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No description available.

No description available.

No description available.

One particular challenge of brain connectomics deals with inferring differences in the brain due to diseases such as Alzheimer's. More specifically, structural connectomics aims at investigating the connectivity between regions in the brain based on the distribution of neuronal fibers. The first step in generating structural connectomes is to perform tractography reconstruction on diffusion MRI (dMRI) data, to extract the most likely pathways of neural fibers. However, current tractography reconstruction algorithms suffer from having high sensitivity and low specificity. Thus, the following steps  of creating, analyzing and deriving graphs metrics from connectivity maps based on tractography impair the reliable assessment of structural connectivity. A promising method to improve tractography and subsequent structural connectomes is to apply tractogram filtering methods. In this study, the impact of tractogram filtering on structural connectomics and derived graph measures of subjects with mild cognitive impairment (MCI), specifically using spherical-deconvolution informed filtering of tractograms (SIFT), is experimentally examined. Moreover, the study also aims at inferring the effects of tractogram filtering in machine-learning based classification of the aforementioned structural connectomes. The pipeline in this experimental setup uses registration tools from FSL, tractography tools from MRTrix3Tissue as well as Keras for classification. The results from the given experiments show, that graph measures such as nodestrength and betweenness centrality are altered for the individual nodes. This leads to new connectomes with nodes, which are more important after tractogram filtering. This effect was also seen in connectomes weighted by fractional anisotropy (FA), mean diffusivity (MD) and radial diffusivity (RD). Moreover, structural connectomes based on filtered tractograms yield a higher classification performance. The best classification performance was reached with 88.65% on raw connectomes. Limiting factors in this experimental setup are identified as the small number of subjects at hand and computation time and the errors introduced by image registration and tractography parameterization.

Research has demonstrated that everyday functional abilities are compromised in mild cognitive impairment (MCI), a transitional stage between normal cognitive aging and dementia, as well as in healthy aging. These functional changes have been shown to be strong predictors of future decline, highlighting their importance. However, early changes in everyday functioning remain poorly characterized, largely due to a scarcity of sensitive measures capable of detecting subtle disruption. Recent research suggests that eye-tracking methodology may be effective in addressing this gap. Fifty-two participants (27 younger adults and 25 non-demented older adults) completed a novel eye-tracking task involving passive viewing of a naturalistic scene and verbalization of a task goal (e.g., make coffee, pack a lunch). Participants also completed a performance-based measure of everyday action that required them to enact the same tasks (e.g., coffee, lunch) that were included in the eye-tracking paradigm, self-report measures of functional ability, and neuropsychological measures. Mixed ANOVAs were conducted to examine group (young, old) and condition (passive viewing, verbalization)/task (simple, complex) effects on eye-tracking and everyday action performance. Independent samples t-tests/Mann-Whitney U tests were conducted to examine group differences in eye-tracking and everyday action performance. Correlation analyses across all measures were conducted to evaluate the potential mechanisms of eye-tracking and everyday action results. Results showed no significant group differences in the primary eye-tracking variables, but both groups made a lower proportion of fixations to distractor (i.e., non-target) objects during task verbalization compared to passive scene viewing. Older adults made more inefficient actions during performance-based everyday task completion, particularly when task demands were high. Eye tracking and everyday action variables were related to different measures of self-reported functional ability. Finally, eye-tracking variables were primarily related to neuropsychological measures of executive functions/working memory, whereas everyday action performance was most strongly related to measures of verbal learning and memory. These findings suggest that age-related functional changes at the level of eye movements may occur after changes in behavioral performance of everyday tasks. Importantly, performance-based assessment of everyday action appears sensitive to age-related decline. Additionally, naturalistic eye movements and everyday task performance may reflect distinct components of self-reported functioning and may be driven by distinct cognitive processes. Future research with refined naturalistic eye-tracking tasks and samples with a wider range of impairment is necessary to further explore these findings and improve characterization and detection of risk for dementia. / Psychology

Background: Mild Cognitive Impairment (MCI) is seen as a state between normal aging and dementia, with patients having an increased risk of developing Alzheimer’s disease (AD) and other sorts of dementia. MCI has been linked to a change in gut microbiota which impacts the microbiota-gut-brain axis (MGBA), consequently affecting neurological functions. A way of altering microbiota and thereby promoting cognitive health is through the administration of prebiotics, probiotics, and synbiotics. Aim: This systematic literature review aims to assess the impact of prebiotics, probiotics, and synbiotics on MCI by compiling existing data on the matter. Methods: Three databases - Web of Science, Cochrane, and PubMed - were searched and articles were included based on the following inclusion criteria: (1) randomized clinical trials (RCTs), (2) conducted on adults evaluated with MCI during the study, (3) including a prebiotic, probiotic, or synbiotic intervention of any kind, (4) comparing the intervention with a placebo or control group, (5) written in English, (6) reporting the main outcome of cognitive function using any neuropsychological evaluation test. Results: Five studies were included in the final selection. These studies showed that cognitive function improved after probiotic intervention, significantly affecting several cognitive domains: attention, calculation, orientation in time, and delayed memory. Two studies showed that subjects with low cognitive scores at baseline benefited more from probiotic supplementation compared to high-scoring subjects. Conclusions: Probiotics appear to improve cognition in MCI subjects; however, further research is needed to conclude the effects of prebiotics and synbiotics.

Objectives: To determine the contribution of cerebral amyloid angiopathy to cognitive impairment in MCI and dementia. Methods: Patients with subjective memory impairment (SMI), amnestic and non-amnestic mild cognitive impairment ((n)aMCI), Alzheimer's disease (AD), mixed and vascular dementia (MD/VD) from our memory clinic were included in this retrospective analysis. Patients underwent neuropsychological testing and cranial magnetic resonance imaging (MRI). Magnetic resonance imaging data sets were analyzed regarding the presence of CAA-related MRI biomarkers to determine CAA prevalence. ANOVAs were used to investigate the contribution of CAA to cognitive impairment within diagnostic groups and to determine whether differences in cognitive test performance between the diagnostic groups are mediated by total CAA burden. Results: 475 patients (222 male, 253 female) with SMI (n = 47), naMCI (n = 41), aMCI (n = 189), early AD (n = 9), AD (n = 114), MD (n = 71) and VD (n = 4) were included. Mean age was 73.2 (9.9) years. CAA prevalence was 14.9% in SMI, 14.6% in naMCI, 24.3% in aMCI, 22.2% in early onset AD, 18.4% in late onset AD, 46.5% in MD and 25% in VD. Patients with possible and probable CAA were older than patients without CAA. In particular, diagnosis of aMCI, early onset AD, MD and VD showed high CAA prevalence. In AD but not in aMCI, CAA diagnosis significantly influenced test performance in the CERAD word list recall (F (1,78) = 4505; p = 0.037; partial eta-square = 0.055). Differences in cognitive test performance between the diagnostic groups of naMCI, aMCI, AD and MD were mediated by total CAA burden within AAT simply nouns subtest (F (2,39) = 4059; p = 0.025; partial eta-square = 0.172) and in CERAD verbal fluency test (F (3,129) = 3533; p = 0.017; partial eta-square = 0.076). Conclusion: This retrospective analysis demonstrates high prevalence rates of CAA in cognitive diagnoses. Our data suggest that comorbid CAA independently impacts cognitive test performance in the course of AD with presumably stage-dependent effects. Especially in patients with AD comorbid CAA additionally impairs memory function. Total CAA small vessel disease burden further modulates psychometric differences in cognitive test performance between diagnostic groups regarding word finding and word fluency capabilities.

In the framework of this thesis, we focused on two inflammatory markers, MCP-1, and galectin-3, to evaluate the impact of MTH on inflammation levels in patients suffering from AMI complicated by CS. Furthermore, the relationship between MCP-1 and galectin-3 levels within the first three days of post-admission and the risk of 30-day all-cause mortality was also investigated.

Superhydrophobic coatings (SHC) with excellent self-cleaning and corrosion resistance property is developed on magnetite coated AISI SAE 1020 steel by using a simple immersion method. Roughness measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), contact angle measurement (CAM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), and qualitative characterization of self-cleaning behavior, antifouling property and durability of the coatings are assessed. A water contact angle as high as 152o on the coated surface with excellent self-cleaning and resistivity to corrosion and good longevity in atmospheric air is obtained. Self-cleaning test results prove that these surfaces can find applications in large scale production of engineering materials. Potentiodynamic polarization tests and EIS tests confirm that the superhydrophobic low carbon steel surfaces have better resistance to corrosion compared to bare steel and magnetite coated steel in 3.5% NaCl solution. But the longevity of the coated steel surfaces in 3.5% salt solution is limited, which is revealed by the immersion durability test. However, hydrophobic coatings (HC) have better stability in normal tap water, and it can stay unharmed up to 15 days. Finally, hydrophobic coatings on low carbon steel surface retains hydrophobic in open atmosphere for more than two months. Results of this investigation show surface roughness is a critical factor in manufacturing hydrophobic steel surfaces. Higher contact angles are obtained for rougher and more uniform surfaces. A linear mathematical relationship (y =6x+104; R2 = 0.93) is obtained between contact angle (y) and surface roughness (x).