On stress/strain state in a rotating disk

In the framework of mechanics of continuum bodies, the problem of stress/strain state in a high-speed rotating disk of constant thickness has been considered. The material of the disk is assumed to be homogeneous, elastic/perfectly-plastic. In the plastic zone, the stresses and plastic strains are related by some associated law similar to the one employed in deformation theory of plasticity. The general algorithm of the solution covers any smooth plasticity function. At some steps of the algorithm, it is possible to get analytical expressions, particularly, for the quadratic Mises yield criterion. For the given model, the notion of control parameters (external and internal) has been introduced. The allowable boundaries of external parameters have been defined as well. For some states of the disk, the coherent values of external parameters have been obtained. The results are represented graphically to show various states of the disk. The usage of piecewise plasticity functions has been briefly discussed. The results obtained can be used in preliminary engineering design and related numerical codes.info:eu-repo/semantics/publishedVersio

THE CLINICAL SIGNIFICANCE OF MATRIX METALLOPROTEINASES IN RHEUMATOID ARTHRITIS PATIENTS (REVIEW OF THE LITERATURE AND OUR OWN DATA)

Matrix metalloproteinases (MMPs) are a group of over 20 proteolytic enzymes responsible for cleavage of protein components of the extracellular matrix. Three types of MMPs play an important role in the development of joint damage in patients with rheumatoid arthritis (RA): collagenases (MMP1, 8 and 13), stromelysins (MMP3), and gelatinases (MMP9). MMP3 is considered to be one of the key mediators of joint damage. Increased serum level of MMP is not specific for RA and may be registered in other rheumatic diseases (osteoarthritis, psoriatic arthritis, gout, ankylosing spondylitis, systemic lupus erythematosus); however, monitoring of the level of MMP is of particular clinical importance in patients with RA. MMP3 serum level may be a useful marker of disease activity. Several studies have shown a correlation of MMP3 concentration with clinical and laboratorial parameters of inflammatory activity (ESR and C-reactive protein – CRP) in RA patients. The elevated level of MMP3 is associated with radiological changes in joints and can also be a predictor of severe destructive lesions in RA patients. Evaluation of the MMP3 level can also be useful for monitoring the therapy effectiveness using both standard disease-modifying antirheumatic drugs (DMARDs) and genetically engineered biological drugs (GEBD). Thus, evaluation of MMP3 concentration is useful for assessing disease activity and efficacy of treatment with DMARDs and GEBD, as well as for predicting the severity of destructive changes in joints

AUTOIMMUNE RHEUMATIC DISEASES: RESULTS AND PROSPECTS FOR RESEARCHES

According to the present-day views, autoimmunity is a complex pathological process, the essence of which is intolerance and hence a pathological immune response to intrinsic tissue components (autoantigens), which underlies the pathogenesis of a broad spectrum of human autoimmune diseases. Recently, diverse immune disorders underlying autoimmune rheumatic diseases (ARD) and syndromes have been revealed; an association has been found between the development of ARD and autoinflammatory diseases and syndromes; a classification of human immunoinflammatory diseases has been elaborated. The paper considers the results of the authors’ investigations of ARD treatment with innovative biologics, the pathogenetic mechanisms and diagnosis of ARD, by conducting immunological and molecular biological studies of a wide range of molecular and cellular biomarkers (autoantibodies, acute phase proteins, cytokines, chemokines, vascular endothelial activation markers, complement system components, lymphocyte subpopulations, bone and cartilage tissue metabolic products, genetic, epigenetic, transcriptomic markers), and approaches to personalized treatment of ARD

Wave diffraction problems on periodical sets of heterogeneities in the stratified media

The universal approach to solving the diffraction problems on the periodical set of heterogeneities in the stratified media is proposed. The infinite periodic grating consisting of thin conducting bands embedded into a dielectric plate is considered as an example. The boundary value problem for the quasi-periodic potential functions is equivalent to the pair summatorial functional equation for the Floquet coefficients. At first, it is advisable to solve the auxiliary diffraction problem for the stratified medium in the case when the heterogeneities are moved off. The heterogeneities generate the field perturbation; it is a solution of a similar pair equation. Secondly, we need to define new unknown variables in such way that the pair equation should have the standard form. To get this result we propose to use the boundary value conditions on the heterogeneities. Then the other conditions on the media interface can be transformed to standard form. The dual equation is equivalent to regular infinite set of linear algebraic equations for the coefficients of decomposition of the electromagnetic field by Floquet harmonics. In the case of elastic waves the wave diffraction problems on the periodical sets of heterogeneities can be reduced to vector dual summatorial functional equations. The electromagnetic wave diffraction problems on the periodical knife grating was investigated by analogous scheme

Role of hepcidin in the development of anemia in patients with rheumatoid arthritis

Chronic disease anemia (CDA) diagnosed in many patients with rheumatoid arthritis (RA) was described in the early 1970s. As earlier noted, iron metabolic disturbances in CDA are its diagnostic feature and the discovery of hepcidin, an iron-regulatory acute-phase protein, could largely clarify an association between the immune mechanism of impaired iron homeostasis and the development of CDA. Objective: to define the role of hepcidin in the differential diagnosis of CDA and true iron deficiency in patients with RA. Subjects and methods. The investigation enrolled 76 patients with RA (1987 ACR criteria) admitted to the Research Institute of Rheumatology, Russian Academy of Medical Sciences, to be treated. The patients were divided into two groups. A study group comprised anemic patients (n = 47). The WHO criteria for anemia were considered to be hemoglobin (Hb) levels of below 120 g/l for women and below 130 g/l for men. A control group consisted of non-anemic patients (n = 29). The anemic and non-anemic patients were matched for age (45.5±14.3 and 49.8±14.3 years, respectively) and disease duration (2 months to 20 years) (p > 0.05). Iron metabolic parameters, such as serum iron, total serum iron-binding capacity (TSIBC), iron transferrin saturation (ITS), transferrin receptors, and serum ferritin (SF), were studied and the level of hepcidin prohormone was estimated by direct enzyme immunoassay (Hepcidin Prohormone Enzyme Immunoassay Kit, IBL, Germany) in all the patients to be analyzed. Cytokines, such as interleukin 6, tumor necrosis factor-а) were determined by enzyme immunoassay (Bender MedSystems, Austria). The Institute’s differential diagnostic algorithm involving SF, TSIBC, and ITS was used to diagnose iron deficiency. The diagnosis was based on two stages of estimating iron values: isolated iron-deficiency anemia (IDA) was diagnosed if SF was below the normal value (< 40 μg/l). If the patient had SF of μ40 μg/l with a simultaneous rise of TSIBC above the normal level (> 70 μg/l) and a drop of ITS (> 20%), he/she might be suspected as having the mixed genesis of anemia, in which both iron deficiency and CDA are detectable. The other patients could be diagnosed as having isolated CDA. Results. The study has established that irrespective of the hemoglobin level, the content of serum hepcidin prohormone in the examined patients with RA averaged 89.2±65.1 pg/ml and was much higher than that in donors (64.9+21.6 pg/ml; р < 0.05). An analysis of the blood biochemical parameters characterizing iron metabolism showed that, whether they were anemic or non-anemic, the patients with RA, as compared with donors, were found to have an elevated level of SF that is an acute-phase indicator and reflects the high activity of an inflammatory process. To rule out IDA, the anemic patients with RA were subdivided into 3 subgroups according to the differential diagnostic algorithm. Subgroup 1 included patients with isolated CDA (n = 13 patients (28% of those in the study group)); Subgroup 2 consisted of 17 (32%) patients with anemia of mixed genesis (CDA ± IDA), and Subgroup 3 comprised 17 patients with IDA. An analysis of the clinical and laboratory parameters in RA independent of the nature of anemia demonstrated that only the patients with isolated CDA had significantly higher mean values of hepcidin prohormone (120.3±56.1 pg/ml) as compared to the control group (90.3±37.9 pg/ml) and RA patients with iron deficiency (both isolated IDA and that of mixed genesis). The same subgroup had a higher inflammatory RA activity characterized by the highest values of DAS 28, C-reactive protein, and SF. Conclusion. Hepcidin is a negative regulator of iron metabolism and may be used for the differential diagnosis of CDA and true iron deficiency in patients with RA

ROCK FAILURE INFLUENCE OF THE BLOCK-HIERARCHICAL STRUCTURE OF ROCKS ON THE PECULIARITIES OF SEISMIC WAVE PROPAGATION

The analysis is performed for the parameters of long pendulum-type waves in a one-dimensional periodic system with an arbitrary hierarchical structure. A case study is carried out into the wave propagation peculiarities in an impact-excited system of equal rigid blocks with parting layers differing in rigidity. The pendulum wave velocity in the automodel block-hierarchical system is determined

Spinning and rotating strings for N=1 SYM theory and brane constructions

We obtain spinning and rotating closed string solutions in AdS_5 \times T^{1,1} background, and show how these solutions can be mapped onto rotating closed strings embedded in configurations of intersecting branes in type IIA string theory. Then, we discuss spinning closed string solutions in the UV limit of the Klebanov-Tseytlin background, and also properties of classical solutions in the related intersecting brane constructions in the UV limit. We comment on extensions of this analysis to the deformed conifold background, and in the corresponding intersecting brane construction, as well as its relation to the deep IR limit of the Klebanov-Strassler solution. We briefly discuss on the relation between type IIA brane constructions and their related M-theory descriptions, and how solitonic solutions are related in both descriptions.Comment: 35 pages. Dedicated to the memory of Ian I. Kogan. References adde

Diagnostic methodics of personal development of university students in studying the humanities

© The author(s). The urgency of the research of diagnostic methodics of personal development of university students in studying the humanities does not lose its science - based and practice - oriented value and at the present transitional time, which has put higher education before the need to train professionals with personal qualities as required to modify the social structure of the labor market and the needs of the personality. The purpose of the article is in scientific - practical justification of the set of diagnostic methodics of personal development of students and experimental verification of their efficiency in the process of studying the humanities. The article presents: theoretical - methodic foundations of the structure, content and implementation techniques of diagnostic methodics of personal development of students in studying the humanities and identifies practical significance of the methodic for the formation of competent professionals demanded by modern job market. The leading method of this study is to monitor the personal development of university students in the process of studying the humanities. The article stuff is designed for university teachers of humanities, young scientists and students, who are interested in research activities in the humanitarian sphere. It is recommended to university methodists and students of further teacher training centers of continuing professional education