Influence copolymers of ethylene with vinyl acetate on the physicochemical properties of Bitumen

The results of experiments are presented concerning the modification of road bitumen by ethylene copolymer with vinyl acetate (EVA). This polymeric additive make a strong structure-forming influence on bitumen. At that the penetration value changes most rapidly at 25 °C. The higher the concentration of copolymer and the content of the ester groups in it, the less the penetration depth of the binder needle. The introduction of excess amount of copolymers with vinyl acetate groups develops a spatial structure conjugated with asphaltene associates, and providing the stability of all bitumen heterogeneous system. The reduction of elongation and brittleness temperature is revealed at the introduction of low molecular EVA, which allows to obtain the binders with improved low temperature properties. The most intensive change of properties is achieved by the introduction of EVA into bitumen with the molecular weight of 25,000, which is manifested in softening temperature increase with brittleness temperature reduction, and the extension of plasticity range by 8-20 °C. At the same time the introduction of granulated EVA into bitumen with high molecular weight leads to a significant increase of softening and brittleness temperature and ductility interval decrease. The study results showed that the bituminous compositions modified by EVA with a high content of vinyl acetate groups are somewhat inferior to the softening temperature and the extensibility of the compositions, modified by EVA with a low content of ester groups, because of the greater initial plasticity of the copolymer in the second case

The supplementary education teacher’s portfolio: Essence, functions, structure and design principles

© 2015, Mediterranean Center of Social and Educational Research. All rights reserved. The article discloses the contradictions, which define the necessity and possibility to use teacher’s portfolio in the system of children’s supplementary education. It gives the author’s interpretation of the concept «supplementary education teacher’s portfolio», defines objectives, the portfolio functions and the principles of its design. The article offers the author’s structure of the supplementary education teacher’s portfolio, which reflects the main directions of the teacher’s professional activities, allows demonstrating the achievements and the results of these activities. The authors describe the alternatives to use the portfolio in supplementary education. The article reveals the risks of portfolio implementation in the institutions of supplementary education. Practical recommendations for the teacher’s portfolio development given in the article are practice– oriented. The article addresses the administration and the teachers of the children’s supplementary education institutions, the lecturers of the teacher’s training colleges, who train future teachers of the supplementary education as well as the educators of the extended education within the process of the professional skills improvement for supplementary education teachers

Биазеотропия в трехфазных системах

Evolution of diagrams of biazeotropic three-phase mixture methyl tert-butyl ether - water at high pressure was considered.Рассмотрена эволюция диаграмм биазеотропной трехфазной смеси метил-трет-бутиловый эфир - вода при повышенном давлении

Possibilities of using branched-chain amino acids for the treatment and prevention of sarcopenia in elderly and old patients (literature review)

Due to the high prevalence of sarcopenia among elderly and old patients, early prevention and treatment of sarcopenia and its complications are relevant. Protein supplements can be used to maintain muscle strength and mass during aging. The possibility of using branched-chain amino acids (BCAAs) in the treatment and prevention of sarcopenia in geriatric patients is of scientific interest. BCAAs promote the synthesis and inhibit the degradation of muscle tissue proteins, are involved in the regulation of tissue sensitivity to insulin, ammonia utilization, the tricarboxylic acid cycle, etc.Search strategy. The search for scientific articles for literature review was carried out in the PubMed and PubMed Central databases. The selection criterion was scientific articles published up to December 2022. We used the following search keywords: “branched-chain amino acids”, “BCAA”, “body composition”, “sarcopenia”, “aging”. The 2019 European Working Group on Sarcopenia in Older People 2 (EWGSOP2) Consensus was included in the list of articles.Conclusions. The possibility of using BCAAs in elderly and old patients for the prevention and treatment of sarcopenia is a relevant topic that continues to be actively studied. The effectiveness of BCAA supplementation in the diet is debatable as long as sufficient protein is consumed daily. On the other hand, BCAA supplementation may be justified in cases where it is not possible to consume enough high-quality protein in the diet. More research is needed on this topic

Diabetic autonomic neuropathy is a barrier to achieving glycemic control

Diabetic autonomic neuropathy is the second most common form of damage to the nervous system in diabetes mellitus as a result of disorders of the central and/or peripheral parts of the autonomic nervous system. On average, its frequency of occurrence is about 40%, and 60% or more with an increase in the duration of diabetes over than 10 years. Diabetic autonomic neuropathy is characterized by polysyndromism of clinical manifestations. In this regard, a number of forms of diabetic autonomic neuropathy are distinguished both in the form of an isolated violation of the function of organs and systems, and with their combined defeat. In the pathogenesis of autonomic neuropathy, vascular and metabolic changes common to the development of diabetic polyneuropathy play an important role. The most significant risk factors for the development of diabetic autonomic neuropathy are the patient's age, duration of diabetes mellitus, and a higher average HbA1c. The development and progression of diabetic autonomic neuropathy depends on glycemic control, but its forms such as gastrointestinal and impaired recognition of hypoglycemia (asymptomatic hypoglycemia) can cause poor compensation for diabetes. This article discusses the various clinical manifestations of gastrointestinal autonomic neuropathy. Attention is drawn to the fact that the clinical picture is often nonspecific and asymptomatic, which complicates timely diagnosis. The gastrointestinal form of diabetic autonomic neuropathy leads to limited performance, social maladaptation of patients, dramatically reduces the quality of life of patients with diabetes mellitus. In clinical practice, the doctor must remember that it can significantly affect the achievement of glycemic control, as a result of a violation of the digestion and passage of food, as well as a violation of the pharmacokinetics of hypoglycemic drugs. Impaired recognition of hypoglycemia also makes it difficult to compensate well. These complications require a personalized approach to the patient from the doctor, and strict and frequent self-control of glycemia with the help of a modern glucometer from the patient to maintain optimal glycemic control and prevent possible hypoglycemic conditions

The specifics of cardiovascular disease and the role of self-monitoring in patients with type 2 diabetes

High risk of cardiovascular complications in patients with diabetes mellitus (DM) is a global health problem. Preventing the onset and progression of the pathology in diabetes should be primarily considered in terms of its maximum compensation, where the leading role belongs to patient education and adequate self-monitoring of blood glucose

The role of sulfonylures in the treatment of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is one of the most common diseases in the world accounting for about 85--90% of the total number of people with diabetes. More than 80% of these patients are overweight or obese, and lead sedentary lifestyles. If earlier T2DM was considered "a disease of the elderly", now half of patients suffering from the disease are people of working age. Reduced working ability as well as financial burden of prevention and treatment of late complications of DM are a significant problem for the healthcare system and society as a whole. At the same time, T2DM therapy involving effective medicines which are convenient and have minimum side effects could markedly reduce treatment costs

Biazeotropy in three-phase mixtures

Evolution of diagrams of biazeotropic three-phase mixture methyl tert-butyl ether - water at high pressure was considered

Influence copolymers of ethylene with vinyl acetate on the physicochemical properties of Bitumen

The results of experiments are presented concerning the modification of road bitumen by ethylene copolymer with vinyl acetate (EVA). This polymeric additive make a strong structure-forming influence on bitumen. At that the penetration value changes most rapidly at 25 °C. The higher the concentration of copolymer and the content of the ester groups in it, the less the penetration depth of the binder needle. The introduction of excess amount of copolymers with vinyl acetate groups develops a spatial structure conjugated with asphaltene associates, and providing the stability of all bitumen heterogeneous system. The reduction of elongation and brittleness temperature is revealed at the introduction of low molecular EVA, which allows to obtain the binders with improved low temperature properties. The most intensive change of properties is achieved by the introduction of EVA into bitumen with the molecular weight of 25,000, which is manifested in softening temperature increase with brittleness temperature reduction, and the extension of plasticity range by 8-20 °C. At the same time the introduction of granulated EVA into bitumen with high molecular weight leads to a significant increase of softening and brittleness temperature and ductility interval decrease. The study results showed that the bituminous compositions modified by EVA with a high content of vinyl acetate groups are somewhat inferior to the softening temperature and the extensibility of the compositions, modified by EVA with a low content of ester groups, because of the greater initial plasticity of the copolymer in the second case