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The dependence of the conductivity of the films of hafnium oxide HfO2synthesized in different modes is studied. Depending on the modes of synthesis, the conductivity of HfO2at a fixed electric field of 1.0 MV/cm changes by four orders of magnitude. It is found that the conductivity of HfO2is limited by the model of phonon-assisted tunneling between the traps. The thermal and optical energies of the traps Wt= 1.25 eV and Wopt= 2.5 eV, respectively, in HfO2are determined. It is found that the exponentially strong scattering of the conductivity of HfO2is due to the change in the trap density in a range of 4 × 1019–2.5 × 1022cm–3. In the cathodoluminescence spectra of HfO2, a blue band with the energy of 2.7 eV is observed which is due to the oxygen vacancies. A correlation between the trap density and intensity of cathodoluminescence, as well as between the trap density and refractive index, is found. A nondestructive in situ method for the determination of the trap density of hafnium oxide with the use of the measurement of the refractive index is proposed. The optimum values of the concentrations of oxygen vacancies for emitting devices on the basis of the films of HfO2are found.

Nanocrystalline yttrium oxide (Y2O3) thin films were made by sputter deposition onto silicon (100) substrates keeping the deposition temperature fixed at 300 °C. The surface/interface chemistry, Y–O bonding, and optical constants of the Y2O3film surface and Y2O3–Si interface were evaluated by the combined use of X-ray photoelectron spectroscopy (XPS), depth-profiling, and spectroscopic ellipsometry (SE). XPS analyses indicate the binding energies (BEs) of the Y 3d doublet; i.e., the Y 3p5/2and Y 3d3/2peaks are located at 117.0 and 119.1 eV, respectively, characterizing yttrium in its highest chemical oxidation state (Y3+) in the grown films. The optical model is constructed based on the XPS depth profiles, which indicate that the Y2O3//Si heterostructure can be represented with Y2O3filmYxSiyOzinterfacial compoundSi substrate. Such a model accounts for the experimentally determined ellipsometry functions and accurately produces the dispersive index of refraction (n(λ)) of Y2O3and YxSiyOz. The n(λ) of Y2O3and YxSiyOzfollows Cauchy’s dispersion relation, while the YxSiyOzformation accounts for degradation of optical quality.

A delayed visual differentiation task using stimuli of different colors was used in rhesus macaques to study the characteristics of visual recognition, short-term memory, and the responses of neurons recorded simultaneously in the visual and prefrontal areas of the cortex, along with their relationships with the site of intracortical (fields 17 or 46) perfusion of the glutamate receptor antagonist 2-amino-5-phosphonovaleric acid (APV). The behavioral characteristics and spike activity of individual cells in cortical fields 17 and 46 were recorded before and after perfusion with APV and after washing away of traces of APV. Multifactor dispersion analysis showed that the effect of APV in monkeys consisted of decreases in the probability of correct responses, leading to a decrease (two-fold) in the duration of short-term storage of information and a significant increase in the motor reaction time. The probability of correct solutions depended on the site of APV perfusion in the cortex, while the motor response time was independent of the perfusion site. Perfusion of field 46 with APV, unlike perfusion of field 17, altered the spike activity only of neurons in the prefrontal cortex, while no significant changes were seen in the neuron activity of the visual cortex. The actions of APV were accompanied by significant desynchronization of neuron activity in these two areas as compared with the level of synchronization in normal conditions; after traces of APV were washed away, the extent of desynchronization decreased. The neurophysiological correlates of cognitive dysfunctions associated with degradation of visual recognition and short-term memory due to modification of glutamatergic structures by blockade of NMDA receptors are discussed.

The effects of perfusion of field 17 with the glutamate receptor antagonist 2-amino-5-phosphonovaleric acid (APV) on the characteristics of visual recognition and short-term memory were studied, along with the effects of APV on the responses of neurons in the visual and prefrontal areas of the cortex in rhesus macaques. In the test for delayed visual differentiation of stimuli of different colors, behavioral data were recorded simultaneously with multichannel recordings of the spike activity of single cells in cortical field 17 (directly within the microdialysis zone) and field 8. Multifactor dispersion analysis (ANOVA) showed that APV significantly worsened the behavioral characteristics in monkeys, with significant reductions in the duration of short-term storage of information (by factors of 2–4) and significant increases in the motor response times. These changes in cognitive characteristics induced by APV were accompanied by changes in the spike activity of neurons in the visual and prefrontal areas of the cortex during the sensory analysis and delay stages; changes in spike activity consisted of significant desynchronization. These results show that cognitive dysfunctions consisting of worsening of short-term remembering of information and increases in the duration of motor responses during exposure to APV may be caused by desynchronization of neuron activity in various areas of the cortex, these being involved in neuron ensembles responsible for the mechanisms of short-term memory, in which glutamatergic structures play an important role.

Thermodesorption processes of mono-and multilayers of fatty acids and their salts with 14 to 24 carbon atoms were investigated by ellipsometry and IR spectroscopy. Cadmium, calcium, strontium, and barium salt layers, unlike the layers of pure acids, have a complex phase composition which includes not only separate acid and salt phases, but also intermediate acid-salt forms. The initial phase composition of multilayer systems determines their thermodesorption spectrum observed upon heating the samples. It was found that before the removal of molecules to the gaseous phase, phase transitions are possible in the films, similar to those observed in crystals and caused by the change of molecular conformations in the layer. Energy characteristics of thermodesorption processes are estimated for pure acid layers and for separate phases in salt layers. Possible qualitative models of the processes are discussed.

Abstract: The effects of modification of NMDA-ergic structures by microdialysis perfusion in the prefrontal cortex (field 8) with NMDA glutamate (2 mM) on visual recognition and short-term memory (STM) were studied in rhesus macaques, using methods based on the deferred differentiation of stimuli of different colors. Impulse activity of neurons in the prefrontal and visual cortex was measured during these experiments, both before and after administration of NMDA. NMDA increased (2-fold) the duration of short-term retention of information and significantly reduced the latent period of the motor response at all delay periods, and also produced significant changes in neuron activity in the prefrontal cortex: depending on the stage of behavior, activity decreased in 60–75% of neurons and increased in 8–26%. NMDA produced significant increases in the cross-correlation coefficients between the responses of neurons in the visual and prefrontal cortex. The results showed that glutaminergic structures in the prefrontal cortex are involved in processes of visual recognition and STM in monkeys. The effect of NMDA, which synchronized cortical neuronal processes, improved the short-term understanding of visual information.

Abstract: After the injection of the antioxidant, oxymethacil (4–5 μg/kg), in an investigation in monkeys of the processes of delayed visual recognition, their cognitive characteristics were significantly improved.: the duration of the short-term storage of information increased (by a factor of 2–3) and the time of the motor reaction decreased. The improvement of the cognitive characteristics was accompanied by changes in the neuronal activity in the visual cortex at all stages of recognition. The activity of the majority of the neurons increased in the case of discrimination without delay; it decreased significantly in the case of delayed discrimination. The administration of oxymethacil induced an increase in the auto-and cross-correlation coefficients in the respondent reactions of the recorded groups of neurons. The results obtained suggest that oxymethacil possesses nootropic properties, and the participation of the visual cortex of monkeys in the realization of these properties for the improvement of cognitive characteristics.

Abstract: Monkeys performed a task of delayed visual differentiation of differently colored stimuli in behavioral experiments. The impulse activity of individual neurons of the prefrontal and inferotemporal cortex before and after the systemic administration of a blocker of M-cholinoreceptors, amyzil (0.8–1.0 mg/kg), was recorded simultaneously. Deterioration of the characteristics of recognition induced by amyzil was accompanied mainly by a significant increase in the activity of neurons of the prefrontal cortex which was dependant on the stage of recognition, and intensified with an increase in the delay interval. The impulse activity of the neurons of the inferotemporal cortex varied in the process without a regular pattern: at some stages of recognition it increased, at others it was inhibited. Amyzil induced a substantial decrease in the coefficients of cross correlation between the simultaneous respondent reactions of groups of neurons of the prefrontal and inferotemporal cortex. The results obtained point to the fact that the cholinergic structures of the inferotemporal and prefrontal cortex participate, at various stages of visual recognition in monkeys, in the formation of the dynamic functional systems which make their specific contribution to informational processes.

Abstract: The impulse activity of individual neurons of the prefrontal and inferotemporal cortex was recorded during the performance of a task of delayed visual differentiation of stimuli of various colors in monkeys before and after the systemic administration of the antioxidant, oxymethacil (4–5 mg/kg). The improvement in cognitive characteristics induced by oxymethacil was accompanied by changes in the activity of neurons of the prefrontal cortex in which activation dependant upon the stage of recognition and intensifying during an increase in the duration of the delay predominated. Inhibition of activity predominated during recognition without delay in these neurons; by contrast, activation predominated in neurons of the inferotemporal cortex under these conditions. During delayed differentiation, the activity of these neurons under the influence of oxymethacil changed principally in the same way as in neurons of the prefrontal cortex: activation predominated in the majority of the stages of recognition. Oxymethacil induced a substantial increase in the coefficients of cross correlation between simultaneous respondent reactions of groups of neurons in these different areas of the cortex. The results obtained attest to the contribution of neuronal structures of the prefrontal and inferotemporal cortex to the improvement of cognitive characteristics of monkeys in the presence of the effect of oxymethacil, and to the increase in synchronization of informational processes in these regions of the cortex.

Abstract: The activity of individual neurons of the visual cortex was recorded simultaneously in behavioral experiments on monkeys before and after the systemic administration of a blocker of M-cholinoreceptors, amizil (0.8–1.0 mg/kg). The animals were trained to delayed visual differentiation of stimuli of various colors. After the administration of amizil, the characteristics of recognition deteriorated substantially: the duration of the storage of information in short-term memory sharply declined, while the time of the motoric reaction increased. The deterioration of these characteristics was accompanied by inhibition of the activity of the neurons of the visual cortex, inhibition which depended on the stage of recognition, and which intensified when there was an increase in the delay interval. The results obtained suggest that cholinergic mechanisms of the visual cortex are included in visual recognition, and apparently play various functional roles at various stages of behavior.

The influence of an effective antioxidant, oxymethacil, was studied in a model of the disruption of visual recognition induced by the antidepressant fluoracyzine. The normal discrimination of black and white visual stimuli in monkeys is restored with the systemic administration of oxymethacil in a dose of 3 mg/ kg following disruption brought about by the effect of fluoracyzine. The discrimination of colored visual stimuli, as in the norm, is restored following the systemic administration of oxymethacil in a dose of 4 mg/kg. The results obtained attest to the corrective properties of oxymethacil.

We discuss a method of measurement of particle velocity behind a shock-wave front in a condensed dielectric medium. The method is based on recording of the electromotive force(emf) that is induced in a current-carrying coil when the shock wave deforms it. A toroidal probe coil was used to reduce electrical noise. A current of 500 A was supplied to the coil by means of aperiodic discharge of a capacitor. The recordedemf amplitude is proportional to the measured particle velocity and equals 20 V for a velocity of1 km/sec. The influence of some phenomena accompanying shock-wave propagation along the coil on the accuracy of the particle-velocity measurements was estimated.

Abstract: A model of brief oxygen supply disruption was created in monkeys trained to a delayed visual spatial choice. A substantial reorganization of the impulse activity of neurons of the visual and prefrontal cerebral cortex, accompanied by disturbances in behavioral reactions, was observed during brief hypoxia (2.5 min); the motor reaction was not restored for several hours in the monkeys during a delayed visual spatial choice. The reorganization of the activity consisted in the appearance of successive phases of hyperactivation and inhibition. The frequency of the impulse activity in the phase of hyperactivation was higher in prefrontal cortex neurons. Successive phases of inhibition and hyperactivation were also identified in the posthypoxic period of restoration in the structure of the activity. The duration of the posthypoxic inhibition and the ratio of the frequencies of posthypoxic hyperactivation to the baseline frequency in the reactions of prefrontal cortex neurons was substantially greater than in the neurons of the visual cortex.

Abstract: The impulse activity of groups of neurons of the visual, prefrontal, and inferotemporal cortex was recorded simultaneously in behavioral experiments on monkeys solving a problem of delayed visual differentiation of variously colored stimuli. The neurophysiological correlates of the decision-making processes were studied. Erroneous motoric reactions were accompanied in all monkeys by significant reorganizations of the patterns of impulse activity of the neurons. In the case of correct solutions of the monkeys, synchronization in time and cross-correlation which was significant in magnitude between the activity of the groups of neurons were observed. Incorrect solutions were accompanied by desynchronization and by a decrease in cross-correlation between the activity of these groups of neurons. Possible decision-making mechanisms and the causes of the desynchronization of the informational processes during erroneous reactions are discussed.

Behavioral experiments were carried out in which monkeys had to solve a task involving delayed visual discrimination, and activity was simultaneously recorded from several neurons of the visual, prefrontal, and lower temporal regions of the cortex before and after modification of cholinergic (by systemic infusion of the M-cholinoceptor blocker amizil) and glutaminergic (by intracortical perfusion with glutaminergic agonists and antagonists, i.e., NMDA, aminophosphonovalerianic acid (APV) and aminophosphonobutyric acid (APB)) systems. Amizil and APV reduced the duration of short-term information retention and increased the delay before the motor response was made. Worsening of these parameters was accompanied by a significant level of desynchronization of activity in the groups of neurons studied. NMDA and APB improved short-term memory and increased neuron synchronization. The role of synchronization of information processes in the mechanisms of short-term memory and the involvement of the cholinergic and glutaminergic systems are discussed.

The effect of intracortical perfusion with the glutamate agonist NMDA on visual recognition and short-term memory, as well as on the responses of visual cortex neurons, were studied in rhesus macaques. A microdialysis technique was used in combination with multichannel microelectrode recording of single cortical cells in the immediate vicinity of the dialysis tube in a behavioral experiment in which the monkey had to solve a task involving delayed visual differentiation of stimuli of different colors. NMDA altered the characteristics of recognition in monkeys. The duration of information storage in short-term memory was increased significantly (2–4-fold), and there was a significant reduction in the motor response time for all delay periods. These changes were accompanied by a significant rearrangement of neuron activity in the visual cortex at all stages of the behavioral task. At different stages of the task, 70–85% of the neurons showed 2–5-fold increases in activity, while 6–20% showed reductions in activity. These results demonstrate an involvement of visual cortex glutaminergic structures in the processes of visual recognition and short-term memory, as well as a nootropic effect obtained by intracortical administration of NMDA.

The quinoline ring in imidazo[4,5-f]quinolines is more reactive than the imidazole ring with respect to nucleophiles (phenyllithium and sodium amide). An assumption, which is confirmed by molecular orbital calculations and the pKa values, is expressed that the direction of the corresponding reactions is primarily determined by the relative basicity of the aza groups (the nucleophile attacks the C atom next to the more basic nitrogen atom) and not by the magnitude of the positive charge or the energy of anionic localization on the C2 and C7 atoms in the neutral molecule.

It was shown by IR spectroscopy that 2-benzazolonitrile oxides, which are formed by the action of triethylamine on 2-benzazolylmethylhydroxamoyl chlorides, are extremely labile; the presence and nature of a substituent near the fulmide group and the basicity of the heterocyclic fragment of the molecule have a great effect on their stabilities.

Experiments with application of the "Ellips-SPEK" spectral ellipsometric SPR (Surface Plasmon Resonance) analyzer, validating the results on the basis of ProteOn XPR36, revealed the differences in the values of velocity constants of specific interactions of monoclonal highly specific antibodies with tumor M2-pyruvate kinase on the surface of blood serum biochips in patients with various stages colorectal carcinoma (CRC) and location of metastases (AUC 0.89). Scanning ellipsometry enabled to reveal a significant increase of biomolecule surface effective thickness resulting from the specific "antigen-antibody" interaction in the group of patients with extrahepatic and hepatic metastases, as compared to the control group with healthy patients (p<0.0001-0.05). Raman spectroscopy of blood serum demonstrated the differences in peak intensity within the range of 1005-1520 cm-1 in the same groups of patients (p<0.0001-0.05) with a 90% predictive accuracy of the method applied at early stages of the disease. The results obtained can be used for development of methods for early diagnosis of CRC, localization of different metastases, relapses and control of the quality of administered therapy.

The aim of this work was to assess the potential of the optical methods for studying erythrocytes (Er) and blood serum (BS) of patients with colorectal cancer (CC).

The aim of this work was to study red blood cells (RBC) electrical, viscoelastic properties, the levels of intracellular macroergic compounds, changes in the conformation of porphyrin, content of hemoglobin (Hb) complexes of patients with resistant hypertension (RH) for identification of pathogenic features of the disease.