volumes is heritable, and identify 48 significantly associated loci (40 novel at the time of analysis). Annotation of these loci by utilizing gene expression, methylation and neuropathological data identified 199 genes putatively implicated in neurodevelopment, synaptic signaling, axonal transport, apoptosis, inflammation/infection and susceptibility to neurological disorders. This set of genes is significantly enriched for Drosophila orthologs associated with neurodevelopmental phenotypes, suggesting evolutionarily conserved mechanisms. Our findings uncover novel biology and potential drug targets underlying brain development and disease.
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| 6. |
- Suemnig, A., et al.
(författare)
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Motivational factors for blood donation in first-time donors and repeat donors : a cross-sectional study in West Pomerania
- 2017
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Ingår i: Transfusion Medicine. - : Wiley. - 0958-7578 .- 1365-3148. ; 27:6, s. 413-420
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This study aimed to analyse motivational factors for blood donation in different donor groups.BACKGROUND: As the demographic change will result in a decrease of the population in age groups of blood donors, the risk of blood product shortage increases.METHODS: During a 12-month period, every sixth blood donor presenting at the blood donation centre of the University Hospital was asked to complete a self-administered questionnaire assessing motivational factors for blood donation. Despite the formalised enrolment protocol, frequent donors were over-represented in the study cohort, which was adjusted by weighting donors with different numbers of donations per year in such a way that the distribution of numbers of donations per year was the same in the sample as in the donor population.RESULTS: Of 2443 participants, 14·3% were first-time and 85·3% repeat donors. To "help other people" (>90%) and receiving "medical assessment of my blood values" (63-69%) were the strongest motivational factors in all donor groups. Receiving remuneration (49·2% vs 38·1%) was more important for repeat donors than for first-time donors, whereas it was the opposite for "being taken by a friend to the donor clinic" (47·0% vs 15·5%). A potentially important observation is that 33·9% of frequent donors reported feeling physically better after blood donation compared to infrequent donors (29·5%).CONCLUSION: Identification of motivational factors can lead to the design of targeted motivation campaigns for blood donation. The underlying cause of the perceived well-being after blood donation requires further studies.
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