Actual Task Research Articles

Sorption Preconcentration of Heavy Metals on Graphene Oxide for Analysis of Waters by Electrothermal Vaporization ICP-OES

Background: Heavy metals (HMs) such as Cr, Hg, Pb, etc., are major threats to human health due to their toxic and carcinogenic properties. So, the determination of HMs concentrations in waters is an actual and important task. Methods: In this paper, the method includes a preliminary concentration of HMs and other analytes (Ag, Au, Ba, Be, Bi, Cr, Hg, In, Pb, Sn, and Zn) from water solutions on the graphene oxide and subsequent analysis of slurries of sorbent by electrothermal vaporization inductively coupled plasma optical emission spectrometry (ETV-ICP-OES) is developed for the first time. Results: The high efficiency of analytes sorption on graphene oxide made it possible to significantly increase the sensitivity of the analysis. The limits of detection of Ag, Au, Ba, Be, Bi, Cr, Hg, In, Pb, Sn, and Zn from 0.7 to 300 ng L-1 are achieved for ETV-ICP-OES analysis. The use of electrothermal vaporization for sample introduction allows the analysis of sorbent suspensions and avoids the desorption stage, reduces sample dilution, increases the preconcentration factor, and improves limits of detection (LODs) of analytes by 2-33 times compared to routine inductively coupled plasma optical emission spectrometry analysis (ICP-OES) with sorption preconcentration. Conclusion: For Ba, Be, Bi, Cr, In, Pb, Sn, and Zn ETV-ICP-OES provides LODs from 2 to 33 times lower compared to conventional ICP-OES analysis with sorption preconcentration due to higher preconcentration factor and transport efficiency of introducing of the analytes concentrates into the ICP. The developed method was applied to the analysis of real tap and mineral water samples. The results of analysis by ETV-ICP-OES with preconcentration of trace elements and ICP-OES were in good agreement. As a result of lower LODs of analytes, ETV-ICP-OES analysis provides the determination of concentrations of Ba, Bi, Sn, and Pb in tap and mineral water samples.

Design and Evaluation of a Leader–Follower Isomorphic Vascular Interventional Surgical Robot

Vascular interventional surgical robots (VISRs) can help doctors to avoid X-ray radiation. This paper proposes a leader–follower isomorphic robot where the structural form and operational logic are completely identical. The doctor’s operation on the leader robot is precisely replicated on the follower robot, enabling delivery and rotation capabilities. It can further achieve collaborative operation. This control system adopts a four-channel scheme based on acceleration and can achieve approximately ideal transparency. The leader–follower delivery error of the catheter/guidewire is less than 1 mm, and the leader–follower rotation error of the guidewire is less than 0.3° in an actual intervention task based on a human vascular model. Subsequently, the cumulative sum (CUSUM) method was used to evaluate the learning curve of the robot system, demonstrating that both operators could master the operation method within 10 trials. We classified operators with different operational experience using machine learning methods. The classification process includes time-frequency domain feature extraction, feature selection based on the Relief method and random forest (RF) method, and a BP neural network (NN) classifier. The results indicate that this method can achieve accuracy of 94%. This paper comprehensively discusses the robot system from the perspectives of the mechanism design, control methods, and evaluation methods, providing valuable insights for the design of related robotic systems.

Association of self-monitoring performance of cognitive performance with personal diurnal preference when sleep-deprived

ABSTRACT In modern society, many workers struggle with sleep deprivation due to their work schedules and excessive workloads. Accurate self-awareness and self-monitoring abilities are crucial for workers to adopt risk-coping strategies and protective behaviors when fatigued. The current study examined the relationship between chronotypes and self-monitoring performance during 24 h of sleep deprivation. The study involved 26 male adults in a two-night experiment, and participants’ diurnal preferences were evaluated using the Morningness-Eveningness Questionnaire (MEQ). Self-monitoring performance was calculated by comparing actual task performance with self-rated predicted or post-estimated performance in the psychomotor vigilance task (PVT) and Digit Symbol Substitution Task (DSST). The study found that task and self-monitoring performances in the PVT and DSST were maintained until around 4:00 h, after which they began to deteriorate. Individuals with a higher MEQ score, indicating a stronger tendency towards a morning type, showed inaccurate self-monitoring, particularly in the final quarter of the sleep deprivation experiment, due to overly optimistic predictions. However, only prediction accuracy and not post-estimation showed this correlation. This study highlights the importance of considering an individual’s chronotype in workplace management, particularly in workplaces with irregular work timings, rotating shifts, and long working hours, to ensure better occupational safety.

CLINICAL JUSTIFICATION OF THE EFFICIENCY OF USING IMPROVED METHODS OF DETERMINING AND FIXING OCCLUSAL RELATIONSHIPS IN PATIENTS WITH PARTIAL EDENTULOUS

Determining the optimal occlusal relationships according to the anatomical and functional features of the maxillofacial system (MFS) and subsequent adaptation till physiological functions are restored is an actual task during prosthetic treatment of patient with partial edentulous with help of fixed and removable partial denture (FPD, RPD). Purpose: to establish the effectiveness of the proposed methods of determining and fixing of the occlusal relationships based on the study of clinical indicators in patients who simultaneously use FPD and RPD for prosthetic therapy. Material and Methods. Our study included 120 patients aged 55-70 years with partial edentulous without endocrine and systemic disorders, acute forms of periodontal tissues diseases and good level of individual oral hygiene who came to the Department of Stomatology of Postgraduate Education of Ivano-Frankivsk National Medical University for prosthetic treatment. Prosthetic treatment was carried out with FPD, RPD using the proposed methods of forming occlusal relationships (group 1) and generally accepted methods (group 2). Each study group was divided into two subgroups: a – patients without occlusal disorders, and b – patients with occlusal disorders and vertical occlusion dimension (VOD) loss. The examination of each person included the collection of anamnesis and complaints, general dental examination, the determination of the Russell periodontal index (PI), the assessment of occlusal relationships and the condition of the temporomandibular joint (TMJ) according to "Hamburg protocol". Results and conclusions. The analysis of patient’s complaints and anamnesis, the data of the objective dental examination, and assessment of the periodontal tissue condition established the effectiveness of the proposed methods of determining and fixing occlusal relationships in patients with partial edentulous simultaneously treated with FPD and RPD. In addition, 23.3% more people of the 2a subgroup felt tension and fatigue of the masticatory muscles a week after treatment than in 1a subgroup, and 36.7% more - in the 2b subgroup than in 1b after a year of FPD and RPD use (p< 0,05). There were significantly more patients with signs of eccentric supraocclusion in the 2a subgroup a year after prosthetic treatment than in 1a (30±0.09% (9) and 3.3±0.03% (1)), and with signs of centric supraocclusion in the 2b subgroup - 36.7±0.09% (11), against 10±0.06% (6) in 1b (p <0.05). Also, there was observed a positive effect of proposed method of determining and fixing of the occlusal relationships during prosthetic treatment on TMJ a year after prosthetic treatment with FPD and RPD. There were 16.7% and 13.3% fewer people in 1a and 1b subgroups with one positive symptom of the “Hamburg protocol” and 6.7% and 40% fewer persons with two positive symptoms, compared to the data received before treatment. There was an increase by 13.3% of number of patients with one positive symptom according to “Hamburg protocol” in the 2a subgroup and by 10% of persons with two symptoms. It was determined a decrease of patients with two positive symptoms according to “Hamburg protocol” in 2b subgroup by 10% after one year. An improvement of periodontal tissues condition of abutment teeth was evaluated by PI assessment after a year of observation of patients. It was established that the average value of PI in subgroup 1b was significantly lower by 57.6% than in subgroup 2b, and it was lower in subgroup 1a by 39.3% than in patients of subgroup 2a (р<0,05).

More to Lose: The Adverse Effect of High Performance Ranking on Employees’ Preimplementation Attitudes Toward the Integration of Powerful AI Aids

Despite the growing availability of algorithm-augmented work, algorithm aversion is prevalent among employees, hindering successful implementations of powerful artificial intelligence (AI) aids. Applying a social comparison perspective, this article examines the adverse effect of employees’ high performance ranking on their preimplementation attitudes toward the integration of powerful AI aids within their area of advantage. Five studies, using a weight estimation simulation (Studies 1–3), recall of actual job tasks (Study 4), and a workplace scenario (Study 5), provided consistent causal evidence for this effect by manipulating performance ranking (performance advantage compared with peers versus no advantage). Studies 3–4 revealed that this effect was driven in part by employees’ perceived potential loss of standing compared with peers, a novel social-based mechanism complementing the extant explanation operating via one’s confidence in own (versus AI) ability. Stronger causal evidence for this mechanism was provided in Study 5 using a “moderation-of-process” design. It showed that the adverse effect of high performance ranking on preimplementation AI attitudes was reversed when bolstering the stability of future performance rankings (presumably counteracting one’s concern with potential loss of standing). Finally, pointing to the power of symbolic threats, this adverse effect was evident both in the absence of financial incentives for high performance (Study 1) and in various incentive-based settings (Studies 2–3). Implications for understanding and managing high performers’ aversion toward the integration of powerful algorithmic aids are discussed. Funding: This work was supported by the Coller Foundation. Supplemental Material: The supplemental material is available at https://doi.org/10.1287/orsc.2023.17515 .

MATHEMATICAL MODEL AND OPTIMIZATION ALGORITHM ACCORDING TO THE CRITERIA OF MINIMUM CONTACT STRESS FOR INVOLUTE SPUR GEARS WITH INCREASED CONTACT RATIO

Reducing the mass and dimensions of involute spur gears is an actual task of modern mechanical engineering. One of the perspective ways to solve it is the use of gearing with an increased working tooth depth and profile contact ratio εα ≥ 2. The study is devoted to the development of optimal design methods for such gears. Optimality criteria is formulated as follows: the contact stresses in the pitch point must take a minimum value when all constructive, geometric, kinematic, and technological constraints are met, first, when the profile contact ratio εα ≥ 2 is ensured. Variables planning are defined. These are addendum coefficients of the basic racks tooth for pinion and wheel h*a1, h*a2; profile angle of the basic rack α; addendum modification coefficient of the pinion x1. Formed a system of constraints for the variables planning: the main functional constraint of the minimum value of the profile contact ratio: εα ≥ 2; constraint for the addendum coefficients of the basic racks tooth for pinion and wheel h*a1, h*a2; constraint for profile angle of the basic rack α; constraint for addendum modification coefficients x1, x2; absence of the cutter interference for tooth dedendum; absence of the sharpening for tooth addendum; absence of the mesh interference; ensuring the bending strength of pinion and wheel teeth. A method for solving the problem of optimal design is chosen. The method of probing the space of design parameters was chosen from all the variety. The points of the LPτ-sequence are used as test points. The method allows you to operate with a significant number of parameters – up to 51, provides a sufficiently large number of evenly distributed test points – up to 220. The algorithm for optimal design of gear has been developed. The main stages of the algorithm are as follows: setting input data (numerical constraints on design variables, gear parameters and its load); generation of LPτ-sequence for variables planning with simultaneous consideration of their numerical constraints; checking of functional constraints; additional verification calculations (if necessary) of the gearing contact strength; formation of an array of possible solutions; searching of the best solution variant (the test point corresponding to the minimum value of the objective function) by sorting the array.

Modelling situations of social interaction as a condition for enriching the social experience of high school students

The article proposes to consider the essence of the pedagogical situation as a meaningful specification of the spatio-temporal act of pedagogical interaction and the context of the conditions in which the actions of the teacher and other subjects of the pedagogical process are carried out. The peculiarities of object, subject and subject-object pedagogical situations are analysed. Attention is focused on the fact that the optimal solution to the pedagogical situation is provided by the experience, intuition, effectiveness of the teacher's planning or improvisation. It is noted that the situation of social interaction is a type of pedagogical situation with a social dominant. The components of the social interaction situation are: target component (motivational support, indicative information, goal setting); content component (subject area and actual task or system of tasks); operational component (methods of interaction of participants, type and directions of activity); reflexively – a critical component (valuable content of activity, social interaction skills, reflection of one's own experience).

The effect of the in ovo injections of dextrin and L-carnitine in conditions of thermal stress during the incubation period on the embryonic development and growth of broiler chickens

The embryonic thermal stress due to the overheating is a common problem of the incubation of broiler eggs and hence the search for the methods of metabolic corrections of the related shifts in the embryonic development can be practically actual task. The aim of the research was to study the effect of the in ovo injections of heat stressed chicken embryos with the combination of dextrin (as glucose source) and L-carnitine on the efficiency of incubation and early postnatal growth rate. The study was performed in 2020 on incubated eggs, embryos and chicken of Cobb-500 final hybrid cross. Three groups of eggs (n = 62) were formed for each temperature regime of incubation: without injections, physiological saline injection, injections with the solutions of dextrin (10%) and L-carnitine (0.6%). The eggs were injected with physiological saline, the solutions of dextrin and L-carnitine at the 17th day of incubation. Then the incubation was carried out in hatchers at normal temperature (37.2 °С) and increased temperature (38.5–39.0 °С). The increased temperature during hatching period on average among the groups decreased the hatchability of eggs by 6.1 % and relative weight of chicken by 0.96 %. The injection in ovo with the mixture of dextrin and L-carnitine 1.6–3.2 % increased the hatchability of eggs incubated at increased and normal temperature, respectively. The live weight of day-old chicks injected in ovo with the solution of dextrin and L-carnitine at normal temperature was significantly higher by 1.3–2.3 % (p <0.05) as compared with control groups. Neonatal growth rate was higher in chicken injected in embryonic period with dextrin and L-carnitine both at normal and increased temperature – live weight of 7-day chicken of the experimental groups was 5.9 and 5.1 % higher (p <0.05) compared with the control groups of the same temperature regime. In chicken incubated at increased temperature the differences remained to 35 days of age and were 5.7 % (р <0.05). Biochemical variations were noted in blood parameters of embryos of the control and experimental groups that proved the absorption of exogene nutrients and biologically active substances by the embryo. Thus, in blood plasma of 17-day embryos injected in ovo with the solution of dextrin and L-carnitine the concentrations of glucose significantly increased by 1.6-1.7 % (p< 0.001) and triglycerides by 46.2 % (p <0.05). So, by injecting the incubated eggs during hatching period with the solution of dextrin and L-carnitine, the neonatal growth rate of chicken raised at normal and increased temperature and during heat stress as well. No significant effect of the injection on the hatchability of eggs in conditions of thermal stress in the hatching period was found.

Влияние трансформаций информационно-коммуникативной среды человека на смены социальных парадигм

Shifts in social paradigms (SP) are closely linked to the semantic and technological aspects of the evolving information-communication medium (ICM), which is undergoing radical changes. The essence of a human manifests itself differently depending on the dominant SP and the corresponding ICM. Consequently, an actual task is to analyse their connections, for which purpose this paper provides the first extensive review of key views on this relationship and their classification. A human as a socially conditioned entity is formed in the ICM and forms the SP in public communication. Consolidation and globalization of the ICM, the inclusion of each individual in it ensure the growth of suprapersonal structures of the noosphere, which can lead humanity along the path of coevolution, form the ethics of responsibility and a new SP (according to O.A. Gabrielyan, I.E. Suleimenov).

Application of the bacterial C-DAG system to analyze the ability of amyloids to seed protein aggregation <i>in vitro</i>

The search for new amyloid proteins, as well as the study of their properties, is an actual task, which can be solved by a number of different model systems. One of the most popular is the C-DAG approach. It is based on the analysis of aggregation of the investigated proteins on the surface of Escherichia coli cells. According to the original protocol, it can be used to demonstrate one of the characteristic properties of amyloids: the ability to bind the amyloid-specific dye Congo red and demonstrate apple-green birefringence. In addition, the C-DAG technique allows one to analyze the morphology of aggregates and their resistance to detergents. In this work, we tested using Sup35NM as an example whether aggregates on the surface of bacterial cells can act as inducers of aggregation of the corresponding protein.

Poetics of surrealism by Boris Poplavsky

Poetry of Boris Poplavsky is a phenomenon quite interesting for Russian literature. His texts in most critical works are assessed as experimental, complex, shocking. For Poplavsky, a special role was played not only by the form, but also by the syncretic consolidation of heterogeneous poetic devices, in particular, surreal ones. The purpose of this article is to identify the signs of surrealism in the poet's lyrical heritage. In the course of the study, the receptive approach seems to be the most effective, since it will allow not only to determine the poet's choice of artistic means, but also generalize the aesthetic principles of the author's worldview. Open visualization of Boris Poplavsky's texts marks the orientation towards the laws of surrealism. Effective for the poet is an escape from reality, immersion in an unreal, conditionally visible space. Consequently, the actual task of lyrics is reduced not to a literal display of realities, but to the concretization of a possible, intuitive deciphering of phenomena, processes, even oneself. An independent view of the world, abstraction and independence, building a new paradigm of artistry, provocation, creative dialogue in the listening mode - this is what distinguishes the poetry of Boris Poplavsky among poets of the early twentieth century. The work can become a certain impulse for the creation of new works with an emphasis on the principles of surrealism of the specified author. An alternative view in the art of modernism, with all the reluctance to follow the classics, still does not exclude the dualistic beginning. Boris Poplavsky is a holistic figure, parametric, complex, in fact, this is what actualizes the discussion qualification of the analysis of his texts. The poetics of surrealism gave the poet the opportunity to reveal the probable volume of connotations of the visual level, to bring the philosophy of assessing reality to a systemic, hierarchical paradigm. This material can be used in university practice, as well as in the study of the work by Boris Poplavsky.

Synthesis of Aluminum Complexes Based on 2,6‐Bis(2‐hydroxyphenyl)Pyridines: Efficient Initiators for Ring‐Opening Polymerization of Cyclic Esters

AbstractThe search for new initiators based on nontoxic metal complexes, allowing for the controlled production of polycaprolactone (PCL) and polylactide (PLA) is an actual task. In the present work, we report the synthesis of aluminum complexes 6a and 6b based on substituted 2,6‐bis(2‐hydroxyphenyl)pyridine pro‐ligands. The compositions and structures of the novel compounds were established by elemental analysis and 1H, 13C, NMR spectroscopy in the solid state by X‐ray diffraction analysis (6a and 6b). All the synthesized aluminum complexes are monomeric. Complexes 6a and 6b (in presence of benzyl alcohol (BnOH)) turned out to be active in the ring opening polymerization (ROP) of ε‐caprolactone (ε‐CL), L‐, rac‐lactide (L‐, rac‐LA) gave PCL and PLA with high molecular weights. The mechanism of the polymerization reaction for compounds С, 6a, and 6b was also investigated using the density functional theory (DFT) method. The substituent effect analyzed in terms of percent buried volume and non‐covalent interactions. The values of calculated Gibbs free activation energies correspond to the trend found experimentally.

Multi-UAV Path Planning for Air-Ground Relay Communication Based on Mix-Greedy MAPPO Algorithm

With the continuous development of modern UAV technology and communication technology, UAV-to-ground communication relay has become a research hotspot. In this paper, a Multi-Agent Reinforcement Learning (MARL) method based on the ε-greedy strategy and multi-agent proximal policy optimization (MAPPO) algorithm is proposed to address the local optimization problem, improving the communication efficiency and task execution capability of UAV cluster control. This paper explores the path planning problem in multi-UAV-to-ground relay communication, with a special focus on the application of the proposed Mix-Greedy MAPPO algorithm. The state space, action space, communication model, training environment, and reward function are designed by comprehensively considering the actual tasks and entity characteristics such as safe distance, no-fly zones, survival in a threatened environment, and energy consumption. The results show that the Mix-Greedy MAPPO algorithm significantly improves communication probability, reduces energy consumption, avoids no-fly zones, and facilitates exploration compared to other algorithms in the multi-UAV ground communication relay path planning task. After training with the same number of steps, the Mix-Greedy MAPPO algorithm has an average reward score that is 45.9% higher than the MAPPO algorithm and several times higher than the multi-agent soft actor-critic (MASAC) and multi-agent deep deterministic policy gradient (MADDPG) algorithms. The experimental results verify the superiority and adaptability of the algorithm in complex environments.

ПРОБЛЕМЫ И ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ АЛЮМИНАТНЫХ ЦЕМЕНТОВ ДЛЯ ПОЛУЧЕНИЯ НЕФОРМОВАННЫХ ОГНЕУПОРОВ

The growth of production and improvement of technologies in various industries stipulates the need for materials that ensure the durability of thermal unit linings. This is predetermined by the need to create high-alumina cements (HAC) despite the suc-cesses achieved in the field of expanding their range and improving their quality, i.e. their creation is an important and actual task. Among the various directions of research on improving the technical properties of HAC, the researcher’s attention is at-tracted by the influence of changing the technological parameters on the processes of cement clinker formation. Among such pa-rameters, special attention is paid to the chemical composition of the raw material mixture, its homogeneity, firing temperature, cooling rate, introduction of various additives, etc. The question of refractory properties of high-alumina cement is also dis-cussed. A separate issue is the refractory properties of high-alumina cements. The task of this study was to consider the physico-chemical and technical properties of aluminate cements and to establish the main problems and prospects for the use of alumi-nate cements for the production of non-molded refractories. Improvement of heat-resistant properties of non-formed refractories based on aluminate cements can be provided by the introduction of more refractory additives into the raw material mixture dur-ing clinker firing. However, in this case, formation of hydration inactive compounds in the cement composition can be expected, which can lead to a decrease in cement strength. The methodological basis is the analysis of literature data on the search, synthe-sis and application of refractory additives for aluminate cements. The result of the study was the identification of the list of addi-tives providing higher heat-resistant properties of non-formed refractories based on aluminate cements. The most promising and the most demanded at present is the use of zirconium compounds in combination with a mineralizer for firing. The importance of large-scale scientific research in this area is also substantiated.

DLT-GAN: Dual-Layer Transfer Generative Adversarial Network-Based Time Series Data Augmentation Method

In actual production processes, analysis and prediction tasks commonly rely on large amounts of time-series data. However, real-world scenarios often face issues such as insufficient or imbalanced data, severely impacting the accuracy of analysis and predictions. To address this challenge, this paper proposes a dual-layer transfer model based on Generative Adversarial Networks (GANs) aiming to enhance the training speed and generation quality of time-series data augmentation under small-sample conditions while reducing the reliance on large training datasets. This method introduces a module transfer strategy based on the traditional GAN framework which balances the training between the discriminator and the generator, thereby improving the model’s performance and convergence speed. By employing a dual-layer network structure to transfer the features of time-series signals, the model effectively reduces the generation of noise and other irrelevant features, improving the similarity of the generated signals’ characteristics. This paper uses speech signals as a case study, addressing scenarios where speech data are difficult to collect and the limited number of speech samples available for effective feature extraction and analysis. Simulated speech timbre generation is conducted, and the experimental results on the CMU-ARCTIC database show that, compared to traditional methods, this approach achieves significant improvements in enhancing the consistency of generated signal features and the model’s convergence speed.

Few-Shot Learning Method for Continuous Prediction of Rock Mechanical Parameters Based on Logging Data.

The stratigraphic sequence displays pronounced variations in lithological and physical characteristics along the vertical axis. The acquisition of vertically continuous variations in stratigraphic rock mechanical parameters is essential for the detailed characterization of stratigraphy, particularly in reservoir layers. Moreover, mechanical parameters are essential for the establishment of a rock mechanical stratigraphic framework. However, the existing research methods cannot obtain the complete stratum rock mechanics parameters by relying solely on a small number of rock samples. In this study, a method for continuously predicting rock mechanic parameters within geological sequences by using geophysical logging data was proposed. The method aims to solve the problems of sample scarcity and global geological feature extraction in the continuous prediction of rock mechanics parameters. This methodology achieves the continuous extraction of stratigraphic features, generation of samples, and prediction of the mechanical parameters. The research result showed that the stratigraphic feature extractor of the logging autoencoder possesses global stratigraphic perception capabilities. Stratigraphic feature extractors can precisely identify and pinpoint key locations where stratigraphic properties change, such as lithological transitions and abnormal parts within thick rock layers. The fake rock mechanical samples produced by the generator exhibit data characteristics identical to those of the genuine samples. The rock mechanics parameter prediction model with the ability to extract stratigraphic features performs significantly better than traditional models when evaluated on real data sets (the mean square errors for the friction angle and cohesion are 17.2 and 12.65, respectively, mean absolute errors are 2.85 and 2.64, respectively, and R2 values are both 0.91) and produces more reasonable calculation results in the actual prediction task of Longtan Formation rock mechanics parameters compared to traditional models. This study provides an extensive applicable methodological framework to address the issues of insufficient samples and continuous prediction of geological parameters in the field of geology.

The socio-cultural discourse of falsifications of national history and the actual tasks of school humanitarian education

The socio-cultural discourse of falsifications of national history and the actual tasks of school humanitarian education

Определение типа текстуры в сверхрешетках Co/Cu

The study of the state of interlayer boundaries (interfaces) in various multilayer systems is an actual and difficult task, for the solution of which local methods are used. The effectiveness of nuclear magnetic resonance (NMR) in the study of Co/Cu superlattices has been shown many times. However, in the published works nuclear magnetic resonance was used to determine the type of crystal lattice in cobalt layers and the features of the structure of Co/Cu interfaces. In the present work, a method for determining the type of texture formed in Co/Cu superlattices is proposed. The method is based on the interpretation of NMR and X-ray diffraction data using three-dimensional modeling of the structure of interlayer interfaces.

Peptide stimulation effect on organotypic culture development of neuroendocrine tissues

Introduction. One of the actual task of modern biology and medicine. Is the creation of bioregulator preparation, which can stimulate the neuroendocrine system of organism. Purpose of study. Study of effect of polypeptide complex from brain cortex (PPCbc) and from pancreas (PPCp) of calfs on the cellular proliferation in organotypic culture of nerve and endocrine of young and old rats. Methods. The adequate method of organotypic tissue culture of tissue from young and old rats was used for quick biologically activity of peptides screening. Results. The square index (SI) of nerve and endocrine tissues explants were increased statistically reliable, as compared to the control, also in young and old rats, under the polypeptides complexes effect. Conclusion. The data obtained produce the base for working and quick testing of preparations for treatment of patients with pathology in brain cortex and endocrine tissues

Neurophysiological dynamics of metacontrol states: EEG insights into conflict regulation

Understanding the neural mechanisms underlying metacontrol and conflict regulation is crucial for insights into cognitive flexibility and persistence. This study employed electroencephalography (EEG), EEG-beamforming and directed connectivity analyses to explore how varying metacontrol states influence conflict regulation at a neurophysiological level. Metacontrol states were manipulated by altering the frequency of congruent and incongruent trials across experimental blocks in a modified flanker task, and both behavioral and electrophysiological measures were analyzed. Behavioral data confirmed the experimental manipulation's efficacy, showing an increase in persistence bias and a reduction in flexibility bias during increased conflict regulation. Electrophysiologically, theta band activity paralleled the behavioral data, suggesting that theta oscillations reflect the mismatch between expected metacontrol bias and actual task demands. Alpha and beta band dynamics differed across experimental blocks, though these changes did not directly mirror behavioral effects. Post-response alpha and beta activity were more pronounced in persistence-biased states, indicating a neural reset mechanism preparing for future cognitive demands. By using a novel artificial neural networks method, directed connectivity analyses revealed enhanced inter-regional communication during persistence states, suggesting stronger top-down control and sensorimotor integration. Overall, theta band activity was closely tied to metacontrol processes, while alpha and beta bands played a role in resetting the neural system for upcoming tasks. These findings provide a deeper understanding of the neural substrates involved in metacontrol and conflict monitoring, emphasizing the distinct roles of different frequency bands in these cognitive processes.