Global generalized solutions for Maxwell-alpha and Euler-alpha equations

We study initial-boundary value problems for the Lagrangian averaged alpha models for the equations of motion for the corotational Maxwell and inviscid fluids in 2D and 3D. We show existence of (global in time) dissipative solutions to these problems. We also discuss the idea of dissipative solution in an abstract Hilbert space framework.Comment: 27 pages, to appear in Nonlinearit

Hexaazide octahedral molybdenum cluster complexes: synthesis, properties and the evidence of hydrolysis

This article reports the synthesis, crystal structure of new molybdenum hexaazide cluster complex (ⁿBu₄N)₂[{Mo₆I₈}(N₃)₆] (3) and comparison of its photophysical and electrochemical properties to those of earlier reported analogues (ⁿBu₄N)₂[{M₆X₈}(N₃)₆] (X = Cl, Br). Additionally, the dimerisation of 3 as a result of hydrolysis was revealed by mass spectrometry and single crystal X-Ray diffraction. Indeed, the structurally characterised compound (ⁿBu₄N)₄[{Mo₆I₈}(N₃)₅)₂O] represents the first example of oxo-bridged dimer of octahedral molybdenum clusters complexes

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

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

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

Cellular internalisation, bioimaging and dark and photodynamic cytotoxicity of silica nanoparticles doped by {Mo₆I₈}⁴⁺ metal clusters

Silica nanoparticles (SNPs) doped by hexanuclear molybdenum cluster complexes [{Mo₆X₈}L₆]n (X = Cl, Br, or I; L = various inorganic or organic ligands) have been recently suggested as materials with a high potential for biomedical applications due to both the outstanding photoluminescent properties and the ability to efficiently generate singlet oxygen upon photoirradiation. However, no studies were undertaken so far to prove this concept. Therefore, here we examined the potential of photoluminescent SNPs doped by {Mo₆I₈}⁴⁺ for such applications as bioimaging and photodynamic therapy using human epidermoid larynx carcinoma (Hep-2) cell line as a model. Our results demonstrated both: (i) significant luminescence from cells with internalised molybdenum cluster doped SNPs combined with the low cytotoxicity of particles in the darkness and (ii) significant cytotoxicity of the particles upon photoirradiation. Thus, this research provides strong experimental evidence for high potential of molybdenum cluster doped materials in such biomedical applications as optical bioimaging, biolabeling and photodynamic therapy

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

Experimental method replacement of the osteo-chondral defects of the large joints (first results)

Objective: to develop and offer an original method of treatment of bone and cartilage defects of hyaline cartilage on the example of the knee joint.Materials and Methods: a prospective study conducted on experimental animals (sheep) in an amount of 30 individuals, whose age was from 1.5 to 3 years, weight was from 20 to 30 kg. All individuals divided into 3 representative groups of 10 individuals, depending on the method of replenishment of the joint defect. In all groups, a full-thickness defect of the articular cartilage performed to a subchondral bone 4.5 mm in diameter on the loaded surface of the inner condyle of the thigh. Distinct bone-cartilage fragments examined visually, evaluating the nature of the edges of the articular cartilage defect, the condition of its blood filling, the depth of the defect, the degree of closure of the defect by the emerging fibrous-cartilaginous layer. The area of the defect of the subchondral plate studied morphologically using light microscopy.Results: The best results are shown in group 3, where the bone-cartilaginous defects are practically fully replaced macroscopically and microscopically managed to trace the architectonics of the newly formed hyaline-like tissue, which indicates good early results of the application of the described method.Conclusions: the proposed original method of treatment of bone and cartilage defects of the knee joint allowed to get good results in the early stages. It is necessary to further observe the behavior of the regenerate in all experimental groups