ОСОБЕННОСТИ ОКИСЛЕНИЯ ДИСПЕРСНОГО АЛЮМИНИЯ В УСЛОВИЯХ ВЫСОКИХ ТЕМПЕРАТУР И ДАВЛЕНИЙ

In recent times, researchers are interested in ultra and nanopowders of oxide ceramics and functional materials based on them. This article describes the results of obtaining an aluminum hydroxide powder – boehmite produced by the method of hydrothermal oxidation of aluminum. Boehmite obtained by this technology is characterized by high phase purity (according to the XRD-analysis there is well-crystallized boehmite). It is found that the hydrothermal synthesis, carried out by combustion in pre- and supercritical water, can be considered as an effective method of obtaining extra pure nanocrystalline hydroxides (boehmite) and oxides of aluminum (corrundum). In the case of realization of oxides and hydroxides of aluminum and also the technology of obtaining hydrogen and heat energy, this process can be considered to be highly profitable.В последние годы все больший интерес проявляется к исследованиям ультра- и нанодисперсных систем на основе оксидокерамических порошков и функциональных материалов на их основе. В представленной работе приводятся результаты получения порошка гидроксида алюминия – бемита, полученного по технологии гидротермального окисления, который характеризуется высокой фазовой чистотой (по данным рентгенофазного анализа присутствует хорошо закристаллизованный бемит). Установлено, что гидротермальный синтез, осуществляемый путем сжигания в до- и сверхкритических водных средах, можно рассматривать как эффективный способ получения особо чистых нанокристаллических гидроксидов (бемит) и оксидов (корунд) алюминия. При условии реализации оксидов и гидроксидов алюминия как товарных продуктов, а также технологии получения водорода и тепловой энергии, представленный процесс может относится к высокорентабельным.

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

Comparative analysis of echocardiographic and electrocardiographic data of survivors and deceased patients with COVID-19 (sub-analysis of the international register “Dynamics analysis of comorbidities in SARS-CoV-2 survivors”)

Aim. To carry out comparative analysis of echocardiographic and electrocardiographic (ECG) data of survivors and deceased patients with COVID-19 (sub-analysis of the international register “Dynamics analysis of comorbidities in SARS-CoV-2 survivors”).Material and methods. The study presents the results of a sub-analysis of the international AKTIV registry, which was called AKTIV CARDIO. Data were collected from 9 medical centers in the Russian Federation. AKTIV CARDIO included 973 hospitalized patients, of which 50 patients died during hospitalization.Results. Comparative analysis of echocardiographic parameters revealed that 4 parameters differed in deceased patients compared to survivors: left ventricular ejection fraction (LVEF), right ventricular end diastolic dimension (RV EDD), right atrial (RA) short axis diameter and pulmonary artery systolic pressure (PASP). RA short axis diameter was higher in deceased patients compared with survivors (38,0 [36,0; 39,0] versus 35,0 [33,0; 38,0] mm, p=0,011). RV EDD was higher in deceased patients than in survivors (3,0 [29,0; 33,0] vs 28,0 [27,0; 32,0] mm, p=0,019). LVEF was lower in deceased patients compared with survivors (55 [52; 55] vs 60 [56; 65]%, p<0,001). PASP was higher in deceased patients compared with survivors (25 [21; 35] vs 20 [19; 25] mm Hg, p=0,006). Correlation analysis found that the largest number of correlations with markers of the infection severity was observed for RA short axis diameter and RV EDD. A comparative analysis of ECG data revealed that in deceased patients, compared with survivors, atrial fibrillation (AF) (21,4% vs 6,06%, p=0,001) and supraventricular premature beats (14,3% vs 3,36%, р=0,004) occurred more often. In addition, deceased patients had longer QTc interval (440 [416; 450] vs 400 [380; 430] ms, p<0,001).Conclusion. Comparative analysis of echocardiographic data showed that deceased patients have more pronounced right heart remodeling, higher PASP and lower LVEF. Patient survival was related to RV and RA sizes. Right heart enlargement was associated with markers of infection severity. Echocardiographic parameters characterizing the right heart side can probably be independent prognostic factors in the acute COVID-19 period

Lipid profile in hospitalized patients with COVID-19 depending on the outcome of its acute phase: data from the international registry "Dynamics analysis of comorbidities in SARS-CoV-2 infection survivors"

Aim. To study the lipid profile in hospitalized patients with coronavirus disease 2019 (COVID-19) depending on the outcome of its acute phase according to the AKTIV international registry.Material and methods. The AKTIV registry included men and women over 18 years of age with a diagnosis of COVID-19, who were treated in a hospital. A total of 9364 patients were included in the registry, of which 623 patients were analyzed for levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C) and triglycerides on days 1-2 of hospitalization. The level of high-density lipoprotein cholesterol (HDL-C) was calculated using the Friedewald equation.Results. We found that a decrease in LDL-C level was significantly associated with an unfavorable prognosis for hospitalized patients with COVID-19. This pattern persisted in both univariate and multivariate analyses. LDL-C levels in the final multivariate model had a significant relationship with the prognosis (an increase in the death risk by 1,7 times with a decrease per 1 mmol/l). In addition, we found that the survival of patients with an indicator level of <2,45 mmol/l is significantly worse than in patients with an LDL-C level ≥2,45 mmol/l. All patients with high LDL-C ((≥4,9 mmol/l) survived, while among patients with low LDL-C (<2,45 mmol/l. All patients with high LDL-C ((≥4,9 mmol/l) survived, while among patients with low LDL-C (<1,4 mmol/l), mortality was 13,04%, which was significantly higher than in patients with LDL-C ≥1,4 mmol/l (6,32%, p=0,047).Conclusion. A decrease in LDL-C in the acute period is significantly associated with an unfavorable prognosis for hospitalized patients with COVID-19. Determination of LDL-C can be included in the examination program for patients with COVID-19. However, the predictive value of this parameter requires further study in prospective clinical studies

International register “Dynamics analysis of comorbidities in SARS-CoV-2 survivors” (AKTIV) and the register “Analysis of hospitalizations of comorbid patients infected during the second wave of SARS-CoV-2 outbreak” (AKTIV 2)

The organizer of the registers “Dynamics analysis of comorbidities in SARSCoV-2 survivors” (AKTIV) and “Analysis of hospitalizations of comorbid patients infected during the second wave of SARS-CoV-2 outbreak” (AKTIV 2) is the Eurasian Association of Therapists (EAT). Currently, there are no clinical registries in the Eurasian region designed to collect and analyze information on long-term outcomes of COVID-19 survivors with comorbid conditions. The aim of the register is to assess the impact of a novel coronavirus infection on long-term course of chronic non-communicable diseases 3, 6, 12 months after recovery, as well as to obtain information on the effect of comorbidity on the severity of COVID-19. Analysis of hospitalized patients of a possible second wave is planned for register “AKTIV 2”. To achieve this goal, the register will include men and women over 18 years of age diagnosed with COVID-19 who are treated in a hospital or in outpatient basis. The register includes 25 centers in 5 federal districts of the Russian Federation, centers in the Republic of Armenia, the Republic of Kazakhstan, the Republic of Kyrgyzstan, the Republic of Belarus, the Republic of Moldova, and the Republic of Uzbekistan. The estimated capacity of the register is 5400 patients

International register “Dynamics analysis of comorbidities in SARS-CoV-2 survivors” (AKTIV SARS-CoV-2): analysis of predictors of short-term adverse outcomes in COVID-19

The international AKTIV register presents a detailed description of out- and inpatients with COVID-19 in the Eurasian region. It was found that hospitalized patients had more comorbidities. In addition, these patients were older and there were more men than among outpatients. Among the traditional risk factors, obesity and hypertension had a significant negative effect on prognosis, which was more significant for patients 60 years of age and older. Among comorbidities, CVDs had the maximum negative effect on prognosis, and this effect was more significant for patients 60 years of age and older. Among other comorbidities, type 2 and 1 diabetes, chronic kidney disease, chronic obstructive pulmonary disease, cancer and anemia had a negative impact on the prognosis. This effect was also more significant (with the exception of type 1 diabetes) for patients 60 years and older. The death risk in patients with COVID-19 depended on the severity and type of multimorbidity. Clusters of diseases typical for deceased patients were identified and their impact on prognosis was determined. The most unfavorable was a cluster of 4 diseases, including hypertension, coronary artery disease, heart failure, and diabetes mellitus. The data obtained should be taken into account when planning measures for prevention (vaccination priority groups), treatment and rehabilitation of COVID-19 survivors