Ранние изменения клинико-лабораторных показателей у пациентов, умерших от COVID-19

261,435,768 COVID-19 infections were detected worldwide, of them 5,207,634 deaths were registered. Identifying markers of the patient severity early in the course of the disease can facilitate the assessment of the risk of adverse outcome.The objective: To compare values of laboratory parameters and their changes during treatment of patients with a complicated course of COVID-19 infection.Subjects and Methods. 56 patients were included in the study, all of them were hospitalized to COVID Hospital of the Clinic of Bashkir State Medical University, Russian Ministry of Health, from September 30, 2021 to November 15, 2021, and their complicated course of the disease necessitated transfer to the intensive care unit (ICU). The laboratory evaluation included the following: a general blood and urine counts, blood chemistry including urea and creatinine, liver transaminases, and blood coagulogram (prothrombin time (PTT), prothrombin index (PTI), thrombin time, fibrinogen, and blood clotting time).Results. In the group of patients with a fatal outcome on the day of transfer to ICU, lymphocytopenia, eosinopenia, elevated values of creatinine, total bilirubin, transaminases, C-reactive protein, D-dimer, and ferritin were noted. Also on this day, microscopic hematuria, proteinuria and cylindruria were detected in the urine tests of most patients in this group during treatment.Conclusion. Critical deviations in the results of hematological and biochemical tests were revealed. Particular attention should be paid to such parameters as the level of erythrocytes, lymphocytes, eosinophils, glucose, urea, creatinine, total bilirubin, aspartate aminotransferase, alanine aminotransferase, creatine kinase, C-reactive protein, D-dimer, and ferritin.По данным на 01.12.2021 г., во всем мире выявлено 261 435 768 заболевших COVID-19, из которых 5 207 634 умерли. Выявление маркеров тяжести состояния пациентов на ранних сроках заболевания может облегчить оценку риска неблагоприятного исхода.Цель: сравнить значения лабораторных показателей и их динамику в процессе лечения пациентов с осложненным течением COVID-19.Материал и методы: в исследовании приняли участие 56 пациентов, госпитализированных в ковид-госпиталь клиники ФГБОУ ВО «БГМУ» Минздрава России с 30.09.2021 г. по 15.11.2021 г., осложненное течение заболевания которых вызвало необходимость перевода в отделение реанимации и интенсивной терапии (ОРИТ). Объем лабораторного обследования: общий анализ крови и мочи, биохимический анализ крови с определением уровней мочевины и креатинина, печеночных трансаминаз, коагулограмма крови (протромбиновое время, протромбиновый индекс, тромбиновое время, фибриноген, время свертывания крови).Результаты. В группе пациентов с летальным исходом в день перевода в ОРИТ отмечены лимфоцитопения, эозинопения, повышенные значения креатинина, общего билирубина, трансаминаз, С-реактивного белка, D-димера и ферритина. Также в этот день в анализах мочи у большинства пациентов данной группы в ходе лечения были обнаружены микроскопическая гематурия, протеинурия и цилиндрурия.Заключение. Выявлены критические отклонения в результатах гематологических, биохимических анализов. Особое внимание должно быть уделено таким показателям, как уровень эритроцитов, лимфоцитов, эозинофилов, глюкозы, мочевины, креатинина, общего билирубина, аспартатаминотрансферазы, аланинаминотрансферазы, креатинкиназы, С-реактивного белка, D-димера, ферритина

Comparing the Effect of Nanoclays on the Water-resistance of Intumescent Fire-retardant Coatings

This paper reports a study into the effect of nanoclays on the water-resistance of the intumescent system ammonium polyphosphate/melamine/pentaerythritol/titanium dioxide/polymer (ethylene vinyl acetate (EVA) or styrene acrylate (SA). It has been established that adding nanoclay to a coating based on ethylene vinyl acetate increases the fire resistance limit of a metal plate by 30 %, and to a coating based on styrene acrylate – by 50 %. At the same time, coatings that include the EVA polymer are characterized by greater fire-retardant efficiency and less water resistance than coatings containing the SA polymer. It has been shown that intumescent coatings, regardless of the nature of the polymer, under the conditions of 80 % humidity over 800 days their reduce fire-protective properties by an average of 10 %. The loss of coating fire resistance occurs due to the leaching of pentaerythritol, ammonium polyphosphate, and polymer degradation by hydrolysis. The admixtures of nanoclays with a high degree of exfoliation to the studied system create a barrier effect and maximize the chemical formulation of the intumescent coating. The fireproof properties of coatings with organically-modified montmorillonite admixtures are maintained or reduced to 5 % under the conditions of 80 % humidity over 800 days. It has been determined that the direct effect of water on the coating over a period of more than 2 days leads to a significant decrease in the swelling coefficient of intumescent coatings, regardless of the content of a nanoclay admixture in their composition. At the same time, the half-decay period of coatings without nanoclay, calculated on the basis of solubility constant in water, is 0.5 days. For coatings, which include the admixtures of organically-modified nanoclays, the half-decay period increases to 2 days. The results reported in this paper could be recommended for designing water-proof fire-resistant reactive-type nano-coatings with prolonged service life

Comparison of Fire Resistance of Polymers in Intumescent Coatings for Steel Structures

Thermal destruction of fire-retardant intumescent coating of the composition of ammonium polyphosphate (APP)/melamine (MA)/pentaerythrite (PE)/titanium oxide (TiO2)/polymer, which can be applied for fire protection of steel structures, was studied. The influence of polymers of different nature – ethylene-vinyl acetate (EVA), vinyl acetate versatate (VAVV), styrene acrylates, and vinyl toluene acrylate on the processes of formation of a coke layer and fire-retardant effectiveness of appropriate coatings was determined.Chemical transformations of polymers EVA and styrene acrylate in the intumescent system of ARR/MA/PE/TiO2 in the temperature range of 200–800 °С were studied. It was established that the processes of the thermal destruction of vinyl acetate polymer are more harmonized with chemical reactions of the components of the intumescent system than similar processes for acrylate aromatic polymers.Thermal-oxidation destruction of intumescent compositions at the temperatures of 200–800 °С was explored. It was shown that basic chemical processes with polymers of EVA and VAVV begin after 300 °С and flow in the temperature range of 350–600 °С. It was found that the noticeable degradation of the carbon-phosphorus frame of intumescent compositions with styrene acrylate polymers begins at 450 °С, which is almost by 150 °С below the temperature of degradation of the compositions containing vinyl acetate binders.The conducted fire tests demonstrate that intumescent compositions with the use of acrylate aromatic polymers are more effective at the low coating thickness in ensuring the fire resistance boundary of 30 min. In order to ensure higher values of fire resistance, it is necessary to use intumescent coatings containing vinyl acetate co-polymers as the polymer component.The study of the impact of polymers of intumescent coatings on the boundary of fire resistance of steel structures has scientific and practical significance for the development of differentiated fire protection means, oriented to the given class of fire resistance. Fire-retardant intumescent compositions examined in this study can be used as the basis for the formulations of materials for fire protection of building structures under conditions of a standard fir