A non-covalently bound redox indicator for electrochemical CRISPR-Cas12a and DNase I biosensors.

A rapid and accurate biosensor for detecting disease biomarkers at point-of-care is essential for early disease diagnosis and preventing pandemics. CRISPR-Cas12a is a promising recognition element for DNA biosensors due to its programmability, specificity, and deoxyribonuclease activity initiated in the presence of a biomarker. The current electrochemical CRISPR-Cas12a-based biosensors utilize the single-stranded DNA (ssDNA) self-assembled on an electrode surface and covalently modified with the redox indicator, usually methylene blue (MB).

Structure and inference in hypergraphs with node attributes.

Many networked datasets with units interacting in groups of two or more, encoded with hypergraphs, are accompanied by extra information about nodes, such as the role of an individual in a workplace. Here we show how these node attributes can be used to improve our understanding of the structure resulting from higher-order interactions. We consider the problem of community detection in hypergraphs and develop a principled model that combines higher-order interactions and node attributes to better represent the observed interactions and to detect communities more accurately than using either of these types of information alone.

Prosthetic rehabilitation of patients with maxillary oncology defects using zygomatic implants.

Purpose: Prosthetics for patients after oncological resection of the upper jaw is a complex problem associated with the physiological and anatomical separation of the oral cavity and the nasal/paranasal region. This study reports the clinical results of the use of the zygomatic implants for prosthetic rehabilitation in patients with maxillectomy due to upper jaw tumors.

Materials And Methods: The study included 16 patients who underwent prosthetic rehabilitation using a zygomatic implant after maxillectomy period from 2021 to 2023.

Investigation of the Strain-Stress Field in Nanoscale Multilayer Systems by the Phase Plane Method.

This paper presents the results of the study of stress relaxation fields, deformation, and temperature of the system of nanostructured multilayer coatings. In the work, a nonlinear relationship between strain and stress was used to take into account nonlinear effects in the mechanism of nanostructure formation. The paper assumes that a friction surface is provided by the self-organization of shear components: both stress and strain on the one hand, and temperature on the other.

A voltammetric study of nitrogenase MoFe-protein using low-potential electron transfer mediators.

The molybdenum-iron protein (MoFeP), a component of the enzyme nitrogenase, catalyzes the reduction of an array of small molecules, including N to NH. In microorganisms, during the catalytic cycle, MoFeP receives electrons from the obligate biological redox partner iron protein (FeP) in a process coupled to the hydrolysis of two MgATP per one electron transferred. Despite the favorable redox properties of the cofactors, the requirement of the MgATP hydrolysis significantly decreases the energy efficiency of MoFeP.

Structural, Magnetic, and Magneto-Optical Properties of Thin Films of BaM Hexaferrite Grown by Laser Molecular Beam Epitaxy.

Thin films of BaM hexaferrite (BaFeO) were grown on α-AlO(0001) substrates by laser molecular beam epitaxy. Structural, magnetic, and magneto-optical properties were studied using medium-energy ion scattering, energy dispersive X-ray spectroscopy, atomic force microscopy, X-ray diffraction, magneto-optical spectroscopy, and magnetometric techniques, and the dynamics of magnetization by ferromagnetic resonance method. It was shown that even a short time annealing drastically changes the structural and magnetic properties of films.

The Fe Protein Cycle Associated with Nitrogenase Catalysis Requires the Hydrolysis of Two ATP for Each Single Electron Transfer Event.

A central feature of the current understanding of dinitrogen (N) reduction by the enzyme nitrogenase is the proposed coupling of the hydrolysis of two ATP, forming two ADP and two Pi, to the transfer of one electron from the Fe protein component to the MoFe protein component, where substrates are reduced. A redox-active [4Fe-4S] cluster associated with the Fe protein is the agent of electron delivery, and it is well known to have a capacity to cycle between a one-electron-reduced [4Fe-4S] state and an oxidized [4Fe-4S] state. Recently, however, it has been shown that certain reducing agents can be used to further reduce the Fe protein [4Fe-4S] cluster to a super-reduced, all-ferrous [4Fe-4S] state that can be either diamagnetic ( = 0) or paramagnetic ( = 4).

Impact of the COVID-19 pandemic on routine immunization services in Yerevan and vaccinations against COVID-19 in Armenia.

Introduction: The coronavirus disease (COVID-19) has led to millions of deaths around the world. The indirect effects of the pandemic, include disruption of routine immunization services.

Methodology: We conducted a retrospective review to assess the impact of the pandemic on routine immunization in Yerevan and the vaccinations against COVID-19 in Armenia.

A colorimetric method to measure in vitro nitrogenase functionality for engineering nitrogen fixation.

Biological nitrogen fixation (BNF) is the reduction of N into NH in a group of prokaryotes by an extremely O-sensitive protein complex called nitrogenase. Transfer of the BNF pathway directly into plants, rather than by association with microorganisms, could generate crops that are less dependent on synthetic nitrogen fertilizers and increase agricultural productivity and sustainability. In the laboratory, nitrogenase activity is commonly determined by measuring ethylene produced from the nitrogenase-dependent reduction of acetylene (ARA) using a gas chromatograph.

[Establishment of mechanisms for the occurrence of blood imprints, taking into account their qualitative and quantitative indicators].

The purpose of the study is to establish the mechanisms for the formation of blood imprints, taking into account morphological features and some quantitative indicators of these blood traces. An analysis of the results of experimental modeling of contact marks (blood prints) resulting from the impact of a gloved hand is presented. The type of impact (shock, pressure) and duration of pressure (short-term pressure 1 - 3 sec, long-term pressure 20 - 120 sec) were determined.

Knowledge, Attitude, and Practice of Physicians Regarding Vaccinations in Yerevan, Armenia: A Case Study of HPV.

This paper highlights the low levels of vaccine coverage and high levels of reported vaccination hesitancy in Yerevan, Armenia, that present profound challenges to the control of disease through routine vaccination programmes. We draw on investigations of hesitancy towards the introduction of new vaccines, using the Human Papillomavirus (HPV) vaccine Gardasil as a case study, to interrogate underlying challenges to vaccine acceptance. We analyse primary data from the introduction of Gardasil, first used in Armenia in 2017, to investigate how levels of medical knowledge amongst physicians in 20 health facilities in Yerevan, Armenia, regarding vaccine science influence attitudes towards the introduction of a newly developed vaccine.

Introducing multi-modal enteral medication reduced morbidity and mortality associated with necrotising enterocolitis.

Aim: Necrotising enterocolitis (NEC) is still a disease with high morbidity and mortality. The aim of the study was to analyse retrospectively whether the introduction of a multi-modal three-component enteral medication regimen resulted in a change in morbidity and mortality in neonates with NEC.

Methods: When diagnosis of NEC was established, the following multi-modal three-component enteral medication regimen was administered enterally (via nasogastric tube): an antibiotic, an antifungal agent and a probiotic.

An Efficient Viologen-Based Electron Donor to Nitrogenase.

Nitrogenase catalyzes the reduction of N to NH, supporting all biological nitrogen fixation. Electron donors to this enzyme are ferredoxin or flavodoxin () and sodium dithionite (). Features of these electron donors put a limit on spectrophotometric studies and electrocatalytic applications of nitrogenase.

Mouse Parthenogenetic Embryonic Stem Cells with Biparental-Like Expression of Imprinted Genes Generate Cortical-Like Neurons That Integrate into the Injured Adult Cerebral Cortex.

One strategy for stem cell-based therapy of the cerebral cortex involves the generation and transplantation of functional, histocompatible cortical-like neurons from embryonic stem cells (ESCs). Diploid parthenogenetic Pg-ESCs have recently emerged as a promising source of histocompatible ESC derivatives for organ regeneration but their utility for cerebral cortex therapy is unknown. A major concern with Pg-ESCs is genomic imprinting.

[Dynamics of eeg and psychophysiological indicators of acute poisoning neurotoxicants on the stage of rehabilitation on the background of different methods of treatment].

Aim: To evaluate the dynamics of functional activity of brain structures underlying cognitive functions in patients with encephalopathy due to poisoning with neurotoxicants on the stage of rehabilitation.

Material And Methods: Fifty-six patients were examined. The main group consisted of 40 patients treated with intravenous injections with mexidol (n=10), combination of mexidol with non-pharmacological methods - mesodiencephalic modulation (MDM) (n=10), hyperbaric oxygenation (HBO) (n=10) and the combination of MDM and HBO (n=10).

Cooperative electrocatalytic alcohol oxidation with electron-proton-transfer mediators.

The electrochemical oxidation of alcohols is a major focus of energy and chemical conversion efforts, with potential applications ranging from fuel cells to biomass utilization and fine-chemical synthesis. Small-molecule electrocatalysts for processes of this type are promising targets for further development, as demonstrated by recent advances in nickel catalysts for electrochemical production and oxidation of hydrogen. Complexes with tethered amines that resemble the active site of hydrogenases have been shown both to catalyse hydrogen production (from protons and electrons) with rates far exceeding those of such enzymes and to mediate reversible electrocatalytic hydrogen production and oxidation with enzyme-like performance.

Optically Addressable Silicon Vacancy-Related Spin Centers in Rhombic Silicon Carbide with High Breakdown Characteristics and ENDOR Evidence of Their Structure.

We discovered a family of uniaxially oriented silicon vacancy-related centers with S=3/2 in a rhombic 15R-SiC crystalline matrix. We demonstrate that these centers exhibit unique characteristics such as optical spin alignment up to the temperatures of 250°C. Thus, the range of robust optically addressable vacancy-related spin centers is extended to the wide class of rhombic SiC polytypes.

Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA.

Biosensors for the detection of benzaldehyde and γ-aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below -0.15 V (vs.

Dendritic polyglycerol-poly(ethylene glycol)-based polymer networks for biosensing application.

This work describes the formation of a new dendritic polyglycerol-poly(ethylene glycol)-based 3D polymer network as a matrix for immobilization of the redox enzyme periplasmatic aldehyde oxidoreductase to create an electrochemical biosensor. The novel network is built directly on the gold surface, where it simultaneously stabilizes the enzyme for up to 4 days. The prepared biosensors can be used for amperometric detection of benzaldehyde in the range of 0.

Size exclusion deep bed filtration: experimental and modelling uncertainties.

A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions.

Critical analysis of uncertainties during particle filtration.

Using the law of propagation of uncertainties we show how equipment- and measurement-related uncertainties contribute to the overall combined standard uncertainties (CSU) in filter permeability and in modelling the results for polystyrene latex microspheres filtration through a borosilicate glass filter at various injection velocities. Standard uncertainties in dynamic viscosity and volumetric flowrate of microspheres suspension have the greatest influence on the overall CSU in filter permeability which excellently agrees with results obtained from Monte Carlo simulations. Two model parameters "maximum critical retention concentration" and "minimum injection velocity" and their uncertainties were calculated by fitting two quadratic mathematical models to the experimental data using a weighted least squares approximation.

Statistical description of the collective motion of nanoparticles.

A synergetic model allowing the description of a Brownian motion of active nanoparticles within the framework of the Lorenz three-parameter system is developed. The fluctuation's influence on the transition between different motion regimes is investigated. A diagram of possible motion modes of an active nanoparticle group and the corresponding stationary values of velocity are analyzed.

Enzyme electrode for aromatic compounds exploiting the catalytic activities of microperoxidase-11.

Microperoxidase-11 (MP-11) which has been immobilised in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode catalyzes the conversion of aromatic substances. This peroxide-dependent catalysis of microperoxidase has been applied in an enzyme electrode for the first time to indicate aromatic compounds such as aniline, 4-fluoroaniline, catechol and p-aminophenol. The electrode signal is generated by the cathodic reduction of the quinone or quinoneimine which is formed in the presence of both MP-11 and peroxide from the substrate.

Recombination processes in systems based on doped ionic crystals with impurity-related nanostructures.

Recombination processes leading to the tunnelling afterglow and photostimulated luminescence in systems based on host ionic crystals with impurity-related nanostructures-promising phosphors for x-ray storage-were studied by means of luminescence, EPR and optically detected magnetic resonance. It was found that in the x-ray irradiated CsBr:Eu and CsBr:Pb crystals the energy released in the spin-dependent tunnelling recombination of electron-hole pairs and self-trapped excitons in the host crystal is directionally transferred to the impurity-related low-dimensional structures. To identify the origin of recombining electron and hole centres, their EPR spectra were detected by monitoring the tunnelling afterglow and the photostimulated luminescence including the emission bands of the low-dimensional structures.