[Influence of chronic obstructive pulmonary disease on hospital outcomes of percutaneous coronary interventions in patients with acute coronary syndrome].

AIM: To evaluate the impact of chronic obstructive pulmonary disease (COPD) on hospital outcomes of percutaneous coronary interventions (PCI) in patients with acute coronary syndrome (ACS). MATERIALS AND METHODS: A cohort prospective study of the COPD effect on mortality and coronary microvascular obstruction (CMVO, no-reflow) development after PCI in ACS was carried out. 626 patients admitted in 2019-2020 were included, 418 (67%) - men, 208 (33%) - women. Median age - 63 [56; 70] years. Myocardial infarction with ST elevation identified in 308 patients (49%), CMVO - in 59 (9%) patients (criteria: blood flow <3 grade according to TIMI flow grade; perfusion <2 points according to Myocardial blush grade; ST segment resolution <70%). 13 (2.1%) patients died. Based on the questionnaire "Chronic Airways Diseases, A Guide for Primary Care Physicians, 2005", 2 groups of patients were identified: 197 (31%) with COPD (≥17 points) and 429 (69%) without COPD (<17 points). Groups were compared on unbalanced data (÷2 Pearson, Fisher exact test). The propensity score was calculated, and a two-way logistic regression analysis was performed. The data were balanced by the Kernel "weighting" method, logistic regression analysis was carried out using "weighting" coefficients. Results as odds ratio (OR) and 95% confidence interval. RESULTS: The conducted research allowed us to obtain the following results, depending on the type of analysis: 1) analysis of unbalanced data in patients with COPD: OR death 3.60 (1.16-11.12); p=0.03; OR CMVO 0.65 (0.35-1.22); p=0,18; 2) two-way analysis with propensity score: OR death 3.86 (1.09-13.74); p=0.04; OR CMVO 0.61 (0.31-1.19); p=0.15; 3) regression analysis with "weight" coefficients: OR death 12.49 (2.27-68.84); p=0.004; OR CMVO 0.63 (0.30-1.33); p=0.22. CONCLUSION: The presence of COPD in patients with ACS undergoing PCI increases mortality and does not affect the incidence of CMVO.

Interhemispheric Asymmetry and Personality Traits of Brain-Computer Interface Users in Hand Movement Imagination.

Personality traits of users can affect the success in controlling brain-computer interfaces (BCIs), and the activity of right and left brain structures may differ depending on personality traits. Earlier, it was not known, how the success of BCI control with different personality traits is associated with interhemispheric asymmetry. In this work, the dependence of the success of imagination of movements, estimated by the success of recognition of EEG signals during imagination of hand movements compared to rest state, on the user's personal characteristics was studied. It is shown that in single control of BCI by naive subjects, recognition success in imagining right-hand (RH) movements was higher in expressive sensitive extroverts, and in imagining left-hand movements (LH) it was higher in practical, reserved, skeptical, and not very sociable persons. It is suggested that this phenomenon may be based on interhemispheric differences in dopamine level and in the way of encoding movement information.

[Biomechanical Analysis of Posture and Movement Coordination in Standing Human During Trunk Bending in the Sagittal Plane].

In most motor acts to achieve a behavioral goal requires coordination of posture and movement. In this paper, such coordination is studied by the example of human trunk bending in. the sagittal plane. Such movements are difficult to study because both components of this motor act (main - bending per se, and "accessory" - posture aimed on equilibrium. maintenance) involve massive movements of body segments, which complicates separation of these components. Their separation is based on the modem ideas about the special features of the posture component as compared with the main component. It is shown that the main and posture components correspond to the move- ments along eigenvectors of the dynamic equation. These movements are unique because they demonstrate at the same time "kinematic" as well as "dynamic" synergies. They were called there- fore "natural synergies". The coordination of natural synergies is investigated in human during standing on the wide and narrow supports. It is shown that the experimentally observed coordination is close to optimal, providing minimum movement of the center of pressure. This ensures the center of pressure Position keeping inside the support area that is necessary for equilibrium maintenance.

[The Changes in the Hemodynamic Activity of the Brain during Moroe Imagery Training with the Use of Brain-Computer Interface].

With the use of functional MRI (fMRI), we studied the changes in brain hemodynamic activity of healthy subjects during motor imagery training with the use brain-computer interface (BCI), which is based on the recognition of EEG patterns of imagined movements. ANOVA dispersion analysis showed there are 14 areas of the brain where statistically sgnificant changes were registered. Detailed analysis of the activity in these areas before and after training (Student's and Mann-Whitney tests) reduced the amount of areas with significantly changed activity to five; these are Brodmann areas 44 and 45, insula, middle frontal gyrus, and anterior cingulate gyrus. We suggest that these changes are caused by the formation of memory traces of those brain activity patterns which are most accurately recognized by BCI classifiers as correspondent with limb movements. We also observed a tendency of increase in the activity of motor imagery after training. The hemodynamic activity in all these 14 areas during real movements was either approximatly the same or significantly higher than during motor imagery; activity during imagined leg movements was higher that that during imagined arm movements, except for the areas of representation of arms.

[Brain-Computer Interface: the First Clinical Experience in Russia].

Motor imagery is suggested to stimulate the same plastic mechanisms in the brain as a real movement. The brain-computer interface (BCI) controls motor imagery by converting EEG during this process into the commands for an external device. This article presents the results of two-stage study of the clinical use of non-invasive BCI in the rehabilitation of patients with severe hemiparesis caused by focal brain damage. It was found that the ability to control BCI did not depend on the duration of a disease, brain lesion localization and the degree of neurological deficit. The first step of the study involved 36 patients; it showed that the efficacy of rehabilitation was higher in the group with the use of BCI (the score on the Action Research Arm Test (ARAT) improved from 1 [0; 2] to 5 [0; 16] points, p = 0.012; no significant improvement was observed in control group). The second step of the study involved 19 patients; the complex BCI-exoskeleton (i.e. with the kinesthetic feedback) was used for motor imagery trainings. The improvement of the motor function of hands was proved by ARAT (the score improved from 2 [0; 37] to 4 [1; 45:5] points, p = 0.005) and Fugl-Meyer scale (from 72 [63; 110 ] to 79 [68; 115] points, p = 0.005).

[Sources of electrophysiological and foci of hemodynamic brain activity most relevant for controlling a hybrid brain­Computer interface based on classification of EEG patterns and near-infrared spectrography signals during motor imagery].

The method is described for joint use of electroencephalography and near-infrared spectrography for location of sources of electrophysiological and focuses of hemodynamic brain activity during motor execution and imagination. The sources of electrophysiological and focuses of hemodynamic activity the most relevant for controlling the hybrid brain-computer interface based on motor imagery are revealed and discussed.

[Arm Motor Function Recovery during Rehabilitation with the Use of Hand Exoskeleton Controlled by Brain-Computer Interface: a Patient with Severe Brain Damage].

We studied the dynamics of motor function recovery in a patient with severe brain damage in the course of neurorehabilitation using hand exoskeleton controlled by brain-computer interface. For estimating the motor function of paretic arm, we used the biomechanical analysis of movements registered during the course of rehabilitation. After 15 weekly sessions of hand exoskeleton control, the following results were obtained: a) the velocity profile of goal-directed movements of paretic hand became bell-shaped, b) the patient began to extend and abduct the hand which was flexed and adducted in the beginning of rehabilitation, and c) the patient began to supinate the forearm which was pronated in the beginning of rehabilitation. The first result is an evidence of the general improvement of the quality of motor control, while the second and third results prove that the spasticity of paretic arm has decreased.

[Septal Activation and Control of Limbic Structures].

Coherent activation of limbic system structures as the main function of theta-rhythm is widely discussed in the literature. However until now does not exist the common view on its generation in these brain structures. The model of septal theta-rhythmic activation and control of limbic structures is suggested basing on the literature and own experimental data.

[Localization of brain electrical activity sources and hemodynamic activity foci during motor imagery].

Studied are sources of brain activity contributing to EEG patterns which correspond to motor imagery. The accuracy of their classification determines the efficiency of brain-computer interface (BCI) allowing for controlling external technical devices directly by brain signals without involving muscle activity. Sources of brain activity are identified by Independent Component Analysis. Those independent components for which the BCI classification accuracy are at maximum are treated as relevant for motor imagery task. Two of the most relevant sources demonstrate strictly exposed event related desynchronization and synchronization of mu--rhythm during imagery of contra--and ipsilateral hands. These sources are localized by solving inverse EEG problem taking into account individual geometry of brain and its covers provided by anatomical MRI images. The sources are shown to be localized in BA 3A relating to proprioceptive sensitivity of the contralateral hand. Their positions are closed to foci of BOLD activity obtained by fMRI.

[Motor imagery and its practical application].

The mechanisms underlying the process of motor imagery are similar to the motor control mechanisms. It can be used for motor learning in patients with movement disorders. Motor imagery may be the only one method for recovery of motor function in patients with severe paresis. It was the prerequisite of increased scientist interest in motor imagery during last decade. Brain-computer interface technology can support the motor imagery trainings.

[Principles of neurorehabilitation based on brain-computer interface and biologically plausible control of the exoskeleton].

The paper examines neurophysiological basis for development and performance of brain-computer interface (BCI) that permits cerebral activity alone to control computers or other external technical devices. BCI based on the discrimination of EEG patterns related to an imagery of extremity movements is considered. The problem of BCI application to restoring of motor functions in patients with motor disabilities is discussed.

[Bayesian classifier for brain-computer interface based on mental representation of movements].

This paper proposes Bayesian approach to classification of EEG patterns on the basis of imaginary movements of extremities based on analysis ofcovariance matrices of native EEG recordings. An efficacy of a Brain-Computer Interface (BCI) based on the proposed classifier is evaluated. Bayesian classifier is shown to be competitive with the MCSP (Multiclass Common Spatial Patterns) classifier known from the literature as one of the efficient variant for BCI implementation. The influence of eye movement and blinking artifacts on the BCI performance is investigated. It is shown that the presence of such artifacts does not affect the classification accuracy.

Excitation of high-intensity terahertz surface modes of plasma slab under action of p-polarized two-frequency laser radiation.

The excitation of the terahertz (THz) high-intensity surface modes when the two-frequency p-polarized laser radiation interacts with a plasma slab is studied. It was found that the significant amplification of the laser field in the plasma slab occurs when p-polarized laser radiation is incident at the angle of total reflection. It is shown that, under the action of laser radiation ponderomotive forces, the resonant excitation of the THz mode of the plasma slab occurs if the frequency difference of the laser fields coincides with the eigenfrequency of the surface mode. It is established that the giant increase in the energy flux density of the THz mode occurs when p-polarized laser radiation is incident at the angle of total reflection on the near-critical plasma slab with rare electron collisions if the conditions of resonant excitation are satisfied. It is shown that in this case the energy flux density of THz mode can significantly exceed the laser intensity.

Closed-loop and open-loop control of posture and movement during human trunk bending.

Closed-loop (CL) and open-loop (OL) types of motor control during human forward upper trunk bending are investigated. A two-joint (hip and ankle) biomechanical model of the human body is used. The analysis is performed in terms of the movements along eigenvectors of the motion equation ("eigenmovements" or "natural synergies"). Two analyzed natural synergies are called "H-synergy" (Hip) and "A-synergy" (Ankle) according to the dominant joint in each of these synergies. Parameters of CL control were estimated using a sudden support platform displacement applied during the movement execution. The CL gain in the H-synergy increased and in the A-synergy decreased during the movement as compared with the quiet standing. The analysis of the time course of OL control signal suggests that the H-synergy (responsible for the prime movement, i.e. bending per se) is controlled according to the EP theory whereas for the associated A-synergy (responsible for posture adjustment, i.e. equilibrium maintenance) muscle forces and gravity forces are balanced for any its final amplitude and therefore the EP theory is not applicable to its control.

Using an Artificial Neural Network to Predict Coronary Microvascular Obstruction (No-Reflow Phenomenon) during Percutaneous Coronary Interventions in Patients with Myocardial Infarction.

The aim of the study was to develop, evaluate, and validate an artificial neural network to predict coronary microvascular obstruction (CMVO) during percutaneous coronary interventions (PCI) in patients with myocardial infarctions (MI) based on the parameters, which are routinely available in an operating room when choosing a surgical approach. Materials and Methods: 5621 patients with MI and emergency PCI were retrospectively selected from the database of the City Clinical Hospital No.13 (Nizhny Novgorod, Russia); among them, there were 3935 men (70%) and 1686 women (30%), their mean age was 61.5±10.8 years. CMVO was recorded in 201 (4%) patients (the blood flow in the infarction-related artery after PCI was less than 3 points according to TIMI flow grade). The following input parameters were assessed: age, gender, past history of coronary artery disease, previous revascularization, presence of ST-segment elevation, a class of acute heart failure, a fact of systemic thrombolytic therapy administration and its effectiveness, symptom-to-balloon time, severity of coronary thrombosis and atherosclerosis, the number of stents and the number of operated coronary arteries. The sampling was divided into a training group (n=4060), a testing group (n=717), and an independent validation group (n=844). Results: We developed an artificial neural network by a fully connected multilayer perception with forward signal propagation and two hidden layers (the area under the ROC curve - 0.69) to predict CMVO based on the subsampling for training and testing. The network model was tested on an independent subsampling (the area under the ROC curve - 0.64, negative predictive value - 97.4%, positive predictive value - 14.6%). Conclusion: The developed artificial neural network enables to use the parameters routinely available in an operating room when choosing a surgical approach and predict CMVO development during PCI in MI patients with accuracy sufficient for practical use.

[Influence of CA1 hippocampal field on theta-activity in rats under urethane anesthesia].

The influence of CA1 hippocampal field on the theta-activity production depending on the efficiency of CA1 synaptic inputs was studied in urethanized rats. The long-term posttetanic potentiation (LTP) of Shaffer collaterals resulted in an increase in the theta-power in hippocampal EEG without change in its frequency. A high correlation was shown between the increase in the theta-power and the amplitude of the local potentials induced by LTP. The mechanisms and the functional role of the observed relations between the LTP and theta activity are discussed.

[Kinematic characteristics of the voluntary cyclic trunk movements in patients at the early stage of Parkinson's disease].

Patients with the initial stage of Parkinson disease (PD) and matched controls performed repetitive bendings and turnings in standing position. Tasks included trunk movements in each of the anatomical planes: sagittal, frontal and axial. Electromagnetic system Flock of Birds was used for movement registration. Sensors were fixed at different segments of subject's body. Joint angles in the ankle, hip and torso as well as coordinates of the center of pressure served as output parameters. The amplitudes of joint angles were found to be lower in PD patients. Performance of the axial rotation revealed most pronounced differences. Thus, the amplitudes of joint angles of trunk movements in different anatomical planes reliably discriminate between PD patients and healthy subjects.

[Dynamics of benthic communities in the central trench of the Barents Sea].

Based on the data collected in five marine expeditions of the Murmansk Marine Biological Institute from 2002 through 2007, the spatial and temporary variability of benthic communities in the Central Depression of the Barents Sea (licensed plot of the Shtokmanovskoe condensed gas deposit) has been analyzed. The range of quantitative characteristics and the variability of species composition of deep-water zoobenthos have been determined. The influence of an insignificant change in the collecting method on the obtained results has been examined.

[The electrode for selective nociceptive stimulation: use experience and prospect for application in nociception studies in a human].

Electrode for selective nociception specific stimulation was described by H. Kaube et al. in 2000. The aim of this work was to test this electrode in assessment of nociceptive reactions of the segmental and suprasegmental levels. The method of nociception specific blink reflex based on the use of this electrode was applied in a modified variant for examination of patients with a tension type headache. A decrease in the nociceptive reflex threshold was revealed in patients with episodic headaches (as compared to healthy volunteers). Both the reflex and pain thresholds were decreased in patients with a chronic headache. These results indicate the sensitization of nociceptive structures in patients with a headache. Cerebral evoked potentials elicited by skin stimulation of face and extremities with Kaube electrode were studied in healthy volunteers. The dominance of the late components (100-300 ms) considered to be of nociceptive origin was revealed in the pattern of evoked potentials. Thus, the electrode assures a high degree of selectivity of the pain-specific stimulation. Its adaptation for assessment of various nociceptive reactions can perfect the neurophysiological methods of nociception studies.

A model of reward choice based on the theory of reinforcement learning.

A model explaining behavioral "impulsivity" and "self-control" is proposed on the basis of the theory of reinforcement learning. The discount coefficient gamma, which in this theory accounts for the subjective reduction in the value of a delayed reinforcement, is identified with the overall level of dopaminergic neuron activity which, according to published data, also determines the behavioral variant. Computer modeling showed that high values of gamma are characteristic of predominantly "self-controlled" subjects, while smaller values of gamma are characteristic of "impulsive" subjects.