Solid-state synthesis and characterization of ferromagnetic Mn5Ge3 nanoclusters in GeO/Mn thin films

Mn5Ge3 films are promising materials for spintronic applications due to their high spin polarization and a Curie temperature above room temperature. However, non-magnetic elements such as oxygen, carbon and nitrogen may unpredictably change the structural and magnetic properties of Mn5Ge3 films. Here, we use the solid-state reaction between Mn and GeO thin films to describe the synthesis and the structural and magnetic characterization of Mn5Ge3(Mn5Ge3Oy)-GeO2(GeOx) nanocomposite materials. Our results show that the synthesis of these nanocomposites starts at 180°С when the GeO decomposes into elemental germanium and oxygen and the resulting Ge atoms immediately migrate into the Mn layer to form ferromagnetic Mn5Ge3 nanoclusters. At the same time the oxygen atoms take part in the synthesis of GeOx and GeO2 oxides and also migrate into the Mn5Ge3 lattice to form Mn5Ge3Oy Nowotny nanoclusters. Magnetic analysis assumes the general nature of the Curie temperature increase in carbon-doped Mn5Ge3Cx and Mn5Ge3Oy films. Our findings prove that not only carbon, but oxygen may contribute to the increase of the saturation magnetization and Curie temperature of Mn5Ge3-based nanostructures

Modern trends in diagnostics and prediction of results of anti-vascular endothelial growth factor therapy of pigment epithelial detachment in neovascular agerelated macular degeneration using deep machine learning method (literature review)

Detachment of the pigment epithelium is the separation of the basement membrane of the retinal pigment epithelium from the inner collagen layer of Bruch’s membrane, which occurs in 80 % of cases in patients with neovascular age-related macular degeneration. The outcome of anti-VEGF therapy for pigment epithelial detachment may be adherence of the pigment epithelium, the formation of pigment epithelium tear, or preservation of the detachment. The pigment epithelium tear of 3–4th degrees can lead to a sharp decrease in visual acuity.Most retrospective studies confi rm the absence of a proven correlation between anatomical and functional outcomes in the treatment of pigment epithelial detachment in cases of maintaining the integrity of the pigment epithelium monolayer, and therefore the main attention of researchers is focused on studying the morphological features of pigment epithelial detachment during therapy with angiogenesis inhibitors. Modern technologies of spectral optical coherence tomography make it possible to evaluate detailed quantitative parameters of pigment epithelium detachment, such as height, width, maximum linear diameter, area, volume and refl ectivity within the detachment.Groups of Russian and foreign authors identify various biomarkers recorded on optical coherence tomography images. Dynamic registration of such biomarkers expands the ability of clinicians to predict morphological changes in pigment epithelial detachment during anti-VEGF therapy, as well as to optimize treatment regimens to prevent complications in the form of pigment epithelium tear leading to a decrease in visual acuity.Modern methods of deep machine learning and the use of neural networks allow achieving higher accuracy in diff erentiating the types of retinal fluids and automating the quantitative determination of fl uid under the pigment epithelium. These technologies allow achieving a high level of compliance with manual expert assessment and increasing the accuracy and speed of predicting morphological results of treatment of pigment epithelium detachments

A clinical case of central retinal artery occlusion after pneumonia caused by SARS-CoV-2 (COVID-19)

In domestic and foreign medical periodical literature, highlighting the problem of ophthalmopathology against the background of coronavirus infection, the lesion of the anterior segment of the eye is most often described. It is extremely hard to find reports about pathology of the retina, optic nerve or central parts of the visual analyzer. However, it is widely acknowledged that there is a high risk of developing coagulopathy against the background of COVID-19 infection, which leads to occlusion and thrombosis of retinal vessels, ischemic neuropathies. The problem of irreversible loss of vision due to circulatory disorders of the retinal vessels was urgent even before the wide spread of coronavirus infection due to the high prevalence of atherosclerosis, hypertension and type 1 and 2 diabetes in the population. Also, it is widely known that occlusions and thrombosis of retinal vessels can be formidable harbingers of the developing life-threatening conditions. Knowledge about the high risk of vascular ophthalmopatology against the background of a previous COVID-19 infection by the primary echelon ophthalmologists, early diagnostics and treatment of ischemic conditions of the posterior segment of the eye will reduce the frequency of irreversible vision loss due to these diseases, secondary neovascular glaucoma cases, and will also help to send patients to the multidisciplinary hospitals in a timely manner for the prevention of fatal complications of coagulopathy. The article provides a brief overview of foreign literary sources regarding the history of outbreaks of coronavirus infection in the world, as well as possible ways of damage to the organ of vision by the coronavirus. A clinical case of damage to the vascular bed of the retina in both eyes due to coagulopathy against the background of pneumonia caused by COVID-19 is presented, which is actual due to the low illumination of similarly cases

The role of small intestine in pathogenesis of common variable immune deficiency

The article presents the results of examination of 32 patients with common variable immune deficiency (barn) with involvement in the pathological process of the digestive system. The features of the clinical picture, the content of immunoglobulins in the blood serum, morphological structure of the mucosa of small intestine as well as treatment. Special attention is paid to the small intestine in the pathogenesis of the barn

Damage to the Cardiovascular System in Patients with SARS-CoV-2 Coronavirus Infection. Part 1: Predictors of the Development of an Unfavorable Prognosis

Aim. To evaluate the effect of sinus tachycardia and reduced left ventricular ejection fraction (LVEF) on the prognosis of patients with a verified diagnosis of a new coronavirus infection SARS-CoV-2.Material and methods. The study included 1,637 patients with a verified diagnosis of a new coronavirus infection SARS-CoV-2. The average age of the patients was 58.8±16.1 years. More than half of the patients admitted to the hospital had a history of cardiovascular diseases: hypertension was diagnosed in 915 (56%) patients, coronary artery disease – in 563 (34%), chronic heart failure – in 410 (25%). 294 (17.9%) patients suffered from diabetes mellitus. The unfavorable course of new coronavirus infection was assessed by the fact of being in the intensive care unit (ICU), the use of mechanical ventilation and death.Results. An unfavorable course of coronavirus infection was observed in 160 (9.8%) patients. Statistical analysis revealed that 341 (20.8%) patients with COVID-19 were diagnosed with sinus tachycardia, which required the appointment of pulse-reducing therapy. The occurrence of sinus tachycardia in patients with COVID-19 significantly increased the risk of death (odds ratio [OR] 1.248, confidence interval [CI] 1.038-1.499, p=0.018), increased the likelihood of mechanical ventilation use (OR 1.451, CI 1.168-1.803, p<0.001) and stay in the ICU (OR 1.440, CI 1.166-1.778, p<0.001).In 97 (5.9%) patients during hospital stay during echocardiography, a decrease in LVEF of less than 50% was diagnosed. A decrease in myocardial contractile function in patients with COVID-19 with high reliability increased the risk of death (OR 1.744, CI 1.348-2.256, p<0.001), increased the likelihood of using the mechanical ventilation (OR 1.372, CI 1.047-1.797, p=0.022) and stay in the ICU (OR 1.360, CI 1.077-1.716, p=0.010).Conclusion. The appearance of sinus tachycardia and reduced LVEF are in dependent predictors of the unfavorable course of COVID-19 in relation to factors such as death, the use of mechanical ventilation and the stay of patients in the ICU. Early pharmacological correction of cardiovascular lesions should be one of the goals of the management theese patients

Damage to the Cardiovascular System in Patients with SARS-CoV-2 Coronavirus Infection. Part 2: Correction of Myocardial Systolic Dysfunction

Aim. To study changes in myocardial contractile function when prescribing mineralocorticoid receptor antagonists of spironolactone in patients after coronavirus infection SARS-CoV-2 with symptoms of chronic heart failure (CHF).Materials and methods. The study included 90 hospitalized patients with a diagnosis of SARS-CoV-2 coronavirus infection. The inclusion criteria were: age from 18 to 85 years; the presence of CHF with a preserved or mildly reduced left ventricular ejection fraction (LVEF). The patients were randomized into two groups: group I (n=60) included patients who, for 6 months after discharge from the hospital, in addition to standard drug therapy for CHF, took spironolactone at a dose of 25 mg per day; group II (comparison group; n=30) included patients who received standard drug therapy without additional prescription of spironolactone. The study groups were comparable in age, gender, prevalence of hypertension, coronary heart disease, diabetes mellitus, obesity and severity of CHF; the drug therapy given to the patients had no significant differences. Assessment of LV systolic function, exercise tolerance (six-minute walk test, TSW), quality of life (questionnaire EQ-5D-5L) were performed.Results. When repeated echocardiography was performed after 6 months of treatment, there was a significant improvement in LV systolic function in group I patients. In group I, after 6 months of treatment, there was a significant decrease in the proportion of patients with moderately reduced LVEF (from 30 [50%] to 12 [20%]; p<0.001), and a significant increase in the number of patients with preserved LVEF (from 30 [50%] to 48 [80%], p=0.002). In group II, the number of patients with moderately reduced LVEF did not significantly change. After 6 months of treatment, all patients showed an increase in exercise tolerance. During the test with a six-minute walk, group I patients showed an increase in the index from 316.8±63.5 to 432.9±41.3 meters; group II patients from 337.6±42.7 to 407.6±38.9 meters. The values of the six-minute walking test after 6 months of treatment were significantly higher in group I patients when compared with group II patients. When assessing the quality of life using the EQ-5D-5L questionnaire, it was found that at the time of inclusion of patients in the study, all patients noted the presence of any health problems in one or more components. The average indicator of health status, measured by a 100-point visual analog scale, after 6 months was 71.8±9.2 in patients of group I and was significantly higher than the same indicator in group II – 63.7±9.1. There were no adverse events in the study groups during the entire observation period.Conclusion. A significantly more pronounced improvement in systolic and diastolic left ventricle function, as well as quality of life, was found in the group of CHF patients with preserved or moderately reduced LVEF, who received spironolactone for 6 months after the SARS-CoV-2 infection in addition to standard therapy, compared with patients without aldosterone antagonists