Разработка композиции на основе полимочевины с увеличенным сроком жизни

Objectives. Improvement of the technology for obtaining polymer-sprayed coatings based on polycarbodiimides (polyureas) with high chemical, hydrolytic, and abrasive resistance and improved physical and mechanical properties, as well as obtainment of polyurea compositions with a lifetime of at least 5 min without loss performance characteristics (i.e., “hand-applied” polyureas) suitable for repair of coatings already in use.Methods. The reaction rate between isocyanate and amino groups is almost a hundred times higher than that between isocyanate and hydroxyl groups, necessitating the use of special highperformance and high-pressure installations equipped with self-cleaning mixing chambers and heating of components. The following are determined from the obtained materials: strength, elongation at break according to the standard method, Taber abrasion, and Shore hardness.Results. Three methods of slowing down the reaction are investigated: 1) the synthesis of prepolymers with the content of NCO groups from 10.5% to 18%; 2) the addition of a plasticizer into the prepolymer in the amount of 1–10 mass parts; and 3) the introduction of polyesters into the composition and radiation of the so-called “hybrid” systems. When using 14% polyesters with a molecular weight of 2000 Da, only “hybrid” systems make it possible to obtain compositions with a lifetime of more than 5 min. At the same time, the tensile strength decreases by 20%, and the abrasion increases by 40%; however, such “hybrid” systems have a higher adhesion force and are cheaper than pure polyureas, allowing them to be used as “repair” systems.Conclusions. The developed composition and technology of applying “hybrid” systems allow for the repair of existing coatings without using specialized devices. “Manual” polyurea is easy to use and does not require special training. Цели. Совершенствование технологии получения полимерных напыляемых покрытий на основе поликарбодиимидов (полимочевин), с высокой химической, гидролитической и абразивной стойкостью и улучшенными физико-механическими показателями, а также, получение полимочевинных композиций с временем жизни не менее 5 мин без потери эксплуатационных характеристик (полимочевин «ручного» нанесения), пригодных для ремонта уже эксплуатирующихся покрытий.Методы. Скорость реакции между изоцианатными и аминогруппами практически в сто раз превышает скорость реакции между изоцианатными и гидроксильными группами, что вызывает необходимость использовать специальные высокопроизводительные установки высокого давления, оснащенные самоочищающимися смесительными камерами и обогревом компонентов. У полученных материалов определяли прочность, удлинение на разрыв по стандартной методике, истираемость по Таберу и твердость по Шору.Результаты. Исследованы три способа замедления реакции: во-первых, синтез предполимеров с содержанием NCO-групп от 10.5% до 18%; во-вторых, введение в предполимер пластификатора в количестве 1–10 масс.ч.; в-третьих, введение в композицию полиэфиров и получения «гибридных» систем. Показано, что только «гибридные» системы при использовании полиэфиров с молекулярной массой 2000 Да, в количестве 14% позволяют получить композиции с временем жизни более 5 мин. При этом прочность на разрыв снижается на 20%, истираемость увеличивается на 40%, но такие «гибридные» системы имеют более высокую силу адгезии и дешевле по сравнению с чистыми полимочевинами, что позволяет использовать их в качестве «ремонтных» систем.Выводы. Разработанный состав и технология нанесения «гибридных» систем позволяют производить ремонтные работы существующих покрытий без применения специализированных устройств. Полимочевина «ручного» нанесения удобна в эксплуатации и не требует специальной подготовки.

Изотопный состав снежного покрова Байкальского региона

Deuterium and oxygen‑18 are standard water tracers which are widely used to investigate hydrological processes and to trace the moisture sources. In this study, we collected bulk samples taken from the snow cover in the Baikal region distributed from the city Yakutsk to the Lake Baikal. Ulan-Ude had been chosen as a key site to study the snow cover in more details. It has been shown that during the winter season δ18O values in Ulan-Ude reach −39‰ that is typical for the inland air masses of meridional or western transport. The aim of this study was to describe the spatial variability of concentrations of the isotopes deuterium (2H) and oxygen‑18 (18O) in the snow cover.Стабильные изотопы водорода и кислорода – природные трассеры гидрологического цикла, которые используются в исследованиях гидрологических процессов и для нахождения источника влаги. В статье приводятся данные по снежному покрову Трансбайкальского региона от г. Якутск до озера Байкал. Улан-Удэ был выбран в качестве ключевого участка для более детального изучения снежного покрова. Показано, что в зимний период значения δ18O снега в г. Улан-Удэ достигают −39‰, что типично для внутриконтинентальных воздушных масс – результатов меридионального и западного переноса. Цель статьи – описать пространственную изменчивость содержания стабильных изотопов водорода и кислорода в снежном покрове

Clinical features of post-COVID-19 period. Results of the international register “Dynamic analysis of comorbidities in SARS-CoV-2 survivors (AKTIV SARS-CoV-2)”. Data from 6-month follow-up

Aim. To study the clinical course specifics of coronavirus disease 2019 (COVID-19) and comorbid conditions in COVID-19 survivors 3, 6, 12 months after recovery in the Eurasian region according to the AKTIV register. Material and methods.The AKTIV register was created at the initiative of the Eurasian Association of Therapists. The AKTIV register is divided into 2 parts: AKTIV 1 and AKTIV 2. The AKTIV 1 register currently includes 6300 patients, while in AKTIV 2 — 2770. Patients diagnosed with COVID-19 receiving in- and outpatient treatment have been anonymously included on the registry. The following 7 countries participated in the register: Russian Federation, Republic of Armenia, Republic of Belarus, Republic of Kazakhstan, Kyrgyz Republic, Republic of Moldova, Republic of Uzbekistan. This closed multicenter register with two nonoverlapping branches (in- and outpatient branch) provides 6 visits: 3 in-person visits during the acute period and 3 telephone calls after 3, 6, 12 months. Subject recruitment lasted from June 29, 2020 to October 29, 2020. Register will end on October 29, 2022. A total of 9 fragmentary analyzes of the registry data are planned. This fragment of the study presents the results of the post-hospitalization period in COVID-19 survivors after 3 and 6 months. Results. According to the AKTIV register, patients after COVID-19 are characterized by long-term persistent symptoms and frequent seeking for unscheduled medical care, including rehospitalizations. The most common causes of unplanned medical care are uncontrolled hypertension (HTN) and chronic coronary artery disease (CAD) and/or decompensated type 2 diabetes (T2D). During 3- and 6-month follow-up after hospitalization, 5,6% and 6,4% of patients were diagnosed with other diseases, which were more often presented by HTN, T2D, and CAD. The mortality rate of patients in the post-hospitalization period was 1,9% in the first 3 months and 0,2% for 4-6 months. The highest mortality rate was observed in the first 3 months in the group of patients with class II-IV heart failure, as well as in patients with cardiovascular diseases and cancer. In the pattern of death causes in the post-hospitalization period, following cardiovascular causes prevailed (31,8%): acute coronary syndrome, stroke, acute heart failure. Conclusion. According to the AKTIV register, the health status of patients after COVID-19 in a serious challenge for healthcare system, which requires planning adequate health system capacity to provide care to patients with COVID-19 in both acute and post-hospitalization period

Risk Controlling of Gastrointestinal Bleeding in Comorbid Patients with Cardiovascular Diseases

The issues of prevention of thromboembolic complications (TE) in the management of patients with atrial fibrillation (AF) are of leading importance. Recently, non-vitamin K antagonist oral anticoagulants (NOACs), previously known as new oral anticoagulants are used in the treatment and prevention of TE in patients with AF. A lot of data has been accumulated, in which the NOACs indications have been revised. As a result, the updating has been done in the Recommendations of European Society of Cardiology (2016), the project of Russian Society of Cardiology Guidelines (2017), as well as in the new Recommendations of the European Heart Rhythm Association (2018). At the same time, the issues of prevention ща hemorrhagic complications, especially gastrointestinal bleeding, remain unresolved. Currently, there are no clinical guidelines on the use of NOACs from the standpoint of prevention of gastrointestinal bleeding, as well as definition of the risk of gastrointestinal bleeding in the treatment of NOACs. The authors analyze the recommended algorithms for the evaluation of the risk of gastrointestinal bleeding in NOACs using

Vaginal infections in patients of childbearing age: ways for optimization of treatment in the outpatient setting

Despite the considerable success in managing the medical process and medical screening of women of childbearing age, the treatment of vaginal infection remains an urgent problem that requires periodic correction of the prescribed therapy. This made the authors conduct a study, which was aimed at investigating the optimization aspects of the comprehensive therapy regimens for vaginal infections (VI) that combine the use of etiotropic drugs with the extract of Aloe Barbadenis Multi-Gyn ActiGel and systemic enzyme therapy as compared to the prescription of monotherapeutic etiotropic regimen. The study evaluated the effectiveness of different treatment regimens of VIs based on the dynamics of clinical and laboratory parameters, as well as the safety and tolerability of different therapies based on the registration of adverse events.Based on the study results, we would advise to include the plant extract of Aloe Barbadenis Multi-Gyn ActiGel and Wobenzym into the therapy of patients with VIs induced by the  vaginal dysbiosis and caused by bacterial vaginosis and candidiasis vulvovaginitis-associated microorganisms to improve the elimination of the pathogen and provide a normal titre of lactobacilli with preservation of their functional activity, which eventually restores the impaired vaginal microcenosis and maintains a normal vaginal flora and simultaneously provides a high safety and good tolerability of the proposed treatment regimen

CLINICAL SIGNIFICANCE OF MICROALBUMINURIA IN FORMATION OF VASCULAR DISEASES OF POSTERIOR EYE SEGMENT IN WOMEN AFTER PREECLAMPSIA, POSSIBILITIES OF PROGNOSIS

The purpose of study is to assess the clinical significance of microalbuminuria (MAU) in pregnant women with preeclampsia in formation of vascular eye pathology in long-term postpartum period.Material and methods. In retrospect, according to medical records, analysis of somatic condition of 114 women who had preeclampsia during pregnancy was carried out, and presence / absence of MAU during pregnancy were determined. MAU was detected in the 3rd trimester of pregnancy using test strips «Woerhringer Ingelheim» (Austria), considering the test to be positive with a value of 30 mg/day and more. The age of women at time of research was from 24 to 52 years, the period after suffering preeclampsia was 12.5 ± 6.5 years. Two groups were formed: the main – 35 women with initial MAU during pregnancy; the comparison – 79 women who had no MAU during pregnancy. The controls were 36 women with physiological pregnancy and delivery.Results and discussion. In period after delivery, vascular diseases of posterior eye segment occurred in 14 people in the main group (40 %) and 15 people in the comparison group (19 %). In the control group in this period, vascular pathology of posterior eye segment was formed in 2 women.Conclusion. Statistically significant increase of frequency of formation of vascular pathology of posterior eye segment in postpartum period was revealed in women, who had pregnancy complicated by preeclampsia and MAU in the 3rd trimester, which increased through 10 and more years after delivery. The initial presence of MAU during pregnancy can be the marker of increased risk of formation of vascular pathology of posterior eye segment at different periods of the postpartum period

Isotope composition of snow сover in the Lake Baikal area

Deuterium and oxygen‑18 are standard water tracers which are widely used to investigate hydrological processes and to trace the moisture sources. In this study, we collected bulk samples taken from the snow cover in the Baikal region distributed from the city Yakutsk to the Lake Baikal. Ulan-Ude had been chosen as a key site to study the snow cover in more details. It has been shown that during the winter season δ18O values in Ulan-Ude reach −39‰ that is typical for the inland air masses of meridional or western transport. The aim of this study was to describe the spatial variability of concentrations of the isotopes deuterium (2H) and oxygen‑18 (18O) in the snow cover