Deep microrelief measurement and stereo photography in scanning electron microscopy

Fundamental differences between standard photography and micro-object imaging in a scanning electron microscope are analyzed. Basic ways of taking stereograms with a scanning electron microscope by the object rotation method and the observing technique are described. It is shown that stereo photography correctly estimates the spatial arrangement of features in objects with an intricate microrelief and makes it possible to very accurately calculate the depth of this relief (which sometimes exceeds the field of vision at large magnifications) in wide limits (from 0.5 to 100.0 μm). Using the developed surface of Li₄Ti₅O1₂ oxide and GaAs whiskers as examples, a stereographic computational method based on linear measurements of the same area on the object before and after rotation is demonstrated.     

Electrophysiological Activity and Survival Rate of Rats Nervous Tissue Cells Depends on D/H Isotopic Composition of Medium

The deuterium content modification in an organism has a neuroprotective effect during the hypoxia model, affecting anxiety, memory and stress resistance. The aim of this work was to elucidate the possible mechanisms of the medium D/H composition modification on nerve cells. We studied the effect of an incubation medium with a 50 ppm deuterium content compared to a medium with 150 ppm on: (1) the activity of Wistar rats’ hippocampus CA1 field neurons, (2) the level of cultured cerebellar neuron death during glucose deprivation and temperature stress, (3) mitochondrial membrane potential (MMP) and the generation of reactive oxygen species in cultures of cerebellar neurons. The results of the analysis showed that the incubation of hippocampal sections in a medium with a 50 ppm deuterium reduced the amplitude of the pop-spike. The restoration of neuron activity was observed when sections were returned to the incubation medium with a 150 ppm deuterium content. An environment with a 50 ppm deuterium did not significantly affect the level of reactive oxygen species in neuron cultures, while MMP decreased by 16–20%. In experiments with glucose deprivation and temperature stress, the medium with 50 ppm increased the death of neurons. Thus, a short exposure of nerve cells in the medium with 50 ppm deuterium acts as an additional stressful factor, which is possibly associated with the violation of the cell energy balance. The decrease in the mitochondrial membrane potential, which is known to be associated with ATP synthesis, indicates that this effect may be associated with the cell energy imbalance. The decrease in the activity of the CA1 field hippocampal neurons may reflect reversible adaptive changes in the operation of fast-reacting ion channels.     

Measuring the Electric Field Strength of Microwave Radiation at the Frequency of the Radiation Transition Between Rydberg States of Atoms 85Rb

Optics and Spectroscopy - The spectral characteristics of the resonance effect of the electromagnetic-induced transparency (EIT) of rubidium atomic vapors induced by intense radiation with a...     

Monte Carlo Simulation of Hydrogen Absorption in Palladium and Palladium-Silver Alloy

Russian Physics Journal - The paper presents Monte Carlo simulation of the hydrogen absorption in palladium and palladium-silver alloy of the composition PdxAg1–x (x = 0.7–0.9) at...     

Effect of Laser-Induced Optical Breakdown on the Structure of Bsa Molecules in Aqueous Solutions: An Optical Study

The influence of laser radiation of a typical surgical laser on the physicochemical properties of the Bovine Serum Albumin (BSA) protein was studied. It was established that the physicochemical characteristics of optical breakdown weakly depend on the concentration of protein molecules. At the same time, the patterns observed for an aqueous solution of BSA irradiated with a laser for different time periods were extremely similar to the classical ones. It was established that after exposure to laser radiation, the optical density of protein solutions increases. At the same time, the intensity of BSA fluorescence due to aromatic amino acid residues decreases insignificantly after exposure to laser radiation. In this case, the position of the excitation and emission maximum does not change, and the shape of the fluorescence spot on 3D maps also does not change significantly. On the Raman spectrum after exposure to laser radiation, a significant decrease in 1570 cm⁻¹ was observed, which indicates the degradation of α-helices and, as a result, partial denaturation of BSA molecules. Partial denaturation did not significantly change the total area of protein molecules, since the refractive index of solutions did not change significantly. However, in BSA solutions, after exposure to laser radiation, the viscosity increased, and the pseudoplasticity of aqueous solutions decreased. In this case, there was no massive damage to the polypeptide chain; on the contrary, when exposed to optical breakdown, intense aggregation was observed, while aggregates with a size of 400 nm or more appeared in the solution. Thus, under the action of optical breakdown induced by laser radiation in a BSA solution, the processes of partial denaturation and aggregation prevail, aromatic amino acid residues are damaged to a lesser extent, and fragmentation of protein molecules is not observed.     

Justification of an integro-functional method for diffraction problems in the presence of a half-space

In the present paper, we consider the discrete sources method as applied to the analysis of a scalar problem of the diffraction of a plane wave on a particle partly immersed in an absorbing half-space. The convergence of the method is proved with the use of a system of surface integral equations. We prove the Fredholm property of the obtained system and its unique solvability.     

On the mechanism of current instability in organic semiconductors

A mechanism responsible for current instability effects at the metal — organic film — aqueous solution of organic semiconductor interface is developed and discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 3–5, November, 2005.     

Magneto-optical Kerr effect enhancement at the Wood's anomaly in magnetoplasmonic crystals

Magneto-optical Kerr effect enhancement in longitudinal and transversal configurations is systematically studied in one- and two-dimensional magnetoplasmonic crystals based on the nanostructured nickel films. Spectral dependences of magneto-optical effects demonstrate resonant features with the Fano-type lineshape in the spectral vicinity of the Wood's anomaly associated with excitation of surface magnetoplasmons in Voigt and Faraday configurations, respectively.