220,413 results match your criteria: "Russia; S. Konukorlu Medical Center[Affiliation]"

We develop a novel key routing algorithm for quantum key distribution (QKD) networks that utilizes a distribution of keys between remote nodes, i.e., not directly connected by a QKD link, through multiple non-overlapping paths.

View Article and Find Full Text PDF

While there are many works on the applications of machine learning, not so many of them are trying to understand the theoretical justifications to explain their efficiency. In this work, overfitting control (or generalization property) in machine learning is explained using analogies from physics and biology. For stochastic gradient Langevin dynamics, we show that the Eyring formula of kinetic theory allows to control overfitting in the algorithmic stability approach-when wide minima of the risk function with low free energy correspond to low overfitting.

View Article and Find Full Text PDF

Entropy as a Tool for the Analysis of Stock Market Efficiency During Periods of Crisis.

Entropy (Basel)

December 2024

Department of Corporate Finance and Public Finance, Faculty of Economics and Finance, Wroclaw University of Economics and Business, 53-345 Wroclaw, Poland.

In the article, we analyse the problem of the efficiency market hypothesis using entropy in moments of transition from a normal economic situation to crises or slowdowns in European, Asian and US stock markets and the economy in the years 2007-2023 (2008-2009, U.S. financial sector crises; 2020-2021, Pandemic period; and the 2022-2023 period of Russia's attack on Ukraine).

View Article and Find Full Text PDF

Carbapenem-resistant (CRE) are a global health threat due to their high morbidity and mortality rates and limited treatment options. This study examines the plasmid-mediated transmission of virulence and antibiotic resistance determinants in carbapenem-resistant () and () isolated from Russian hospitals. : We performed short- and long-read whole-genome sequencing of 53 clinical isolates (48 and 5 ) attributed to 15 genetic lineages and collected from 21 hospitals across nine Russian cities between 2016 and 2022.

View Article and Find Full Text PDF

Aminoglycosides are one of the first classes of natural antibiotics which have not lost relevance due to their broad spectrum of action against Gram-positive, Gram-negative bacteria and mycobacteria. The high growth rate of antimicrobial resistance (AMR) together with the severe side effects of aminoglycosides increase the importance of developing improved semisynthetic derivatives. In this work, we proposed a synthetic route to new tobramycin derivatives modified at the 6″-position with aminoalkylamine or guanidinoalkylamine residues.

View Article and Find Full Text PDF

: In 2022, the World Health Organization highlighted the necessity for the development of new antifungal agents. Polyene antibiotics are characterized by a low risk of drug resistance; however, their use is limited by low solubility and severe side effects. : A series of -alkylated derivatives of amphotericin B and nystatin A as well as their -(2-hydroxyethyl)amides were synthesized.

View Article and Find Full Text PDF

Irumamycin (Iru) is a complex polyketide with pronounced antifungal activity produced by a type I polyketide (PKS) synthase. Iru features a unique hemiketal ring and an epoxide group, making its biosynthesis and the structural diversity of related compounds particularly intriguing. In this study, we performed a detailed analysis of the biosynthetic gene cluster (BGC) to uncover the mechanisms underlying Iru formation.

View Article and Find Full Text PDF

: Empirical antibacterial therapy for febrile neutropenia reduces mortality due to Gram-negative blood stream infections (BSIs). Pediatric guidelines recommend monotherapy with an antipseudomonal beta-lactam or a carbapenem and to add a second anti-Gram-negative agent in selected situations. We evaluated the changes in the proportions of resistance of beta-lactam monotherapies vs.

View Article and Find Full Text PDF

Consortium of 2029 and 7247 Strains Shows In Vitro Bactericidal Effect on and, in Combination with Prebiotic, Protects Against Intestinal Barrier Dysfunction.

Antibiotics (Basel)

November 2024

Department of Biomolecular Sciences, School of Life Sciences, Chemistry and Pharmacy, Faculty of Health, Science, Social Care and Education, Kingston University London, Kingston upon Thames KT1 2EE, UK.

(CJ) is the etiological agent of the world's most common intestinal infectious food-borne disease, ranging from mild symptoms to fatal outcomes. The development of innovative synbiotics that inhibit the adhesion and reproduction of multidrug-resistant (MDR) CJ in animals and humans, thereby preserving intestinal homeostasis, is relevant. We have created a synbiotic based on the consortium of 2029 (LC2029), 7247 (LS7247), and a mannan-rich prebiotic (Actigen).

View Article and Find Full Text PDF

Background/objectives: Due to a narrow therapeutic window, side-effects, toxicities, and individual pharmacokinetics (PK) variability, WHO classifies vancomycin (VCM) as a "watch antibiotic" whose use should be monitored to improve clinical effectiveness. Availability and ease of use have made the immunoassay technique the basic tool for the therapeutic drug monitoring (TDM) of VCM concentrations.

Methods: The present study describes the development of a TDM tool for VCM based on anti-eremomycin (ERM) antibody enzyme-linked immunosorbent assay (ELISA).

View Article and Find Full Text PDF

Gut Microbiota Modulation: A Novel Strategy for Rheumatoid Arthritis Therapy.

Biomolecules

December 2024

Laboratory of Biomedical Technologies, Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russia.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that leads to joint inflammation, progressive tissue damage and significant disability, severely impacting patients' quality of life. While the exact mechanisms underlying RA remain elusive, growing evidence suggests a strong link between intestinal microbiota dysbiosis and the disease's development and progression. Differences in microbial composition between healthy individuals and RA patients point to the role of gut microbiota in modulating immune responses and promoting inflammation.

View Article and Find Full Text PDF

Gramicidin A in Asymmetric Lipid Membranes.

Biomolecules

December 2024

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31/4 Leninskiy Prospekt, 119071 Moscow, Russia.

Gramicidin A is a natural antimicrobial peptide produced by . Its transmembrane dimer is a cation-selective ion channel. The channel is characterized by the average lifetime of the conducting state and the monomer-dimer equilibrium constant.

View Article and Find Full Text PDF

Core-Shell PLGA Nanoparticles: In Vitro Evaluation of System Integrity.

Biomolecules

December 2024

Faculty of Chemical and Pharmaceutical Technologies and Biomedical Preparations, D. Mendeleev University of Chemical Technology of Russia, Miusskaya pl. 9, Moscow 125047, Russia.

The objective of this study was to compare the properties of core-shell nanoparticles with a PLGA core and shells composed of different types of polymers, focusing on their structural integrity. The core PLGA nanoparticles were prepared either through a high-pressure homogenization-solvent evaporation technique or nanoprecipitation, using poloxamer 188 (P188), a copolymer of divinyl ether with maleic anhydride (DIVEMA), and human serum albumin (HSA) as the shell-forming polymers. The shells were formed through adsorption, interfacial embedding, or conjugation.

View Article and Find Full Text PDF

The first monomeric pyridoxal-5'-phosphate (PLP)-dependent transaminase from a marine, aromatic-compound-degrading, sulfate-reducing bacterium Tol2, has been studied using structural, kinetic, and spectral methods. The monomeric organization of the transaminase was confirmed by both gel filtration and crystallography. The PLP-dependent transaminase is of the fold type IV and deaminates D-alanine and ()-phenylethylamine in half-reactions.

View Article and Find Full Text PDF

This study describes the applicability of the fluorescence polarization assay (FPA) based on the use of FITC-labeled oligosaccharide tracers of defined structure for the measurement of active lysozyme in hen egg white. Depending on the oligosaccharide chain length of the tracer, this method detects both the formation of the enzyme-to-tracer complex (because of lectin-like, i.e.

View Article and Find Full Text PDF

Diversity of Endolysin Domain Architectures in Bacteriophages Infecting Bacilli.

Biomolecules

December 2024

Laboratory of Bacteriophage Biology, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Federal Research Center, Prospect Nauki, 5, 142290 Pushchino, Russia.

The increasing number of antibiotic-resistant bacterial pathogens is a serious problem in medicine. Endolysins are bacteriolytic enzymes of bacteriophages, and a promising group of enzymes with antibacterial properties. Endolysins of bacteriophages infecting Gram-positive bacteria have a modular domain organization.

View Article and Find Full Text PDF

Amoebozoa is a group of single-celled organisms that change their shape during locomotion. However, there is a taxon-specific complex of morphological characters inherent in the moving amoebae, known as locomotive forms. Actin is one of the proteins most important for amoeboid movement that, together with actin-binding proteins, construct the architecture of the cytoskeleton in the amoeboid cells.

View Article and Find Full Text PDF

Amino acid analogues with a phosphorus-containing moiety replacing the carboxylic group are promising sources of biologically active compounds. The -phosphinic group, with hydrogen-phosphorus-carbon (H-P-C) bonds and a flattened tetrahedral configuration, is a bioisostere of the carboxylic group. Consequently, amino--phosphinic acids undergo substrate-like enzymatic transformations, leading to new biologically active metabolites.

View Article and Find Full Text PDF

Metabolomics investigates final and intermediate metabolic products in cells. Assessment of the human metabolome relies principally on the analysis of blood, urine, saliva, sweat, and feces. Tissue biopsy is employed less frequently.

View Article and Find Full Text PDF

NAD+ plays a pivotal role in energy metabolism and adaptation to external stimuli and stressful conditions. A significant reduction in intracellular NAD+ levels is associated with aging and contributes to the development of chronic cardiovascular, neurodegenerative, and metabolic diseases. It is of particular importance to maintain optimal levels of NAD+ in cells with high energy consumption, particularly in the brain.

View Article and Find Full Text PDF

The article is devoted to the creation of enzymatic nanoreactors based on polystyrene-block-poly(acrylic acid) (PS-b-PAA) copolymers containing bioscavengers capable of neutralizing toxic esters both in the body and in the environment. Block copolymers of different amphiphilicity, hydrophilicity and molecular weights were synthesized and characterized using gel permeation chromatography, NMR and UV spectroscopy. Polymeric nanocontainers in the absence and presence of human butyrylcholinesterase were made by film hydration and characterized by dynamic light scattering and microscopy methods.

View Article and Find Full Text PDF

N-glycome analysis of individual proteins and tissues is crucial for fundamental and applied biomedical research and medical diagnosis and plays an important role in the evaluation of the quality of biopharmaceutical and biotechnological products. The interest in this research area continues to grow annually, thereby increasing the demand for the high-throughput profiling of human blood plasma N-glycome. In response to this need, we have developed an optimized, simple, and rapid protocol for the N-glycome profiling of human plasma proteins.

View Article and Find Full Text PDF

Macrophages in Calcific Aortic Valve Disease: Paracrine and Juxtacrine Disease Drivers.

Biomolecules

December 2024

Laboratory of Regenerative Biomedicine, Institute of Cytology, Russian Academy of Sciences, Saint-Petersburg 194064, Russia.

A significant role in the pathogenesis of CAVD is played by innate immunity cells, such as macrophages. In stenotic valves, macrophages have enhanced inflammatory activity, and the population's balance is shifted toward pro-inflammatory ones. Pro-inflammatory macrophages release cytokines, chemokines, and microRNA, which can directly affect the resident valvular cells and cause valve calcification.

View Article and Find Full Text PDF

The review examines recent advances in the design and synthesis of 1,3-selenazole derivatives since 2000. Various synthetic approaches to 1,3-selenazoles and reaction conditions are discussed. The beneficial properties of 1,3-selenazoles, especially their biological activity, are emphasized.

View Article and Find Full Text PDF

Background/objectives: In recent years, knowledge management and digital innovation have become pivotal in transforming healthcare systems, driving efficiency and enhancing patient outcomes. This study presents a bibliometric analysis of research trends at the intersection of knowledge management and digital innovation in healthcare, examining the scope, impact, and evolution of scholarly work in this domain.

Methods: Using a comprehensive dataset from the Scopus database, we analyzed 419 publications from 1985-2023 to identify influential authors, journal collaborations, and emerging topics and methodologies in the field.

View Article and Find Full Text PDF