Key Points Question Does the pathological α-synuclein (αSyn P ) detected by immunohistochemistry in the skin of individuals with Parkinson disease (PD) have aggregation seeding activity, and is skin αSyn P seeding activity a potential biomarker for diagnosis of PD and other synucleinopathies? Findings In this diagnostic study including skin samples from 160 autopsies and 41 biopsies, a statistically significant increase in αSyn P seeding activity was observed in individuals with PD and synucleinopathies compared with controls with tauopathies and nonneurodegenerative diseases. Meaning Skin αSyn P has aggregation seeding activity in patients with PD and non-PD synucleinopathies and may be a biomarker for antemortem diagnosis of PD and other synucleinopathies.

The mechanism of phase transformation in nanocrystalline TiO 2 powders at ambient temperature during high energy ball milling and the role of brookite phase in anatase-to-rutile phase transformation were investigated by the use of Rietveld analysis of X-ray diffraction patterns and Raman spectroscopy methods. The milling process was performed on a fully anatase phase nanocrystalline TiO 2 powder via a high energy planetary ball mill with different ball-to-powder weight ratios followed by annealing of the as-milled samples. Some transformation from anatase-to-brookite was observed in all as-milled powders by high resolution transmission electron microscopy. It was proposed that brookite occurs at the {112} twin surfaces of anatase phase and therefore promotes anatase-to-rutile phase transformation. Based on the XRD and Raman results, it was proposed that brookite appears as an essential intermediate phase in mechanically induced anatase-to-rutile phase transformation which facilitates the phase transformation at ambient temperatures and also at higher temperatures during the post-annealing step.