Influence of the Addition of Alumina Nanofibers on the Strength of Epoxy Resins.

The paper describes the effect of the addition of alumina nanofibers on the mechanical properties of the epoxy resin. Alumina nanofibers functionalized with epoxypropyl functional groups are used in this work. The dependence of the mechanical characteristics on the amount of the additive, as well as the features of its distribution in the material, is investigated. In the work, nanocomposites were obtained, which are epoxy resin with aluminum oxide nanofibers. The mechanical properties of the samples were studied by bending tests and differential mechanical analysis (DMA). It has been shown that the addition of alumina nanofibers leads to an increase in ultimate flexural strength. The maximum of this increase is near the percolation threshold of alumina nanofibers in epoxy resin. With the addition of 0.2% alumina nanofibers, the ultimate flexural strength increases from 41 to 71 MPa. It is shown that after exceeding the percolation threshold of nanofibers, the ultimate strength decreases. In this case, the elastic modulus increases from 0.643 to 0.862 GPa. DMA is shown that the glass transition temperature decreases with increasing amount of the additive. This indicates a decrease in the molecular weight of the polymer. By implication, this suggests that the hardener connects the epoxypropyl functional groups on the nanofibers and the epoxy groups in the resin, and as a result of this process, the nanofibers become natural polymer chain length limiters. The data obtained from mechanical testing and differential mechanical analysis can be used to strengthen epoxy resins in polymer composite materials and molding compositions.

[Heart reHeart remodeling in patients with severe systolic dysfunction due tocancer chemotherapymodeling in patients with severe systolic dysfunction due tocancer chemotherapy.]

Objective Comparative analysis of structural and functional specific features of the heart in patients with toxic cardiomyopathy (TCMP) with a low left ventricular ejection fraction (LVEF) and severe, chronic heart failure (CHF) and in patients with idiopathic dilated cardiomyopathy (DCMP) and similar LVEF and CHF severity.Materials and Methods This observational, single-site study included 15 patients with TCMP (12 of them received treatment including anthracycline antibiotics and 3 patients received targeted therapies) and 26 patients with idiopathic DCMP. Data of echocardiography were compared for patients with TCMP and DCMP with comparably low LVEF of <40 %.Results In patients with severe heart damage associated with antitumor therapy with low LVEF, volumetric and linear indexes of left and right ventricles and the left atrium (left atrial volume index (LAVI), 33.7 (21.5-36.9) ml / m2; right ventricular end-diastolic dimension (RVDd), 2.49 (1.77-3.53) cm; and end-diastolic volume index (EDVI), 78.0 (58.7-90.0) ml / m2) were considerably less than in the DCMP group (LAVI, 67.1 (51.1-85.0) ml / m2; RVDd, 4.05 (3.6-4.4) cm; and EDVI, 117.85 (100.6-138.5) ml / m2, p<0.0001). Furthermore, LV wall thickness and pulmonary artery systolic pressure did not differ in these groups. Both in men and women with TCMP, LAVI and EDVI were significantly less than in men and women with DCMP.Conclusion The study showed significant differences in parameters of cardiac remodeling. In TCMP patients as distinct from DCMP patients, despite a pronounced decrease in LVEF, LV dilatation was absent or LV volumetric parameters were moderately increased with a more severe somatic status.

[Results of 3 years work of the Russian hospital register of chronic heart failure (RUssian hoSpital Heart Failure Registry - RUS-HFR): relationship between management and outcomes in patients with chronic heart failure].

AIM: To analyze management and outcomes in patients with CHF managed by specialists in heart failure (HF) or general cardiologists/physicians in real-life clinical practice. MATERIALS AND METHODS: Survival rate, rehospitalization rate, general health condition, and the administered therapy were evaluated for HF patients with reduced LV ejection fraction at three years of discharge from cardiological hospitals. These patients had been included in a prospective, multicenter, observational study, "The Russian Hospital HF Registry" (RUS-HFR). The first group consisted of patients who were managed at a specialized HF department of the Federal Center and followed up at the outpatient stage by a cardiologist specializing in HF (Group 1, St.­Petersburg; n =74). The other two groups (Group 2 and Group 3) included patients who were managed at other cardiological departments of the Federal Center (n=186) or the Regional Center (n=130) and subsequently followed up at the place of residence. RESULTS: After the discharge from the hospital, 58-95 and 12-19% of RUS-HFR patients were followed up by a cardiologist or a physician, respectively, on an outpatient basis while 5-23% of patients did not visit a doctor at all. In three years, the survival rate of Group 1, 2, and 3 patients was 80 vs. 78 (р>0.05) vs. 52% (р0.05) vs. 100% (p1,2.