This thesis aims to investigate if the endothelial protein C receptor is expressed in the murine kidney. This was done by performing flow cytometry and Western blot analysis on cultivated murine kidney endothelial cells (mKECs) as well as SDS-PAGE and Western blot analysis on murine kidney tissue. Flow cytometry was also performed on cultivated ARPE19 and 4T1 cells for comparison. It was discovered that ≥95,5% of the mKECs, ≥93,6% of the ARPE19 cells and ≥60,9% of the 4T1 cells express the receptor according to the flow cytometry data. A dot blot was performed to validate the primary antibody used for detection of EPCR in Western blot and SDS-PAGE. According to the dot blot, the primary antibody can be visualised in the dilution range from 1:2000 to 1:10. The dot blot also showed that the secondary antibody binds specifically to the primary antibody. Yet, Western blot analysis did not detect the receptor neither in mKECs nor tissue lysate. This was likely due to the fact that the primary antibody used did not bind specifically to the receptor, and may not be applicable for this method. SDS-PAGE did not show any indication that the receptor was present in the kidney tissue. In conclusion, it was discovered that the EPCR was expressed in the murine kidneys endothelial cells through flow cytometry, but the presented methods for Western blot and SDS-PAGE could not confirm the expression of the receptor.

Aluminium har flera fördelar inom konstruktion och produktframtagning. Aimpoint AB har resonerat för kostnad samt viktreducering i sikteshuset Micro T-2. Syftet med rapporten var att undersöka möjligheterna att implementera polymera material som tillfredsställer framlagd kravspecifikation för Aimpoint AB. Målet med arbetet var att identifiera lämpligt material i form av polymer, med lämplig tillverkningsmetod som kan appliceras för sikteshuset utan att påverka de mekaniska egenskaperna negativt.  Lämpliga material som identifierades under litteraturstudien i arbetet var termoplasterna polyfenylensulfid (PPS) och polyetereterketon (PEEK) med implementerat kolfiber. Valet av polymerbaserade material utgjorde ett mindre omfång av lämpliga tillverkningsmetoder, som med hjälp av leverantörer och kostnadskalkylscenarier i Excel jämfördes.  Med hjälp av tredimensionella verktyg utfördes FEM-analyser i ABAQUS CAE® av det exemplifierade sikteshuset. Baserat på simuleringarna i ABAQUS CAE®, presenterar arbetet en jämförelse mellan befintligt sikteshus av Al6082-T6 och sikteshus av polymera material med implementerad förstärkning för modellen Micro T-2. Simuleringarna konstaterade deformation vid det dynamiska explicita fallet mot en konstruerad laminatskiva enligt standarden MIL-STD-810G.  För att bekräfta material och tillverkningsmetod krävs vidare undersökning. Detta för att med säkerhet besvara arbetets frågeställningar då FEM - analyser är en approximativ lösning. / SvenskaAluminum has several advantages in construction and product development. Aimpoint AB requires to reduce both the costs and the weight of their aluminum reflex sight of model Micro T-2.   The aim with the report was to investigate the possibility to implement polymeric materials as a substitute to aluminum that fulfills the requirements specification set by the manufacturer Aimpoint AB.   In addition to that, the aim was also to find suitable polymeric materials with an alternative production technique that is applicable for the reflex sight without compromising the mechanical integrity.  Suitable materials identified during the literature part of this report were two types of thermoplastic materials, polyphenylene sulfide (PPS) and polyetheretherketone (PEEK), both with addition of carbon fiber. The selection process of the polymeric materials was based on several factors and together with contractors, different cost estimation scenarios were compared in Excel. By help from three dimensional tools, FEM-analysis of the sight were performed in ABAQUS CAE®. Based on the results from the simulations performed in ABAQUS CAE®, the report presents a comparison between the original aluminum sight with the two types of carbon fiber reinforced thermoplastic sights. During the dynamic explicit case the simulation was performed as a drop test against a laminate board according to standard MIL-STD-810G. The results of the simulation presented a deformation of the tested sight. To confirm the material and manufacturing method, further investigation is required. This is necessary to address the questions posed in the current project since the FEM - analysis is an approximate solution. / <p>2023-06-28</p>

One of the major goals of this thesis is to investigate the extent to which correspondence noise, (i.e., the false pairing of dots in adjacent frames) limits motion detection performance in random dot kinematograms (RDKs). The performance measures of interest are Dmax and Dmin i.e., the largest and smallest inter-frame dot displacement, respectively, for which motion can be reliably detected. Dmax and threshold coherence (i.e., the smallest proportion of dots that must be moved between frames for motion to be reliably detected) in RDKs are known to be affected by false pairing or correspondence noise. Here the roles of correspondence noise and receptive field geometry in limiting performance are investigated. The range of Dmax observed in the literature is consistent with the current information-limit based interpretation. Dmin is interpreted in the light of correspondence noise and under-sampling. Based on the psychophysical experiments performed in the early parts of the dissertation, a model for correspondence noise based on the principle of receptive field scaling is developed for Dmax. Model simulations provide a good account of psychophysically estimated Dmax over a range of stimulus parameters, showing that correspondence noise and receptive field geometry have a major influence on displacement thresholds.

No description available.

CdSe quantum dots produced by organometallic synthesis are useful as tunable emitters for photonic devices and as multi-colored protein markers for biomedical imaging, applications requiring bright and narrow emission. A diffusion-limited model helped monitor growth rates via photoluminescence and absorbance spectroscopy, in order to characterize synthesis kinetics in stearic acid, dodecylamine, and in trioctylphosphine oxide. The nucleation rate increased with Se concentration, while the growth rate followed the Cd concentration. Emission peak widths, emission redshift rates, nanocrystal growth rates, and reactant concentrations all decreased to a minimum when emission reached the critical wavelength, at a reaction completion time, tc. The temperature dependence of 1/tc and of redshift rates followed Arrhenius behavior governed by activation energies, which were tailored by the choice of solvent. Synthesis in solvents, such as stearic acid, with lower activation energies produced faster initial nanocrystal growth and longer critical wavelengths. The highest photoluminescence quantum yield was generally at wavelengths shorter than the critical wavelength, when moderate growth rates enabled surface reconstruction while precursors were still available. / Ph. D.

The study of neural and behavioural mechanisms of perceptual decision making is often done by experimental tasks involving the categorization of sensory stimuli. Among the key perceptual tasks that decision neuroscience researchers use are motion discrimination paradigms that include tracking and specifying the net direction of a single dot or a group of moving dots. These motion discrimination paradigms, such as the random-dot motion task, allow the measurement of the participant's perceptual decision making abilities in multiple task difficulty levels by varying the amount of noise in the sensory stimuli. Computational models of perceptual decision making, such as the drift-diffusion model, are widely used to analyze the behavioural measurements from these motion discrimination experiments. However, the standard drift-diffusion model can only analyze the average measures like reaction times or the proportion of correct decisions to explain the behavioural data. In the past decade, an emerging computational modeling approach was introduced to analyze the choice behaviour based on precise noise patterns in the sensory stimuli. These computational models that use spatiotemporal stimulus details have shown promise in the single-trial analysis of motion discrimination behaviour. In this thesis, I further develop the advanced computational models of perceptual decision making that use spatiotemporal dynamics of motion stimuli to provide detailed explanations of perceptual choice behaviour. First, I demonstrate the usefulness of equipping an extended Bayesian Model, equivalent to the extended drift-diffusion model, with trial-wise stimulus information leading to a significantly better explanation of behavioural data from a single-dot tracking experiment. Second, I show that the extended drift-diffusion model constrained by spatiotemporal stimulus details can explain the consistent biased choice behaviour in response to stochastic motion stimuli. Based on this model-based analysis, I provide evidence that the source of the observed biased choice behaviour is the presence of subtle motion information in the sensory stimuli. These results further emphasize the effectiveness of using spatiotemporal details of stochastic stimuli in detailed model-based analyses of the experimental data and provide computational interpretations of the data related to underlying mechanisms of perceptual decision making.

[pt] s pontos quânticos de grafeno têm potencial para aplicações biológicas devido às suas propriedades ópticas e de tamanho nanométrico. Este estudo investigou por 28 dias (672 h) as interações de GQDs de diferentes precursores (ácido cítrico + ureia e ácido cítrico + tioacetamida) com biomoléculas modelo (albumina sérica humana - HSA) e DNA do timo de bezerro (ctDNA). Os GQDs-ureia mostraram estabilidade no diâmetro hidrodinâmico (12 nm) e carga superficial (-7 mV). Já os GQDs-tioacetamida apresentaram agregação progressiva de 5,0 nm iniciais para 22,7 nm após 28 dias, sem sedimentação devido à compensação de cargas preservando a dispersão coloidal. Ensaios revelaram supressão da fluorescência da HSA com aumentos na concentração dos GQDs. A constante de interação (Ki) GQDs-ureia oscilou inicialmente, estabilizando após 48 h. Para GQDs-tioacetamida houve menor flutuação de Ki ao longo de 672 h, indicando rearranjos conformacionais das biomoléculas com os GQDs antes do equilíbrio. A interação com o DNA, acompanhada por titulação absorciométrica no UV-Vis mostrou biointeração fraca de natureza hidrofóbica/eletrostática para ambos GQDs, com constantes de ligação aparentes (∼105 L mol−1). Ensaio com brometo de etídio revelou alterações na estrutura do DNA sem intercalação dos GQDs.Testes estatísticos confirmam a reprodutibilidade das interações dos GQDs com proteínas (HSA) e DNA no período de 28 dias (95 por cento de confiança). A estabilidade dos parâmetros de quantificação ao longo do tempo sugere a viabilidade dos GQDs como sondas analíticas após longos períodos de bioconjugação. Assim, o estudo apresenta bases metrologicamente sólidas para aplicação segura de GQDs em tecnologias biomédicas, expandindo o entendimento da relação tempo-estrutura-atividade nesses nanossistemas. / [en] Graphene quantum dots have potential for biological applications due to their optical properties and nanometric size. This study investigated for 28 days (672 h) the interactions of GQDs from different precursors (citric acid + urea and citric acid + thioacetamide) with model biomolecules (human serum albumin - HSA) and Calf thymus DNA (ctDNA). The GQDs-urea showed stability in hydrodynamic diameter (12 nm) and surface charge (- 7 mV). In contrast, GQDs-thioacetamide showed progressive aggregation from 5.0 nm initially to 22.7 nm after 28 days, without sedimentation due to charge compensation preserving colloidal dispersion. Tests revealed quenching of HSA fluorescence with increases in GQD concentration. The GQDs-urea interaction constant (Ki) fluctuated initially, stabilizing after 48 h. For GQDs-thioacetamide there was less fluctuation in Ki over 672 h, indicating conformational rearrangements of the biomolecules with the GQDs before equilibrium. Interaction with DNA monitored by UV-Vis photometric absorption titration showed weak bio-interaction of a hydrophobic/electrostatic nature for both GQDs, with apparent binding constants (∼105 L mol−1). Ethidium bromide assay revealed changes in DNA structure without intercalation of the GQDs. Statistical tests confirm the reproducibility of GQDs interactions with proteins (HSA) and DNA over 28 days (95 percent confidence). The stability of the quantification parameters over time suggests the viability of GQDs as analytical probes after long periods of bioconjugation. Thus, the study presents metrologically sound bases for the safe application of GQDs in biomedical technologies, expanding the understanding of the time-structure-activity relationship in these nanosystems.

No / Raman spectroscopy was evaluated as a non-destructive analytical tool for the characterisation of white substances in burials. In addition, Fourier transform Raman spectroscopy was used to assess the conversion of hydrated lime into calcium carbonate. Fourteen samples of white substances from archaeological and forensic sites were analysed and characterised. The results show that not all white residues in burials are lime. Lime can easily be mistaken for other building materials (gypsum), for minerals (brushite) or degraded metal (cerussite). This study highlights the need for chemical analysis of white residues when encountered in burials. Analytical information derived from Raman spectra of white substances can further assist in the interpretation of the taphonomic processes of burials and their funerary context. Copyright (c) 2014 John Wiley & Sons, Ltd.

The ordinary cross product in R3 is a widespread tool in mathematics and other sciences. It has applications in many areas such as several variable calculus, abstract algebra, geometry, and physics. In this thesis, we investigate in which Euclidean spaces R𝑛 there exist cross products. Based on the properties of the cross product in R3, we introduce two different notions of a cross product in R𝑛. Our first definition is based on the Pythagorean property and the perpendicular property of the cross product in R3. By direct calculation, we show that there is exactly one cross product in R1, no cross product in R2, and exactly two cross products in R3. We also show that if R𝑛 has a cross product, then 𝑛 = 1, 3, or 7. Our second definition uses the following self-selected properties of the cross product in  R3: the triple property, and the nondegeneracy property, leading to the notion of a semi-crossproduct. By direct computation, we discover that R3 has exactly two semi-cross products, which coincide with its cross products, moreover, there does not exist any semi-cross product in R1 or R2. The main result of the thesis is that there are no semi-cross products in R𝑛 for 𝑛 ≥ 4. As far as we know, the results of this chapter are new.

[pt] Uma sonda fotoluminescente do tipo turn-on foi avaliada para a detecção de putrescina usando pontos quânticos de grafeno (GQDs). Diferentes nanopartículas de carbono fotoluminescentes foram preparadas usando a abordagem bottom-up, usando ácido cítrico como precursor, sozinho ou misturado com outros compostos contendo heteroátomos (N e/ou S) visando funcionalização da nanoestrutura. Observou- se que as nanopartículas preparadas com ácido cítrico e tioureia (GQDs-TU) apresentaram melhor perfil aumento da fotoluminescência (resposta analítica) na presença dessa amina biogênica. As condições experimentais foram ajustadas para o melhor perfil de resposta e para obter os parâmetros analíticos de mérito. No ensaio em batelada, a curva analítica normalizada (concentração L-L0 versus PUT) foi linear (R2 = 0,9498) até 90 mg L1 . O limite de quantificação (LOQ) foi de 15,1 mg L-1 e o limite de detecção (LOD) foi de 4,5 mg L-1 . Além disso, a estratégia proposta para a determinação indireta de putrescina foi adaptada para um sistema de análise por injeção em fluxo (FIA) a fim de aumentar a frequência analítica, diminuir os resíduos e automatizar a quantificação do analito. Após a otimização do ensaio, com a faixa linear cobrindo o intervalo até 50 mg L-1 (R2 = 0,9980), os valores de LOD e LOQ foram 3,0 mg L1 e 9,9 mg L-1 , respectivamente. / [en] A photoluminescent turn-on probe was evaluated for putrescine detection using graphene quantum dots (GQDs). Different photoluminescent carbon nanoparticles were prepared using a bottom-up approach, employing citric acid as a precursor, either alone or mixed with other compounds containing heteroatoms (N and/or S) for nanostructure functionalization. It was observed that the nanoparticles prepared with citric acid and thiourea (GQDs-TU) exhibited a more pronounced increase in photoluminescence (analytical response) when exposed to this biogenic amine. Experimental conditions were fine-tuned to optimize the response profile and obtain the analytical parameters of merit. In the batch assay, the normalized analytical curve (L-L0 concentration versus PUT) was linear (R2 = 0,9498) up to 90 mg L-1 . The limit of quantification (LOQ) was 15,1 mg L-1 and the limit of detection (LOD) was 4,5 g L-1 . Furthermore, the proposed strategy for the indirect determination of putrescine was adapted for a flow injection analysis (FIA) system to increase the analytical frequency, reduce waste, and automate analyte quantification. After optimization of the assay, with the linear range covering the range up to 50 mg L-1 (R2 = 0,9980), the LOD and LOQ values were 3,0 mg L-1 e 9,93 mg L-1 , respectively.