On the nonlinear problem of the three-axis reorientation of a three-rotor gyrostat in the game noise model

The nonlinear game problem of the three-axis reorientation of an asymmetric solid body with three flywheels (rotors) has been solved. Acceptable levels of uncontrollable noise depending on given constraints of control moments have been estimated. © 2013 Pleiades Publishing, Ltd

Anomalous diffusion in polymers: long-time behaviour

We study the Dirichlet boundary value problem for viscoelastic diffusion in polymers. We show that its weak solutions generate a dissipative semiflow. We construct the minimal trajectory attractor and the global attractor for this problem.Comment: 13 page

Replacement of the large joints osteochondral defects

Rationale. Injuries and diseases of large joints occupy a leading place in the list of urgent problems in orthopedics. Various methods of treatment for this pathology are regularly offered in the literature, but most of them do not allow restoring a full-fledged hyaline cartilage.Background. To improve the results of organ-preserving treatment in patients with osteo-chondral defects of large joints.Material and methods. А prospective study was conducted on 30 large animals (60 knee joints) aged 1.5 to 3 years. We divided the animals into 3 groups of 10 individuals (20 joints) in each, based on the method of replacement of the osteo-chondral defect. In all cases, a full-layer defect formed from the hyaline cartilage by a mill with a diameter of 4.5 mm, depth of 7 mm with the capture of the subchondral bone in the medial condyle of the right thigh. Artificial defects were restored by one of the following methods. The left joint was considered a control joint and the defect formed by the same technique was not filled.Results. The result was evaluated in 1 month, 3 months and 6 months viewing the nature and degree of defect filling. Specific volumes of such tissues as chondrocytes, cartilage matrix and the average depth of the defect from the thickness of the native cartilage were better in group 3, and connective tissue was less in group 3.Conclusion. In the group without defect replacement, the  obtained data are comparable with the studies of other authors, according to which bone and cartilaginous defects practically do not regenerate on their own. Our proposed method with the use of extracellular collagen matrix, autocartilage and plate rich plasma is less aggressive in comparison with autochondroplasty and the result can be more stable compared to microfracturing or tunnelization

Water-soluble hybrid materials based on {Mo₆X₈}⁴⁺ (X = Cl, Br, I) cluster complexes and sodium polystyrene sulfonate

Development of water-soluble forms of octahedral molybdenum clusters {Mo₆X₈}⁴⁺ (X = Cl, Br, I) is strongly motivated by the tremendous potential that these complexes have for biological applications, namely as agents for bioimaging and photodynamic therapy. In these work we report the first water-soluble hybrid materials, which represent sodium polystyrene sulfonate doped by molybdenum clusters, and evaluation of their photophysical and biological properties (dark and photoinduced cytotoxicity and cellular uptake) with the use of cervical cancer (HeLa) and human epidermoid larynx carcinoma (Hep-2) cell-lines as models

Bone marrow edema in terms of joint pathology

New possibilities of modern medical science open up prospects for instrumental and laboratory diagnostics of many pathological conditions, unknown or not previously diagnosed in the practice of an orthopedist. These include bone marrow edema. Not only orthopedic traumatologists, but also rheumatologists, neurosurgeons, general practitioners, rehabilitation therapists, morphologists, and many others today face this concept in a variety of definitions, concepts of etiology, pathogenesis, and clinical recommendations for treatment.The authors performed a systematic review by using four open resources: electronic scientific library (elibrary), PubMed, SciVerse (Science Direct), and Scopus.The complexity of pathology lies in the fact that in each specific case, the development of treatment tactics requires a personal interpretation of the entire variety of data obtained and a case by case approach

The current state of the problem of soft tissue defects replacement in the lower extremities in conditions of chronic osteomyelitis

Based on the data of scientific literature, the current state of the problem of soft tissue defects replacement in the lower extremities in conditions of chronic osteomyelitis has been analyzed. Taking into account certain requirements for the replacement of defects of this nature, the following reconstructive tasks have been indicated. First of all, for adequate restoration of the skin with simultaneous relief of the purulent-necrotic process, it is necessary to use blood-supplied tissue complexes, which, if possible, should be formed from tissues similar to those surrounding the defect. The predominant use of technically and economically beneficial interventions is of great importance. The most suitable are loco-regional flaps with axial blood supply, among which the most promising are perforant flaps. It is necessary to develop an algorithm for defects reconstruction using loco-regional perforant flaps, depending on the defect area. It is also necessary to conduct a comparative analysis of the anatomical advantages and effectiveness of using various perforant and insular flaps on the vascular pedicle. A one-stage orthoplastic approach will allow the most effective use of the achievements of reconstructive plastic surgery in orthopedics to restore limb function, which will improve the results of treatment of patients

ОТКАЗЫ И СРОК СЛУЖБЫ ГРУЗОВОГО ВАГОНА

The authors consider choice of possible methods to define failures and lifetime of freight cars taking into account the safety criterion. They propose classification of failures, cars’ readiness rate, operation intensity, responsibilities of different levels of the railway cars’ departments.Методологические подходы  к определению отказов и срока  службы грузового вагона по критерию  безопасности. Классификация  отказов, коэффициент готовности  вагонов, интенсивность  их эксплуатации. Сферы  ответственности подразделений  вагонного хозяйства

On iterating concentration and periodic regimes at the anomalous diffusion in polymers

Diffusion of a penetrating liquid in a polymeric material does not often satisfy the classical diffusion equations and requires taking relaxational (viscoelastic) properties of the polymer into account. We investigate a boundary value problem on a bounded domain in space for the set of equations modelling this abnormal diffusion. It is proved that, for any sufficiently short time segment and any stress prescribed at the beginning of this segment, there exists a global in time weak solution of the boundary value problem (a pair: concentration - stress) such that the concentrations at the beginning and at the end of the segment are the same. Under an additional assumption on coefficients, existence of time-periodic weak solutions (without any restrictions of the period length) is shown.Comment: 26 pages, in Russia