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Abstract Recent studies have shown that the knowledge of society about the functioning of the brain does not correspond to neuroscience data. The high prevalence of neuromyths can become a problem in the development of educational technologies. The goal of this study is to identify the prevalence of neuromyths among pre-service teachers and students of other faculties. The prevalence of neuromyths among 958 university students was studied using an anonymous survey. It was found that the specialty influenced the results: chemistry and biology students, as well as physics, mathematics, and computer science students, answered better. The effect of education is weak. Nevertheless, it has led to an alignment of results between the specialties in the older group. Self-education has a significant positive effect on students’ recognition of neurofacts. The study confirms that certain neuromyths are especially popular among students and allows us to draw conclusions about the prevalence of neuromyths among future teachers.

Genes of the small nucleolar RNA host gene (SNHG) family may participate in oncogenesis through the regulatory functions of encoded long non-coding RNAs (lncRNAs) and by influencing formation of small nucleolar RNAs and ribosome biogenesis. The aim of this work was to evaluate changes in the methylation levels and extent of co-methylation of the SNHG family lncRNA genes (SNHG1, GAS5/SNHG2, SNHG6, SNHG12, SNHG17) in clinical samples of ovarian cancer (OC) as an indication for the similarity of their roles in oncogenesis. Analysis of a representative set of 122 OC samples by quantitative methylation-specific PCR showed a statistically significant (p < 0.01-0.0001) increase in the methylation level of all five studied lncRNA genes. There was also a correlation between the increased methylation levels of GAS5, SNHG6, and SNHG12 and OC progression (clinical stage, tumor size, and metastasis), indicating possible functional significance of hypermethylation of these genes. For four genes (SNHG1, GAS5, SNHG6, and SNHG12), a statistically significant pairwise positive correlation of methylation levels (co-methylation) was observed (rs > 0.35; p ≤ 0.001), which was in agreement with the GEPIA 2.0 data (426 OC samples) showing co-expression of these genes (rs > 0.5; p < 0.001). The correlation between the expression levels of GAS5 and SNHG6 was confirmed by RT-qPCR (rs = 0.46; p = 0.007). Bioinformatics analysis predicted miRNAs common for the SNHG1, GAS5, SNHG6, and SNHG12 lncRNA and potentially capable of interacting with one or more of these lncRNAs via competing endogenous RNA mechanism, as well as mRNAs, whose expression might be affected by the studied lncRNAs. We also investigated a possible involvement of genes for these mRNAs in oncogenesis-related processes, such as RNA processing and splicing and epithelial–mesenchymal transition. As a result of this work, four SNHG family lncRNAs with coregulation and joint putative biological functions in the pathogenesis of OC were identified. [ABSTRACT FROM AUTHOR]

Fluorescently labeled and conjugated (strept)avidins are widely used for imaging biotinylated molecules in immunological assays and histochemistry. We showed that besides biotin, these proteins bind glycans, including fragments of mammalian glycoproteins and glycolipids, in particular, ABO blood group antigens, oligolactosamines, and 6-O-sulfated oligosaccharides. This interaction is inhibited in a dose-dependent manner by micromolar concentrations of polymeric, but not monomeric, glycan conjugates (i.e., requires polyvalence). Taking into account the cluster organization of cell glycans (glycoproteins and glycolipids), the ability of (strept)avidins to bind glycans might be a source of errors in the analysis of carbohydrate-containing samples, which can be prevented by avoiding a large excess of (strept)avidin in analytical systems. [ABSTRACT FROM AUTHOR]

Background: In Russia, the following two questionnaires are mainly used to study the burnout syndrome: Maslach Burnout Inventory (MBI) and Boyko's Burnout Inventory (BBI). Despite the fact that the questionnaires are based on different theoretical models and composition of the scales, they evaluate essentially the same construct. A few published sources provide data on correlations between the results of measuring burnout using these methods. However, the presence of a correlation does not imply the comparability of the methods. The goal of our study was to compare the results of MBI and BBI as well as to develop a methodology for reciprocal recalculation of their burnout estimates. Methods: MBI and BBI scales were employed to diagnose the burnout syndrome. Our study included 117 men aged 41–44 years. The total scores obtained by the two methods, as well as the subscale scores, were compared using the correlation analysis, the cross-comparative analysis, and the Bland–Altman plot method, while the associations between the results were estimated with odds ratio (OR) and 95% confidence interval (CI). Results: The total scores (integral indicators based on summing the scores of all subscales and taking into account differences in the weights of scale scores) demonstrated a high similarity in measuring the severity of the burnout. All three dimensions of burnout sensu MBI correlated with the total BBI score. Conclusion: The comparison (MBI vs. BBI) demonstrated the consistency of the results, which implied the possibility of comparing data yielded by the studies based on the two questionnaires (MBI and BBI). [ABSTRACT FROM AUTHOR]

Benzothiazolium ylides generated in situ from benzothiazolium salts by the action of triethylamine reacted stereoselectively with α-cyanocinnamamides to form 1,2,3,3a-tetrahydropyrrolo[2,1-b][1,3]benzothiazoles in 15–91% yields. The resulting compounds were significantly more stable than their analogs derived from quinolinium ylides (KuINin), inhibitors of HIV-1 post-integrational repair. [ABSTRACT FROM AUTHOR]

As major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carbon fluxes and wood formation across the Northern hemisphere, from carbon assimilation and the formation of non-structural carbon compounds to their incorporation in woody tissues. We show temporally coupled seasonal peaks of carbon assimilation (GPP) and wood cell differentiation, while the two processes are substantially decoupled during off-peak periods. Peaks of cambial activity occur substantially earlier compared to GPP, suggesting the buffer role of non-structural carbohydrates between the processes of carbon assimilation and allocation to wood. Our findings suggest that high-resolution seasonal data of ecosystem carbon fluxes, wood formation and the associated physiological processes may reduce uncertainties in carbon source-sink relationships at different spatial scales, from stand to ecosystem levels. Forest carbon source and sink processes may have contrasting climatic sensitivities. This analysis on 177 coniferous forest sites shows that carbon fluxes and wood formation are coupled but not fully synchronous at intra-annual scales, with peaks in cambial activity preceding those in photosynthesis and respiration. [ABSTRACT FROM AUTHOR]

In this Review, we explore natural product antibiotics that do more than simply inhibit an active site of an essential enzyme. We review these compounds to provide inspiration for the design of much-needed new antibacterial agents, and examine the complex mechanisms that have evolved to effectively target bacteria, including covalent binders, inhibitors of resistance, compounds that utilize self-promoted entry, those that evade resistance, prodrugs, target corrupters, inhibitors of ‘undruggable’ targets, compounds that form supramolecular complexes, and selective membrane-acting agents. These are exemplified by β-lactams that bind covalently to inhibit transpeptidases and β-lactamases, siderophore chimeras that hijack import mechanisms to smuggle antibiotics into the cell, compounds that are activated by bacterial enzymes to produce reactive molecules, and antibiotics such as aminoglycosides that corrupt, rather than merely inhibit, their targets. Some of these mechanisms are highly sophisticated, such as the preformed β-strands of darobactins that target the undruggable β-barrel chaperone BamA, or teixobactin, which binds to a precursor of peptidoglycan and then forms a supramolecular structure that damages the membrane, impeding the emergence of resistance. Many of the compounds exhibit more than one notable feature, such as resistance evasion and target corruption. Understanding the surprising complexity of the best antimicrobial compounds provides a roadmap for developing novel compounds to address the antimicrobial resistance crisis by mining for new natural products and inspiring us to design similarly sophisticated antibiotics.This Review examines the diverse strategies utilized by naturally occurring antibiotics and suggests how they have provided, and will in future provide, inspiration for the design of novel antibiotics. [ABSTRACT FROM AUTHOR]

Let K and M be locally finite quasivarieties of finite type such that K ⊂ M . If K is profinite then the filter [ K , M ] in the quasivariety lattice Lq (M) is an atomic lattice and K has an independent quasi-equational basis relative to M . Applications of these results for lattices, unary algebras, groups, unary algebras, and distributive algebras are presented which concern some well-known problems on standard topological quasivarieties and other problems. [ABSTRACT FROM AUTHOR]

Whether from environmental and occupational hazards or from topical pharmaceuticals, the human skin comes into contact with various chemicals every day. In vivo experiments not only require large investments of both time and money, but in vivo experiments can also be unethical due to the need to intentionally or incidentally expose humans or animals to toxic chemicals. Comparatively, in vitro experiments offer ethical and financial advantages when combined with the opportunity to selectively choose chemicals for experimentation. With in vivo experimentation being so infeasible, many scientists have chosen to make their in vitro data available publicly. Using these data, a detailed database containing 73 chemicals was created with a robust set of descriptors to be used in connection with mathematical modeling to predict diffusion, permeability, and partition coefficients. This resulting database is tailored to be easily used in various coding languages. [ABSTRACT FROM AUTHOR]

A three-level constitutive model that describes from concurrent positions the behavior of materials with monotonic and non-monotonic strain diagrams is considered. An effect of the anisotropy and strengthening coefficients of the crystal, the average value of the grain diameter and distribution density of structural defects on the macroscopic behavior of the polycrystal is established. Thereto, three postulates are used: averaged connections, extremum of discrepancy between the macroscopic measures and their microscopic analogues, and orthogonality of stress and strain fluctuations. Based on the constructed system of governing equations, the specific effects of the structural characteristics of the polycrystal on macroscopic strain diagrams and elasticity constants are studied. [ABSTRACT FROM AUTHOR]

Constructing electronic models of neurons has several goals. First, it aims to reproduce the dynamics of biological neurons and their networks (simulation). Second, the resulting networks can be used for neuroprosthetics. In the brain, most neurons themselves are in a non-oscillatory mode, and brain rhythms arise due to their collective dynamics. In this case, very small ensembles of neurons can act as rhythm generators. Such ensembles can be constructed and studied within the framework of a electronic experiment. In this work, a circuit of several (from eight to fifteen) FitzHugh–Nagumo electronic oscillators with electronic synapses (sigmoid coupling function and delay were implemented) was constructed. Oscillatory modes were realized in this circuit as a result of collective dynamics, with their frequency being controlled with changing a delay in the synapse and/or altering the number of elements in the ring. The oscillatory modes coexist with a stable fixed point and may be activated by means of short time external driving. Thus, the presented generator is capable of well reproducing both a slowly gradual change in the main oscillation frequency and its sharp change, with both of these phenomena well diagnosed from time series of brain local field potentials at limbic epilepsy. [ABSTRACT FROM AUTHOR]

In this paper, we propose a fluorescence-lifetime imaging microscopy (FLIM) multiplexing system based on the fluorogen-activating protein FAST. This genetically encoded fluorescent labeling platform employs FAST mutants that activate the same fluorogen but provide different fluorescence lifetimes for each specific protein-dye pair. All the proposed probes with varying lifetimes possess nearly identical and the smallest-in-class size, along with quite similar steady-state optical properties. In live mammalian cells, we target these chemogenetic tags to two intracellular structures simultaneously, where their fluorescence signals are clearly distinguished by FLIM. Due to the unique structure of certain fluorogens under study, their complexes with FAST mutants display a monophasic fluorescence decay, which may facilitate enhanced multiplexing efficiency by reducing signal cross-talks and providing optimal prerequisites for signal separation upon co-localized and/or spatially overlapped labeling. A genetically encoded labeling system uses smallest-in-class fluorogen-activating protein tags for time-resolved fluorescence multiplexed cellular imaging, offering monoexponential decay and potential for sophisticated fluorescence lifetime analysis. [ABSTRACT FROM AUTHOR]

Objective: Glioblastoma multiforme (GBM) is the most aggressive and fatal malignant primary brain tumor. The enhancement of the survival rate for glioma patients remains limited, even with the utilization of a combined treatment approach involving surgery, radiotherapy, and chemotherapy. This study was designed to assess the expression of IDH1, TP53, EGFR, Ki-67, GFAP, H3K27M, MGMT, VEGF, NOS, CD99, and ATRX in glioblastoma tissue from 11 patients. We investigated the anticancer impact and combined effects of cathelicidin (LL-37), protegrin-1 (PG-1), with chemotherapy—temozolomide (TMZ), doxorubicin (DOX), carboplatin (CB), cisplatin (CPL), and etoposide (ETO) in primary GBM cells. In addition, we examined the effect of LL-37, PG-1 on normal human fibroblasts and in the C6/Wistar rat intracerebral glioma model. Methods: For this study, 11 cases of glioblastoma were evaluated immunohistochemically for IDH1, TP53, EGFR, Ki-67, GFAP, H3K27M, MGMT, VEGF, NOS, CD99, and ATRX. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to study cells viability and to determine cytotoxic effects of LL-37, PG-1 and their combination with chemotherapy in primary GBM cells. Synergism or antagonism was determined using combination index (CI) method. Finally, we established C6 glioblastoma model in Wistar rats to investigate the antitumor activity. Results: Peptides showed a strong cytotoxic effect on primary GBM cells in the MTT test (IC50 2–16 and 1–32 μM) compared to chemotherapy. The dual-drug combinations of LL-37 + DOX, LL-37 + CB (CI 0.46–0.75) and PG-1 + DOX, PG-1 + CB, PG-1 + TMZ (CI 0.11–0.77), demonstrated a synergism in primary GBM cells. In rat C6 intracerebral GBM model, survival of rats in experimental group (66.75 ± 12.6 days) was prolonged compared with that in control cohort (26.2 ± 2.66 days, p = 0.0008). After LL-37 treatment, experimental group rats showed significantly lower tumor volumes (31.00 ± 8.8 mm3) and weight (49.4 ± 13.3 mg) compared with control group rats (153.8 ± 43.53 mg, p = 0.038; 82.50 ± 7.60 mm3, respectively). Conclusions: The combination of antimicrobial peptides and chemical drugs enhances the cytotoxicity of chemotherapy and exerts synergistic antitumor effects in primary GBM cells. Moreover, in vivo study provided the first evidence that LL-37 could effectively inhibit brain tumor growth in rat C6 intracerebral GBM model. These results suggested a significant strategy for proposing a promising therapy for the treatment of GBM. [ABSTRACT FROM AUTHOR]

Many microorganisms are capable of anaerobic respiration in the absence of oxygen, by using different organic compounds as terminal acceptors in electron transport chain. We identify here an anaerobic respiratory chain protein responsible for acrylate reduction in the marine bacterium Shewanella woodyi. When the periplasmic proteins of S. woodyi were separated by ion exchange chromatography, acrylate reductase activity copurified with an ArdA protein (Swoo_0275). Heterologous expression of S. woodyiardA gene (swoo_0275) in Shewanella oneidensis MR-1 cells did not result in the appearance in them of periplasmic acrylate reductase activity, but such activity was detected when the ardA gene was co-expressed with an ardB gene (swoo_0276). Together, these genes encode flavocytochrome c ArdAB, which is thus responsible for acrylate reduction in S. woodyi cells. ArdAB was highly specific for acrylate as substrate and reduced only methacrylate (at a 22-fold lower rate) among a series of other tested 2-enoates. In line with these findings, acrylate and methacrylate induced ardA gene expression in S. woodyi under anaerobic conditions, which was accompanied by the appearance of periplasmic acrylate reductase activity. ArdAB-linked acrylate reduction supports dimethylsulfoniopropionate-dependent anaerobic respiration in S. woodyi and, possibly, other marine bacteria. [ABSTRACT FROM AUTHOR]

Genes of putative reductases of α,β-unsaturated carboxylic acids are abundant among anaerobic and facultatively anaerobic microorganisms, yet substrate specificity has been experimentally verified for few encoded proteins. Here, we co-produced in Escherichia coli a heterodimeric protein of the facultatively anaerobic marine bacterium Vibrio ruber (GenBank SJN56019 and SJN56021; annotated as NADPH azoreductase and urocanate reductase, respectively) with Vibrio cholerae flavin transferase. The isolated protein (named Crd) consists of the sjn56021-encoded subunit CrdB (NADH:flavin, FAD binding 2, and FMN bind domains) and an additional subunit CrdA (SJN56019, a single NADH:flavin domain) that interact via their NADH:flavin domains (Alphafold2 prediction). Each domain contains a flavin group (three FMNs and one FAD in total), one of the FMN groups being linked covalently by the flavin transferase. Crd readily reduces cinnamate, p-coumarate, caffeate, and ferulate under anaerobic conditions with NADH or methyl viologen as the electron donor, is moderately active against acrylate and practically inactive against urocanate and fumarate. Cinnamates induced Crd synthesis in V. ruber cells grown aerobically or anaerobically. The Crd-catalyzed reduction started by NADH demonstrated a time lag of several minutes, suggesting a redox regulation of the enzyme activity. The oxidized enzyme is inactive, which apparently prevents production of reactive oxygen species under aerobic conditions. Our findings identify Crd as a regulated NADH-dependent cinnamate reductase, apparently protecting V. ruber from (hydroxy)cinnamate poisoning. [ABSTRACT FROM AUTHOR]

Quinone derivatives of triphenylphosphonium have proven themselves to be effective geroprotectors and antioxidants that prevent oxidation of cell components with participation of active free radicals – peroxide (RO2·), alkoxy (RO·), and alkyl (R·) radicals, as well as reactive oxygen species (superoxide anion, singlet oxygen). Their most studied representatives are derivatives of plastoquinone (SkQ1) and ubiquinone (MitoQ), which in addition to antioxidant properties also have a strong antibacterial effect. In this study, we investigated antibacterial properties of other quinone derivatives based on decyltriphenylphosphonium (SkQ3, SkQT, and SkQThy). We have shown that they, just like SkQ1, inhibit growth of various Gram-positive bacteria at micromolar concentrations, while being less effective against Gram-negative bacteria, which is associated with recognition of the triphenylphosphonium derivatives by the main multidrug resistance (MDR) pump of Gram-negative bacteria, AcrAB-TolC. Antibacterial action of SkQ1 itself was found to be dependent on the number of bacterial cells. It is important to note that the cytotoxic effect of SkQ1 on mammalian cells was observed at higher concentrations than the antibacterial action, which can be explained by (i) the presence of a large number of membrane organelles, (ii) lower membrane potential, (iii) spatial separation of the processes of energy generation and transport, and (iv) differences in the composition of MDR pumps. Differences in the cytotoxic effects on different types of eukaryotic cells may be associated with the degree of membrane organelle development, energy status of the cell, and level of the MDR pump expression. [ABSTRACT FROM AUTHOR]

Discharges of different epilepsies are characterized by different signal shape and duration. The authors adhere to the hypothesis that spike-wave discharges are long transient processes rather than attractors. This helps to explain some experimentally observed properties of discharges, including the absence of a special termination mechanism and quasi-regularity. Analytical approaches mostly cannot be applied to studying transient dynamics in large networks. Therefore, to test the observed phenomena for universality one has to show that the same results can be achieved using different model types for nodes and different connectivity terms. Here, we study a class of simple network models of a thalamocortical system and show that for the same connectivity matrices long, but finite in time quasi-regular processes mimicking epileptic spike-wave discharges can be found using nodes described by three neuron models: FitzHugh – Nagumo, Morris – Lecar and Hodgkin – Huxley. This result takes place both for linear and nonlinear sigmoid coupling. [ABSTRACT FROM AUTHOR]

Widespread soil contamination with oil and the toxicity of petroleum hydrocarbons to soil biota make it extremely important to study microbial responses to oil stress. Soil metabolites reflect the main metabolic pathways in the soil microbial community. The examination of changes in the soil metabolic profile and metabolic function is essential for a better understanding of the nature of the pollution and restoration of the disturbed soils. The present study aimed to assess the long-term effect of oil on the ecological state of the soil, evaluate quantitative and qualitative differences in metabolite composition between soil contaminated with oil and non-contaminated soil, and reveal biologically active metabolites that are related to oil contamination and can be used for contamination assessment. A long-term field experiment was conducted to examine the effects of various oil concentrations on the biochemical properties and metabolic profile of the soil. Podzolic soil contaminated with oil demonstrated the long-term inhibition of soil biological activity and vegetation. Oil affected the metabolic activity of soil fungi increasing the production of toxic metabolites. A metabolomic approach was employed to determine soil metabolites. The metabolite profile was found to vary greatly between oil-contaminated and non-contaminated soils. Carbohydrates had the largest number of metabolites negatively affected by oil, while the content of organic acids, phenolic compounds, and terpenoids was mainly increased in oil-contaminated soil. The evaluation of the long-term impact of oil on microbial metabolism can make a valuable contribution to the assessment of soil quality and the activity of soil microorganisms being under stress from oil pollution. The results contribute to a further understanding of the role of microorganisms in the ecological functions of contaminated soil, which can be useful in the development of rehabilitation strategies for disturbed sites. [ABSTRACT FROM AUTHOR]

Neutrophils play a dual role in protecting the body. They are able to penetrate infected tissues and destroy pathogens there by releasing aggressive bactericidal substances. While into the surrounding tissues, the aggressive products secreted by neutrophils initiate development of inflammatory processes. Invasion of neutrophils into tissues is observed during the development of pneumonia in the patients with lung diseases of various etiologies, including acute respiratory distress syndrome caused by coronavirus disease. Synthetic corticosteroid hormone dexamethasone has a therapeutic effect in treatment of lung diseases, including reducing mortality in the patients with severe COVID-19. The acute (short-term) effect of dexamethasone on neutrophil adhesion to fibrinogen and concomitant secretion was studied. Dexamethasone did not affect either attachment of neutrophils to the substrate or their morphology. Production of reactive oxygen species (ROS) and nitric oxide (NO) by neutrophils during adhesion also did not change in the presence of dexamethasone. Dexamethasone stimulated release of metalloproteinases in addition to the proteins secreted by neutrophils during adhesion under control conditions, and selectively stimulated release of free amino acid hydroxylysine, a product of lysyl hydroxylase. Metalloproteinases play a key role and closely interact with lysyl hydroxylase in the processes of modification of the extracellular matrix. Therapeutic effect of dexamethasone could be associated with its ability to reorganize extracellular matrix in the tissues by changing composition of the neutrophil secretions, which could result in the improved gas exchange in the patients with severe lung diseases. [ABSTRACT FROM AUTHOR]

Recent studies have shown that the knowledge of society about the functioning of the brain does not correspond to neuroscience data. The high prevalence of neuromyths can become a problem in the development of educational technologies. The goal of this study is to identify the prevalence of neuromyths among pre-service teachers and students of other faculties. The prevalence of neuromyths among 958 university students was studied using an anonymous survey. It was found that the specialty influenced the results: chemistry and biology students, as well as physics, mathematics, and computer science students, answered better. The effect of education is weak. Nevertheless, it has led to an alignment of results between the specialties in the older group. Self-education has a significant positive effect on students' recognition of neurofacts. The study confirms that certain neuromyths are especially popular among students and allows us to draw conclusions about the prevalence of neuromyths among future teachers. [ABSTRACT FROM AUTHOR]

Population density is known to affect the health and survival of many species, and is especially important for social animals. In mice, living in crowded conditions results in the disruption of social interactions, chronic stress, and immune and reproductive suppression; however, the underlying mechanisms remain unclear. Here, we investigated the role of chemosignals in the regulation of mouse physiology and behavior in response to social crowding. The pheromone 2,5-dimethylpyrazine (2,5-DMP), which is released by female mice in crowded conditions, induced aversion, glucocorticoid elevation and, when chronic, resulted in reproductive and immune suppression. 2,5-DMP olfaction induced genome destabilization in bone marrow cells in a stress-dependent manner, providing a plausible mechanism for crowding-induced immune dysfunction. Interestingly, the genome-destabilizing effect of 2,5-DMP was comparable to a potent mouse stressor (immobilization), and both stressors led to correlated expression changes in genes regulating cellular stress response. Thus, our findings demonstrate that, in mice, the health effects of crowding may be explained at least in part by chemosignals and also propose a significant role of stress and genome destabilization in the emergence of crowding effects. [ABSTRACT FROM AUTHOR]

Equilibrium in the quaternary CaO–P2O5–H2CO3–H2O system at 298 K in air was studied in a region of low concentrations of liquid-phase components. We revealed a dependence of the composition of resultant equilibrium solid phases on the Ca/P ratio of the initial components and on pH of the equilibrium liquid phase. It was found that the entire region of the system having low concentrations of liquid-phase components is occupied by variable-composition compounds with apatite structure. Two types of carbonate-containing apatite compounds were detected. The first type of apatite forms at 5.4 ≤ pH ≤ 7.0, contains HPO42− groups in the lattice, and has an invariant point with brushite CaHPO 4 · 2H 2 O at pH ≈ 5.4. The second type arises at pH > 7.0, does not contain an acidic group, and has an invariant point with CaCO3 at pH ≥ 8. [ABSTRACT FROM AUTHOR]

Nanomaterials are one of the most promising classes of advanced materials with fine-tuned biological activities. This is evidenced by the presence of redox activity of a number of nanoparticles aimed at inhibiting free radicals and/or mimicking the functions of enzymes. At the same time, it is impossible to study the expression of these biological properties without the use of well-standardized, representative techniques that provide availability, high precision, sensitivity, and selectivity of the measured characteristics. A method that satisfies these requirements is chemiluminescence analysis, which is widely used both in clinical analysis and to characterize the antioxidant activity of substances of natural or synthetic origin. Recently, a trend of using chemiluminescence analysis to study the biological activity of nanomaterials has appeared as a suitable alternative to spectroscopic and electrochemical techniques. This review briefly describes the examples of successful applications of chemiluminescence methods to study radical-binding and enzyme-like activities of nanomaterials. We discuss the data about the effect of the used reagents (radical-generating systems, chemiluminescence activators) and experimental conditions on the obtained values characterizing the nanomaterials activity. [ABSTRACT FROM AUTHOR]

Water-soluble chlorin e6 cationic derivatives with one and two galactose fragments at the quaternized nitrogen atom were synthesized, and the dark and photoinduced cytotoxicity of the obtained compounds was evaluated. [ABSTRACT FROM AUTHOR]

N-Phthalimidoaziridines were synthesized from 3,5-disubstituted 1,2,4-oxadiazoles containing alkenyl and pyridine fragments. N-Phthalimidoaziridines were heated in the presence of N-arylmaleimide to give the corresponding N-phthalimidopyrrolidines. The synthesized N-phthalimidoaziridines and N-phthalimidopyrrolidines contain several pharmacophoric groups (the aziridine, oxadiazole, pyridine, and phthalimide moieties) making them potential active ingredients of medicines. [ABSTRACT FROM AUTHOR]

The aim of the present study, endorsed by the Union of European Neonatal and Perinatal Societies (UENPS) and the Italian Society of Neonatology (SIN), was to analyze the current delivery room (DR) stabilization practices in a large sample of European birth centers that care for preterm infants with gestational age (GA) < 33 weeks. Cross-sectional electronic survey was used in this study. A questionnaire focusing on the current DR practices for infants < 33 weeks' GA, divided in 6 neonatal resuscitation domains, was individually sent to the directors of European neonatal facilities, made available as a web-based link. A comparison was made between hospitals grouped into 5 geographical areas (Eastern Europe (EE), Italy (ITA), Mediterranean countries (MC), Turkey (TUR), and Western Europe (WE)) and between high- and low-volume units across Europe. Two hundred and sixty-two centers from 33 European countries responded to the survey. At the time of the survey, approximately 20,000 very low birth weight (VLBW, < 1500 g) infants were admitted to the participating hospitals, with a median (IQR) of 48 (27–89) infants per center per year. Significant differences between the 5 geographical areas concerned: the volume of neonatal care, ranging from 86 (53–206) admitted VLBW infants per center per year in TUR to 35 (IQR 25–53) in MC; the umbilical cord (UC) management, being the delayed cord clamping performed in < 50% of centers in EE, ITA, and MC, and the cord milking the preferred strategy in TUR; the spotty use of some body temperature control strategies, including thermal mattress mainly employed in WE, and heated humidified gases for ventilation seldom available in MC; and some of the ventilation practices, mainly in regard to the initial FiO2 for < 28 weeks' GA infants, pressures selected for ventilation, and the preferred interface to start ventilation. Specifically, 62.5% of TUR centers indicated the short binasal prongs as the preferred interface, as opposed to the face mask which is widely adopted as first choice in > 80% of the rest of the responding units; the DR surfactant administration, which ranges from 44.4% of the birth centers in MC to 87.5% in WE; and, finally, the ethical issues around the minimal GA limit to provide full resuscitation, ranging from 22 to 25 weeks across Europe. A comparison between high- and low-volume units showed significant differences in the domains of UC management and ventilation practices. Conclusion: Current DR practice and ethical choices show similarities and divergences across Europe. Some areas of assistance, like UC management and DR ventilation strategies, would benefit of standardization. Clinicians and stakeholders should consider this information when allocating resources and planning European perinatal programs. What is Known: • Delivery room (DR) support of preterm infants has a direct influence on both immediate survival and long-term morbidity. • Resuscitation practices for preterm infants often deviate from the internationally defined algorithms. What is New: • Current DR practice and ethical choices show similarities and divergences across Europe. Some areas of assistance, like UC management and DR ventilation strategies, would benefit of standardization. • Clinicians and stakeholders should consider this information when allocating resources and planning European perinatal programs. [ABSTRACT FROM AUTHOR]

Methylotrophic yeast Komagataella phaffii is widely used in biotechnology for recombinant protein production. Due to the practical significance of these yeasts, it is extremely important to properly select cultivation conditions and optimize the media composition. In this study the effect of biotin starvation on gene expression in K. phaffii at transcriptome level was investigated. It was demonstrated, that the response of K. phaffii cell to biotin deficiency strongly depends on the carbon source in the medium. In the media containing glycerol, biotin deficiency led to activation of the genes involved in biotin metabolism, glyoxylate cycle, and synthesis of acetyl-CoA in cytoplasm, as well as repression of the genes, involved in lipo- and gluconeogenesis. In the methanol-containing media, biotin deficiency primarily led to repression of the genes, involved in protein synthesis, and activation of cell response to oxidative stress. [ABSTRACT FROM AUTHOR]

Cytochrome CYP102A1 (P450 BM3) of Priestia megaterium (bas. Bacillus megaterium) has several unique functional features and thus provides an ideal object for directed evolution and other synthetic applications. Previously, the CYP102A1-LG23 mutant with 14 mutations in the heme part was obtained that hydroxylates several androstanes at C7β with the formation of products with the anti-inflammatory and neuroprotective activities. In this study, synthetic cyp102A1-LG23 gene encoding the P450 BM3 mutant was expressed as a component of either monocistronic operon or bicistronic operon containing the gdh (glucose dehydrogenase, GDH) or zwf2 (glucose 6-phosphate dehydrogenase, G6PD) gene in Mycolicibacterium smegmatis BD cells. The recombinant bacteria were able hydroxylate androst-4-ene-3,17-dione (AD) into 7β-OH-AD. Their biocatalytic activity was increased twice by increasing the solubility of CYP102A1-LG23 protein in the cells and supplementing the cells with the additional cofactor regeneration system by introducing GDH and G6PD. The maximum 7β-OH-AD yield (37.68 mol%) was achieved by co-expression of cyp102A1-LG23 and gdh genes in M. smegmatis. These results demonstrate the possibility of using synthetic genes to obtain recombinant enzymes and expand our understanding of the processes involved in steroid hydroxylation by bacterial cytochromes. The data obtained can be used to develop new approaches for microbiological production of 7β-hydroxylated steroids in genetically modified Mycolicibacterium species. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) is an abundant, dynamic mRNA modification that regulates key steps of cellular mRNA metabolism. m6A in the mRNA coding regions inhibits translation elongation. Here, we show how m6A modulates decoding in the bacterial translation system using a combination of rapid kinetics, smFRET and single-particle cryo-EM. We show that, while the modification does not impair the initial binding of aminoacyl-tRNA to the ribosome, in the presence of m6A fewer ribosomes complete the decoding process due to the lower stability of the complexes and enhanced tRNA drop-off. The mRNA codon adopts a π-stacked codon conformation that is remodeled upon aminoacyl-tRNA binding. m6A does not exclude canonical codon-anticodon geometry, but favors alternative more dynamic conformations that are rejected by the ribosome. These results highlight how modifications outside the Watson-Crick edge can still interfere with codon-anticodon base pairing and complex recognition by the ribosome, thereby modulating the translational efficiency of modified mRNAs. m6A is an mRNA modification that slows down translation elongation. Here, Jain et al. show that m6A delays decoding and increases tRNA drop-off from the ribosome by favoring alternative codon conformations that are rejected by the ribosome. [ABSTRACT FROM AUTHOR]

Earth system models and various climate proxy sources indicate global warming is unprecedented during at least the Common Era1. However, tree-ring proxies often estimate temperatures during the Medieval Climate Anomaly (950–1250 ce) that are similar to, or exceed, those recorded for the past century2,3, in contrast to simulation experiments at regional scales4. This not only calls into question the reliability of models and proxies but also contributes to uncertainty in future climate projections5. Here we show that the current climate of the Fennoscandian Peninsula is substantially warmer than that of the medieval period. This highlights the dominant role of anthropogenic forcing in climate warming even at the regional scale, thereby reconciling inconsistencies between reconstructions and model simulations. We used an annually resolved 1,170-year-long tree-ring record that relies exclusively on tracheid anatomical measurements from Pinus sylvestris trees, providing high-fidelity measurements of instrumental temperature variability during the warm season. We therefore call for the construction of more such millennia-long records to further improve our understanding and reduce uncertainties around historical and future climate change at inter-regional and eventually global scales.Annually resolved Fennoscandian tree-ring anatomy records show that the climate of the current industrial era is substantially warmer than that of the medieval period. [ABSTRACT FROM AUTHOR]

The kinetics of the thermal decomposition of pure Larix sibirica arabinogalactan (AG) and AG-stabilized Bi2Te3 nanoparticles was studied. The analysis was performed using thermogravimetry, differential scanning calorimetry and pyrolysis product mass-spectrometry at the heating rates of 10, 20, and 40 K min−1 in an argon atmosphere. Kinetic triplet of the samples was determined by such conventional linear integral isoconversional methods as Kissinger–Akahira–Sunose, Ozawa–Flynn–Wall, Starink and applying Criado's master plot methodology. The study revealed the size-dependent behavior of thermal decomposition of Bi2Te3 nanoparticles. It was found that activation energy (Ea) of moisture desorption decreased after the introduction of Bi2Te3 nanoparticles into AG. The increase of their mean size from 33.6 to 71.0 nm was accompanied by a significant reduction of the mean Ea of moisture desorption from 74.0 to 48.5 kJ mol−1. Besides, the introduction of nanoparticles led to the appearance of an additional decomposition stage most probably corresponding to the removal of water, more strongly bound with the surface of nanoparticles. The stage has sufficiently high Ea values of 506.8 kJ mol−1 for sample with mean nanoparticle size of 33.6 nm and 563.4 kJ mol−1 for one of 71.0 nm. This directly indicates that the size factor of the bismuth telluride crystal nanophase determines the overall thermal stability of the nanocomposites. In particular, this reveals the catalytic role of Bi2Te3 nanoparticles in the general mechanism of thermal decomposition of polysaccharide-based nanocomposites with the prevailing influence of the surface interaction of Bi2Te3 nanoparticles with polysaccharide macromolecules. The findings on the thermal decomposition of AG-stabilized Bi2Te3 nanoparticles should be considered when predicting potential applications of polysaccharide-based thermoelectric nanomaterials. [ABSTRACT FROM AUTHOR]

The work is focused on the analysis of thermomechanical stresses in silicon during pulse current heating of interconnections which were exposed to single current pulses with a duration of up to 250 µs and a current density amplitude of up to 2 × 1011 A/m2. When modeling thermal "loads", film conductors on silicon with a thickness of up to 3 µm and a width of 10–75 µm were considered. Based on the experimental oscillograms taken from sections of the test structures during the passage of a current pulse and the calculation performed, the maximum temperatures on the silicon surface near the thermal shock source were determined. It has been experimentally revealed that the passage of current pulses with an amplitude of 2 × 1011 A/m2 and a duration of up to 250 µs leads to thermal destruction of interconnects and contributes to the formation of plastic deformation regions in the near-surface layer of silicon. It was revealed that with a decrease in the track width, the nature of the melting of the film conductor does not change. It was also established that a significantly higher specific energy is required to melt narrower tracks. The analysis of the maximum temperature gradients identified the places of the most probable cracking. The formation of cracks in the near-surface layer of a semiconductor at a depth of 2.5 µm after the passage of a single current pulse was experimentally detected. An assessment was made of the magnitude of mechanical stresses arising in the structure during thermal shock. [ABSTRACT FROM AUTHOR]

By using nonlinear equations of constraints between macro- and micro-states, the regularities of changes in the limiting values of stress and strain invariants in microinhomogeneous media are studied. It is shown that the extreme relative moduli of stress tensor deviators in polycrystals with a cubic lattice are invariant with respect to external conditions of reversible force and depend only on the crystal anisotropy factor. In the irreversible region of deformation, analytical relations are obtained for bulk and tensile normal stresses. The effect of cyclic change in bulk and tensile stresses in some subelements under external monotonic loading has been established. It is shown that, on the basis of nonlinear equations of constraints, a complex pattern of material failure can be described using the theory of maximum normal stresses at the local level. [ABSTRACT FROM AUTHOR]

Polycation-based coatings represent a promising class of protective antimicrobial coatings. Water-soluble complexes of poly(diallyldimethylammonium chloride) (PDADMAC) with sodium polyacrylate (PANa) have been studied by turbidimetry. It has been shown that the addition of the polyanion (12 mol %) to the polycation leads to the formation of an interpolyelectrolyte complex (IPEC) stable with respect to phase separation in water-salt media with salt concentrations as high as 0.1–0.2 M. In contrast to the traditional method of obtaining coatings from IPEC by layer-by-layer deposition, we have studied the preparation of the coatings directly from a solution of water-soluble IPEC on a hydrophilic glass surface and a surface of more hydrophobic polycarbonate. It has been found that the formation of IPEC makes it possible to increase the resistance of the coating to wash-off with water compared to the individual PDADMAC coating on both types of substrates. [ABSTRACT FROM AUTHOR]

A complex of soil actinomycetes in the upper horizon of Grumusol (Vertisol) on the western coast of Lake Kinneret in the vicinity of Tiberias (Lower Galilee, Israel) was studied. A high-throughput screening of the antibiotic activity of 26 isolates of the genus Streptomyces using on a dual reporter system revealed the strain 3IZ-6, which had the ability to inhibit protein synthesis. This strain was assigned to Streptomyces rochei according to the polyphase taxonomy approach. The active substance of S. rochei 3IZ-6 was isolated and purified using solid-phase extraction and high-performance liquid chromatography. Toeprint analysis and mass spectrophotometric data allowed us to identify this active compound as borrelidin, a known inhibitor of protein biosynthesis. When co-cultivated on solid media, strain 3IZ-6 is able to suppress the growth of phytopathogenic microorganisms Fusarium solani, F. sambucinum, and Botrytis cinerea, as well as the quarantine object Curtobacterium flaccumfaciens. The cultural liquid of 3IZ-6 had a pronounced phytotoxic effect on the seeds of common wheat (Triticum aestivum L.). Strain Streptomyces rochei 3IZ-6 can find application in biotechnology as a producer of borrelidin, a valuable natural compound with a wide spectrum of antibiotic activity, which can be used as a biocontrol agent for crop protection from phytopathogens and weeds. [ABSTRACT FROM AUTHOR]

Membrane proteins are one of the keystone objects in molecular biology, but their structural studies often require an extensive search for an appropriate membrane-like environment and an efficient refolding protocol for a recombinant protein. Isotropic bicelles are a convenient membrane mimetic used in structural studies of membrane proteins. Helical membrane domains are often transferred into bicelles from trifluoroethanol–water mixtures. However, the protocols for such a refolding are empirical and the process itself is still not understood in detail. In search of the optimal refolding approaches for helical membrane proteins, we studied here how membrane proteins, lipids, and detergents interact with each other at various trifluoroethanol–water ratios. Using high-resolution NMR spectroscopy and dynamic light scattering, we determined the key states of the listed compounds in the trifluoroethanol/water mixture, found the factors that could be critical for the efficiency of refolding, and proposed several most optimal protocols. These protocols were developed on the transmembrane domain of neurotrophin receptor TrkA and tested on two model helical membrane domains—transmembrane of Toll-like receptor TLR9 and voltage-sensing domain of a potassium channel KvAP. [ABSTRACT FROM AUTHOR]

HIV stigma is associated with negative physical and mental health outcomes. Intersectional stigma among persons living with HIV (PLHIV) results from interrelated, synergistic impacts of experiencing multiple stigma forms. Its relation with mental health outcomes is still an emerging area of study in this key population. This study aimed to evaluate associations of intersectional stigma, defined as endorsing high levels of HIV and substance use stigmas, with depressive and anxiety symptoms in a cohort of 111 PLHIV who inject drugs in St. Petersburg, Russia. Over a third of participants (37%) reported experiencing intersectional stigma (i.e., both stigma scores above the median). In adjusted analysis, lower Patient Health Questionnaire depression scale (PHQ-9) scores (beta (β=-4.31, 95% CI: -7.11 – -1.51, p = 0.003) and Generalized Anxiety Disorders Scale (GAD-7) scores (β=-3.64, 95% CI: -5.57 – -1.71, p < 0.001) were associated with having low scores for both HIV and substance use stigmas. Lower PHQ-9 scores (β=-3.46, 95% CI: -5.72 – -1.19, p = 0.003) and GAD-7 scores (β=-3.06, 95% CI: -4.62 – -1.50, p < 0.001) were also associated with high stigma on either HIV or substance use stigma scales. Controlling for demographics, depressive symptoms approximately linearly increased from both forms of stigma low to experiencing either form of stigma high to experiencing intersectional stigma, while levels of anxiety symptoms were comparable among participants with both types of stigma low and one stigma high. Participants who experienced intersectional stigma reported the greatest severity of both depressive and anxiety symptoms, as compared to individuals who endorsed low stigma scores (i.e., low stigma on both HIV and substance use stigma scales) or high scores of only one form of stigma. This suggests that intersectional stigma in this population of PLHIV who inject drugs in Russia is linked with worsened mental health outcomes, exceeding the effects of experiencing one form of stigma alone. Interventions to help people cope with intersectional stigma need to consider affective symptoms and tailor coping strategies to address impacts of multiple forms of mental health distress. [ABSTRACT FROM AUTHOR]

The problem of the relationship between local and general mechanical parameters that describe the thermoreological properties of polycrystalline materials is considered. The change of parameters describing the relationship between stress and strain oscillations at two levels of the structure is analyzed. The assumption of the invariance of the density distribution function of the elastic boundaries of sub-elements in the process of irreversible deformation is used. This study is based on the principles of discrepancy between the macroscopic measures and the microscopic analogs and the orthogonality of stress and strain oscillations. It is shown that at small values of the curing factor of subelements typical for the stages of easy-sliding single crystals, this model describes such specific effects as plateau or yield drop and change of elastic properties under irreversible deformations. [ABSTRACT FROM AUTHOR]

Heat-treated serpentine products from mining wastes have been examined to remediate highly contaminated soil with total concentration of Cu 10470 mg/kg and Ni 5300 mg/kg. The series of laboratory and field experiments (for 10 years) were conducted. The modified Tessier method was used to assess the metals geochemical mobility. The effect of hydration on the chemical stability of the components and sorption properties of thermally activated serpentine were studied. The hydration of heat-treated serpentine decreased the leaching of the main components (Mg and Si) that indicates their partial binding in a newly formed compound—magnesium silicate. Hydration of heat-treated serpentine did not lead to the changes in the phase composition and the geochemical mobility of the precipitated Ni and Cu compounds. The hydration affected the sorption value at the 1 day of the interaction but after 30 days this difference partially leveled. A laboratory experiment showed that thermally activated serpentine was effective for the Cu and Ni sorption from sulfate solutions. The substantial changes in chemical properties of soil mixtures after ten years of the field experiment were found. In the first year of the field experiment, the pH values of soil mixtures were alkaline (9.4–9.9) and were significantly higher compared to the pH 4.0 of the initial peat soil. Over 10 years, the soil pH at the experimental sites gradually decreased and reached values of 7.2–8.6. The introduction of thermoactivated serpentines led to a decrease in the share of the most mobile exchangeable fraction. The most noticeable effect of thermoactivated serpentines on metal mobility in the polluted peat soil revealed for Cu; its migration coefficient decreased from 1.8 in the peat soil to 0.7 in the mixtures with heat-treated serpentines. The sum of Cu mobile fractions in the experimental variants became lower compared with initial peat by 50–70%, while Fe was lower by 30%, and Zn—by 80%. The increase in the proportion of the most strongly bound fraction was observed for all metals in the experimental variants compared with initial soil. The coefficient of metal accumulation for Ni and Cu was significantly lower than 1, indicating protective mechanisms in plants. The high content of mobile Mg and Ca compounds seems to be the determining factor in this process. The grass communities forming in the 10-years experiment showed high productivity and stability even under constant airborne industrial pollution. The thermally activated serpentine minerals can be recommended for the in situ remediation of landscapes with completely lost vegetation during the long-term impact of industrial emissions. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the research was to study the direction, dynamics, and features of the restoration of the main ecological functions of different podzolic soils disturbed by oil pollution. Materials and methods: Soil contamination with crude oil was carried out in field experiments at two sites near St. Petersburg, Russia. Loamy soddy-podzolic soil (Umbric Albeluvisol) and sandy illuvial-ferruginous podzol (Podzol), the most common in the region, were the objects of study. Key indicators were used to investigate the dynamics of self-purification processes of oil-contaminated soils: (1) the rate of carbon dioxide emission by the soil, which quantitatively characterizes the mineralization of petroleum hydrocarbons by microorganisms, was determined by the absorption method in laboratory conditions; (2) toxicological rate of soils and water extracts from them was determined by eluate and substrate bioassay; (3) the value of aboveground biomass and the projective vegetation cover were determined by direct weighing out and visually. Content of petroleum products in soils was determined by infrared spectrometry. Results and discussion: Self-purification and self-recovery dynamics in the oil-contaminated soils differed significantly depending on the soil type. The rate and intensity of oil biodegradation in the sandy podzol due to the activity of microorganisms, as well as the rate and degree of restoration of vegetation cover, were significantly lower compared to the soddy-podzolic soil, despite the same level of oil pollution. Podzol was characterized both by a higher degree of toxicity and a lower rate of its decline compared to the soddy-podzolic soil. The soddy-podzolic soil at the maximum level of pollution restored the disturbed basic ecological functions in 4 years. In podzol, with a comparable high pollution level, by the end of the fifth year, acute toxicity remained and there was practically no vegetation. Conclusions: The factors affecting the rate of oil degradation should be associated primarily with the chemical and microbiological parameters of soils and the characteristics of the vegetation growing on them. Different levels of stability of the loamy soddy-podzolic soil and sandy podzol in conditions of oil pollution, and the peculiarities of the processes of their natural recovery, should be taken into account in environmental regulations, when determining the maximum permissible residual oil concentrations in soils, as well as in the development of effective methods for their reclamation. [ABSTRACT FROM AUTHOR]

The main male hormone, testosterone is obtained from cheap and readily available phytosterol using the strains of Mycolicibacterium neoaurum VKM Ac-1815D, or Ac-1816D. During the first "oxidative" stage, phytosterol (5–10 g/L) was aerobically converted by Ac-1815D, or Ac-1816D to form 17-ketoandrostanes: androstenedione, or androstadienedione, respectively. At the same bioreactor, the 17-ketoandrostanes were further transformed to testosterone due to the presence of 17β-hydroxysteroid dehydrogenase activity in the strains ("reductive" mode). The conditions favorable for "oxidative" and "reductive" stages have been revealed to increase the final testosterone yield. Glucose supplement and microaerophilic conditions during the "reductive" mode ensured increased testosterone production by mycolicibacteria cells. Both strains effectively produced testosterone from phytosterol, but highest ever reported testosterone yield was achieved using M. neoaurum VKM Ac-1815D: 4.59 g/l testosterone was reached from 10 g/l phytosterol thus corresponding to the molar yield of over 66%. The results contribute to the knowledge on phytosterol bioconversion by mycolicibacteria, and are of significance for one-pot testosterone bioproduction from phytosterol bypassing the intermediate isolation of the 17-ketoandrostanes. [ABSTRACT FROM AUTHOR]

A three-component reaction of ethyl trifluoropyruvate, methyl ketones, and ethylenediamine or 1,3-diaminopropane afforded hexahydropyrrolo[1,2-a]imidazol-5-ones and hexahydropyrrolo[1,2-a]pyrimidin-6-ones. When using an excess of ethyl trifluoropyruvate in reactions with acetone and diamines, dipyrrolo[1,2-a:2',1'-b]imidazole-3,8-dione and dipyrrolo[1,2-a:2',1'-b]pyrimidine-3,9-dione were obtained. An aldol mechanism for the formation of the bi- and tricyclic compounds was proposed, and their diastereomeric structure was established. Some of the obtained heterocycles were found to possess analgesic activity. [ABSTRACT FROM AUTHOR]

Cholesterol oxidase is a highly demanded enzyme used in medicine, pharmacy, agriculture, chemistry, and biotechnology. It catalyzes oxidation of 3β-hydroxy-5-ene- to 3-keto-4-ene- steroids with the formation of hydrogen peroxide. Here, we expressed 6xHis-tagged mature form of the extracellular cholesterol oxidase (ChO) from the actinobacterium Nocardioides simplex VKM Ac-2033D (55.6 kDa) in Escherichia coli cells. The recombinant enzyme (ChONs) was purified using affinity chromatography. ChONs proved to be functional towards cholesterol, cholestanol, phytosterol, pregnenolone, and dehydroepiandrosterone. Its activity depended on the structure and length of the aliphatic side chain at C17 atom of the steroid nucleus and was lower with pregnenolone and dehydroepiandrosterone. The enzyme was active in a pH range of 5.25÷6.5 with the pH optimum at 6.0. Kinetic assays and storage stability tests demonstrated that the characteristics of ChONs were generally comparable with or superior to those of commercial ChO from Streptomyces hygroscopicus (ChOSh). The results contribute to the knowledge on microbial ChOs and evidence that ChO from N. simplex VKM Ac-2033D is a promising agent for further applications. [ABSTRACT FROM AUTHOR]

GNAO1 encephalopathy is an orphan genetic disease associated with early infantile epilepsy, impaired motor control, and severe developmental delay. The disorder is caused by mutations in the GNAO1 gene, leading to dysfunction of the encoded protein Gαo1. There is no cure for this disease, and symptomatic therapy is ineffective. Phenotypic heterogeneity highlights the need for a personalized approach for treating patients with a specific clinical variant of GNAO1 and requires the study of the disease mechanism in animal and cell models. Towards this aim, we developed an approach for modeling GNAO1 encephalopathy and testing gene therapy drugs in primary neurons derived from healthy mice. We optimized the delivery of transgenes to Gαo1-expressing neurons using recombinant adeno-associated viruses (rAAV). We assessed the tropism of five neurotropic AAV serotypes (1, 2, 6, 9, DJ) for Gαo1-positive neurons from the whole mouse brain. The DJ serotype showed the highest potential as a reporter delivery vehicle, infecting up to 66% of Gαo1-expressing cells without overt cytotoxicity. We demonstrated that AAV-DJ also provides efficient delivery and expression of genetic constructs encoding normal and mutant Gαo1, as well as short hairpin RNA (shRNA) to suppress endogenous Gnao1 in murine neurons. Our results will further simplify the study of the pathological mechanism for clinical variants of GNAO1, as well as optimize the testing of gene therapy approaches for GNAO1 encephalopathy in cell models. [ABSTRACT FROM AUTHOR]