Phase transitions and phase diagram of the ferroelectric perovskite NBT-BT by anelastic and dielectric measurements

The complex elastic compliance and dielectric susceptibility of (Na_{0.5}Bi_{0.5})_{1-x}Ba_{x}TiO_{3} (NBT-BT) have been measured in the composition range between pure NBT and the morphotropic phase boundary included, 0 <= x <= 0.08. The compliance of NBT presents sharp peaks at the rhombohedral/tetragonal and tetragonal/cubic transitions, allowing the determination of the tetragonal region of the phase diagram, up to now impossible due to the strong lattice disorder and small distortions and polarizations involved. In spite of ample evidence of disorder and structural heterogeneity, the R-T transition remains sharp up to x = 0.06, whereas the T-C transition merges into the diffuse and relaxor-like transition associated with broad maxima of the dielectric and elastic susceptibilities. An attempt is made at relating the different features in the anelastic and dielectric curves to different modes of octahedral rotations and polar cation shifts. The possibility is also considered that the cation displacements locally have monoclinic symmetry, as for PZT near the morphotropic phase boundary.Comment: 11 pages, 9 figures, submitted to Phys. Rev.

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

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

Kinetics of fragmentation and dissociation of two-strand protein filaments: Coarse-grained simulations and experiments.

While a significant body of investigations have been focused on the process of protein self-assembly, much less is understood about the reverse process of a filament breaking due to thermal motion into smaller fragments, or depolymerization of subunits from the filament ends. Indirect evidence for actin and amyloid filament fragmentation has been reported, although the phenomenon has never been directly observed either experimentally or in simulations. Here we report the direct observation of filament depolymerization and breakup in a minimal, calibrated model of coarse-grained molecular simulation. We quantify the orders of magnitude by which the depolymerization rate from the filament ends koff is larger than fragmentation rate k- and establish the law koff/k- = exp[(ε‖ - ε⊥)/kBT] = exp[0.5ε/kBT], which accounts for the topology and energy of bonds holding the filament together. This mechanism and the order-of-magnitude predictions are well supported by direct experimental measurements of depolymerization of insulin amyloid filaments.This research was supported by the ERC, EPSRC, BBSRC, and the Newman Foundation.This is the author accepted manuscript. The final version is available from the American Institute of Physics via http://dx.doi.org/10.1063/1.496236

Predictive role of quantification of myocardial fibrosis using delayed contrast-enhanced magnetic resonance imaging in nonischemic dilated cardiomyopathies: a systematic review and meta-analysis

Aim. The present study aims to provide a systematic review and meta-analysis to investigate the prognostic role of assessing the severity of myocardial fibrosis using delayed contrast-enhanced magnetic resonance imaging in nonischemic dilated cardiomyopathies.Material and methods. We searched PubMed, Google Scholar for studies that examined the predictive value of quantifying late gadolinium enhancement (LGE) areas in patients with nonischemic dilated cardiomyopathy. Unadjusted hazard ratios (HR) from studies with similar scoring criteria were pooled for meta-analysis.Results. Nine studies were retrieved from 782 publications for this systematic review and meta-analysis. In total, 2389 patients (mean age, 51,9 years; mean follow-up, 39,3 months) were included in the analysis. Meta-analysis showed the extent of LGE was associated with an increased risk of arrhythmic end point (HR: 1,09/1% LGE; 95% CI: 1,02-1,18; p=0,01), major adverse cardiovascular events (HR: 1,07/1% LGE; 95% CI: 1,01-1,13; p=0,03) and all-cause mortality (HR: 1,09/1% LGE; 95% CI: 1,04-1,13; p&lt;0,0001).Conclusion. The severity of LGE by cardiac magnetic resonance predicts arrhythmic events (ventricular arrhythmia and sudden death), major adverse cardiovascular events and all-cause mortality. Assessment of LGE can be used as an effective tool for stratifying risk in patients with nonischemic dilated cardiomyopathy

Folded Three-Spin String Solutions in AdS_5 x S^5

We construct a spinning closed string solution in AdS_5 x S^5 which is folded in the radial direction and has two equal spins in AdS_5 and a spin in S^5. The energy expression of the three-spin solution specified by the folding and winding numbers for the small S^5 spin shows a logarithmic behavior and a one-third power behavior of the large total AdS_5 spin, in the long string and in the short string located near the boundary of AdS_5 respectively. It exhibits the non-regular expansion in the 't Hooft coupling constant, while it takes the regular one when the S^5 spin becomes large.Comment: 14 pages, LaTeX, no figures, a reference adde

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

New advances in Raman study of polyvinylchloride structure

In this work we investigated Raman spectra of a number of industrial grades of polyvinylchloride powder and films, prepared from solutions in tetrahydrofuran and acetophenone. The number and spectral characteristics of the Raman lines in the spectral regions of the C-Cl stretching vibrations and in the region of the C-H and CH2 stretching vibrations were evaluated

CHANGES OF CYTOKINE LEVELS DURING THERAPY WITH METHOTREXATE AND ADALIMUMAB IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS (REMARCA STUDY)

Objective: to estimate changes in cytokine profile versus disease activity in patients with early rheumatoid arthritis (RA) who use methotrexate (MTX) and adalimumab (ADA) in accordance with the treat-to-target concept. Subjects and methods. Forty-five patients (35 women; median age 53.5 [46; 59.5] years) with early RA (median dura- tion 7.0 [4.0; 11.5] months; DAS28 5.8 [4.9; 6.4]; rheumatoid factor positivity (RF+) 91%; anti-cyclic citrullinated peptide antibody positivity (ACCP) + 96%) were examined. In all the patients, MTX as the first agent was subcuta- neously used in a dose of 10 mg/week with its rapid escalation up to 20-25 mg/week. Serum cytokine concentrations were determined using the xMAP multiplexing technology before and 12 and 24 weeks after therapy. Results. Following 12 weeks of therapy, DAS28 mean value decreased to 4.33 [3.5; 5.2] (p &lt; 0.05 vs baseline). Twenty- nine (64.4%) patients responded to treatment. It was decided to continue MTX monotherapy in 23 patients (a monotherapy group) and in 22 patients ADA was added to therapy due to its inadequate effect in accordance with the standard regimen (a combined therapy group). At 24 weeks, mean DAS28 was 2.9 [2.1; 3.6] and 19 (82.6%) patients responded to treatment in the monotherapy group. In the combined therapy group, DAS28 was 3.4 [3.2; 4.4]; nearly 30% of the patients achieved remission/low disease activity and the number of patients with the high activity of a pathological process also declined significantly (from 59.1 to 13.6%). At 12 weeks, the monotherapy group showed reduction of the level of proinflammatory (interleukin-6 (IL-6), IL-17, tumor necrosis factor-α (TNF-α)), anti-inflammatory (IL-4, IL-5, IL-9, IL-13) cytokines, chemokines (interferon induced protein-10 (IP-10)), and vascular endothelial growth factors (VEGF) (p&lt;0.05); at 24 weeks, there were reductions in IL-6, IL-9, and IL-10, and transforming GF-bb and an increase in IL-10 concentration (p&lt;0.05). At 12 weeks of MTX therapy, the combined therapy group displayed a reduction in IL-6, IL-1Pa, IP-10 (p&lt;0.05); at 24 weeks of treatment (12-week ADA administration) there were decreases in proinflammatory (IL-12), anti-inflammatory (IL-9) cytokines, chemokines (IP-10, monocyte chemoattractant protein, and macrophageal inflammatory protein-1β), VEGF and an elevation of IL-10. Conclusion. Thus, the results of the investigation suggest the high clinical efficiency of therapy with subcutaneous MTX, which is associated with the lower levels of a number of proinflammatory cytokines, chemokines, and growth factors. ADA treatment is also accompanied by decreased disease activity and positive changes in the cytokine profile, by exerting a higher impact on the level of chemokines and growth factors