Purpose This paper aims to examine the impact of three-dimensional (3D) printing technological modes (using fused deposition modelling [FDM]) on physical and mechanical properties of samples from polyphenylenesulfone. Design/methodology/approach For this study, the standard test samples were printed using the FDM method at different filament orientation angles, the gaps between them and a different width. The basic physical and mechanical properties, such as the strength, the elastic modulus and the impact strength, were studied. Findings The authors found that the basic mechanical properties strongly depend on the printing settings. In particular, the elastic modulus generally depends on the air gap between rasters, and it is practically independent of the filament orientation angle. In contrast, the impact strength depends on the orientation and the degree of adhesion between filaments: the highest values are reached at the longitudinal orientation of rasters in the sample (0°) and the minimum value of the air gap (−0.025 mm). However, in selecting the optimal mode of 3D printing, it is necessary to take into account the specific geometry of the printing products and the direction of the stress that it will experience. Originality/value The paper presents the results of the investigation of the influence of FDM printing modes on the mechanical properties of samples from polyphenylenesulfone, including impact strength. The authors studied the mechanisms of the destruction under impact loading and revealed the optimal printing settings for making samples with properties which are not inferior to the injection molded samples.

The effect of oligophenylene sulfone (OPSU) and polycarbonate (PC) on the rheological, mechanical and thermal properties of polyetherimide (PEI) and a carbon-filled composite based on it was studied. It is shown that the introduction of OPSU and PC leads to a decrease in the melt viscosity of PEI and a carbon-filled composite based on it with the preservation of their mechanical properties and heat resistance at a sufficiently high level. It was found that composites with OPSU have higher mechanical and thermal properties compared with composites with PC. Samples from modified carbon-filled PEI were printed by the fused deposit modeling (FDM) method. Three-dimensionally printed samples from carbon-filled PEI modified by OPSU showed significantly higher mechanical properties than composites with PC.

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The effect of the length and concentration of carbon fibers on the rheological, mechanical and thermal properties of high-temperature thermoplastics – polyphenylene sulfone was investigated. As fillers fibers with a length of 0.2 and 3 mm are used.

In a review article based on my own clinical experience of managing patients with acute myocardial injury and fulminant myocarditis, taking into account expert recommendations on the clinical treatment of myocardial damage associated with novel coronavirus infection a National clinical geriatric medical research center, division of cardiovascular diseases, the Chinese geriatrics society, Department of cardiology, Beijing Medical Association and European clinics discusses the pathogenesis, diagnosis and treatment of myocardial damage and FM patients, infected with SARS-CoV-2 in the context of the COVID-19 pandemic. Clinical features and diagnostic criteria are presented, including screening tests of markers of myocardial damage in the form of a highly sensitive troponin test, a natriuretic peptide. The article discusses in detail the pathogenesis and mechanisms of myocardial damage, including immune mechanisms, cytokine storm, systemic inflammation with macro- and microvascular dysfunction and the development of myocardial dysfunction with acute heart failure, hypotension, cardiogenic shock and/or life-threatening heart rhythm disorders caused by hypoxia and metabolic disorders at the cellular level. Features of the clinical course of fulminant myocarditis in infected patients (SARS-CoV-2) in the conditions of the COVID-19 pandemic are presented. For the first time, a detailed histo-morphological analysis of pathological myocardial injuries and complications is presented on the basis of unique autopsy material on post-mortem diagnostics of various pathoanatomic autopsies of those who died from COVID-19 in Moscow. Based on the clinical, functional and morphological material, the Protocol of etiopathogenetic treatment is presented. The basis of standard therapy is considered antiviral drugs, immunoglobulin G, the use of monoclonal antibodies to interleukin-6, anticoagulants, glucocorticoids, depending on the clinical situation, cardioprotectors and symptomatic treatment are recommended to maintain the heart, which in combination can achieve a certain clinical effectiveness. As adjuvant cardioprotective targeted therapy, the sodium salt of phosphocreatine is considered in order to preserve the myocardium, maintain its contractility and vital activity.