Journal: Nature Communications

Article Title: Cognitive functions and underlying parameters of human brain physiology are associated with chronotype

doi: 10.1038/s41467-021-24885-0

Figure Lengend Snippet: a 3D model of the current flow distribution inside the head was calculated based on the finite element method using COMSOL Multiphysics software version 5.2 (details in supplementary information). The electrical current flow induced by 1.0 mA stimulation intensity, and electrode positions C3-Fp2, for anodal (a1, 2, 3), and cathodal (a4, 5, 6) stimulation over the motor cortex is shown. ñ .E refers to the absolute electrical field. b , c post-tDCS cortical excitability alterations after anodal, cathodal, and sham stimulation at the circadian-preferred and non-preferred times in early ( b ) and late ( c ) chronotypes ( n = 32, 16 per group). The results of the repeated measures ANOVA showed significant interactions of stimulation × chronotype × daytime and stimulation × chronotype × daytime × timeline (see Table ). The main effects of time of day and chronotype were not significant, however, they significantly interacted. Stimulation and timepoint did not significantly interact with chronotype or time of day (Table ). Post hoc comparisons (Bonferroni-corrected t tests, two-tailed) of MEP amplitudes to respective baseline values, the sham condition, and respective stimulation conditions at different times of day are marked by symbols in the figures. Filled symbols indicate a significant difference of cortical excitability against the respective baseline values. The floating symbol [*] indicates a significant difference between the real vs sham tDCS conditions, and the floating symbol [**] indicates an additional significant difference between respective timepoints of tDCS conditions at the circadian-preferred vs circadian non-preferred times. Sham stimulation did not induce any significant change in cortical excitability. Data are presented as mean values ± SEM. MEP motor-evoked potential, C3 left motor cortex, Fp2 right supraorbital area, V/m volts per meter.

Article Snippet: Fig. 3 LTP/LTD-like plasticity induction in the motor cortex. a 3D model of the current flow distribution inside the head was calculated based on the finite element method using COMSOL Multiphysics software version 5.2 (details in supplementary information).

Techniques: Software, Two Tailed Test

Journal: Magnetic resonance in medicine

Article Title: Characterizing the Limits of Magnetic Resonance Imaging Near Metallic Prostheses

doi: 10.1002/mrm.25540

Figure Lengend Snippet: Intra-voxel dephasing due to magnetic field inhomogeneities leads to break-down of chemical shift encoded water-fat separation directly adjacent to metallic prostheses in areas where the gradient of the inhomogeneity is most severe. Based on the results shown in figure 7, upper limits of the color-map (black) were chosen to depict regions where the local intra-voxel off-resonance exceeds 6 ppm (383 Hz at 1.5T, 766 Hz at 3T), the point at which intra-voxel off-resonance causes water-fat separation to break down for SNR = 20. White, dotted contour lines represent labeled iso-distances (mm) from the implant surface.

Article Snippet: In order to validate the simulations of off-resonance used in this study, B 0 inhomogeneity was estimated (described below) using a 3D digital model of the same femoral head prosthesis obtained via 3D laser scanning with sub millimeter resolution (ShapeGrabber, Ottawa, ON, Canada).

Techniques: Labeling