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Background. Due to the prevalence of Vitamin D deficiency as well as the frequency of reconstructive surgical interventions followed by dental implantation, the issue arises concerning the effect of Vitamin D on reparative regeneration of bone and osseointegration of dental implants. The purpose — using literature data we are conducting an impact assessment of vitamin D on reparative regeneration of bone tissue, in particular, after oral reconstruction surgeries and dental implantation. Methods. Retrieval, systematization and analysis of scientific data on application of vitamin D supplementation and its effect on reparative regeneration of jaw bone tissue. The conclusions. For the most part, the positive effect exerted on reparative regeneration of jaw bone tissue and osseointegration of dental implants is due to the role of vitamin D in physiological processes evolving in bone tissue, namely maintenance of calcium and phosphate exchange through intestinal absorption and TNF α , RANKL (Receptor activator of nuclear factor kappa-B ligand) and consequently differentiation of precursors to osteoclasts into osteoclasts through VDR stimulation (Vitamin D Receptor) – receptors for further osteogenesis. Also, according to literature data, FGF23 (Fibroblast Growth Factor) protein is a marker of osteoblasts differentiation into osteocytes, it is also known that FGF23 and 1,25( ОН )2D3 are genetically related. FGF23 is the main regulator of both phosphate exchange in bones and metabolism of vitamin D and its metabolites. Besides, indirect anti-inflammatory effect has been observed thanks to inhibition of pro-inflammatory cytokine secretion. Taking into account the abovementioned data, of particular relevance is the definition of serum concentration 25( ОН )D and development of schemes of vitamin D level pre-surgery correction in patients, who have to undergo oral reconstruction surgeries and dental implantation. Mass spectrometry is a promising diagnostic method for determining the level of vitamin D in a body, as it allows to identify the actual amount of vitamin D free from admixture of other steroid hormones. The introduction of this method into clinical practice will allow to monitor the level of vitamin D in patients, receiving reconstructive and rehabilitative treatment.

Aim. To determine the qualitative and quantitative composition of the oral microbiota in patients with medial osteonecrosis of the jaw (MOJ). Materials and methods. Microbiota was evaluated in 15 patients with medial osteonecrosis of the jaw. An assessment was made of 12 groups of optional and obligate-anaerobic microorganisms. Evaluation of the qualitative and quantitative composition of oral microbiota in patients with MOJ was performed by real-time polymerase chain reaction (PCR-RT). Results. The aerobic-anaerobic microbiota composition in patients with MOJ in the oral fluid and separated from the fistula is presented. The values of the total bacterial mass (TBM) and all anaerobic microorganisms in the oral fluid in patients with MOJ before treatment were higher by 1-3 orders of magnitude than in healthy individuals. In the jaw, separated from the fistula in the zone of necrosis of the jaw, these parameters were higher by 2-4 orders than in the oral fluid. Prior to surgery, a course of antibiotic therapy was conducted for 7 days. As a result of the therapy, the parameters of anaerobic microflora in the oral fluid decreased. The use of cefazolin was more effective than lincomycin. In 1 year after surgical treatment, the index of TBM and the indices of anaerobic microorganisms did not differ from those of healthy individuals. Conclusion. Patients with medical osteonecrosis of the jaw have a high level of anaerobic pathogens in the oral microbiota. The course of antibiotic therapy and surgical intervention are effective methods of treatment of MOJ, as they lead to effective sanation, and allow further endoprosthetics.

The numerical dynamic model of a ball-bearing with angular contact and oil lubricant, which allows to study movement of the bearing parts, having six degrees of freedom, is developed. The general parameters, characterizing loading of bearing retainer, are analyzed. The influence of general structural parameters of several ball-bearings on in-service operation conditions of their retainers is analyzed.

The paper investigates the influence of the process of running-in the ends of rollers and sides of cylindrical roller bearings on the conditions of hydrodynamic contact of these parts: the formation of an oil film and friction. For this purpose, the results of finite element modeling of the stress-strain state of the bearing parts in contact: the inner ring, the side flange and a fragment of the axle of the wheelset, and the multi-mass simulation of the dynamics of the bearing operation are used. The influence of the yaw angle of the roller on the size and shape of the contact area on the side is investigated. The dependences for calculating the thickness of the oil film in the contact between the ends of the rollers and the flanges of the bearing rings are being refined, which now make it possible to take into account the misaligned position of these parts during their force interaction. The results are illustrated using the example of a roller bearing of standard size 232926.

Substitution of mandibular defects resulting from injuries and inflammatory bone diseases as well as surgical interventions for tumors is an important medical and scientific problem. The article presents the results of surgical treatment of 8 patients with the use of combined endoprosthesis of the mandible consisting of individual titanium metal structure and titanium silk. This solution provides the possibility for reliable fixation of the soft tissue structures of the lower face region by suturing, including facial and masticatory muscles, improving the biological integration of the endoprosthesis. The combined design shows high efficiency of restoration of both aesthetic and functional characteristics of the mandible, as well as good long term survival rate.Замещение дефектов нижней челюсти, возникающих в результате травм и воспалительных заболеваний кости, а также оперативных вмешательств по поводу опухолевых процессов, составляет важную медицинскую и научную проблему. В настоящей работе показаны результаты хирургического лечения 8 пациентов с применением комбинированного эндопротеза нижней челюсти, состоящего из индивидуальной титановой металлоконструкции и 'титанового шелка'. Данное решение обеспечивает возможность надежной фиксации мягкотканных структур нижней трети лица путем их подшивания, в том числе мимических и жевательных мышц, улучшая биологическую интеграцию эндопротеза. Комбинированная конструкция показала высокую эффективность восстановления как эстетических, так и функциональных характеристик нижней челюсти, а также хороший уровень 'выживаемости' эндопротезов в отдаленном периоде наблюдения.

In patients with drag-induced jaw osteonecrosis which developed in cancer patients due to administration of bisphosphonates for metastases, the microflora of the oral cavity was examined by chromatography-mass spectrometry (HMS). The method of HMS can be used as an additional method of diagnostics in complex clinical cases with ineffective treatment.При медикаментозном остеонекрозе челюстей, развившемся на фоне приема бисфосфонатов, назначаемых по поводу метастазов онкологическим больным, исследовали микрофлору полости рта методом хромато-масс-спектрометрии (ХМС). Метод ХМС может быть использован как дополнение к основным методам диагностики в сложных клинических случаях и при неэффективности лечения.

Partial modernization of the system for automatic control of the process of feeding and producing a fibrous product into the self-weight of a Befama CS-412 carding machine has been accomplished. An improved functional system for control of high-speed carding lattice operation regime, which ensures the set technological procedures, has been developed.

A new approach to modeling of the work performed by cone drill bits at the face is outlined. A virtual model of the dynamic force interaction between a cone drill bit and the face of the hole is proposed. The ADAMS software package is used for the modeling with consideration of frictional forces in the sliding supports, the frictional forces of the equipment components, and the depth of their embedment in the rock. The dynamic forces acting on the teeth during rotation of the cutters, and the distribution of average loads around the rings and cutters of the bit are obtained. The possibility of using the model developed to optimize parameters of bit equipment is demonstrated.

The problem of synthesizing ℋ2-optimal digital control law for a continuous plant with multiple delays is considered. An equivalent discrete system, whose stability and optimality conditions coincide with the corresponding conditions for the initial digital system is constructed. An efficient computational algorithm for constructing the implementation of the equivalent discrete model of the plant in the state space is proposed.

The problem of digital stabilization of continuous plants whose models consist of several blocks of pure input and output delay is considered. A discrete-time model of the closed loop is constructed, and its stability is proved to be equivalent to the stability of the hybrid sampled-data system. The necessary and sufficient stabilizability conditions of the continuous plant with a generalized hold element are obtained.

The problem of improving the quality indices of nonwovens is examined and is solved by optimizing control of the speed regimes of the electromechanical systems used in their production. The use of a multi-motor electric drive in combination with monitoring of the physico-mechanical properties of the fibrous product during the various conversions makes it possible to correct the speed regimes of the machines in the flow line. The authors construct and analyze a functional model of a modernized control system for an automated line designed for the production of bulk nonwovens. Technical solutions for optimizing control of the complex’s high-speed operating regimes are presented to illustrate the use of the model.

A method is presented for synthesis of optimal sampled-data tracking systems with two controllers, one of which is incorporated into the closed loop, while another is placed in feedforward chain. The approach is based on Laplace transform in continuous time and polynomial equations theory. The set of all admissible reference controllers is constructed. The cost function include integral quadratic output and control errors in continuous time.

Consideration is given to a mathematical model of the nonseparating nonstationary motion of an ideal compressible gas in a pipeline with a variable cross section. A method which enables one to calculate changes in the pressure, density, and the velocity at the sites of contraction and expansion of the pipeline without going beyond the scope of a one‐dimensional model is presented.

A method of optimal design of digital tracking systems for continuous-time plants is presented. The method is based on the use of Laplace transformation in continuous time and polynomial equation theory. The cost function employed for quadratic optimization takes system performance in continuous time into account. The structure of optimal digital controller transfer function is investigated and its order is determined explicitly. The possibility of designing optimal tracking system for a neutral plant is analyzed.

In this article, we report on the fabrication and optical properties of highly transparent yttria ceramics for lasers active media with broadband gain profile. Laser synthesis method was used to produce Y 2O 3-based nanopowders doped with 1mol.% Nd 3+ or Yb 3+ for these transparent ceramics. The additives of sesquioxides Lu 2O 3 and Sc 2O 3 were used along with ZrO 2 to disorder the crystalline structure. The porosity and average grain size decrease with these additives and the emission bandwidths of Nd 3+ ( 4F 3/2→ 4I 11/2) and Yb 3+ ( 2F 5/2→ 2F 7/2) transitions widen to 40 and 60nm, respectively. Laser operation with the slope efficiency of 29% was obtained in [(Yb 0.01Lu 0.24Y 0.75) 2O 3] 0.88(ZrO 2) 0.12 ceramic sample. © 2012 Elsevier Ltd.

This paper discusses questions of how to increase the accuracy of an approximation by Zernike polynomials of the displacements of the points of optical surfaces (OSs) in the direction of the optical axis, associated with the discrimination of displacements of the surface as a rigid whole. It is shown that, when going from displacements of the nodal points of an OS obtained by the finite-element method to their approximation by Zernike polynomials, it is expedient to discriminate beforehand that part of the displacements associated with the components of the displacement of the surface as a rigid whole in a direction perpendicular to the optical axis, and, in the case of nonaxisymmetric surfaces, also in the direction of rotation around the optical axis. Examples are given of the implementation of the proposed procedure.

External x-ray recording from radiopharmaceuticals is used in examining linear blood flow in organs and tissues. The method is called radiocirculography and is most widely used in neurology, particularly to examine brain vessels. The hemodynamic state is evaluated from the shapes of the activity-time curves and from the time intervals between these curves, which are interpreted as parameters of the hemodynamic phases (arterial, capillary, and venous).