Apolipoprotein ε4 modifies obesity-related atrophy in the hippocampal formation of cognitively healthy adults.

Characterizing age- and risk-related hippocampal vulnerabilities may inform about the neural underpinnings of cognitive decline. We studied the impact of three risk-factors, Apolipoprotein E4 (APOE4), a family history of dementia, and central obesity, on CA1, CA2/3, dentate gyrus (DG) and subiculum in 158 cognitively healthy adults (38-71 years). Subfields were labelled with the Automatic Segmentation of Hippocampal Subfields (ASHS) and FreeSurfer (version 6) protocols. Volumetric and microstructural measurements from quantitative magnetization transfer and Neurite Orientation Density and Dispersion Imaging were extracted for each subfield and reduced to three principal components capturing apparent myelin/neurite packing, size/complexity, and metabolism. Aging was associated with an inverse U-shaped curve on myelin/neurite packing and affected all subfields. Obesity led to reductions in myelin/neurite packing and size/complexity regardless of APOE and FH status. However, amongst individuals with a healthy Waist-Hip-Ratio, APOE4 carriers showed lower size/complexity than non-carriers. Protocol type did not affect this risk pattern. These findings provide novel evidence for interactive effects between APOE and central obesity on the hippocampal formation of cognitively healthy adults.

Texture and Microstructure Evolution of Ultra-High Purity Cu-0.1Al Alloy under Different Rolling Methods

The microstructure and texture distribution of ultra-high purity Cu-0.1Al alloy target play a key role in the quality of the sputtering film. The Cu-0.1Al alloy sheets were processed by unidirectional (UR) and cross rolling (CR), and X-ray diffraction (XRD), and electron backscatter diffraction (EBSD) technologies were adopted to observe the texture and microstructure evolution. XRD results reveal that the texture types vary greatly in UR and CR due to the change of strain path. As the strain increases to 90%, S texture occupies the most, followed by copper texture in the UR sample, while brass texture dominates the most in the CR sample. Additionally, the orientation density of texture does not increase significantly with the increase of strain but shows a downward trend both in UR and CR modes. EBSD analysis demonstrates that compared with UR, the deformation microstructure in CR is more uniform, and the layer spacing between the deformation bands is smaller, which can reduce the local-region stress concentration. After the completion of recrystallization, the difference in average grain size between the UR and CR-annealed samples is not significant, and the recrystallized grains become much finer with the increase of strain, while more equiaxed grains can be observed in CR-annealed samples.

Transformation of the Microstructure of Fe-Cr Steel during Its Production

EN 1.4016 stainless steels combine good corrosion resistance with good formability and ductility. As such, their most popular applications are related to sheet forming. During re-crystallisation of Fe-Cr steels, deviations from the desired γ-fibre (gamma fibre, <111>||ND) texture promote a decrease in deep drawability. Additionally, α-fibre (alpha fibre, <110>||RD) has been found to be damaging to formability. In this study, an EN 1.4016 basic material and a modified one with optimised settings as regards to chemical composition and manufacturing process, in order to improve the formability properties, are characterised. The phase diagram, microstructure, Lankford coefficients and Electron Backscatter Diffraction (EBSD) (results confirm the evolution of texture during the processing of ferritic stainless steel. Texture is analysed by the interpretation of Orientation Distribution Function (ODF), using orientation density results for each sample obtained in the processing route. The cube ({001} <100>) and rotated cube ({001} <110>) textures dominate the crystal orientation from the slab until the intermediate annealing stage. After final annealing, there is a texture evolution in both materials; the γ-fibre component dominates the texture, which is much more intense in modified material supported by components that show good deep drawability, {554} <225>, and good transition from hot to cold rolling, {332} <113>. The modified composition and process material delivers a better re-crystallisation status and, therefore, the best drawability performance.

Orientation Analysis

Simple figures illustrate the basic concepts: orientation, Euler angles, Euler space, orientation density function, pole density function. The iteration that decisively influenced the development of orientation analysis follows directly from the relationship between the two density functions. The minimum principle defines the initial function and the structure of the iteration. Using model orientation density function, we prove that this kind of orientation analysis is extremely effective.

Non-Parametric Comparison of Crystallographic Orientation Distributions

Revisiting a spiral design for X-ray pole figure measurementsand a symbolic definition of a cumulative crystallographic orientation distributiona one-dimensional deterministic approximately uniform sequential design is appliedto evaluate and cumulate a given orientation density function resulting in a properly definedcumulative crystallographic orientation distribution.It provides a complementary means to compare distributionsin terms of graphs and the Kolomogorov-Smirnov distance.