48 research outputs found

    Heat transfer during nonlinear oscillations of gas in a half-open tube

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    We present results of a study of heat transfer during nonlinear oscillations of a gas in a half-open tube. © 1983 Plenum Publishing Corporation

    Thermoacoustic effect in a resonant semiopen tube

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    Results are given of a theoretical and experimental study of the effect of heating the walls of a semiopen tube under conditions of acoustic resonance. © 1983 Plenum Publishing Corporation

    Features of morphological and ultrastructural organization of the cornea (literature review)

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    The human cornea – the anterior fibrous membrane of the eye, is a unique ordered optical-biological system that is avascular, saturated with nerve endings, includes tissue-specific cells, consists mainly of various types of collagen. An exceptional feature of the collagen layers of the cornea, including the collagen plates of the stroma, is transparency, which provides physiological refraction and light transmission due to the stable supporting properties of the cornea. The data on the morphological structure of the cornea, which is an important element of the optical system of the eye, are of considerable interest not only from theoretical, but also from practical positions. This is due to the fact that the identification of the first signs of deviation from normal physiological morphological and ultrastructural criteria in the cornea allows us to establish the nature of its pathological changes, which can be caused by both hereditary predisposition and local and general disorders. It has been shown that the thinning of the layers of the cornea, a decrease in the density of endotheliocytes or keratocytes signal the development of dystrophic processes in it. In addition to evaluating quantitative morphometric data, changes in qualitative ultrastructural indicators play an important role. In particular it was found that a decrease in the density of endothelial cells is accompanied by an increase in their size and a decrease in the cell nucleus. In addition, a number of degenerative pathological conditions are characterized by a decrease in the diameter of collagen fibrils and a change in the density of fibrillary packaging.This literature review presents basic information, features of morphology, ultrastructural organization and functional purpose of layers and cells of the human cornea

    Draft of Russian Clinical Practice Guidelines «Male hypogonadism»

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    Hypogonadism in males, defined as a decrease in serum testosterone levels in combination with characteristic symptoms and/or signs, can be observed with pathological changes in the testicles and/or pituitary gland, such as Klinefelter’s syndrome, Kallman’s syndrome, as well as in men with metabolic (obesity, diabetes mellitus) or iatrogenic disorders leading to a decrease in androgen production. The draft guidelines cover the extensive range of pathologies that cause hypogonadism development (testosterone deficiency) and focus on its clinical variants, which make up the majority of cases of hypogonadism observed in men. The authors and reviewers are an interdisciplinary group of experts, consisting of endocrinologists, andrologists, urologists - members of the «Russian Association of Endocrinologists» and «Men’s and Reproductive Health» public organizations.Clinical guidelines contain the most reliable evidence available to experts at the time of writing. Nevertheless, recommendations cannot replace clinical experience, and deciding on the start of treatment, choosing a method of therapy, or a drug should always consider the individual characteristics of a specific patient

    The advisory board resolution on the use of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists in type 2 diabetes

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    Type 2 diabetes is characterized by increasing incidence and prevalence all-over the world. Current therapeutic management of type 2 diabetes is complex and is based not only on glycemic control, but also on cardiovascular and renal risks reduction. In previous years the use of sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RA) increased in Russian Federation. Some manufacturers of the most widely used GLP-1 RA reported the supply decline in several countries. On Advisory board with participation of the Russian Endocrinology Association members the topics of SGLT2i and GLP-1 RA use in type 2 diabetes were discussed. The experts made conclusion that the decrease in access to GLP-1 RA does not pose serious risk for treatment of type 2 diabetes patients. SGLT2i show benefits in risk reduction of HF and CKD progression compering to GLP-1 RA, and in general show comparable efficacy in risk reduction of ACVD outcomes.  SGLT2i show less glycemic efficacy in comparison with GLP-1 RA, and their replacement may need adding antidiabetic agents from other groups

    Empagliflozin in patients hospitalized for acute decompensated heart failure: an expert resolution on the discussion of the EMPULSE trial

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    An online expert meeting held on November 17, 2021 reviewed the results of the randomized, double-blind, multinational, parallel-group EMPULSE trial, evaluating the clinical benefit and safety of the sodium-glucose co-transporter-2 inhibitor (SGLT2i) empagliflozin compared with placebo in patients hospitalized with acute decompensated heart failure (ADHF). Patients were included in the study regardless of ejection fraction (EF) and the presence of diabetes and randomized during hospitalization after stabilization. In addition, the EMPULSE trial used a composite result analyzed using a stratified benefit ratio — Win Ratio analysis. There is evidence of clinical benefit of empagliflozin in hospitalized patients with preserved and reduced LVEF, as well as in patients with newly diagnosed ADHF or with acute decompensation of chronic heart failure (CHF) compared with placebo, regardless of type 2 diabetes presence. The importance of the favorable results of the EMPULSE trial and its significance for clinical practice, which implies the early administration of empagliflozin for inpatients, is noted. A number of proposals have been adopted to accelerate the introduction of empagliflozin into clinical practice for patients with ADHF

    Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

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    Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
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