Impact of pulse exposure on chimera state in ensemble of FitzHugh-Nagumo systems.

In this article, we consider the influence of a periodic sequence of Gaussian pulses on a chimera state in a ring of coupled FitzHugh-Nagumo systems. We found that on the way to complete spatial synchronization, one can observe a number of variations of chimera states that are not typical for the parameter range under consideration. For example, the following modes were found: breathing chimera, chimera with intermittency in the incoherent part, traveling chimera with strong intermittency, and others. For comparison, here we also consider the impact of a harmonic influence on the same chimera, and to preserve the generality of the conclusions, we compare the regimes caused by both a purely positive harmonic influence and a positive-negative one.

Impact of white noise in artificial neural networks trained for classification: Performance and noise mitigation strategies.

In recent years, the hardware implementation of neural networks, leveraging physical coupling and analog neurons has substantially increased in relevance. Such nonlinear and complex physical networks provide significant advantages in speed and energy efficiency, but are potentially susceptible to internal noise when compared to digital emulations of such networks. In this work, we consider how additive and multiplicative Gaussian white noise on the neuronal level can affect the accuracy of the network when applied for specific tasks and including a softmax function in the readout layer. We adapt several noise reduction techniques to the essential setting of classification tasks, which represent a large fraction of neural network computing. We find that these adjusted concepts are highly effective in mitigating the detrimental impact of noise.

Conditions of acceleration and deceleration of the cancer cell growth under osmotic pressure.

In this paper, we study a pattern formation in the epidermal layer of skin during tumor development and appearance of a binary surface consisting of healthy and cancer cells forming Turing patterns under external osmotic pressure. The basic methodology of introducing the external influences, for example, time-targeted drug therapy or radiation exposure, influence of electromagnetic fields, laser radiation or other tumor-targeting physical influences act differently in different phases of the cell cycle. In some cases, this can lead to a slowdown in the growth of cancer cells, and sometimes vice versa. Therefore, it is of particular interest to choose the right parameters such as starting time of external pressure, its magnitude and duration depending on the cell cycle of developing cancer cells. We propose a biologically inspired model that allows us to simulate the growth of cancer cells under conditions of osmotic pressure. We divide this growth into two phases. The first is characterized by active cell division, and the second by their growth. In this article, we introduce two types of pressure: short-term and long-term, and looked at what this leads to in different phases. We have found an interesting result, that there are some resonant points in time both in the first and second phases, when the introduction of additional pressure leads to the most significant slowdown in the growth of cancer cells.

The Level of Sex Hormones and Corticosterone in Female Rats during Modeling of Visceral Obesity, Subsequent Physical Activity, and Normalization of the Diet.

The effects of diet-induced visceral obesity and non-drug options of its correction on the level of sex hormones and corticosterone were evaluated in 84 female Wistar rats. During stage I, the rats received either a standard diet (STD) or a high-calorie diet (HCD) for 8 weeks. During stage II, the animals were divided into subgroups depending on obesity correction: without correction (STD control and HCD), transition from HCD to STD (HCD/STD) and/or physical activity (treadmill exercise) for the next 8 weeks (HCD/STD+exercise, STD+exercise, and HCD+exercise). Diet-induced visceral obesity resulted in hyperandrogenization and increased blood corticosterone levels in females. Transition from HCD to STD regardless of physical activity led to normalization of testosterone level and, accordingly, to return to the functional norm of estrogen-androgen balance. The positive effect of moderate physical activity on hormonal status is realized only against the background of a balanced diet or during the transition from HCD to STD.

Endothelin Level in Menopausal Women with Comorbidity of the Acute Phase Middle Severity COVID-19 with Arterial Hypertension and Type 2 Diabetes Mellitus.

The levels of endothelins were assessed in menopausal women with arterial hypertension (AH) and type 2 diabetes mellitus (T2DM) in the acute phase of the moderate COVID-19. Women under observation (age 45-69 years) were divided into two groups. Control group consisted of women (n=16) who did not have COVID-19, were not vaccinated, and had no antibodies to SARS-CoV-2 (IgG). The main group included women (n=63) in the acute phase of the moderate COVID-19 accompanied by pneumonia. According to the clinical and anamnestic data analysis, the main group was divided into subgroups: without AH and T2DM (n=21); with AH and without T2DM (n=32); and with AH and T2DM (n=10). The parameters of clinical blood analysis, as well as endothelin-1, endothelin-2, and endothelin-3 levels were assessed. In women with a moderate COVID-19, the endothelin-1 and endothelin-2 levels were increased compared to the control regardless of AH and T2DM status. We found no statistically significant differences in the studied parameters of endothelial dysfunction between the subgroups of menopausal women in the acute phase of the moderate COVID-19.

Oxidative Damage of DNA, Proteins and C-Reactive Protein Parameters in Girls and Boys with Exogenous Constitutional Obesity.

The parameters of oxidative damage of DNA, proteins, as well as the parameters of the thiol-disulfide system and C-reactive protein in adolescent girls and boys with exogenous constitutional obesity (ECO) were evaluated. In girls and boys with obesity, the levels of 8-hydroxy-2'-deoxyguanosine (marker of DNA destruction) were higher than in controls. Evaluation of the activity of the thiol-disulfide system revealed increased levels of oxidized glutathione (GSSG) and decreased levels of the reduced glutathione (GSH) and GSSG ratio (GSH/GSSG) in adolescents with ECO regardless of the sex in comparison with the control. C-reactive protein was also higher in the ECO groups regardless of the sex. The levels of glutathione peroxidase in obese boys were higher than in girls. In view of the revealed shifts, corrective measures with the prescription of drugs with antioxidant properties are recommended in adolescents with ECO to stabilize the indices.

Alpha Diversity Indices as Indicators of the Variability of Gut Microbiota in Obese Adolescents of Different Ethnicities.

We compared alpha diversity indices of the intestinal microbiota in adolescents with obesity and normal body weight, taking into account their ethnicity. Intestinal biocenosis was studied by metasequencing of amplicon libraries of V3-V4 fragments of the 16S rRNA gene. The alpha diversity of the microbiota was assessed using classical and alternative indices. Statistically significant differences in intestinal microbiota were observed between Russians with obesity and Buryats with normal body weight, as well as between Russians with obesity and Buryats with obesity when assessing the Shannon-Weaver, Chao1 indices, Faith phylogenetic diversity index, ACE, Fisher, Gini coefficient, Margalef, and Menkhinik indices. It was shown that alpha diversity indices can be used to assess significance of differences and variability of the intestinal microbiota in multifactorial diseases such as obesity in adolescents; however, the scope of application of the criteria should be considered.

[Terminology of quantitative optical coherence tomography angiography metrics]. / Osobennosti terminologii kolichestvennykh pokazatelei opticheskoi kogerentnoi tomografii-angiografii.

This review is devoted to the English- and Russian-language terminology of quantitative metrics that are used in the evaluation of images obtained by optical coherence tomography angiography (OCT-A). The paper presents an analysis of the use of terms characterizing intraretinal blood flow (vascular density, perfusion density, skeletonized density, etc.), area and shape of the foveal avascular zone, and choriocapillaris blood flow. The factors causing the heterogeneity of OCT-A terminology are described, including the lack of a unified international nomenclature for OCT-A, features of their Russian translation, inconsistency of the parameters in optical coherence tomography systems of different manufacturers. The article also considers ways to standardize the terminology.

[Neuroendocrine changes among 45-60 years old women with COVID-19 and 12 months after the disease.]

Climacteric women have the post-COVID period clinical features, which can lead to an acceleration of the aging. The study consists in assessing individual parameters of the neuroendocrine system in climacteric women with a moderate course of COVID-19 and 12 months after the disease. Under observation were women aged 45-69 years, who were divided into groups: women who did not have COVID-19, not vaccinated, with no antibodies to COVID-19 (IgG) - control group (n=16); women in the acute phase of COVID-19 with a moderate course, accompanied by pneumonia - main group (n=63); patients from the main group who agreed to be examined 12 months after COVID-19 (n=15). The prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, cortisol, testosterone, 17-OH-progesterone, dihydroepiandrosterone sulfate (DHEA-S) levels were assessed. In women with COVID-19 compared with the control the prolactin level was increased (p=0,0002) and the estradiol (р=0,032), testosterone (p=0,004), cortisol (p=0,009), 17-OH-progesterone (p=0,025) and DHEA-S (p=0,003) levels were reduced. Intragroup comparison of hormones showed a decrease in the prolactin level (р=0,041) and increase in the 17-OH-progesterone (р=0,011) and DHEA-S (р=0,0006) levels 12 months after the disease. With a personalized consideration of this group a decrease in the prolactin level is observed in 73,3% of these patients. In the same period, there was an increase in testosterone levels in 46,7% of women, cortisol - in 73,3% of women, 17-OH-progesterone - in 80% of women, DHEA-S - in 100% of cases. When comparing these hormonal parameters between the group of patients who recovered from COVID-19 12 months ago and the control, no statistically significant differences were found, however, patients were identified in whom prolactin and cortisol exceeded the reference values, although in the acute phase of COVID-19 the values of these indicators corresponded to the reference values.

Pro-and Antioxidant Status in Newborn with COVID-19.

There is practically no information on the state of oxidative stress reactions in newborns with coronavirus infections. At the same time, such studies are extremely important and can contribute to better understanding of the process of reactivity in patients of different ages. The content of pro- and antioxidant status indicators was assessed in 44 newborns with confirmed COVID-19. It was found that the content of compounds with unsaturated double bonds, primary, secondary, and final LPO products were elevated in newborns with COVID-19. These changes were accompanied by higher SOD activity and retinol level and reduced activity of glutathione peroxidase. Contrary to popular opinion, newborns can be a COVID-19-susceptible age group and require more close monitoring of metabolic reactions during the period of neonatal adaptation that is an aggravating background during infection.

Blood Cytokines of the Ovarian Vein Basin in Different Stages of Pelvic Varicose Veins.

We analyzed the blood concentration of pro- and anti-inflammatory cytokines in the ovarian vein basin area in women of the reproductive age with primary pelvic varices. Increase in the disease severity was accompanied by a significant increase in proinflammatory cytokines (TNFα, IL-1ß, IL-2, IL-6, and IL-8) and the proinflammatory index (IL-6/IL-10), whereas anti-inflammatory cytokine production changed ambiguously (increase of IL-4 at stage I, decrease of IL-10 at stage II, significant decrease of IL-4 and IL-10 at stage III). Control of these changes in female patients should probably be an important component of treatment measures and prevention of morphofunctional disorders occurring at disease progression, in particular at stage III of the disease.

Noise-mitigation strategies in physical feedforward neural networks.

Physical neural networks are promising candidates for next generation artificial intelligence hardware. In such architectures, neurons and connections are physically realized and do not leverage digital concepts with their practically infinite signal-to-noise ratio to encode, transduce, and transform information. They, therefore, are prone to noise with a variety of statistical and architectural properties, and effective strategies leveraging network-inherent assets to mitigate noise in a hardware-efficient manner are important in the pursuit of next generation neural network hardware. Based on analytical derivations, we here introduce and analyze a variety of different noise-mitigation approaches. We analytically show that intra-layer connections in which the connection matrix's squared mean exceeds the mean of its square fully suppress uncorrelated noise. We go beyond and develop two synergistic strategies for noise that is uncorrelated and correlated across populations of neurons. First, we introduce the concept of ghost neurons, where each group of neurons perturbed by correlated noise has a negative connection to a single neuron, yet without receiving any input information. Second, we show that pooling of neuron populations is an efficient approach to suppress uncorrelated noise. As such, we developed a general noise-mitigation strategy leveraging the statistical properties of the different noise terms most relevant in analog hardware. Finally, we demonstrate the effectiveness of this combined approach for a trained neural network classifying the modified National Institute of Standards and Technology handwritten digits, for which we achieve a fourfold improvement of the output signal-to-noise ratio. Our noise mitigation lifts the 92.07% classification accuracy of the noisy neural network to 97.49%, which is essentially identical to the 97.54% of the noise-free network.

[Age-related menopause and carbonyl stress.]

The review analyzes the literature data on studies of redox homeostasis in women with age-related physiological menopause. Despite the ambiguity of the presented results on the lipids, proteins, carbohydrates oxidative modification, most studies allow us to consider this age period as one of the factors in the carbonyl stress development, which is an integral part of aging. The presence of hyperglycemia and free radical pathology are presented as the main causes of the carbonyl stress development, age-related estrogen deficiency, taking into account their antioxidant properties, is considered as one of the triggers for this condition development, and the glutathione system is identified as one of its main inhibitors.

Glutathione Component of Antioxidant Status in Menopausal Women with Insomnia.

The study involved 138 women aged 45-60 years in perimenopause (n=55) and postmenopause (n=83) with insomnia (main groups) and without it (control). The levels of reduced (GSH) and oxidized (GSSG) glutathione and glutathione peroxidase activity were determined in erythrocytes; activities of glutathione S-transferase and glutathione reductase were measured in blood serum. The differences with the control groups were found only in perimenopause: higher glutathione reductase activity and reduced GSSG level and GSH/GSSG ratio in women with insomnia (p<0.05). The results of the comparative analysis between the main groups showed lower glutathione reductase activity, increased GSSG level, and a decrease the GSH/GSSG ratio in the postmenopausal period compared with the perimenopause (p<0.05). These results can be used in choosing the tactics for complex therapy of insomnia in menopausal women to correct free radical homeostasis and prevention of oxidative stress.

Effect of Probiotic Therapy on Hemodynamic Response Associated with Systemic Inflammatory Reaction and Antibiotic-Induced Dysbiosis in Chronic Experiments in Rats.

The effect of probiotic therapy on the main hemodynamic parameters was studied in Wistar rats with modeled syndrome of systemic inflammatory response resulting from chemically induced colitis complicated by antibiotic-induced dysbiosis. Using a wireless telemetry monitoring system in round-the-clock mode, the mean systolic and diastolic BP, HR, and body temperature were measured over 27 days. In the group of animals receiving no probiotics, a significant decrease in feed consumption and body weight loss were observed. By the end of the experiment, BP in this group was lower by 12% and HR was higher by 10% than in the control. In animals treated with a mixture of probiotic strains Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis, all the studied parameters returned to the initial values. Thus, we demonstrated the possibility of using probiotic drugs for the treatment of acute systemic inflammatory process, which should be considered in the development of new treatment protocols in veterinary and medicine.

Superoxide Dismutase Activity in Male and Female Patients of Different Age with Moderate COVID-19.

The study involved 271 patients (132 men and 139 women) with moderate COVID-19. Superoxide dismutase (SOD) activity in erythrocytes was measured spectrophotometrically. In total group of patients (divided into age groups of 18-35, 36-45, 46-60, and 61-90 years), higher SOD activity was found in the 18-35 age group in comparison with the groups 46-60 years (p<0.01) and 61-90 years (p<0.05). Then, the groups were additionally divided by sex. In men, no differences in enzyme activity were found between the age groups. In women of early reproductive age, SOD activity was higher than in groups 36-45, 46-60, and 61-90 years. The sex differences consisted in higher SOD activity in women aged 18-35 years in comparison with men of this age. These data should be taken into account when choosing the tactics of therapy for patients with moderate COVID-19 course.

Biochemical Status of Obese Male Adolescents of Different Ethnicity: Discriminant Analysis in the Identification of the Most Informative Indicators.

Parameters of the lipid metabolism and lipid peroxidation-antioxidant defense system in male adolescents with obesity, representatives of European and Mongoloid ethnicity were evaluated. Discriminant analysis revealed the most informative biochemical parameters for obese male adolescents: glutathione-S-transferase, VLDL cholesterol, glutathione peroxidase, reduced glutathione, and SOD activity for obese male Caucasian adolescents and glutathione-S-transferase, VLDL cholesterol, α-tocopherol, and glutathione peroxidase for Mongoloids obese male adolescents. The use of discriminant analysis allows implementing a differentiated ethnicity-oriented approach to prescribing antioxidant drugs in the complex therapy of obesity.

[Aging and cognitive disorders from the somnology's viewpoint.]

Age-dependent diseases high social burden makes relevant medical technologies development and implementation of human aging process functional state various disorders prenosological diagnosis, treatment and prevention. Age-related activity decrease of the brain functional state and its interdependence with the sleep-wake continuum leads to premature (pathological) aging with manifestations of neurodegeneration. Although disturbances of the sleep-wake cycle functioning are characteristic for the aging process, age-related changes are not always accompanied by cognitive dysfunction. There are sufficient number studies on the molecular level changes in age-related sleep disorders. Aging, sleep disorders and processes of cognitive dysfunction association pathogenetic mechanisms heterogeneity also include metabolism changes. Various neurotransmitters and other biologically active substances, so-called «sleep-promoting substances¼ are involved in the regulation of sleep processes. The urgent need for molecular-cell markers and diagnostic patterns of sleep disorders further scientific search in aging process is promising and will make a significant contribution to the breakthrough technologies development in the pathological aging prevention. The complex architecture of sleep undergoes pronounced changes throughout a person's life. In the literature, the relationship of circadian rhythm disturbances during aging and the development of cognitive dysfunction is actively debated. Approach from the positions of the modern neurobiology, somnology and sleep medicine perspectives seems extremely relevant and timely. This review is devoted to some aspects of age-related in sleep and their molecular-cell markers changes modern scientific research and our own data analysis.

Studies of Molecular Mechanisms Underlying Cardioprotective Action of the ALM-802 Compound.

The mechanisms underlying cardioprotective activity of compound ALM-802 were studied in experiments on rats with chronic post-infarction heart failure. Real-time PCR showed that compound ALM-802 (daily intraperitoneal injections in a dose of 2 mg/kg for 28 days starting from day 91 after myocardial infarction modeling) restored the expression of genes encoding ß1- (p=0.00001) and ß2-adrenoreceptors (p=0.01) and type 2 ryanodine receptors (p=0.008) in the myocardium that was reduced in control animals. These effects can serve as the basis for the ability of the compound to reduce the intensity of remodeling and increase the inotropic function of the left heart ventricle shown earlier in this model.

8-Hydroxy-2'-Deoxyguanosine as an Oxidative Stress Marker in Insomnia.

We performed comparative analysis of 8-hydroxy-2'-deoxyguanosine in women in different climax stages with and without insomnia. The study involved 90 women aged 45 to 60 years divided into perimenopausal (n=30) and postmenopausal (n=60) groups. After questioning using special sleep questionnaires (Insomnia Severity Index, Epworth Sleepiness Scale, Munich Chronotype Questionnaire), the groups were divided into subgroups with insomnia and without it (control). 8-Hydroxy-2'-deoxyguanosine was assayed in blood serum by ELISA. The higher levels of 8-hydroxy-2'-deoxyguanosine in postmenopausal women with insomnia in comparison with the control and perimenopausal patients (p<0.05) attested to oxidative DNA damage in this cohort of patients.