Structural Units Research Articles

Radius Model for Some Cells in Human Body on Multiplicative Calculus

The cell is the basic structure and process unit that carries all the living characteristics of a living thing and has the ability to survive on its own under suitable conditions. The relationship of cell size with nutrient absorption and nutrient consumption in the cell membrane has been examined with the current model using the theory of differential equations in classical analysis. During these examinations, the cell considered was assumed to be spherical. In fact, the shapes of cells vary depending on their functional properties. Many have long appendages, cylindrical parts or branch-like structures. However, in this study, a simple global cell will be discussed, leaving all these complex situations aside. In the current model, the relationship between the change in the radius of the cell and the nutrient absorption and consumption in the cell membrane is detailed using classical differential equations. The answer to the question for which cell size is the consumption rate exactly balanced with the absorption rate was found in classical analysis. The current model consists of first-order differential equations. In this model, the dependent variables are the radius of the cell and the mass of the cell. The classical solutions of these models will be examined, the size of the cell and the cell membrane relationship will be examined, and details will be given with numerical examples. However, in order to consider this biological phenomenon from different perspectives and compare the results, the relevant event will be modeled using multiplicative analysis, one of the Non-Newtonian analyses. The new models will be solved using multiplicative analysis techniques, and the results will be compared with classical analysis. With this new model, it is planned to clarify the results obtained in the classical case, to reveal more clearly the relationship between the size of the cell and nutrient absorption and consumption in the cell membrane, and to obtain important results.

Collaborative Hollow Porous Structure Design and N Doping to Achieve a Win–Win Situation of “Stable” and “Fast” Lithium Battery

ABSTRACTPolymer‐derived SiOC materials are widely regarded as a new generation of anodes owing to their high specific capacity, low discharge platform, tunable chemical/structural composition, and good structural stability. However, tailoring the structure of SiOC to improve its electrochemical performance while simultaneously achieving elemental doping remains a challenge. Besides, the lithium storage mechanism and the structural evolution process of SiOC are still not fully understood due to its complex structure. In this study, a hollow porous SiOCN (Hp‐SiOCN) featuring abundant oxygen defects is successfully prepared, achieving both the creation of a hollow porous structure and nitrogen element doping in one step, finally enhancing the structural stability and improving the lithium storage kinetics of Hp‐SiOCN. In addition, the formation of a fully reversible structural unit, SiO3C─N, through the chemical interaction between N and Si/C, showcases a strong lithium adsorption capacity. Taking advantage of these combined benefits, the as‐prepared Hp‐SiOCN electrode delivers a reversible specific capacity of 412 mAh g−1 (93% capacity retention) after 500 cycles at 1.0 A g−1 and exhibited only 4% electrode expansion. This work offers valuable mechanistic insights into the synergistic optimization of elemental doping and structural design in SiOC, paving the way for advanced developments in battery technology.

An integrative TAD catalog in lymphoblastoid cell lines discloses the functional impact of deletions and insertions in human genomes.

The human genome is packaged within a three-dimensional (3D) nucleus and organized into structural units known as compartments, topologically associating domains (TADs), and loops. TAD boundaries, separating adjacent TADs, have been found to be well conserved across mammalian species and more evolutionarily constrained than TADs themselves. Recent studies show that structural variants (SVs) can modify 3D genomes through the disruption of TADs, which play an essential role in insulating genes from outside regulatory elements' aberrant regulation. However, how SV affects the 3D genome structure and their association among different aspects of gene regulation and candidate cis-regulatory elements (cCREs) have rarely been studied systematically. Here, we assess the impact of SVs intersecting with TAD boundaries by developing an integrative Hi-C analysis pipeline, which enables the generation of an in-depth catalog of TADs and TAD boundaries in human lymphoblastoid cell lines (LCLs) to fill the gap of limited resources. Our catalog contains 18,865 TADs, including 4596 sub-TADs, with 185 SVs (TAD-SVs) that alter chromatin architecture. By leveraging the ENCODE registry of cCREs in humans, we determine that 34 of 185 TAD-SVs intersect with cCREs and observe significant enrichment of TAD-SVs within cCREs. This study provides a database of TADs and TAD-SVs in the human genome that will facilitate future investigations of the impact of SVs on chromatin structure and gene regulation in health and disease.

Freeze–thaw processes correspond to the protection–loss of soil organic carbon through regulating pore structure of aggregates in alpine ecosystems

Abstract. Seasonal freeze–thaw processes alter soil formation and lead to changes in soil structure of alpine ecosystems. Soil aggregates are basic soil structural units and play a crucial role in soil organic carbon (SOC) protection and microbial habitation. However, the impact of seasonal freeze–thaw processes on pore structure and their impact on SOC fractions have been overlooked. This study characterized the pore structure and SOC fractions of soil aggregates of the unstable freezing period, stable frozen period, unstable thawing period and stable thawed period in typical alpine ecosystems via a dry-sieving procedure, X-ray computed tomography scanning and elemental analysis. The results showed that pore networks of 0.25–2 mm aggregates were more vulnerable to seasonal freeze–thaw processes than those of >2 mm aggregates. The freezing process promoted the formation of >80 µm pores of aggregates. The total organic carbon, particulate organic carbon and mineral-associated organic carbon contents of aggregates were high in the stable frozen period and dropped dramatically in the unstable thawing period, demonstrating that the freezing process was positively associated with SOC accumulation, while SOC loss featured in the early stage of thawing. The vertical distribution of SOC of aggregates was more uniform in the stable frozen period than in other periods. Pore equivalent diameter was the most important structural characteristic influencing SOC contents of aggregates. In the freezing period, the SOC accumulation might be enhanced by the formation of >80 µm pores. In the thawing period, pores of <15 µm were positively correlated with SOC concentration. Our results revealed that changes in pore structure induced by freeze–thaw processes could contribute to SOC protection of aggregates.

Photoredox-Catalyzed Regioselective 1,3-Alkoxypyridylation of gem-Difluorocyclopropanes.

Difluoromethylene and pyridine cores are very important structural units in medicinal chemistry. Herein, we report the development of photoredox-catalyzed ring-opening and 1,3-alkoxypyridylation of gem-difluorinated cyclopropanes using 4-cyanopyrines and alcohols, employing cyclopropane radical cations as the key intermediate. The reaction exhibits high regioselectivity under mild conditions and can also be practiced on gram-scale synthesis, telescoped reaction, and late-stage functionalization of biological molecules.

Development of compositions of dinas lightweight materials using combinable additives

The results of the development of compositions of dinas lightweight materials based on quartzites using burnable additives, in particular sawdust, coal waste, and a synthesized mineralizer, are presented. A composition of dinas lightweight material with improved physical and mechanical properties has been developed ― with increased porosity and mechanical strength, low density and low thermal conductivity. The developed composition of lightweight silica material can be used for high-temperature thermal insulation, as well as for lining loaded structural units.

Long-Range Anion Correlations Mediating Dynamic Anharmonicity and Contributing to Glassy Thermal Conductivity in Well-Ordered K2Ag4Se3.

Herein an extremely low (0.32‒0.25 Wm-1K-1) and glassy temperature-dependence (300-600K) of lattice thermal conductivity (κlat)in a monoclinic K2Ag4Se3 is reported. It is found that the effective carrier delocalization, contributed by the perfect p-d* hybridization paradigm, can efficiently facilitate the spatial transfer of electron cloud perturbations induced by the anisotropic thermal vibrations of Ag4 atoms, thereby favoring long-range Se‒Se correlations. The localized rattling-like vibration of Ag4 atoms induce short phonon lifetimes, large scattering phase space, and then a low particle-like propagation. While the correlated interactions mediated competitive expressions between bubble diagrams and loop diagrams can suppress the generation of wavelike phonons from off-diagonal coupling. Ultimately, the AgSe3 structural units can enable the dual confinement of both the particle-like propagation of phonons and wavelike tunneling of coherence. The study highlights that the correlated AgSe3 coordination units can simultaneously target particle-like and wavelike phonons and then reduce their contribution to the κlat by mediating long-range transfer of charge polarization. These fundamental advances will advance the design of crystalline materials with tailored thermal properties.

Synthesis, Structural Analysis and Investigation of Photoluminescence Properties of Mixed Metal Cation Borates

The compounds synthesized in this study are mixed metal borates with the structure of MMeR(BO3)2 (M=Na+, Me=Sr2+, R=La3+, Ce3+, Nd3+, Sm3+ and Er3+). Solid state method was used for synthesis. Unlike the literature, borates containing three cations were synthesized using acetates of the starting materials. In the structure of borates, alkali and earth metal cations are surrounded by six and nine oxygen atoms, respectively. Rare earth metal cations are surrounded by six oxygen atoms. The complex structure of borates makes them strong candidates for nonlinear optics (NLO) applications. Since boron element (B) is coordinated with three or four oxygen atoms, they not only form planar triangles (BO33−) or tetrahedral (BO44−) but also bond with each other to form various structural units. This structural diversity is suitable for the discovery of new compounds with linear optical and nonlinear optical properties. Among these structural units, BO3 groups have attracted great attention due to their nonlinear optical properties, which are capable of producing moderate birefringence and broad ultraviolet (UV) transparency. Borates that do not contain rare earth metal cations are currently used in nonlinear optical applications to produce high-power visible and ultraviolet light. Due to the importance of borate compounds for industry and research, the aim of the study is to synthesize new types of mixed metal borate compounds and to investigate their structural properties. Powder X-ray diffraction (P-XRD), Fourier transform infrared spectroscopy (FT-IR), Inductively Coupled Plasma (ICP) and Thermal Gravimetric Analysis (TGA) techniques were used for the characterization of the synthesized mixed metal borate structures. Photoluminescence properties were investigated by Photoluminescence (PL) Spectroscopy in the application study.

Hydrogeochemical characteristics and evolution of formation water in the continental sedimentary basin: A case study in the Qaidam Basin, China.

In deep formations, oil or gas reservoir rocks are generally accompanied by groundwater with high total dissolved solids (TDS), commonly referred to as "formation water". The enrichment of trace and/or metallic elements such as K, B, Li, Br, Sr in this type of groundwater holds significant industrial values and socioeconomic benefits. However, the processes involved in the burial and generation of formation water remain not fully understood. In this study, totally 468 sets of major ions and trace elements were collected from current study and literatures to investigate the hydrogeochemical characteristics and evolution mechanisms of formation water from different regional geological structure units in Qaidam Basin, China. The results indicated that TDS of formation water in Western (QW), Central (QC) and Northern (QN) units of Qaidam basin ranged from 173 to 290g/L, 101 to 152g/L and 32 to 73g/L, respectively, which were several to dozens of times higher than those of seawater, but lower than those of intercrystalline brine and salt lake water. The enrichment of Ca, Li, B, Br and depletion of Mg and SO42- were observed in the formation water in comparison to seawater and salt lake water. Formation water especially in QC and QW was identified as typical dissolved brine of terrestrial rock origin, experiencing prolonged water-rock interactions. However, the time and degree of water-rock interaction and metamorphism differed regionally due to the sedimentary history and patterns of Qaidam Paleolake. Overall, the large paleolake deposits under the control of multiple tectonic movements laid the material foundation for the burial and generation of the formation water, and a variety of fluids and deep faults became the sources and migration channels for formation water. It mainly experienced two stages, including the sedimentary process of saline strata and the transformation in the later period.

Cyanobacterial hydrothermal carbonization carbon as photocatalyst for selective aerobic oxidation of cyclohexane

The exploration of catalyst preparation techniques that incorporate environmental-friendly methodologies has consistently been the focus of scientific inquiry within the field of green synthesis of oxygen-containing organic chemicals. Herein, a metal-free hydrothermal carbonation carbon (HTCC) has been prepared utilizing cyanobacterial biomass produced during a water bloom in a freshwater lake. The HTCC produced is capable of performing photocatalytic selective oxidation of cyclohexane to cyclohexanol and cyclohexanone (KA oil) under ambient conditions. The use of cyanobacterial biomass allows for the efficient preparation of HTCC, which exhibits a conversion rate of cyclohexane that is 4.1 times of HTCC prepared with alternative carbon sources (glucose). The selectivity to KA oil over the samples are almost 100%. Characterizations and analysis reveal that cyanobacteria can lead to self-doping of nitrogen and hydrophobicity of the resulting HTCC, while sulfuric acid etching endow it with more photoactive sp2 hybridized structure units that contribute to a higher photogenerated carrier separation efficiency. The suitable band structure enables the cyanobacterial HTCC to produce superoxide radicals to oxidize cyclohexane. These findings are of great significance for the development of eco-friendly photocatalysts and the utilization of biomass resources.

The influence of tectonic action on the characteristics of microcrystalline and pore structure of anthracite in Qianbei Coalfield

Tectonic action strongly impacts the coal's microcrystalline and pore structural features. X-ray diffraction (XRD) was employed to analyze the impact of tectonic action on the microcrystalline structure of coal. The pore structure of anthracite was investigated through electron microscope image, mercury intrusion porosimetry and low pressure N2/CO2 adsorption, with a focus on exploring the relationship between the microcrystalline structure of coal and its micropore structure. The results show that under tectonic action, interlayer spacing of the aromatic layer d002 decreases from 0.345 to 0.342 nm, the stacking height Lc decreases from 2.73 to 2.23 nm, the average number of the effective aromatic layer Nave slightly decreases from 6.61 to 6.51, and the crystallite diameter La increases by 0.13 nm, which indicates that tectonic action changes the microcrystalline structure of anthracite. The microcrystalline structure changes from "short and thick" to "long and thin", thus schematic diagram of the anthracite basic structural unit (BSU) under tectonic action was established. The fa of tectonic coal increased by 16.92% compared with that of original coal, and the g increased from 0.85 (original) to 0.89 (tectonic), indicating that the process of aromatization and graphitization of coal was accelerated by tectonic action. Tectonic action plays an important role in promoting pore development, which makes the pore surface of anthracite more rough, the lattice fringe more dense and clear, and increases the pore volume and specific surface area of anthracite by 1.21 and 1.08 times, respectively. Tectonic action can change the BSU of coal, thus producing more nanoscale space. This study holds important implications for comprehending how tectonic action affect the microcrystalline structure of coal as well as its relationship with nanopore structures in tectonic coal.

Unveiling the Antiferromagnetic Properties of Cr2Pbn (n = 3-20) Clusters.

Assembling antiferromagnetic (AFM) clusters is perhaps an effective way to construct AFM materials to meet the increasing demand for micro/nano spintronic devices, which promotes the exploration of AFM clusters. Herein, we unveil the structural evolution, electronic, and AFM properties of Cr2Pbn (n = 3-20) clusters based on density functional theory (DFT) calculations. It is found that the Cr impurities prefer the central axis positions of the skeleton in these Cr2Pbn (n = 3-20) clusters. For sizes n ≤ 6, their structures are exohedral structures with the two Cr atoms exposed outside, endohedral Cr@Pbn configuration with one Cr atom interior appears at size 7, and the resulting endohedral structure is then gradually covered by the additional Pb atoms to form endohedral Cr2@Pbn structures for n = 15-20. All Cr2Pbn clusters are antiferromagnets, except for the ferrimagnetic Cr2Pb11 with a net magnetic moment of 2 μB. The discovered stable Cr2Pb17 cluster can assemble into dimers and trimers while maintaining its geometric structure and AFM properties, indicating the potential of becoming structural units for cluster-assembled AFM materials.

Preparation of durable photonic particles with optimal structural colors

The silica nanosphere-based photonic crystal supraballs demonstrate remarkable structural colors. However, their inadequate mechanical performance limits their potential for extensive industrial applications. In this study, elastomeric polymers were introduced into the internal interstices and surfaces of the supraballs through an emulsion method, forming a protective framework around the structural units. This significantly enhanced the stability and abrasion resistance of the supraballs. Durable supraballs with structural colors were successfully fabricated by optimizing the volume ratio between elastomeric polymers and structural units. Despite the disruption of the close-packed structure typical of photonic crystals caused by the incorporation of elastomeric polymers, the relatively regular arrangement of structural units within the supraballs was sufficient to generate vibrant structural colors. Additionally, durable supraballs in a variety of colors were successfully fabricated by utilizing silica nanospheres with different diameters, meeting the requirements for industrial applications of dyes.

Text units with purpose semantics in a discursive perspective

INTRODUCTION. The correlation of the terms “text units” and “discourse units” is currently opaque due to numerous approaches to defining text units and ambiguous decisions regarding discursive ones. The aim is to identify the features of the correlation of structural units of text and discourse and to establish the specifics of the rhetorical relations of Purpose at the element node level of discourse.MATERIALS AND METHODS. The research is conducted on the basis of contemporary mass media material through an unselected sampling from interviews with Russian political leaders using the methodology of the theory of rhetorical structures, general philological argumentation, as well as conversation and discourse analysis.RESULTS AND DISCUSSION. A structural-semantic dependence is established when identifying the correlation of text units with the purpose semantics and discursive units organized according to the principle of rhetorical relations of the purpose; the specificity of the rhetorical connections of Purpose as relations of the subject type, an asymmetric structure, characterized by a complete paradigm of the signs of polarity and direction is revealed.CONCLUSION. The study has prospects for further study of global structures of natural discourse, as well as practical significance in the context of computational linguistics in the development of algorithms for creating texts using artificial intelligence.

Structural basis for C. elegans pairing center DNA binding specificity by the ZIM/HIM-8 family proteins

Pairing center (PC) on each chromosome of Caenorhabditis elegans is crucial for homolog pairing and initiating synapsis. Within each PC, clusters of 11/12 bp DNA motif recruit one of four paralogous meiosis-specific proteins: ZIM-1, ZIM-2, ZIM-3, or HIM-8. However, the mechanistic basis underlying the specificity of ZIM/HIM-8-PC DNA interaction remains elusive. Here, we describe crystal structures of HIM-8, ZIM-1 and ZIM-2 DNA binding domains (ZF1, ZF2 and CTD) in complex with their cognate PC DNA motifs, respectively. These structures demonstrated the ZF1-2-CTD folds as an integrated structural unit crucial for its DNA binding specificity. Base-specific DNA-contacting residues are exclusively distributed on ZF1-2 and highly conserved. Furthermore, the CTD potentially contributes to the conformational diversity of ZF1-2, imparting binding specificity to distinct PC DNA motifs. These findings shed light on the mechanism governing PC DNA motif recognition by ZIM/HIM-8 proteins, suggesting a co-evolution relationship between PC DNA motifs and ZF1-2-CTD in shaping the specific recognition.

Оцінка соціально-економічного потенціалу Дніпропетровщини: умови створення технічного освітньо-наукового кластеру

The article highlights the concept of a «Technical Educational and Scientific Cluster» (TESC). It is established that its structural foundation is based on a developed university ecosystem, which includes participants in the educational process, infrastructure facilities, and structural units – scientific and educational institutes, colleges, lyceums, incubators, and technoparks, which interact with each other creating a unique synergy aimed at the innovative development of a particular region and industries, such as: engineering, aerospace, transport, chemical, metallurgical, construction, etc. It is determined that the integration of the cluster into the region's economy involves the development of cooperation not only between educational institutions and enterprises but also with local authorities, business associations, and investors, which influence the formation of the region's socioeconomic potential (SEP) and ensure the creation of a favorable environment for the development and implementation of new technologies in production. This contributes to the development of the region's economy, increasing its competitiveness on the global market of goods and services. Emphasis is placed on the university, which plays a key, integrating role and is the core of the cluster, uniting various elements of the ecosystem and ensuring their effective interaction and has a direct and profound impact on the region's SEP. In fact, it becomes an innovative center of the region, not only generating new knowledge and training highly qualified personnel but also creating a powerful synergistic effect by cooperating with businesses. Such a tandem contributes to the rapid commercialization of scientific developments, the birth of new technological startups, and, as a result, the growth of the region's economic potential. At the same time, by involving students in scientific research and entrepreneurial projects, it forms an innovative culture, increases social mobility, and contributes to improving the quality of life of residents, increasing the investment attractiveness of Dnipropetrovsk region, and forming a stable position to changes in the economy. It is emphasized that the development of TESC is impossible without taking into account the specifics of the region's SEP. Constant monitoring of such factors as the level of education, the innovative activity of enterprises, and the investment climate allows adjusting the cluster's development strategy and ensuring its compliance with the needs of the region

Modeling and mechanism of the mechanical interlocking for the carbon fiber/epoxy interphase

The intricate details governing the carbon fiber/epoxy interfacial characteristics at the molecular level have yet to be comprehensively unraveled. One of the reasons is that the effects of carbon fiber (CF) surface structures are oversimplified, leading to misconceptions regarding adhesion mechanisms. To advance knowledge of structure-property relationships, we employed molecular dynamics simulations to provide insights into the complexity of the CF surface and CF/epoxy interphase. A series of turbostratic surface models with different protrusion heights were built via crosslinking basic structural units inside hexagonal prism virtual energy walls to better model the physical and chemical features of a CF surface. Epoxy precursor and curing agent molecules were added and crosslinked to generate the CF/epoxy interphase models before loading the systems in tension and shear. It was found that the spatial variation of composition determines the longitudinal and transversal moduli distribution in the interphase. Moreover, higher protrusion increases the tensile strength and toughness in the transverse direction by transferring part of the tensile loading into the shear component. The mechanical interlocking between the polymer and the CF surface with microvoids and protrusions enhances both the interfacial shear strength and the effectiveness of load transmission.

Influence of Bi2O3 on structural and optical characteristics of PbO⋅B2O3⋅Bi2O3⋅SiO2 glasses

In this study, the influence of Bi2O3 on the structural and optical characteristics of the glass samples with the molar composition of 17PbO⋅23B2O3⋅xBi2O3⋅(60-x)SiO2, prepared using the conventional melt quenching approach, is described. X-ray diffraction spectra reveal the amorphous nature of the prepared series. Density (D), molar volume (Vm), glass transition temperature (Tg), and other physical parameters have been evaluated. FTIR spectra show the presence of bismuth as [BiO3] and [BiO6] structural units and of borate as [BO3] and [BO4] structural units. It is found that the increase in non-bridging oxygens can be attributed to the increase in cut-off wavelength and decrease in bandgap energy with the rise in bismuth concentration. Urbach's energy values demonstrate that the presence of Bi2O3 in the existing glass system might affect the defect concentration. All glass samples possess a high refractive index suggesting that the current glasses may be useful for developing non-linear optical systems.

The hyaluronan-binding activity of aggrecan is important, but not essential, for its specific insertion into perineuronal nets.

Aggrecan (ACAN) is a large, secreted chondroitin sulfate proteoglycan that includes three globular regions named G1, G2, G3, and is decorated with multiple glycosaminoglycan attachments between its G2 and G3 domains. The N-terminal G1 region interacts with the glycosaminoglycan hyaluronan (HA), which is an essential component of the vertebrate extracellular matrix. In the central nervous system, ACAN is found in perineuronal nets (PNNs), honeycomb-like structures that are enriched on parvalbumin-positive neurons in specific neural circuits. PNNs regulate the plasticity of the central nervous system, and it is believed that association between ACAN and HA is a foundational event in the assembly of these reticular structures. Here, we report the co-crystal structure of the G1 region of ACAN in the absence and presence of an HA decasaccharide and analyze the importance of the HA-binding activity of ACAN for its integration into PNNs. We demonstrate that the single immunoglobulin domain and the two Link modules that comprise the G1 region form a single structural unit, and that HA is clamped inside a groove that spans the length of the tandem Link domains. Introduction of point mutations in the glycosaminoglycan-binding site eliminates HA-binding activity in ACAN, but, surprisingly, only decreases the integration of ACAN into PNNs. Thus, these results suggest that the HA-binding activity of ACAN is important for its recruitment to PNNs, but it does not appear to be essential.

СУЧАСНІ ПІДХОДИ ДО ОЦІНКИ КОМПЕТЕНЦІЙ ПРАЦІВНИКІВ ПРОБАЦІЇ

The article is devoted to the directions of forming a comprehensive system for assessing the competencies of probation officers. The author reveals the importance of applying modern methods, tools and approaches to the assessment of probation officers by competencies and performance in HR processes. It is also an opportunity to encourage an employee and give him or her the opportunity to learn or develop in related areas. The purpose of the article is to study modern methods and approaches to assessing the competencies of probation officers used in the field of HR management. The article uses the methods of observation, comparison, generalization, scientific abstraction, and system analysis. When selecting a candidate for a vacant position, passing a probationary period, upgrading skills, transferring to another structural unit, forming a talent pool, and even dismissing an employee, it is important to assess the employee’s knowledge and practical skills at each of these stages. Testing helps determine not only the employee’s qualification level, but also his or her personal qualities. The method is convenient because it allows you to get complete information about an employee, predict his or her behavior in different work situations, and understand whether he or she is in line with the corporate culture. Employee evaluation methods are divided into qualitative and quantitative. The former are more in-depth, while the latter provide broader coverage. In addition, combined methods are used, which involve the use of approaches from both categories. Evaluation of employees and job candidates is an important measure that is essential for proper HR management. It provides insight into the team and each individual employee. This information will help to promote talented and promising employees, catch up with laggards, and get rid of team members who are harmful to the institution. Key words: probation officers, assessment, methods, approaches, competencies, HR management.