Functional MRI comparison of passive and active movement: possible inhibitory role of supplementary motor area:

Recent studies have hypothesized that the supplementary motor area plays a role in motor inhibition. To study this possible role, we used functional MRI study to compare conditions, which require various level of inhibition of motor patterns. Seventeen healthy participants were scanned while executing – actively or passively – rhythmic opening/closing movements of their right hand, with and without congruent visual information. The contrast passive>active movement in the visual guidance condition which requires inhibition in order ‘not’ to perform the movement, yields to significant activation of areas commonly involved in the inhibitory brain circuitry among which, notably, controlateral supplementary motor area

Effect of Dopants on Zirconia Stabilization—An X-ray Absorption Study: I, Trivalent Dopants

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65562/1/j.1151-2916.1994.tb06964.x.pd

On the possibility of synthesizing multilayered coatings in the (Ti,Al)N system by RGPP: A microstructural study

International audienceRadiofrequency magnetron sputtering combined with reactive gas pulsing process was used to synthesize two titanium aluminum nitride multilayer films using a periodically controlled nitrogen flow rate changing from 0.4 to 1 sccm (sample S04-1) and from 0 to 1 sccm (sample S0-1). A metallic TiAl buffer layer was deposited on the etched substrates before the deposition to enhance their adhesion. The films were characterized using mainly transmission electron microscopy and electron diffraction. The role of the crystallinity of the buffer TiAl metallic layer deposited before gas introduction on the growth orientations is emphasized. It is shown that the formation of a multilayer structure is conditioned by stopping periodically and completely the nitrogen flow rate. Particular attention is paid to the role that residual oxygen can play on the microstructure and to transient regime that occurs when the flow rate drops from 1 sccm to 0 sccm

Defect structure of yttria-stabilized zirconia and its influence on the ionic conductivity at elevated temperatures

The defect structure of cubic fluorite structured yttria-stabilized zirconia (ZrO2)(1-x)(Y2O3)(x) has been investigated over the composition range 0.100(3)less than or equal to x less than or equal to 0.241 (10) and temperatures T(K) up to 2780(10) K, using single-crystal specimens. Analysis of neutron and x-ray diffraction data, including both Bragg and coherent diffuse scattering components, has identified three principal types of defects within the fluorite lattice. At low yttria concentrations (xsimilar to 1000 K and give rise to the high ionic conductivity of the material. In light of these observations, we propose that the anomalous decrease in the ionic conductivity with increasing x is a consequence of the decreasing mobility of the isolated defects, possibly due to blockage by the increasing number of static aggregates. [S0163-1829(99)05621-0]