Charge transport mechanism in the forming-free memristor based on silicon nitride.

Nonstoichiometric silicon nitride SiN is a promising material for developing a new generation of high-speed, reliable flash memory device based on the resistive effect. The advantage of silicon nitride over other dielectrics is its compatibility with the silicon technology. In the present work, a silicon nitride-based memristor deposited by the plasma-enhanced chemical vapor deposition method was studied.

Electronic structure and charge transport mechanism in a forming-free SiO -based memristor.

THe memristor is a key memory element for neuromorphic electronics and new generation flash memories. One of the most promising materials for memristor technology is silicon oxide SiO , which is compatible with silicon-based technology. In this paper, the electronic structure and charge transport mechanism in a forming-free SiO -based memristor fabricated with the plasma enhanced chemical vapor deposition method is investigated.

Possible Differential Diagnosis of the Degrees of Rheological Disturbances in Patients with Type 2 Diabetes Mellitus by Dielectrophoresis of Erythrocytes.

Unlabelled: Hemorheological disorders in structural and functional parameters of erythrocytes are involved in the pathological process in type 2 diabetes mellitus (DM).

Aim: to investigate the feasibility of differential diagnosis of the degrees of rheological disturbances in patients with type 2 DM by dielectrophoresis of erythrocytes.

Methods: 62 subjects (58.

Nanoscale potential fluctuations in nonstoichiometrics tantalum oxide.

The atomic and electronic structure of nonstoichiometric amorphous tantalum oxide (TaO ) films of different composition has been investigated by means of electron microscopy, x-ray photoelectron spectroscopy, Raman and infrared spectroscopy. The dispersion of the absorption coefficient and refraction index has been studied by spectral ellipsometry. The optical spectra were interpreted using the results of a quantum-chemical simulation for crystalline orthorhombic TaO .

Charge Transport and the Nature of Traps in Oxygen Deficient Tantalum Oxide.

Optical and transport properties of nonstoichiometric tantalum oxide thin films grown by ion beam deposition were investigated in order to understand the dominant charge transport mechanisms and reveal the nature of traps. The TaO films composition was analyzed by X-ray photoelectron spectroscopy and by quantum-chemistry simulation. From the optical absorption and photoluminescence measurements and density functional theory simulations, it was concluded that the 2.

[MODERN METHODS OF PHYSICAL-CHEMICAL RESEARCH IN GASTROENTEROLOGY PRACTICE: THE EXPERIENCE OF INTERACTION].

Unlabelled: The aim of this work was to assess the potential of some physical and chemical methods for studying erythrocytes and blood serum in gastroenterological practice by the example of colorectal cancer (CC).

Materials And Methods: A total of 26 persons with various stages of colorectal cancer and 16 healthy (control group) were examined. Parameters of erythrocytes and blood serum were investigated by light microscopy, dielectrophoresis in a non-uniform alternating electric field (DEF in NUAEF), terahertz spectroscopy, ellipsometry, Raman-spectroscopy.

Optical properties of LiGaS(2): an ab initio study and spectroscopic ellipsometry measurement.

Electronic and optical properties of lithium thiogallate crystal, LiGaS(2), have been investigated by both experimental and theoretical methods. The plane-wave pseudopotential method based on DFT theory has been used for band structure calculations. The electronic parameters of Ga 3d orbitals have been corrected by the DFT+U methods to be consistent with those measured with x-ray photoemission spectroscopy.

Neurophysiological correlates of delayed visual differentiation tasks in monkeys: the effects of the site of intracortical blockade of NMDA receptors.

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 effects of an NDMA receptor antagonist on delayed visual differentiation in monkeys and rearrangements of neuron spike activity in the visual and prefrontal areas of the cortex.

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.

[Neurophysiological correlates of delayed visual differentiation in monkeys: effect of location of the NMDA-receptor intracortical blockade].

A multi-factor variance analysis revealed that the 2-amino-5-phosphonovalerian acid (APV) effect was manifested in monkeys by a decrease in the number of correct responses entailing a two-fold shortening of the short-term information storage, as well as by an augmentation of the motor responses' time. The correct responses' probability depended on the APV diffusion localisation in the cortex whereas the motor responses' time did not depend on it. The APV effect was accompanied by a desynchronisation of the unit activity in fields 46 and 17.

[Effect of the NMDA receptor antagonist on parameters of delayed visual differentiation and rearrangement of the impulse activity of neurons in visual and prefrontal cortices in monkeys].

With the aid of a multichannel leads the unit activity was recorded in the 17th and 8th cortical fields along with registering behavioural data in Rhesus monkeys. Multi-factor variance analysis revealed that the 2-amino-5-phospho-valeric acid (APV) effect involved a significant worsening of the monkeys' behavioural characteristics: duration of the short-term memory shortened (2-4-fold), motor reactions' time increased, and the changes of cognitive characteristics were always followed by significant rearrangements of the unit activity in the above areas. The data obtained suggest that these cognitive dysfunctions are due to a desynchronisation of unit activity in different areas of the cortex including the neuronal assemblies maintaining the short-term memory mechanisms associated with the glutamatergic structures.

Synchronization processes in the mechanisms of short-term memory in monkeys: the involvement of cholinergic and glutaminergic cortical structures.

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.

Effect of NMDA on the activity of cortical glutaminergic structures in delayed visual differentiation in monkeys.

The effect of intracortical perfusion with the glutamate agonist NMDA on visual recognition and short-term memory, as well as an 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.

Neurophysiological correlates of improvements in cognitive characteristics in monkeys during modification of NMDA-ergic structures of the prefrontal cortex.

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%.

Dynamics of the impulse activity of neurons of the neocortex of monkeys in a visual recognition task after brief oxygen deprivation.

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.

Neurophysiologic correlates of the decision-making processes in the cerebral cortex of monkeys during visual recognition.

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.

[Synchronization processes in the mechanisms of short-term memory in monkeys: the participation of cholinergic and glutaminergic cortical structures].

Administration of amysil blocking M-cholinoreceptors, and APV the duration of short-term storing of information was decreased whereas the motor response time increased. This was followed by a considerable desynchronisation of the unit activity. The NMDA and APB improved the characteristics of the short-term memory.

[The neurophysiological correlates of improvement in the cognitive characteristics of monkeys with modification of the NMDA-ergic structures of the prefrontal cortex].

The effect of the NMDA glutamate agonist on cognitive characteristics and short-term memory (SM) was studied in rhesus monkeys. The NMDA effect manifested itself in doubling the SM term and in changing of the unit activity in the prefrontal cortex. The NMDA also induced a considerable increase in the cross-correlation coefficients between the unit responses in visual and prefrontal cortex.

[The dynamic impulse activity of the neocortical neurons in monkeys with the task of visual recognition after short-term oxygen starvation].

During a 2.5-min. hypoxia in monkeys, a rearrangement of the unit activity occurred in the visual and prefrontal cortex.

Participation of cholinergic structures of the prefrontal and inferotemporal cortex in the processes of visual recognition in monkeys.

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.

Influence of an antioxidant on the impulse activity of neurons of the prefrontal and inferotemporal cortex during visual recognition in monkeys.

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.

An antioxidant-induced improvement in the cognitive characteristics of monkeys: neurophysiological correlates in the visual cortex.

After the injection of the antioxidant, oxymethacil (4-5 micrograms/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 neurophysiological correlates of the processes of decision making in the cerebral cortex during visual recognition in monkeys].

In behavioral experiments on monkeys tested for a delayed visual differentiation of different colours stimuli, neuronal pools were recorded simultaneously in the visual, prefrontal and inferotemporal cortex. Wrong motor responses were always followed by considerable readjustments of the unit activity patterns whereas in right decisions a synchronisation and a cross-correlation occurred between neuronal pools. Possible mechanisms of the decision making and the reasons for the desynchronisation in wrong responses, are discussed.

Processes of visual recognition in monkeys and their neuronal correlates in the visual cortex: the influence of a blocker of M-cholinoreceptors.

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).