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A set of experimental and measurement techniques to study the influence of a plasma jet on the main material parameters of piezoelectric ceramics has been presented. A series of plasma experiments has been carried out using a pulsed plasma jet system. It allows of a metered-dose exposure to plasma of different composition and fluence with a constant particle flux density of 1021/m2, energy flux density of 0.1 MJ/m2 and average particle energy of 100–200 eV in a pulse duration of 15 μs. The study of the effects that a repeated exposure to an extreme heat flux of helium and hydrogen plasmas has on the near-surface layer structure and basic material parameters of mass-produced piezoelectric ceramic samples has been presented. The main result of the research is an experimental confirmation of the surface micro-structuring starting after just a few cycles of plasma exposure while only a slight decrease of the main material parameters as well as the preservation of polarization has been observed for two types of different compositions of PZT-ceramics. A further increase in the number of exposure pulses leads to practically no change of main material parameters of both ceramics, even showing a tendency for recovery instead. [ABSTRACT FROM AUTHOR]

Introduction Primary sensory coding of noxious stimuli is known to be based on specific physiological responses of the polymodal sensory receptors. The nociceptive system plays a key role in terms [...], In the primary sensory neuron, ouabain activates the dual mechanism that modulates the functional activity of [Na.sub.V]1.8 channels. Ouabain at endogenous concentrations (EO) triggers two different signaling cascades, in which the Na,K-ATPase/Src complex is the EO target and the signal transducer. The fast EO effect is based on modulation of the [Na.sub.V]1.8 channel activation gating device. EO triggers the tangential signaling cascade along the neuron membrane from Na,K-ATPase to the [Na.sub.V]1.8 channel. It evokes a decrease in effective charge transfer of the [Na.sub.V]1.8 channel activation gating device. Intracellular application of PP2, an inhibitor of Src kinase, completely eliminated the effect of EO, thus indicating the absence of direct EO binding to the [Na.sub.V]1.8 channel. The delayed EO effect probably controls the density of [Na.sub.V]1.8 channels in the neuron membrane. EO triggers the downstream signaling cascade to the neuron genome, which should result in a delayed decrease in the [Na.sub.V]1.8 channels' density. PKC and p38 MAPK are involved in this pathway. Identification of the dual mechanism of the strong EO effect on [Na.sub.V]1.8 channels makes it possible to suggest that application of EO to the primary sensory neuron membrane should result in a potent antinociceptive effect at the organismal level. Key words: nociception, sensory neuron, organotypic nerve tissue culture, patch-clamp method, Na,K-ATPase. Dans le neurone sensoriel principal, la ouabaine active le double mode d'action qui module l'activite fonctionnelle des canaux [Na.sub.V]1.8. A des concentrations endogenes, la ouabaine (OE) declenche deux cascades de signalisation differentes, dans lesquelles le complexe Na,K-ATPase/Src constitue la cible de la OE et le transducteur du signal. L'effet rapide de la OE est fonde sur la modulation du dispositif d'activation des portes des canaux [Na.sub.V]1.8. La OE declenche une cascade de signalisation tangentielle le long de la membrane neuronale de la Na,K-ATPase aux canaux [Na.sub.V]1.8. Elle suscite un abaissement du transfert de charges efficace du dispositif d'activation des portes des canaux [Na.sub.V]1.8. L'application intracellulaire d'un inhibiteur de la Src kinase, le PP2, permettait d'abolir l'effet de la OE, ce qui montrait l'absence de liaison directe de la OE avec les canaux [Na.sub.V]1.8. L'effet retard de la OE commande probablement la densite des canaux [Na.sub.V]1.8 dans la membrane neuronale. La OE declenche la cascade de signalisation en aval vers le genome neuronal, ce qui devrait se solder par une diminution retard de la densite des canaux [Na.sub.V]1.8. La PKC et la MAPK p38 jouent un role dans cette voie de signalisation. La caracterisation du double mode d'action du puissant effet de la OE sur les canaux [Na.sub.V]1.8 permet de laisser entendre que l'application de OE sur la membrane du neurone sensoriel principal devrait se solder par un puissant effet antinociceptif au niveau de l'organisme. [Traduit par la Redaction] Mots-cles: nociception, neurone sensoriel, culture de tissu nerveux organotypique, methode de patch-clamp, Na,K-ATPase.

The effect of lattice relaxation instability (martensitic transition) on piezoelectric fields (EPE) in spontaneously ordered GaInP2/GaAs epitaxial layers was demonstrated using scanning Kelvin probe microscopy in combination with electron microscopy and optical spectroscopy measurements. The transition manifests itself in the dependence of the surface potential of the epi-layer on the mechanical (cleavage) and thermal (annealing) impacts. This is associated with a switching of the crystal lattice between relaxed and strained martensitic states, corresponding to a change in EPE in the epi-layer. The measured surface potential values (0.2–2.4 V) correspond to EPE within ±100 kV/cm and a strong decrease in |EPE| with increasing layer thickness, indicating the pinning of the Fermi level and piezoelectric doping. Our results open up the prospects for using spontaneously ordered semiconductor alloys to control electronic states in semiconductor nanostructures by controlling their piezoelectric fields. [ABSTRACT FROM AUTHOR]

In hydrosilicates with the structure of chrysotile, pecoraite, and halloysite, elastic strains in the composite hydrosilicate layer are compensated by folding into nanoscrolls. A wide range of such particles with different compositions can be produced by hydrothermal synthesis, which, together with the structural and morphological characteristics, makes them promising adsorbents, capsules, catalysts, and reinforcing components of composite materials. For such potential applications as magnetically controlled adsorbents and catalysts, ferromagnetic chemical elements are included in the composition of the nanoscrolls. Studies of the individual nanoscrolls require special approaches. This article discusses the use of atomic force microscopy for such studies. [ABSTRACT FROM AUTHOR]