G Protein-Coupled Receptors Regulated by Membrane Potential

G protein-coupled receptors (GPCRs) are involved in a vast majority of signal transduction processes. Although they span the cell membrane, they have not been considered to be regulated by the membrane potential. Numerous studies over the last two decades have demonstrated that several GPCRs, including muscarinic, adrenergic, dopaminergic, and glutamatergic receptors, are voltage regulated. Following these observations, an effort was made to elucidate the molecular basis for this regulatory effect. In this review, we will describe the advances in understanding the voltage dependence of GPCRs, the suggested molecular mechanisms that underlie this phenomenon, and the possible physiological roles that it may play.     

Macrolocalization of plastic flow in zinc single crystals oriented for basal glide

The pattern of plastic flow macrolocalization in actively loaded zinc single crystals has been studied. The character of localization consistently varies in accordance with the stage of plastic flow. The results are compared to the analogous data for single crystals with an fcc lattice. The common features and individual peculiarities in evolution of the patterns of plastic flow localization in materials with different crystal structures are revealed.     

Selection of the parameters of a probe during immersion ultrasonic inspection

The effect of a considerable reduction in the frequency of the echo-signal-spectrum peak during loading of a normal transceiver with an immersion medium as compared to loading with steel is established experimentally and theoretically. A theoretical analysis of this phenomenon with the use of a simplified physical model of the probe’s channel is performed, and physical interpretation is presented. Recommendations for selecting certain parameters of probes, which are intended for the use in immersion testing, are suggested.     

Direct observation of a plastic deformation autowave in a zirconium alloy

An analysis is made of the evolution of local deformations during the elongation of samples of fine-grained zirconium alloy. It is established that the deformation distribution patterns exhibit ordered behavior where the types of ordering are closely related to the stages of the deformation curve. The results are compared with similar data from studies of the deformation fields of single-crystal and polycrystalline materials with different types of crystal structures and deformation micromechanisms. It is noted that all these similar results, including those of the present study, may be interpreted using autowave representations. Pis’ma Zh. Tekh. Fiz. 24, 26–30 (January 12, 1998)     

A Theoretical-Experimental Method of Estimating the Nonlinearity of Precision Digital-Analog Converters

The proposed method of estimating the nonlinearity of highly accurate digital-analog converters is based on subdivision of the conversion range of the converter into several parts. It is proposed to calculate the nonlinearity at the beginning and end of each part from the measured increments of the output signal of the converter. An analysis of the error in estimating the nonlinearity of the converter is given.