СТРУКТУРА, ФАЗОВЫЙ СОСТАВ И МЕХАНИЧЕСКИЕ СВОЙСТВА КРИСТАЛЛОВ ZrO2, ЧАСТИЧНО СТАБИЛИЗИРОВАННЫХ Y2O3

The structure of PSZ crystals has been studied as a function of the content of the stabilizing impurity (Y2O3) by X–ray diffraction, transmission electron microscopy (TEM) and atomic−force microscope (AFM). The hardness and fracture toughness have been measured by microindentation. The study has shown that PSZ crystals obtained by directional solidification of the melt consist of two tetragonal phases (t and t’) with varying degrees of tetragonality. Increasing the stabilizing impurity concentration leads to an increase in the volume fraction of the “untransformable” t’ phase. Experiments have shown that an increase in the concentration of the stabilizing impurity leads to a growth in the amount of positively charged oxygen vacancies (the F++–centers) which increase the lattice parameter and stabilize the structure. The character of the twinned structure changes depending on the concentration of the stabilizing impurity. In PSZ crystals with Y2O3 concentration from 2.8 to 3.2 mol. % twins first, second and third orders as well as large twins consist of smaller twin domains are observed. At high concentrations of stabilizing impurities (3.7—4.0 mol. %) the twin structure becomes smaller and more uniform. This suggests that twinning occurs simultaneously and is localized within small volumes. The character of the twinned structure changes depending on the concentration of the stabilizing impurity. This work shows that the quantity of hardening (fracture toughness) is proportional to the content of the transformable t phase.Методами рентгеновской дифрактометрии, атомно-силовой и просвечивающей электронной микроскопии исследована структура кристаллов частично стабилизированного ZrO2 (ЧСЦ) в зависимости от содержания стабилизирующей примеси (Y2O3). Проведены измерения твердости и трещиностойкости методом микроиндентирования. Установлено, что кристаллы ЧСЦ, полученные направленной кристаллизацией расплава, характеризуются наличием двух тетрагональных фаз (t и t’), различающихся степенью тетрагональности. Причем увеличение концентрации Y2O3 в кристаллах приводит к увеличению содержания нетрансформируемой t'-фазы. Экспериментально показано, что рост концентрации стабилизирующей примеси приводит к увеличению количества кислородных положительно заряженных вакансий, (F++-центров), которые увеличивают параметр решетки и стабилизируют структуру. Обнаружено, что повышение концентрации Y2O3 влияет на вид и дисперсность двойниковых доменов. В кристаллах ЧСЦ с концентрацией Y2O3 от 2,8 до 3,2 % (мол.) выявлены двойники первого, второго, третьего порядков, в свою очередь, каждый из двойников содержит внутри двойники следующего порядка. При больших концентрациях стабилизирующей примеси (3,7—4,0 % (мол.)) двойниковая структура становится более мелкой и однородной, двойникование идет одновременно и локализуется в малых объемах. Показано, что величина упрочнения (трещиностойкость) пропорциональна содержанию трансформируемой t-фазы

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

Research achievements in plant resistance to insect pests of cool season food legumes

Plant resistance to at least 17 field and storage insect pests of cool season food legumes has been identified. For the most part, this resistance was located in the primary gene pools of grain legumes via conventional laboratory, greenhouse, and field screening methods. The use of analytical techniques (i.e., capillary gas chromatography) to characterize plant chemicals that mediate the host selection behavior of pest insects offers promise as a new, more rapid way to differentiate between insect-resistant and susceptible plant material. Examples of research achievements in mechanisms of resistance and host-plant resistance within the context of integrated control programs are discussed. Accelerating the development and subsequent releases of insect-resistant cultivars to pulse farmers requires more involvement from interdisciplinary teams of plant breeders, entomologists, plant pathologists, plant chemists, molecular biologists, and other scientist

ANTIHYPERTENSIVE AND VASOPROTECTIVE EFFECTS OF FOSINOPRILE IN PATIENTS WITH ARTERIAL HYPERTENSION

Objective: evaluate antihypertensive and vasoprotective effects of fosinopril in patients with arterial hypertension with a high and very high risk of cardiovascular complications. Material and methods. The open study included 26 Grade 2 hypertensive patients with high and very high cardiovascular risk. Among them were 13 (50%) women, 13 (50%) men, the average age of which was 58.1 ± 10.3 years. Initially, all patients received hydrochlorothiazide diuretic therapy at a dose of 12.5 mg per day and various ACE inhibitors, but target blood pressure levels were not achieved. Fosinopril, an angiotensin converting enzyme (ACE) inhibitor (Monopril, VALEANT LLC, Russia), was administered to correct blood pressure for all patients instead of ACE inhibitors which they received earlier. The patients underwent a complete clinical and instrumental examination. The emphasis was placed on the study of the endothelial function by instrumental and laboratory methods. A test with endothelium-dependent vasodilatation (EDVD) was performed using method D. Celermajer; the total concentration of nitrate- and nitrite ions (NO2, NO3) in the blood serum was determined by the colorimetric method. The results of the examination were compared before administration of the drug and after 4 weeks of treatment. Results. 22 patients (85%) could achieve the target level of blood pressure (less than 140/90 mm Hg) after 8 weeks of fosinopril treatment. Daily monitoring of blood pressure showed a significant decrease in the variability of both systolic (SBP) and diastolic blood pressure (DBP). Initially, the dilatation reaction of the brachial artery was reduced in all patients and averaged to 6.8 ± 1.9%. The level of NO2 was 18.1 ± 0.9 μmol/l, NO3 – 28.8 ± 0.3 μmol/l. After 4 weeks of treatment, the EDVD increased to 7.5 ± 2.9%. The level of NO2 was 19.3 ± 0.4 μmol/l, NO3 – 38.75 ± 0.54 μmol/l. Conclusion. Fosinopril, an ACE inhibitor, had a pronounced antihypertensive effect, and improved endothelial function in patients with hypertension with a high and very high risk of cardiovascular complications after 4 weeks of treatment

THE PROPANORM EFFICACY IN RAPID RELIEF OF SYMPTOMS OF PAROXYSMAL AURICULAR FIBRILLATION

In aim to study efficacy and safety of propafenone (Propanorm), open prospective поп randomized study in-patients with paroxysmal form of auricular fibrillation (AF) was carried out. 31 patients - 16 men (51,6 % ) and 15 women (48,4 % ) with mean age 58, 1± 8 years were included in the study. The paroxysmal form AF was observed in 29 patients (93,5 % ), persistent form - in 2 patients (6,5 % ). The reason of arrhythmia in 21 patients (67,7 % ) was ischemic heart disease, in 12 patients (38,7 % >) - arterial hypertension, in 2 patients (6,4 % ) - rheumatic heart diseases, in 1 patient (3,2 % ) - idiopathic AF. The medication for rapid relief of symptoms of paroxysmal auricular fibrillation was administered in single stress dose 600 mg per os. Propanorm restored the rhythm in 74,2 % > patients. The disorder of intraventricular conduction on EKG became evi-dentin 7 patients (22,5 % ) in time from 2to 16. 5 hours (on average 5, 1 hour), atrioventricular heart block of I stage - in 2 patients (6,45 % ), aberrant ventricular complex - in 2 patients (6,45 % ), pacemaker migration and sinus bradycardia - in 1 patient (3,2 % ). This disorders eliminated independently without special intervention. Extracardiac side effects during single intake were not observed. Propafenone appeared to be high-performed antiarrhythmic medication in rapid relief of symptoms of paroxysmal auricular fibrillation. Its application is possible in the outpatient setting

EFFICACY AND SAFETY OF ALBAREL IN PATIENTS WITH MILD, MODERATE AND SEVERE HYPERTENSION

The aim of the study was to evaluate the efficacy and safety (influence on carbohydrate, lipid and mineral metabolism, as well as nitrogen-excreting function of kidneys) of monotherapy with rilmenidine in patients with mild to moderate AH, as well as treatment of patients with severe AH as multiple combined treatment. 43 patients with essential AH I-HI degree, aged 22 to 79, were enrolled in this open label study after signing an informed consent form. Enrolled patients were divided into 2 groups. Group 1 included 20 outpatients. They received monotherapy with rilmenidine 1 mg daily. Duration of treatment was 12 weeks. Group 2 was comprised of 23 subjects admitted to an in-patient clinic. Those subjects received Albarel 1 mg or 2 mg daily as a component of multiple antihypertensive therapy. Albarel was administered 7-10 days following the admission to clinic as a second to fifth hypotensive drug. Albarel's combinations with diuretics, ACE inhibitors, calcium antagonists, beta-blockers. The result is - monotherapy with Albarel 1-2 mg daily allows to achieve target BP in 77, 8 % patients with mild to moderate AH. With Albarel as a component of multiple therapy target BP is achieved in 65, 2 % patients with severe AH. Effectively decreasing BP Albarel does not change its daily profile. It has no influence on renal function, carbohydrate metabolism, and electrolyte content of blood. Albarel is well tolerated. Adverse effects included mouth dryness and drowsiness, was noted in 2, 33 % cases and did not require drug withdrawal

Structure, phase composition and mechanical properties of ZrO2 partially stabilized with Y2O3

The structure of PSZ crystals has been studied as a function of the content of the stabilizing impurity (Y2O3) by X-ray diffraction, transmission electron microscopy (TEM) and atomic-force microscope (AFM). The hardness and fracture toughness have been measured by microindentation. The study has shown that PSZ crystals obtained by directional solidification of the melt consist of two tetragonal phases (t and t′) with varying degrees of tetragonality. Increasing the stabilizing impurity concentration leads to an increase in the volume fraction of the “untransformable” t′ phase. Experiments have shown that an increase in the concentration of the stabilizing impurity leads to a growth in the amount of positively charged oxygen vacancies (the F++-centers) which increase the lattice parameter and stabilize the structure. The character of the twinned structure changes depending on the concentration of the stabilizing impurity. In PSZ crystals with Y2O3 concentration from 2.8 to 3.2 mol% twins first, second and third orders as well as large twins consist of smaller twin domains are observed. At high concentrations of stabilizing impurities (3.7–4.0 mol%) the twin structure becomes smaller and more uniform. This suggests that twinning occurs simultaneously and is localized within small volumes. The character of the twinned structure changes depending on the concentration of the stabilizing impurity. This work shows that the quantity of hardening (fracture toughness) is proportional to the content of the transformable t phase

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