Neurophysiological signs of changes in the functional state of the nervous system in patients with vibration disease associated with type 2 diabetes mellitus

Introduction. Neurofunctional state is an essential criterion in assessing the quality of the regulatory mechanisms of autonomic and somatic functions that determine the prognosis and course of vibration disease associated with type 2 diabetes mellitus (DM2). Objective of the study is to identify neurophysiological signs of changes in the functional state of the nervous system in patients with vibration disease caused by the combined effects of local and general vibration (VD com.) in combination with DM2. Materials and Methods. The group I included (n = 33) - VD com. patients, group II - 30 cases with VD com., burdened with DM2. We used neuroenergy mapping (NEM), registration of somatosensory evoked potentials (SSEP). Statistica software was used for statistical processing. Results. Analysis of the severity of changes in DC-potential level in both groups established a statistically significant predominance of persons with an increased average DC-potential level. In group II, when compared with group I, there was an increase in the latency of components N9, N10, N11, N13, N18, N20, N25, N30, bipolar DC-potential level Cz-Pz, local DC-potential level in the central lead of the right hemisphere, decrease in DC-potential level in the central parietal region, bipolar pote ntials Fpz -Ts, Cz-Td, Pz-Oz. As a result of discriminant analysis, the following signs were obtained: indices of the latent period of the peak N13, the duration of the interpeak interval N10-N13, DC-potential level of the central parietal, right central, frontal right, frontal central leads. Discussion. The presence of DM2 in VD com. patients accompanied by disturbances in the neurofunctional state caused by a slowdown in the passage of an afferent impulse at the peripheral and central levels, a decrease in energy exchange in the frontal, central-parietal regions with its increase in the occipital, temporal parts of both hemispheres. Conclusion. Neurophysiological signs of changes in the functional state of the nervous system in VD com. patients with DM2 are a decrease in DC-potential level in the parietal central, frontal central, an increase in the latent period of the peak N13, the duration of the inter-peak interval N10-N13, DC-potential level in the central and frontal regions of the right hemisphere of the brain.

Sex-Related Differences in the Interhemispheric Asymmetry of Cerebral Energy Metabolism in Young People Living in the Arctic Zone of the Russian Federation

In the Arctic region, adaptive reactions of the body put pressure on its functional systems and are accompanied by changes in cerebral energy metabolism in the central nervous system. Despite the fact that patterns of interhemispheric asymmetry and interaction are part of the brain’s essential, fundamental mechanism, no data is currently available on the neurometabolic features of interhemispheric asymmetry in men and women living in the Arctic zone of the Russian Federation. The aim of this paper was to identify the differences in cerebral energy metabolism in men and women born and living in the Arctic zone of the Russian Federation with different types of interhemispheric asymmetry according to the distribution of DC-potential level. Materials and methods. The study involved 63 subjects (30 men and 33 women) aged 30–34 years born and living in Arkhangelsk. Cerebral energy metabolism was assessed using the 5-channel Neuro-KM hardware and software complex. Distribution of DC-potential level was analysed by mapping the monopolar values and calculating their gradients. To calculate interhemispheric asymmetry of cerebral energy metabolism, an interhemispheric gradient was used, i.e. the potential difference between the right and left temporal leads (Td-Ts). The obtained DC-potential level results were compared with average standard values. The results of the study indicate differences in the distribution of the processes of cerebral energy metabolism in men and women with different types of hemispheric dominance. The most balanced cerebral metabolism was identified in men with right hemisphere dominance and in women with left hemisphere dominance. The presence of sex-related differences in the hemispheric asymmetry of cerebral energy metabolism may reflect different strategies of adaptation to the climatic conditions of northern latitudes in men and women.

The Relationship between Neuropsychological Performance and Level of Direct Current Potential in Patients with Occupational Diseases from Exposure to Physical Factors

The aim of the study was to identify the peculiarities of neuropsychological indices disorders depending on changes in the level of constant potential in patients with occupational diseases as a result of physical factors.Materials and methods. The study involved 60 patients with vibration disease caused by local vibration (group I), 106 patients with vibration disease caused by combined exposure to local and general vibration (group II), 101 civil aviation pilots with an established diagnosis of professional sensorineural hearing loss (group III), and 50 healthy men (group IV, comparison group) who were not exposed to vibration and noise due to the specifics of their professional activities. Methods of neuro-energy mapping and neuropsychological testing were used.Results. In groups I–II, compared with group IV, an increase in local levels of constant potential (DC-potential level) in the central, right temporal, and central frontal parts of the brain (2.3 (6.5–3.8) mV; –0.3 (–2.1–2.1); 2.1 (–3.4–6.8) and –0.3 (–3.1–4.3); –2.24 (–6.4–3.8); 0.9 (–3.1–8.5) mV at p = 0.005, 0.007 and 0.004 respectively). Differences in the values of DC-potential level gradients in individuals of group III when compared with group IV reached the level of significance in the central, temporal, occipital leads relative to the central frontal (–5.0 (–13.1–3.8); –4.1 (–9.4–5.1); –2.1 (–10.9–6.6); –6.3 (–15.3–1.8) and 2.9 (–3.0–10.6); 2.2 (–4.5–13.8); 5.6 (–7.6–14.1); –1.4 (–7.5–3.9) mV at p = 0.008; 0.009; 0.009, and 0.007 respectively). Cognitive disorders in patients of groups I–III when compared with group IV correspond to a mild disorder of dynamic, constructive praxis and expressive speech (1.40 (0–1,6); 1.43 (0–1,7); 1.2 (0–1,5) and 0.3 (0–1); 0.2 (0–1); 0.06 (0–1) points at p = 0.008, 0.008 and 0.009 respectively).Conclusions. A common neurofunctional sign of a mild impairment of the cognitive sphere in occupational diseases caused by physical factors is an increase in direct current potential level in the frontal-central and parieto-occipital regions, predominantly of the left hemisphere of the brain.

Sex Differences in Cerebral Energy Exchange Among Residents of the Arctic Zone of the Russian Federation

This article presents the sexual characteristics of cerebral energy metabolism in young residents of the Arctic zone according to the distribution of the level of direct constant potential (DC-potential level) of the brain. The study involved 60 people (27 men and 33 women) aged 30-34 years, born and living in the Arctic territory. Assessment of cerebral energy exchange was carried out using a 5-channel hardware-software diagnostic complex «NeuroKM». The distribution of the DC-potential level was analyzed by mapping monopolar values and calculating their gradients. For statistical data processing, the SPSS Statistics26 software package was used. The obtained DC-potentials level results were compared with the average statistical standard values. As a result of the study, gender differences in cerebral energy exchange were revealed in working-age residents born and living in the Arctic zone, depending on gender. In the group of men, there is a higher intensity of cerebral energy exchange in the whole cerebral cortex, the absence of pronounced hemispheric dominance, activation of the central and frontal cortex. In women, there is no predominance of energy exchange in any one area, there are low total indicators, activation of the central and occipital regions of the cortex; connection of the central cortex with the temporal, right-hemisphere dominance of cerebral energy exchange processes. Conclusion. Men are characterized by centralization and tension of regulatory systems, which can be an unfavorable factor in ensuring long-term adaptation to the climatic conditions of the Arctic. Women have a more optimal level of cerebral energy exchange.

Crack Detection and Crack Length Measurement with the DC Potential Drop Method–Possibilities, Challenges and New Developments

The direct current potential drop method (DCPDM) is widely used to determine the crack length in fatigue experiments. In practice, some special features of this method must be considered. Aside from general information on the experimental setup and calibration, some special features of the method, such as the influence of the ambient atmosphere and the application of the method to ferromagnetic materials, are presented and discussed. In addition, with the multiple potential drop measurement, a method is presented which improves the resolution of the DCPDM for detection of cracks and allows to determine crack initiation sites. The capabilities provided by this method are demonstrated on the basis of measurements undertaken on notched round bars and single edged notched specimens.

The Research on DC Loop of Regional Power Grid Caused by the Operation of the Subway

The operation of the subway would change the distribution of the ground potential along the rail, forming a DC loop through the grounding points in a nearby regional power grid and threatening the operational safety of the power system. In this paper, a new DC potential distribution calculation method along the subway is firstly proposed. Secondly, a grid grounding DC loop model is built on the foundation of the stray current principle. Thirdly, factors affecting the current in the grid are also presented and discussed based on the grounding loop model. Finally, a subway operation simulation platform is set up in a laboratory to simulate the operation of subway in situation, and the rationality of the model presented in this paper has been effectively verified.

Rapid Electrochemical Ultra-Sensitive Evaluation and Determination of Daptomycin Based on Continuous Cyclic Voltammetry

Background: In this work, a novel and extra sensitive blood sample determination method for on-line monitoring of Daptomycin is represented. Materials and Methods: This technique is in accordance with the electro-membrane extraction (EME) and stripping fast Fourier transform continuous cyclic voltammetry (SFFTCCV) coupling. Briefly, the potential waveform had become constantly utilized over a Gold Electrode and the electrode impulse was acquired by taking away the base current and developing the current in the particular potential area of oxidation of sample. Results: This method was performed by utilizing a DC potential and migration of Daptomycin from the analyte fluid to the layer of 4-methyl-2-pentanol as well as following migration to the acceptor fluid. Conclusion: A low and valuable detection limit of 3.5 ng ml-1 and quantification limit of 10.2 ng ml-1 are considered as a part of the sensible results of this experiment. Furthermore, efficient linearity in the range of 10.0-600 ng ml-1 was observed.

X80 Steel Corrosion Induced by Alternating Current in Water-Saturated Acidic Soil

X80 steel corrosion induced by alternating current (AC) had been investigated by surface analyses and electrochemical measurements in water-saturated acidic soils. The AC sharply increased the corrosion rate of X80 steel. Moreover, the DC potential of X80 steel shifted toward the negative direction after applying AC density, and decreased with the AC density ascending from 0 A/m2 to 200 A/m2. A power function model, CR = ain + b, was used to reflect the relation between AC density and corrosion rate. γ-FeOOH acting as an oxidizer weakened the protective ability of product film, and further accelerated the corrosion of steel.