Some extremal problems for polygons in the Euclidean plane

The paper is devoted to some extremal problems, related to convex polygons in the Euclidean plane and their perimeters. We present a number of results that have simple formulations, but rather intricate proofs. Related and still unsolved problems are discussed too.Comment: 18 pages, 15 pictures. Typos corrected. Comments are welcome

One property of a planar curve whose convex hull covers a given convex figure

In this note, we prove the following conjecture by A. Akopyan and V. Vysotsky: If the convex hull of a planar curve $\gamma$ covers a planar convex figure $K$, then $\operatorname{length}(\gamma) \geq \operatorname{per} (K) - \operatorname{diam} (K)$. In addition, all cases of equality in this inequality are studied.Comment: 10 pages, 4 figure

Monoclonal Antibodies and Recombinant Proteins for Immune-Diagnostics of Ebola Virus Disease

The review summarizes the literature data on the studies of viral antigens and antibodies, specific to Ebola virus, suitable for the development of a test-system for immune-diagnostics of the disease caused by them. Represented are the results of investigations on the obtainment of hybridoma monoclonal antibodies (MCA), specific to structural viral proteins NP, VP40, and VP35; recombinant proteins NP, VP40, and VP35 in prokaryotic system of E. coli; as well as the possibility to utilize MCA panels for EV viral and recombinant proteins’ detection in ELISA

THE ANALYSIS OF THE METHODS OF APPLYING GLASS SEALANTS TO ASSEMBLE SOFC STACKS

Sealants, which must have high adhesive properties, are important for the operation of SOFC STACKS. At the same time, the technology of applying the sealant has an effect on adhesion [1]. This article discusses various methods of applying glass sealants

Антитела к рецептор-связывающему домену спайкового белка SARS-COV-2: связь с возрастом, пневмонией, длительностью периода после COVID-19

Despite the rapid accumulation of facts about the humoral immune response in COVID-19, there are still no evidencebased answers to questions about the factors influencing the level and duration of the detection period of antibodies to SARS-CoV-2 in the blood.Objective: To assess the prevalence, clinical and demographic associations of IgG antibodies to RBD of the SARSCoV-2 spike protein at different times after COVID-19.Materials and methods. Residents of the Altai region of Russia, Caucasians aged 20-93 years, who had COVID-19 from May 2020 to February 2021 (n = 314), took part in a onetime observational study. The level of antibodies in the blood was measured by enzyme-linked immunosorbent assay 1-14 months after the onset of the clinical manifestation of COVID-19.Results. Anti-RBD IgG antibodies of the SARS-CoV-2 spike protein were detected in 86.9% of the study participants. The dependence of the antibody titer on the duration of the period after COVID-19 was not revealed. The antibody titer was positively correlated with the complication of COVID-19 pneumonia and the volume of lung tissue lesions. The presence of pneumonia COVID-19 and the volume of lung tissue lesions are positively associated with age. Age positively correlated with antibody titer regardless of the pneumonia COVID-19 in the anamnesis.Conclusion. IgG antibodies to RBD of the SARS-CoV-2 spike protein are present in most of the COVID-19 patients. The titer of these antibodies in adults depends on age, complications of pneumonia COVID-19, and probably persists up to 14 months after the first symptoms of infection appear.Несмотря на быстрое накопление фактов о гуморальном иммунном ответе при COVID-19, пока нет доказательных ответов на вопросы о факторах, влияющих на уровень и длительность периода обнаружения антител к SARS-CoV-2 в крови.Цель: оценить распространенность наличия, клинические и демографические ассоциации антител IgG к RBD спайкового белка SARS-CoV-2 в разные сроки после COVID-19.Материалы и методы. В одномоментном обсервационном исследовании приняли участие жители Алтайского края России, европеоиды, в возрасте от 20 до 93 лет, переболевшие COVID-19 в период с мая 2020 г. по февраль 2021 г. (n=314). Уровень антител в крови измеряли через 1–14 месяцев от начала клинической манифестации COVID-19 методом иммуноферментного анализа.Результаты. Антитела IgG к RBD спайкового белка SARS-CoV-2 обнаружены у 86,9% участников исследования. Не выявлено зависимости титра антител от давности COVID-19. Титр антител положительно коррелировал с осложнением пневмонией COVID-19 и объемом поражений легочной ткани. Наличие пневмонии COVID-19 и объем поражений легочной ткани положительно связаны с возрастом. Возраст положительно коррелировал с титром антител независимо от наличия пневмонии COVID-19 в анамнезе.Заключение. Антитела IgG к RBD спайкового белка SARS-CoV-2 имеются у большей части переболевших COVID-19. Титр этих антител у взрослых зависит от возраста, осложнения пневмонией COVID-19 и может сохраняться до 14 месяцев после появления первых симптомов инфекции

Use of by-products of millet, amaranth and sorghum grains in bakery production

The use of additional gluten-free grain raw materials in the form of flour or secondary raw materials of cereal industry in the recipes of bakery products allows regulating the biotechnological processes of dough maturing and proofing, obtaining a finished product with new functional properties and high nutritional value. The purpose of the research is to justify experimentally the use of processed products of amaranth grain and sorghum for the production of bread of high quality and functionality. The methodological basis of the study is presented by a systematic analysis of the technology for the production of bakery products enriched with promising phyto-fortifiers. In accordance with the chosen methodology, the chemical composition is analyzed and the positive effect of the use of flour from millet grain, sorghum and amaranth seeds in the mixture with premium wheat flour on the quality of bread is experimentally justified. It was found that the introduction of these types of additional raw materials had a positive effect on the activation of baking yeast and the maturation of dough. In the production of bread from wheat flour of the highest grade, it is optimal to use these phyto-fortifiers in the amount of 3% by weight of the composite mixture

EXPERIENCE WITH EFFECTIVE COMBINED ANTI-B-CELL THERAPY WITH RITUXIMAB AND BELIMUMAB FOR REFRACTORY GRANULOMATOSIS WITH POLYANGIITIS (WEGENER'S) WITH SEVERE LUNG DAMAGE

Systemic vasculitis (SV) associated with antineutrophil cytoplasmic antibodies (ANCA) is characterized by severe multiple organ lesions with a poor prognosis. The successful introduction of standard therapy with cyclophosphamide (CP) and innovative anti-B-cell therapy with rituximab (RTM) for the treatment of ANCA SV gives no grounds to stop further searching for effective and safe therapy since about 10–15% of patients with ANCA SV are refractory to standard therapy with CP; after the latter, approximately 40% of patients develop recurrences, and granulomatous inflammation in the respiratory organs in granulomatosis with polyangiitis (GPA) can be resistant to RTM treatment, especially following its single cycle. There is increasing evidence that the efficiency of anti-B-cell therapy can be enhanced by adding belimumab (BLM). The paper describes a clinical case of effective sequential combined anti-B-cell therapy with BLM and RTM for remission induction in a female patient who has GPA with severe granulomatous lung injury refractory to previous therapy with CP (a total dose of 6.2 g) and a single cycle of therapy with RTM (a total dose of 2.6 g). BLM was used 12 months after RTM administration because there were no positive changes in lung injury. At 12 months after initiations of treatment with BLM (800 mg twice at a weekly interval, then 800 mg monthly), there was a substantial reduction in the lung parenchymal foci, as evidenced by multislice spiral computed tomography (MSCT); and the treatment was continued for another 6 months, thereafter discontinued due to the occurrence of ulcerative stomatitis. After its relief, RTM was again given at reduced dose cycles of 500 mg every 6 months; lung MSCT showed further improvement and remission achieved. BLM may be effective in treating the GPA patients who are refractory to CP and have an insufficient response to RMT treatment. Combined anti-B-cell therapy aimed at depleting SD20+ B-cells and at blocking BAFF may be a promising area for the treatment of patients with ANCA SV