Explore the vast range of titles available.

Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a byproduct of the very oxidation chemistry it largely initiates. Much effort is focused on the reduction of surface levels of ozone owing to its health and vegetation impacts, but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve owing to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner. The review shows that there remain a number of clear challenges for ozone such as explaining surface trends, incorporating new chemical understanding, ozone–climate coupling, and a better assessment of impacts. There is a clear and present need to treat ozone across the range of scales, a transboundary issue, but with an emphasis on the hemispheric scales. New observational opportunities are offered both by satellites and small sensors that bridge the scales.

This paper presents the development and evaluation of an elective course on Scratch programming specifically designed for specialized computer science education in lyceums. The course aimed to develop students’ algorithmic thinking and digital competencies in 10th and 11th grade through interactive project-based learning. A 12-week pedagogical experiment using a pre-test/post-test design was conducted to assess the course’s effectiveness. The results demonstrated significant improvements in students’ Scratch programming skills and computational thinking abilities, as confirmed by statistical analysis of test scores. The students also reported high satisfaction with the course. This study highlights the potential of integrating a targeted Scratch programming curriculum into lyceum education to foster crucial computational thinking skills and creativity, providing a strong foundation for further computer science learning.

Calcineurin (CaN) is a serine/threonine phosphatase widely expressed in different cell types and structures including neurons and synapses. The most studied role of CaN is its involvement in the functioning of postsynaptic structures of central synapses. The role of CaN in the presynaptic structures of central and peripheral synapses is less understood, although it has generated a considerable interest and is a subject of a growing number of studies. The regulatory role of CaN in synaptic vesicle endocytosis in the synapse terminals is actively studied. In recent years, new targets of CaN have been identified and its role in the regulation of enzymes and neurotransmitter secretion in peripheral neuromuscular junctions has been revealed. CaN is the only phosphatase that requires calcium and calmodulin for activation. In this review, we present details of CaN molecular structure and give a detailed description of possible mechanisms of CaN activation involving calcium, enzymes, and endogenous and exogenous inhibitors. Known and newly discovered CaN targets at pre-and post-synaptic levels are described. CaN activity in synaptic structures is discussed in terms of functional involvement of this phosphatase in synaptic transmission and neurotransmitter release.

Discrete analogs of pseudo-differential operators and equations in discrete Sobolev–Slobodetsky spaces are considered. Using suitable discrete boundary conditions, we prove the unique solvability of the discrete boundary-value problem.

Motivation Application of chemical named entity recognition (CNER) algorithms allows retrieval of information from texts about chemical compound identifiers and creates associations with physical–chemical properties and biological activities. Scientific texts represent low-formalized sources of information. Most methods aimed at CNER are based on machine learning approaches, including conditional random fields and deep neural networks. In general, most machine learning approaches require either vector or sparse word representation of texts. Chemical named entities (CNEs) constitute only a small fraction of the whole text, and the datasets used for training are highly imbalanced. Methods and results We propose a new method for extracting CNEs from texts based on the naïve Bayes classifier combined with specially developed filters. In contrast to the earlier developed CNER methods, our approach uses the representation of the data as a set of fragments of text (FoTs) with the subsequent preparati`on of a set of multi- n -grams (sequences from one to  n  symbols) for each FoT. Our approach may provide the recognition of novel CNEs. For CHEMDNER corpus, the values of the sensitivity (recall) was 0.95, precision was 0.74, specificity was 0.88, and balanced accuracy was 0.92 based on five-fold cross validation. We applied the developed algorithm to the extracted CNEs of potential Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro) inhibitors. A set of CNEs corresponding to the chemical substances evaluated in the biochemical assays used for the discovery of Mpro inhibitors was retrieved. Manual analysis of the appropriate texts showed that CNEs of potential SARS-CoV-2 Mpro inhibitors were successfully identified by our method. Conclusion The obtained results show that the proposed method can be used for filtering out words that are not related to CNEs; therefore, it can be successfully applied to the extraction of CNEs for the purposes of cheminformatics and medicinal chemistry.

Abstract—The article presents an analysis of spatial trends in the development of public–private partnership (PPP) in Russia. The analysis is performed on a large base of PPP projects and reveals the main spatial imbalances and contradictions, uneven development of PPP across regions of the Russian Federation, and prevalence of small projects. It is emphasized that improving the institutional environment of territories is important for intensification of PPP processes. The current distribution of PPP investments across the Russian Federation indicates that the goals of improving the population’s quality of life prevail over the national-economic goal of strengthening connectivity of the country’s territory.

The behavior of a series of polysubstituted 4,4′-dipyrromethanes, namely 1,1′-bis{2-amino-1-[2-(vinyloxy)ethyl]-5-sulfanyl-1 H -pyrrol-4-yl}ethanes, under electron impact (70 eV) has been studied for the first time. The title compounds were synthesized in one preparative step from propargylamines, 2-(vinyloxy)ethyl isothiocyanate, and alkylating agents. Except for 5,5′-bis[(allyl-, propargyl-, and cyanomethyl)sulfanyl]­dipyrromethanes, the examined compounds give rise to stable molecular ions which decompose along three main pathways with the formation of four key cations. Two fragmentation pathways involve cleavage of the C–S bonds in the sulfanyl substituent and with the pyrrole ring to produce [ M – R 2 ] + and [ M – SR 2 ] + ions, respectively. The third pathway is associated with cleavage of the C–C bond between the pyrrole ring and methylene bridge connecting the pyrrole ring. In this case, two ions can be formed with the abundance ranging from 3 to 100%, depending on the substituent structure. The most abundant (up to 100% relative intensity) are radical cations [ M – R 2 – SR 2 ] + · . The resulting fragment ions are stabilized via cyclization involving the vinyloxyethyl group.

The behavior of previously unknown 3- and 5-(1 H -pyrrol-1-yl)- and 3-(1-methyl-1 H -pyrrol-2-yl)thiophen-2-amines under electron impact (70 eV) and chemical ionization (reactant gas methane) has been studied. The title compounds were synthesized in one pot from lithiated 1-propa-1,2-dien-1-yl-, 1-prop-2-yn-1-yl-, and 1-methyl-2-prop-1-yn-1-yl-1 H -pyrroles, isothiocyanates, and methyl iodide. Under electron impact, all compounds formed stable molecular ions ( M + · , I rel 100%) which underwent fragmentation along two common pathways, C–N bond cleavage in the amine substituent with charge localization on the sulfur atom and generation of [ M – R] + ions (first pathway) and [ M – Me] + ions (second pathway). An exception was N -butyl-substituted thiophenamine which showed no [ M – Me] + ion in the mass spectrum. The stability of these ions depended on the nature of the R substituent. Thus, the [ M – R] + ion peak (R = Alk) had the highest intensity ( I rel 28–91%), whereas the [ M – R] + ions (R = Ar) were the least abundant ( I rel 3–8%). In contrast, the intensity of the [ M – Me] + ion peak in the mass spectra of N -aryl-substituted thiophenamines ( I rel 28–52%) was higher than the intensity of the corresponding ion peak of N -alkyl analogues ( I rel 14–41%), except for N -ethyl-3-(1-methyl-1 H -pyrrol-2-yl)thiophen-2-amine, in the spectrum of which the intensity of the [ M – Me] + ion peak was 57%. The [ M – R] + and [ M – Me] + ions derived from all N , N -dimethylthiophen-2-amines had the same m / z value and structure. The third fragmentation pathway was observed only for N -alkylthiophenamines; it involved α-cleavage in the amine substituent with charge localization on the exocyclic nitrogen atom. The fragmentation pathways of ions derived from all thiophenamines studied were proposed on the basis of analysis of tandem mass spectra (MS 2 ). All 3-(1 H -pyrrol-1-yl)thiophen-2-amines under chemical ionization with methane as reactant gas easily underwent protonation, charge transfer, and electrophilic addition processes, and the resulting M + · , [ M + H] + and [ M + Et] + gave high-intensity peaks in the mass spectra.

A method for calculating the impact of forest insects on carbon deposition processes in forest cenoses is proposed. A method for assessing “lost profit” in forest ecosystems during forest insect outbreaks associated with the cessation of carbon deposition after the removal of the photosynthetic apparatus of trees is considered. Calculations of the substance balance during food consumption by phyllophagous insect caterpillars are described. Indicators of food prices during feeding on leaves and needles of different tree species are proposed for quantitative analysis of changes in the carbon stock associated with the activity of forest insects, and methods for calculating carbon emissions into the atmosphere during insect feeding are described. A scheme for monitoring the removal of phytomass by insects during an outbreak using remote sensing data is considered.

Reactive oxygen species (ROS) have been considered for many years as negative regulators in the cardiovascular system. Indeed, excessive production of ROS characterizes many cardiovascular diseases. The damaging effect of ROS can be especially pronounced in a newborn organism, since during this period their vasoconstrictor effect in pulmonary arteries remains as high as in pre-term fetus and the antioxidant systems have not yet formed. Therefore, in the first hours and days of independent life, pulmonary arteries tend to contract, primarily due to the low bioavailability of endothelial NO, which increases the risk of developing pulmonary hypertension in newborns. At the same time, during the perinatal period, ROS play an important role in the adaptive reactions of the circulatory system. ROS provide occlusion of the ductus arteriosus and separation of the pulmonary and systemic circulations soon after birth, and also contribute to the contraction of peripheral vessels during hypoxia, which often accompanies the delivery, and therefore provide priority blood supply to the brain in these conditions. The vasomotor effect of ROS is also pronounced in early postnatal ontogenesis, but it has a different character. In the first weeks of life, the action of ROS serves as one of the mechanisms for increasing endothelium-dependent relaxation of pulmonary vessels. In addition, during early postnatal ontogeny, ROS may play an important role in the regulation of systemic vascular tone. This review outlines the current understanding of the vasomotor role of ROS in the vessels of the pulmonary and systemic circulations and considers the mechanisms of ROS effects on the functioning of vascular endothelial and smooth muscle cells in the perinatal and early postnatal periods.