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BACKGROUND: Fractures of the lower jaw accounts for up to 85% of the total number of fractures of the facial bones. Its damage leads to the formation of temporary and persistent functional disorders of the stomatognathic apparatus. Understanding the regularities of the processes of restoring the motor functions of the mandible and chewing apparatus is necessary for planning and improving rehabilitation programs in these patients. AIM: To examine the degree and rate of restoration of the amplitude of movements of the mandible in the long-term period of the rehabilitation stage of patients with mandibular fractures. MATERIAL AND METHODS: A prospective study was conducted on 40 patients with unilateral and bilateral mandibular fractures, who made up two groups depending on the volume of treatment according to current clinical protocols: group 1 included 22 people who underwent double-jaw splinting during treatment, and group 2 included 18 people who, according to indications, also underwent osteosynthesis of the mandible with subsequent intermaxillary immobilization in the postoperative period. One year after the removal of splinting structures, all mobile patients underwent a clinical assessment of the range of motions of the lower jaw. RESULTS: Even 1 year after the successful treatment of patients in the acute period of trauma, despite the implementation of myogymnastics in the rehabilitation period, the range of motions of the lower jaw remains limited. In group 1, after 1 year of observations, the average values correspond to the lower limits of the norms according to literature data: opening, 4.35 cm; with protrusion, 0.78 cm; laterotrusion with unilateral fractures in the damaged side, 0.95 cm; intact, 0.91; bilateral, the damaged side 1 (right), 0.86 cm, damaged side 2 (left), 0.86 cm. In group 2, during the observation period, these indicators remained significantly lower, not reaching the limits of the norm in any case. Moreover, in both groups, their values were significantly lower than those of the healthy volunteers CONCLUSIONS: Data obtained on the patterns of restoration of the range of motion of the lower jaw after sustaining a fracture and prolonged immobilization in the long-term justify the need to develop and conduct mandatory early comprehensive rehabilitation measures. Their clinical effectiveness should be confirmed from the standpoint of evidence-based medicine, which enables the comprehensive assessment of the function of the stomatognathic apparatus. This study established indicators that can be considered control criteria when performing relevant studies.

Three-dimensional printing opens up many opportunities for use in traumatology and orthopedics, because it takes into account personal characteristics of the patients. Modern methods of high-resolution medical imaging can process data to create threedimensional images for printing physical objects. Today, three-dimensional printers are able to create a model of any complexity of shape and geometry. The article provides a review of the literature about three-dimensional digital modeling in shaping implants for osteosynthesis. Data search was carried out on the Scopus, Web of Scince, Pubmed, RSCI databases for the period 2012–2022. The effectiveness of three-dimensional printing for preoperative modeling of bone plates has been confirmed: implants perfectly corresponds with the unique anatomy of the patient, since the template for it is based on the materials of computed tomography. Individual templates can be useful when the geometry of patients' bones goes beyond the standard, and when improved results of surgery are expected due to better matching of implants to the anatomical needs of patients.

We reviewed scientific literature on the problem of osteosynthesis of long tubular human bones, published during the last 10 years. The Scopus, Web of Scince, Pubmed, RSCI databases were searched for the articles reporting the results of clinical studies and biomechanical experiments using plate osteosynthesis. The advantages and disadvantages of minimally invasive plate osteosynthesis for different segments have been revealed. The articles reported a lower probability of displacement development in minimally invasive plate osteosynthesis in comparison with intramedullary osteosynthesis, good biological conditions for fracture healing, decreased rate of complications of postoperative wounds due to reduced incisions. In the concept of biological osteosynthesis, the advantage of axial dynamization and fracture micro-mobility over absolute rigidity was noted. The study also revealed the influence of the parameters of a plate and osteosynthesis technique on the rigidity of the plate-bone system, such as: the working length of the plate, the number of screws on the plate, types of screws (cortical or locking), the plate material and its profile. The bone osteosynthesis seemed to have new directions of evolution. These include far cortical locking screws allowing micromobility under the plate, providing a "controlled dynamization". An experimental technology of Active Locking Plates has been reported, where the screws with angular stability are locked in holes on elastic sliding elements providing micromobility of the screw relative to the plate. In general, all the visible results differed in various studies and, sometimes, contradicted each other.

In the literature, the treatment of patients with Achilles tendon ruptures begins with diagnosis and diagnosis. Depending on the classification of Achilles tendon rupture, treatment tactics are determined. From our point of view, the existing classification of Achilles tendon ruptures does not sufficiently reflect and systematize the approach to surgical treatment, which served as a more detailed study and addition to the existing classification of Achilles tendon ruptures.

Today autografts are considered to be an optimal material for bone grafting. However, the collection of material and its clinical use is associated with several serious drawbacks, and therefore, in reconstructive surgery, a search for alternative treatment approaches is being conducted. A bone transplant from another person (allo-osteoplasty) is the most natural and logical option for replacing an autobone. Since 1965, allogeneic implants of a partially demineralized bone matrix combining osteoinductive and osteoconductive action have been used in clinical practice. However, the clinical results of the use of this material turned out to be ambiguous, which is due, first of all, to the significant variability of the osteoplastic potential of its various samples. For this reason, in clinical practice, sometimes preference is given to samples of non-demineralized allobone, which retain its structure longer. In this paper, we consider factors affecting the osteoinductive activity of a partially demineralized bone matrix, related both to the technological issues of its preparation and to the clinical conditions of use. Issues of the possible improvement of this material were discussed with a view to its further use in medical practice.

This article presents a clinical example of treatment of a patient with secondary post-traumatic deformity of the proximal femur due to a solitary bone cyst. The cyst cavity was filled with spongeous bone homograft LYO-57, which served as a substrate for a consistent bone regeneration. The quality of the formed bone made it possible to perform corrective osteotomy of the proximal femur with stable osteosynthesis for the secondary deformity. The results of treatment allow us to recommend this type of homotransplant for the treatment of patients with solitary bone cysts.

Planovalgus foot deformity is one of the most common orthopedic conditions detected in childhood. According to the literature, it is present in 70% of children under 11 years with various degree of severity. Without timely correction, the common complications of this deformity are: arthrosis of the talonavicular joint, valgus deformity of the knee joints, impaired posture and functional scoliosis, pain syndrome, impaired function of the lower extremities, which is an indication for surgical treatment of this pathology. The article presents a clinical case report of surgical treatment of a patient with severe planovalgus foot deformity. The main stages of surgical correction were tendon-muscle plasty, subtalar arthroeresis and Cotton osteotomy (wedging osteotomy of the medial sphenoid bone). Relying on the results of surgical treatment of the patient, we conclude that the use of the combination of methods is valid for the treatment of patients with severe planovalgus foot deformity.

Aim to evaluate the effectiveness of restoring the lateral ankle ligament complex using local tissues according to the Brostrom Gould technique in patients with different post-traumatic periods. Material and methods. In 2021, in total 15 patients with lateral ankle instability underwent clinical and instrumental examination and received surgical treatment for this pathology. The patients were divided into three groups depending on the time passed from the primary injury. Group 1 included patients with a post-traumatic period up to 5 years, Group 2 up to 10 years and Group 3 more than 10 years. The ankle instability was assessed before and after surgery using the AOFAS and Karlsson Peterson scales. Results. In Groups 1 and 2, the patients were satisfied with the results of treatment They could restore the intensity of their physical activity to the level they had before the injury. The patients from Group 3 were not content with the results of treatment and reported the remaining pain, swelling, and joint instability. Conclusion. With a disease duration of up to 5 years, Brostrom Gould procedure provides excellent results and remains the preferred treatment for lateral ankle instability. This technique can be successfully used in patients with the post-injury period up to 10 years, if their life-style does not imply the regular intensive load on the ankle. If the history of the disease is more than 10 years, the Brostrom Gould procedure is ineffective, in such cases other complex treatment methods should be used.

Study goal — To evaluate the efficacy of plate osteosynthesis in the treatment of patients with inflammatory complications of mandibular fractures on a large sample. Material and Methods — We conducted a retrospective analysis of medical records collected over 15 years in a group of patients with inflammatory complications of mandibular fractures. The analysis included medical records of patients who underwent plate osteosynthesis operations performed according to the surgical algorithm adopted in the clinic, in combination with a simultaneous directed antibacterial effect on the microflora of the pathological focus and osteoplastic replacement of defects. We identified 164 medical records meeting the search criteria distributed among two study groups. Group A included hospitalized patients with developed abscesses and phlegmons of soft tissues surrounding the fracture area. For them, two-stage surgical intervention was performed. Group B consisted of patients who had no suppurative process in soft tissues, which allowed them undergoing one-stage surgical treatment. Results — Good, satisfactory, and unsatisfactory surgical outcomes were obtained in 82.6%, 14.9%, and 2.4% of the patients, respectively. The differences between the comparison groups were not statistically significant. Conclusion — The clinical effectiveness of an integrated approach to the surgical treatment of patients with inflammatory complications of mandibular fractures, based on providing stable fixation of connected fragments as a critical factor in bone wound healing via osteosynthesis, was confirmed on large samples in both comparison groups.

The application of a filler wire in the traditional process of arc surfacing with a flux cored wire in the environment of protective gases is proposed. A flux cored wire of the electrode wire composition is shown to be used as a filler wire. The optimum surfacing parameters, which ensure stable formation of a deposited coating, are determined. The use of a filler wire is found to redistribute the energy balance, to decrease the melting depth of the base metal, and to increase the surfacing speed.

Objective. To compare the shape and size of human contralateral humerus bones based on the «Autoplan» program to justify the possibility of using healthy bone in a preoperative planning for bone osteosynthesis (on the example of the humerus). Methods. 20 patients underwent computed tomography of the chest, shoulder girdleand upper extremities. Two-dimensional medical imaging of separate layers were converted into three-dimensional models of the humerus bone STL format, which is used for 3D printing in all 3D printers. Preliminary registration to superimpose the mirrored left humerus bone on the right one was carried out for at least 4 key points; their matching in shape and size was analyzed. A comparison was made of the contralateral humerus bones of one patient according to computed tomograms of 20 people. The main anatomical landmarks of the humerus bones and the distance between adjacent points were selected for comparison when the bones were superimposed on each other. Superimposed humeral bones were compared using the Hausdorff distance calculation algorithm, which is used to measure the difference between scanned models and the ground-truth model separately. To visualize the result of calculating of Hausdorff distance, that is, the difference between the bones, color mapping of the latter was performed, where the proximity to red color means the difference tends to zero, the proximity to blue - to 1 cm (the maximal obtained difference). Results. The greatest difference was recorded in humeral heads - up to 6.8 mm, and in the epicondyle: the medial epicondyle - up to 4.5 mm, the lateral epicondyle - up to 4.4 mm. Color mapping allowed to see that the difference between the heads of the humerus increases from the center of the articular surface to the attachment points of the capsule. At the level of the diaphysis, from the anatomical neck to the condyles, the size differencesamong allbones in 20 patients was no more than 1.5 mm. Conclusion. Thereby, the comparison of the shape and size of the contralateral bones of the human humerus based on the «Autoplan» program will allow applying a three-dimensional model of healthy contralateral bone in the preoperative planning for bone osteosynthesis: thus reducing the surgical risks and injury for the patient. What this paper adds For the first time, the use of a 3-dimensional model for a preoperative planning method for long tubular bone osteosynthesis using the contralateral healthy bone for affected bone has been proposed. It has been found that in the preoperative period during osteosynthesis of the diaphysis of long tubular bones, it is possible to use a healthy contralateral bone for plate of the damaged bone (on the example of the humerus fracture). The identity of the shape and size of the humerus diaphyses with an accuracy of 1.5 mm has been proved, and the possibility of using a 3-dimensional model of a healthy bone for preoperative planning for long tubular bone osteosynthesis is justified.

The article deals with the selection of sites for the construction of nuclear installations, radioactive waste disposal sites and other facilities for the use of nuclear energy. The review of modern approaches to the selection of sites for placement of near-surface radioactive waste disposal points shows that the system research in this area is not fully presented, and is mainly aimed at solving problems of an engineering-geological nature for the location area, as well as the choice of materials for engineering protection barriers. In this paper, using the example of radioactive waste disposal sites, we review the requirements set by the regulatory documents of the Russian Federation and the International Atomic Energy Agency in the field of site selection. The authors proposed additions to the methodology for selecting sites for the construction of low-and medium-level waste disposal sites based on the system and GIS analysis of the ALARA principles, as well as the method of weighted evaluation of criteria and their pairwise comparisons. The multi-criteria nature of the site selection problem is proposed to be described by GIS analysis of data with drawing the corresponding limiting and preferred requirements directly on the map of the area, which is shown in the article by the example of selecting sites for radioactive waste disposal points. Taking into account the necessary requirements at various stages of the life cycle, as well as their significance, can be assessed by weighted estimates and pairwise comparisons, followed by their introduction into the GIS analysis. This approach allows to choose rational options for placing potential sites, taking into account the life cycle of the object, in a rational way, with compliance with all necessary regulatory requirements.

Objectives the development of a preoperative planning method for long tubular bone osteosynthesis using the contralateral healthy bone. Material and methods.To justify the usage of the opposite limbs intact segment model in order to reconstruct the damaged one, their matching in shape and size was analyzed. We built three-dimensional models of the right and left segments of the upper limbs of 20 people and compared them using the Hausdorff distance calculation algorithm. For treatment of a 24-year-old patient with a closed humerus fracture, an individual stereolithographic surgical template with fracture lines was created with the help of computed tomography data of the healthy humerus bone processed by AUTOPLAN EXPERT software. This template was used for pre-bending the plate for osteosynthesis. The plate positioning on the template defined the surgical approach, taking into account the anatomical structures located in the projection of the fracture line and the plate. The technique of "reverse bone reposition" on the prepared plate was applied. Results.With the help of the created 3D models we revealed the size differences of the symmetrical segments of upper limbs. The greatest difference in the limits was registered in the area of the epiphyses (heads of the humeri) up to 6.8 mm, and the smallest throughout the entire diaphysis, less than 1.5 mm. Due to preoperative planning there were no intraoperative and postoperative complications, the installation of the plate and osteosynthesis was convenient. The fracture consolidation took place in 3 months. Conclusion.The proposed method has a number of advantages. It is possible to make a stereolithographic template even for a seriously damaged bone with a copied fracture line. This allows the surgeon to plan the details of osteosynthesis, to model the plate according to the template, to determine the required length and shape of the surgical approach, thus reducing the surgical risks and injury for the patient.

The use of chromium carbides in flux-cored wire for applying abrasion-resistant coatings is considered. It is found that such use of chromium carbides does not result in reinforcement of the resulting coatings by intact carbide particles. However, the replacement of ferrochrome by chromium carbides changes the structure of the wire and coatings, with increase in the hardness.

The effect of chromium carbide introduced into the charge of a flux cored wire on the structure and properties of the hardfacing deposit is considered. Hardfacing is performed in a shielding gas atmosphere using a flux cored wire. The composition of the flux cored wire is selected so that the iron-based hardfacing deposit alloyed with the Cr–B–Nb–C system is achieved. In hardfacing, chromium carbide decomposes and alloys the hardfacing deposit with chromium and carbon; this leads to the formation of chromium carbides in the hardfacing deposit and to an increase in its hardness. On average, the presence of chromium carbide in the charge of a flux cored wire leads to an increase in the wear resistance of the hardfacing deposit.

The use of chromium carbides to harden surfaced metal that is subject to abrasive wear is considered. With correct hardening of the applied layer, carbide formation extends the working life.

The paper presents the results of research on the influence of the conditions of volume electric arc surfacing on the geometric accuracy of “cube” type objects with dimensions of 20 × 20 × 20 mm made of 09Mn2Si and 06Cr19Ni9Ti steel fillers. It has been found that the actual length and width dimensions of the samples surfaced with 09Mn2Si steel generally are exceeded and the dimensions in height are smaller than the specified dimensions of the model. This may be due to the melt spreading over the substrate during the formation of the first layers. The optimal surfacing conditions for cube type objects made of 09Mn2Si steel have been defined. When surfacing the samples of 06Cr19Ni9Ti steel, spreading does not occur; however, all actual dimensions are smaller than the specified ones. This might be caused by shrinkage processes that proceed in the deposited layers during their solidification. The most optimal mode for samples made of 06Cr19Ni9Ti steel is the mode in which the reduction in length and width was no more than 2.5%, and that in height was 13.5%. Studies on the influence of the welding arc voltage and the grade of the filler material on the width of the deposited track has confirmed the tendency of 09Mn2Si steel to spread over the substrate in the entire voltage range studied (11–19 V). The microstructure of the deposited samples has been investigated. Tensile tests of the deposited samples at room temperature have shown that the samples have a set of acceptable mechanical properties that exceed the reference values. This is a proof that the deposition process occurs at a high level of quality without formation of incomplete fusion and porosity areas.

The most common surgical access techniques employed in patients with orbital floor fractures are associated with a risk of complications, such as implant infection, migration, epiphora, lower eyelid retraction, ectropion, diplopia worsening, retrobulbar hematoma, emphysema, “white-eyed” syndrome, enophthalmia relapse, hypoglobus, and persistent diplopia due to periorbital atrophy. Consequently, alternative access techniques precluding these complications have to be found. To assess the efficacy of transantral approach in the surgical treatment of patients with orbital floor fractures based on results of retrospective analysis of our clinical experience. We performed a retrospective study of medical records and X-ray data of 52 patients with fractures of the floor of the orbit, 18 to 68 years old, treated using transantral approach as described in the article. Titanium plates of special shape were used for orbital floor reconstruction. In 94.2% of the cases, adequate restoration of the floor of the orbit was achieved. It led to regression of the ocular signs. In 4 patients, diplopia remained in extreme gaze positions, which did not require surgical correction. The failed cases were related to incorrect positioning of the plate or fixing screws. No inflammatory complications were observed. Transantral access approach may be a technique of choice in treating patients with orbital floor fractures; it is safe, minimally traumatic, and effective in the early posttraumatic period when the injured area is located in the posterior parts of the floor of the orbit.

Alloplasmic lines are a suitable model for studying molecular coevolution and interrelations between genetic systems of plant cells. Whole chloroplast (cp) and mitochondrial (mt) genome sequences were obtained by the MiSeq System (Illumina). Organelle DNA samples were prepared from a set of 12 alloplasmic barley lines with different cytoplasms of Hordeum vulgare ssp. spontaneum and H. vulgare ssp. vulgare, as well as from their paternal varieties. A bioinformatic approach for analysis of NGS data obtained on an organellar DNA mix has been developed and verified. A comparative study of Hordeum organelle genomes' variability and disposition of polymorphic loci was conducted. Eight types of chloroplast DNA and 5 types of mitochondrial DNA were distinguished for the barley sample set examined. These results were compared with the previous data of a restriction fragment length polymorphism (RFLP) study of organelle DNAs for the same material. Formerly established data about a field evaluation of alloplasmic barley lines were revised in the light of information about organelle genomes gained after NGS. Totally 17 polymorphic loci were found at exons of chloroplast genomes. Seven of the SNPs were located in the genes of the Ndh complex. The nonsynonymous changes of nucleotides were detected in the matK, rpoC1, ndhK, ndhG and infA genes. Some of the SNPs detected are very similar in codon position and in the type of amino acid substitution to the places where RNA editing can occur. Thus, these results outline new perspectives for the future study of nuclear-cytoplasmic interactions in alloplasmic lines.Аллоплазматические линии являются подходящей моделью для изучения молекулярной коэволюции и взаимодействий между генетическими системами растительной клетки. C использованием MiSeq System (Illumina) были определены полногеномные последовательности ДНК органелл клетки – хлоропластов и митохондрий. ДНК органелл выделена из 12 образцов коллекции аллоплазматических линий ячменя с цитоплазмами Hordeum vulgare ssp. spontaneum (H. spontaneum) и H. vulgare ssp. vulgare (H. vulgare), а также из сортов ячменя доноров ядра. Разработан и верифицирован подход к анализу результатов NGS смесей хлоропластной и митохондриальной ДНК для сборки новых полных сиквенсов пластидных и митохондриальных геномов H. vulgare и H. spontaneum. Проведено сравнительное изучение изменчивости геномов органелл, локализованы полиморфные участки. Выделено восемь типов хпДНК и пять типов мтДНК. Полученная информация сопоставлена с результатами предыдущих исследований этих же линий методом полиморфизма длин рестрикционных фрагментов ДНК органелл. На основании сравнения полногеномных последовательностей хпДНК и мтДНК аллоплазматических линий и сортов доноров ядерных геномов пересмотрены полученные для них ранее данные по формированию признаков, связанных с продуктивностью. Семнадцать полиморфных локусов обнаружено в экзонах пластидных генов. Семь из них расположены в генах Ndh комплекса. Несинонимические замены нуклеотидов идентифицированы в генах matK, rpoC1, ndhK, ndhG, infA. Вероятно, некоторые SNP являются точками, где происходит эдитинг, о чем свидетельствуют позиции замены в кодоне и тип аминокислотной замены. Проведенное исследо- вание открывает новые перспективы для изучения ядерно-цитоплазматических взаимодействий на при- мере аллоплазматических линий.

The article is devoted to the problem of attribution of individual works of the commercial and industrial partnership “P.I. Olovyanishnikov's sons”. The article describes for the first time previously unknown divisions of the Partnership, such as the icon painting studio, painting, embroidery and carpentry workshops, brocade factory, and indicates sources confirming their existence. The date of creation of the Church utensils factory in Moscow has been revealed. For the first time, the structure of the Partnership, its staff and their qualifications are analyzed. The relationship between the Partnership and the Stroganov school is revealed. The article analyzes the relationship between Olovyanishnikov and other manufacturers of art products and the artist M.V. Nesterov. The article describes the principles of product separation depending on its artistic merits. We consider the profile reference materials printed publications of the enterprise, which contain information about the types of products of the Partnership.

Introduction/Objective. The most commonly used methods of treatment of mandibular fracture are not always successful in older patients. This is due to decreased regenerative ability, impaired vascularization, osteoporosis, and atrophic changes. The corresponding changes are often found in patients over 50 years of age, especially accompanied with teeth loss. The objective was to review the clinical characteristics of mandibular fractures in older patients based on a retrospective analysis of medical records. Methods. A group of patients over 50 years of age was selected and analyzed among patients with mandibular fractures who had been treated for 10 years. Results. A total of 642 patients over 50 years with 1,003 fracture lines were identified. This represents 8.53% of the total number of patients with mandibular fractures. Comorbidities were diagnosed in 67% of cases. Significant differences in the distribution of the frequency of fracture lines by localization were identified, depending on the presence or absence of occlusal contact. A high incidence rate of open fractures and bone fragment dislocation was observed both in individuals with or without occlusive contact. Conclusion. Patients over 50 years of age are a statistically important group in the general population of patients with mandibular fractures with a number of clinical features. To the author?s knowledge, this study comprises the largest number of patients over the age of 50 with mandibular fractures, including those with edentulous mandible, which ensures the required level of representation, allowing reliable clinical characterization of this contingent of patients.

Acroosteolysis is a rare congenital disease of the musculoskeletal system, first described by Harnasch in 1950. The disease is hereditary. Sporadic cases of the disease are sometimes observed. Men are affected 2-3 times more often than women [1].

At present, there is an increase in the number and proportion of older persons. Accordingly, the requirements to ensure the necessary quality of life of this category of population are increasing. This applies, inter alia, to the issues of their rehabilitation after various diseases and injuries. Among the injuries of the bones of the facial skeleton, the most common type are fractures of the lower jaw. The purpose of this work is to analyze the prevalence, clinical features of mandibular fractures in patients of the older age group and the effectiveness of existing methods of their treatment, according to modern literature data. RSCI, PubMed, Medline databases for the period 1960 - 2019 were used to compile the review. Results. Data from 687 literary sources were used in the preparation of this review. Their analysis shows that older patients represent a stable and statistically significant group, in the General structure of victims with mandibular fractures, and having a number of clinical features, as a result of which conventional methods of treatment are often ineffective. The most common concepts of medical care for this category of patients are characterized. Conclusion. To date, there are no reliable randomized clinical trials based on sufficient statistically material that allows to substantiate the advantages of a particular method of treatment of older patients with mandibular fractures at the evidence level, which requires the continuation of the relevant multicenter clinical studies.

The influence of the parameters of feeding and heating of an additional flux-cored electrode during machine hidden arc welding with an additional hot additive on the process is considered. Beads are deposited onto a 10-mm-thick steel (St3sp steel, GOST 380) plate, and the addition conditions, namely, the distance between the flux-cored electrode and the filler wire and the filler wire feed rate, are varied. The filler wire feed rate is found to depend on the electric current used for heating and to be independent of the distance between the point of introduction of the additional hot additive and the main arc. The limiting amount of the filler wire additive at which the transition from a deposited metal to the base metal is not sharp is determined.

Сalcium phosphate materials have been applied in clinical medicine since 1920. Among calcium phosphate materials, hydroxyapatite (HAp) is traditionally of the greatest interest, because HAp is the main inorganic component of bone tissues. However, synthetic HAр ceramics subjected to high-temperature processing, as it turned out, have a rather limited use as an osteoplastic material. Since 1990, due to advances in chemical technology, new materials of pasty nanocrystalline HAр have been developed, which are promising for the directed influence on the process of bone tissue regeneration. This review briefly summarizes the experimental and clinical data related to the application of micro- and nano-sized hydroxyapatite, and evaluated the potential of pasty nanocrystalline HAp as a material for guided bone regeneration.

The influence of nanoparticles introduced into a molten weld pool using a flux-cored wire on the structure and impact toughness of the weld metal is considered. The use of a flux-cored wire with tungsten carbide particles is shown to decrease the scatter of the impact toughnesses of the weld metal. The use of titanium carbide allows one to increase the average impact toughness.

The influence of tungsten carbide and titanium nitride nanoparticles on the structure and properties of the weld metal of welded joints made by automatic twin submerged arc welding is considered. The nanoparticles have been introduced into the weld pool as a part of the “master alloy” based on nickel powder (PNE-1 according to GOST 9722). It has been shown that modifying the weld metal with tungsten carbide nanoparticles holds promise for enhancing the impact strength. In addition, it has been found that titanium nitride is prone to dissociation under the same conditions. However, microalloying with titanium, which is due to the release of titanium from the nitride, leads to an increase in the impact strength of the weld metal.

A method was proposed for optimizing the process of oil shale pyrolysis with the addition of a cleaning unit. With the use of this method, the degree of removal of H2S and CO2 from pyrolysis gas was almost 100%, which makes it possible to use the resulting gas as fuel.

The relation between the broken rotational symmetry of a system and the topology of its Fermi surface is studied for the two-dimensional system with the quasiparticle interaction f(p, p') having a sharp peak at |p − p'| = q0. It is shown that, in the case of attraction and q0 = 2pF the first instability manifesting itself with the growth of the interaction strength is the Pomeranchuk instability. This instability appearing in the L = 2 channel gives rise to a second order phase transition to a nematic phase. The Monte Carlo calculations demonstrate that this transition is followed by a sequence of the first and second order phase transitions corresponding to the changes in the symmetry and topology of the Fermi surface. In the case of repulsion and small values of q0, the first transition is a topological transition to a state with the spontaneously broken rotational symmetry, namely, corresponding to the nucleation of L ≃ π(pF/q0 − 1) small hole pockets at the distance pF − q0 from the center and the deformation of the outer Fermi surface with the characteristic multipole number equal to L. At q0 → 0, when the model under study transforms to the two-dimensional Nozieres model, the multipole number characterizing the spontaneous deformation is L → ∞, whereas the infinitely folded Fermi curve acquires the Hausdorff dimension D = 2 which corresponds to the state with the fermion condensate.

Aim - to describe the approach to proximal femur fractures treatment in geriatric (elderly and senile) group of patients. Materials and methods. The article presents the analysis of 16 years’ experience of using both classic and author’s technologies according to the developed classification of patient’s functional state. Conclusion. The decision on therapeutic approach for geriatric patients was optimized.

Aim - to improve the results of treatment of patients with complex regional pain syndrome (CRPS) in bone fractures of the lower extremities by applying a new integrated approach. Methods. A new approach to solving the problem of complex regional pain syndrome in fractures of lower limb bones is proposed, including the use of modern minimally invasive methods for surgical treatment of fractures of the lower limb bones, such as blocked osteosynthesis, Fixion technology, use of angular stability plates, metal structures for osteosynthesis of the proximal femur. All these measures help to minimize the negative effect that is produced on the bone by such factors as prolonged immobilization and absence of early movements of the joints, which will make it possible to perform CRPS prophylaxis in bone fractures of the lower limbs more effectively. If it is not possible to prevent the development of CRPS, then it is necessary to administer complex therapy, including psychoemotional correction, adherence to the regime, proper immobilization, rehabilitation exercises, physiotherapy, medical treatment, hyperbaric oxygenation, and gravitational therapy. Results. Clinical tests, radiography, densitometry, method of statistical analysis and mathematical modeling with elements of evidencebased medicine objectively confirmed the activation of the restorative processes in altered tissues of the lower limbs due to the use of the new complex. Conclusion. The analysis of the obtained data of clinical and functional methods of research has proved that the total value of positive results is 80%.

Advances in nanotechnology have made it possible to use nanosized particles for the modification of metals and alloys both in metallurgy and in welding. This article discusses the thermodynamic stability of titanium nitride nanosized particles in a molten pool on the basis of theoretical analysis and experiments. It is demonstrated that, upon the addition of titanium nitride to a molten pool, its dissociation should be expected in the overall temperature range; this has been confirmed experimentally.

This article discusses the possibility of introducing nanosized particles into a molten pool using a flux-cored wire. A flux-cored wire has been proposed with added composite granules obtained upon the combined treatment of nickel powder and nanosized particles. In order to avoid the overheating of particles, it has been proposed to add a flux-cored wire to a molten-pool tail using preheating. The following hardmelting particles have been tested: tungsten carbide (WC), titanium nitride (TiN), and aluminum oxide (Al2O3). It has been demonstrated that the addition of tungsten carbide to a molten pool improves the stability of weld-metal (WM) impact toughness while retaining its average value and the addition of aluminum oxide to a molten pool leads to increased average values of WM impact toughness while retaining its stability. Meanwhile, nanosized particles of titanium nitride in a molten pool are prone to dissociation, which leads to the formation of porosity, thus limiting the field of application of this modifier.

The problem of constructing an integrating system combining bus timetables of different bus depots is considered. We suppose that these bus depots are independent and, possibly, located at different regions of the country. The purpose of this integrated system is, in particular, the easement of finding available bus routes between two given points. To solve this problem, it is proposed to use an approach combining the advantages of mediator and data repository technologies. The article considers a model of three data sources, which are bus depots that display information about their timetables. It is assumed that all sources have similar conceptual schemes, but they have their own specific characteristics. In particular, there may be different names of tables and attributes in different sources and different distribution of attributes throw tables. Also at some sources may be an absence of certain attributes. We construct correspondence tables and a mediator that translate user queries to the sources. To identify the necessary sources, a small auxiliary repository is maintained that contains information about the stop points served by each of the sources. We describe the technology for updating the repository and the executing strategy for the user query, using the information contained in the repository.

The addition of nanodispersed powders to the area of welded joint is a promising control mechanism of controlling the properties of the weld metal. This article is aimed at determining the influence of TiN, TiCN, and WC nanoparticles (

The article presents the experience of operating real pumping stations in urban water supply. The basic principles of practical modeling of the operation of a group of pumps for a common load are considered. The main errors in the modernization of pumping equipment of water supply units are analyzed.

The influence of nanoscale refractory titanium carbide particles on the structure and properties of weld metal in automatic submerged arc welding is considered. Composite granules based on nickel were used to introduce the compound into the composition of the weld pool. Two schemes for introducing granules into the weld pool were tested, characterized by different temperature conditions: to the head part of the welding pool with the help of “ligature” and to the tail section with the help of additional filler wire. The prospects of introducing nano-sized titanium carbide into the tail part of the weld pool as part of a flux-cored wire are shown. With this method, the structure of the weld metal is observed to modify: the average size of the primary crystals of the weld metal is reduced by almost 50%. At the same time, the value of the toughness of the weld metal increases: the average value of this index increases by 36%. When titanium carbide is introduced as part of the “ligature” into the head of the weld pool, despite the effect of modifying (reducing the width of the primary crystals by 30%), the average value of the toughness of the weld metal decreases.

The paper considers the influence of nanosized particles of tungsten and titanium carbides on the structure and properties of the weld metal of welded joints made by automatic submerged-arc automatic arc welding. To add them into the weld pool, an alloying composition was used in the form of composite granules based on nickel powder (PNE-1 as per GOST 9722). The prospects of using nanosized tungsten carbide particles for modifying the weld metal with the aim to increase the values of impact strength were shown. However, titanium carbide in the same conditions leads to a decrease in the average value of impact strength, despite the modifying effect of its use.