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A simple and effective synthetic method for (–)-nopinone via oxidation of (+)-myrtenal by oxone in DMF to form 6,6-dimethylbicyclo[3.1.1]hept-2-en-2-yl formate was proposed. Subsequent hydrolysis of the formate under basic conditions formed nopinone in preparative yields of 61–67%. [ABSTRACT FROM AUTHOR]

A simple and efficient synthesis of cis- and trans-myrtanic acids in preparative yields of 54–58% and 72–74%, respectively, was proposed and consisted of oxidation of cis- and trans-myrtanols by CrO3–AcOH upon addition of the oxidant to a solution of the starting alcohols at room temperature. Tests of the obtained compounds for antifungal activity showed lower activity for the quaternary salts than for the starting acids and greater efficacy for the cis-isomers than for the trans-isomers. However, the alcohols themselves, i.e., cis- and trans-myrtanols and (–)-myrtenol, had the greatest activities. [ABSTRACT FROM AUTHOR]

Short-latency auditory-evoked potentials (AEPs) were recorded non-invasively in the bottlenose dolphin Tursiops truncatus. The stimuli were two sound clicks that were played either monaurally (both clicks to one and the same acoustic window) or dichotically (the leading stimulus (masker) to one acoustic window and the delayed stimulus (test) to the other window). The ratio of the levels of the two stimuli was 0, 10, or 20 dB (at 10 and 20 dB, the leading stimulus was of a higher level). The inter-stimulus intervals (ISIs) varied from 0.15 to 10 ms. The test response magnitude was assessed by correlation analysis as a percentage of the control (non-masked) response. At monaural stimulation, the test response was of a constant magnitude (5–6% of the control) at ISIs of 0.15–0.3 ms and recovered at longer ISIs. At dichotic stimulation, the deepest suppression of the test response occurred at ISIs of 0.5–0.7 ms. The response was slightly suppressed at short ISIs (0.15–0.3 ms) and recovered at ISIs longer than 0.5–0.7 ms. The relation of parameters of the forward masking to echolocation in dolphins is discussed. [ABSTRACT FROM AUTHOR]

Both experimental and clinical liver fibrosis leave a metabolic footprint that can be uncovered and defined using metabolomic approaches. Metabolomics combines pattern recognition algorithms with analytical chemistry, in particular, 1H and 13C nuclear magnetic resonance spectroscopy (NMR), gas chromatography–mass spectrometry (GC–MS) and various liquid chromatography–mass spectrometry (LC–MS) platforms. The analysis of liver fibrosis by each of these methodologies is reviewed separately. Surprisingly, there was little general agreement between studies within each of these three groups and also between groups. The metabolomic footprint determined by NMR (two or more hits between studies) comprised elevated lactate, acetate, choline, 3-hydroxybutyrate, glucose, histidine, methionine, glutamine, phenylalanine, tyrosine and citrate. For GC–MS, succinate, fumarate, malate, ascorbate, glutamate, glycine, serine and, in agreement with NMR, glutamine, phenylalanine, tyrosine and citrate were delineated. For LC–MS, only β-muricholic acid, tryptophan, acylcarnitine, p-cresol, valine and, in agreement with NMR, phosphocholine were identified. The metabolomic footprint of liver fibrosis was upregulated as regards glutamine, phenylalanine, tyrosine, citrate and phosphocholine. Several investigators employed traditional Chinese medicine (TCM) treatments to reverse experimental liver fibrosis, and a commentary is given on the chemical constituents that may possess fibrolytic activity. It is proposed that molecular docking procedures using these TCM constituents may lead to novel therapies for liver fibrosis affecting at least one-in-twenty persons globally, for which there is currently no pharmaceutical cure. This in-depth review summarizes the relevant literature on metabolomics and its implications in addressing the clinical problem of liver fibrosis, cirrhosis and its sequelae. [ABSTRACT FROM AUTHOR]

Convergence of iterative processes applied to implicit completely conservative difference schemes of three-dimensional magnetohydrodynamics in the framework of methods of separate and combined solution of groups of difference equations that are split by physical processes is studied. Estimates of the convergence of iterative processes for the numerical methods considered in this work are obtained. The scope of both the combined and separate methods for solving the 3D difference equations of magnetohydrodynamics is investigated. Taking into account the fact that the study of the presented algorithms is mainly of a qualitative nature, the validity of the obtained estimates is confirmed by numerical experiments, and both model and real problems are considered. Note that the obtained estimates of convergence of the iterative processes make it possible to choose the optimal numerical method for solving difference equations of 3D magnetohydrodynamics at any time step. [ABSTRACT FROM AUTHOR]

The development of reactor technologies and neutrino physics by means of nuclear reactors requires unceasingly refining and extending knowledge of reactors as an antineutrino source. By employing new data on the reactor-antineutrino spectrum and updated nuclear databases and upon taking into account special features of fuel burnup, the thermal energy released in the reactor core per fission event is calculated for a standard operating period of a thermal-neutron reactor. [ABSTRACT FROM AUTHOR]

Aims This study aimed to compare the effects of linear and branched fructooligosaccharides (FOS) extracted from chicory and grass (Lolium perenne), respectively on human microbiota composition, diversity, and metabolism. Methods and results To test the effects of linear and branched FOS on human microbiota we used the artificial in vitro human colon model (TIM-2). Microbiota composition and diversity were assessed by V3–V4 16S rRNA metagenomic sequencing, followed by differential taxa abundance and alpha/beta diversity analyses. SCFA/BCFA production was evaluated by gas chromatography–mass spectrometry. As a result, branched FOS had the most beneficial effects on microbial diversity and metabolite production. Also, branched FOS significantly increased the abundance of commensal bacteria associated with maintaining healthy gut functions and controlling inflammation, such as Butyricicoccus, Erysipelotrichaceae, Phascolarctobacterium , and Sutterella. Linear FOS also significantly increased the abundance of some other commensal gut bacteria (Anaerobutyricum, Lachnospiraceae, Faecalibacterium), but there were no differences in diversity metrics compared to the control. Conclusions The study revealed that branched FOS had the most beneficial effects compared to the linear FOS in vitro , concerning microbiota modulation, and metabolite production, making this a good candidate for further studies in food biotechnology. [ABSTRACT FROM AUTHOR]

Background: The high mortality rate of patients with acute myocardial infarction (AMI) remains the most pressing issue of modern cardiology. Over the past 10 years, there has been no significant reduction in mortality among patients with AMI. It is quite obvious that there is an urgent need to develop fundamentally new drugs for the treatment of AMI. Angiotensin 1–7 has some promise in this regard. Objective: The objective of this article is analysis of published data on the cardioprotective properties of angiotensin 1–7. Methods: PubMed, Scopus, Science Direct, and Google Scholar were used to search articles for this study. Results: Angiotensin 1–7 increases cardiac tolerance to ischemia/reperfusion and mitigates adverse remodeling of the heart. Angiotensin 1–7 can prevent not only ischemic but also reperfusion cardiac injury. The activation of the Mas receptor plays a key role in these effects of angiotensin 1–7. Angiotensin 1–7 alleviates Ca2+ overload of cardiomyocytes and reactive oxygen species production in ischemia/reperfusion (I/R) of the myocardium. It is possible that both effects are involved in angiotensin 1–7‐triggered cardiac tolerance to I/R. Furthermore, angiotensin 1–7 inhibits apoptosis of cardiomyocytes and stimulates autophagy of cells. There is also indirect evidence suggesting that angiotensin 1–7 inhibits ferroptosis in cardiomyocytes. Moreover, angiotensin 1–7 possesses anti‐inflammatory properties, possibly achieved through NF‐kB activity inhibition. Phosphoinositide 3‐kinase, Akt, and NO synthase are involved in the infarct‐reducing effect of angiotensin 1–7. However, the specific end‐effector of the cardioprotective impact of angiotensin 1–7 remains unknown. Conclusion: The molecular nature of the end‐effector of the infarct‐limiting effect of angiotensin 1–7 has not been elucidated. Perhaps, this end‐effector is the sarcolemmal KATP channel or the mitochondrial KATP channel. [ABSTRACT FROM AUTHOR]

Bats are natural reservoirs for many emerging viral diseases. That is why their virome is widely studied. But at the same time, studies of their bacterial gut microbiota are limited, creating a degree of uncertainty about the role of bats in global microbial ecology. In this study, we analyzed gut microbiota of insectivorous Nyctalus noctula and Vespertilio murinus from rehabilitation centers from Rostov-on-Don and Moscow, respectively, and fructivorous Carollia perspicillata from the Moscow Zoo based on V3–V4 16S rRNA metagenomic sequencing. We revealed that microbial diversity significantly differs between the insectivorous and fructivorous species studied, while the differences between N. noctula and V. murinus are less pronounced, which shows that bats' gut microbiota is not strictly species-specific and depends more on diet type. In the gut microbiota of synanthropic bats, we observed bacteria that are important for public health and animal welfare such as Bacteroides, Enterobacter, Clostridiaceae, Enterococcus, Ureaplasma, Faecalibacterium, and Helicobacter, as well as some lactic acid bacteria such as Pediococcus, Lactobacillus, Lactococcus, and Weisella. All these bacteria, except for Bacteroides and Weisella, were significantly less abundant in C. perspicillata. This study provides a direct metagenomic comparison of synanthropic insectivorous and zoo fructivorous bats, suggesting future directions for studying these animals' role in microbial ecology. [ABSTRACT FROM AUTHOR]

Simple Summary: Bats play a significant role in public health and animal welfare as these animals are hosts for emerging pathogens. Urbanization has resulted in the acquisition of these animals' synanthropic behavior. Urban infrastructure suits bats as their hibernacula more than their natural sites due to the absence of predators, relatively high temperatures, and the close location of potential roost sites. However, the microbiota of hibernating bats is little studied, leaving some degree of uncertainty on how the abundance and diversity of gut bacteria are affected by low body temperature and food deprivation. In this study, we investigated the composition of cultivable gut microbiota before, during, and after hibernation of bats in the rehabilitation center. As a result, we observed a high abundance of opportunistic pathogens in the gut microbiota of active bats that had just arrived at the rehabilitation center that they had probably received from the environment. During the hibernation of bats, the abundance of these bacteria was significantly decreased, while the abundance of some other commensals was increased with an overall decrease in microbial diversity. This study shows how hibernation affects bat gut microbiota, pointing to the necessity of investigation of the bat–microbiota relationship during hibernation to prevent emerging diseases. The role of bats in the global microbial ecology no doubt is significant due to their unique immune responses, ability to fly, and long lifespan, all contributing to pathogen spread. Some of these animals hibernate during winter, which results in the altering of their physiology. However, gut microbiota shifts during hibernation is little studied. In this research, we studied cultivable gut microbiota composition and diversity of Nyctalus noctula before, during, and after hibernation in a bat rehabilitation center. Gut microorganisms were isolated on a broad spectrum of culture media, counted, and identified with mass spectrometry. Linear modeling was used to investigate associations between microorganism abundance and N. noctula physiological status, and alpha- and beta-diversity indexes were used to explore diversity changes. As a result, most notable changes were observed in Serratia liquefaciens, Hafnia alvei, Staphylococcus sciuri, and Staphylococcus xylosus, which were significantly more highly abundant in hibernating bats, while Citrobacter freundii, Klebsiella oxytoca, Providencia rettgeri, Citrobacter braakii, and Pedicoccus pentosaceus were more abundant in active bats before hibernation. The alpha-diversity was the lowest in hibernating bats, while the beta-diversity differed significantly among all studied periods. Overall, this study shows that hibernation contributes to changes in bat cultivable gut microbiota composition and diversity. [ABSTRACT FROM AUTHOR]

This study is based on observations of the pulsar B1133+16 conducted on the BSA PRAO antenna array at a frequency of 111 MHz with continuous recording of undetected signal (voltage) in the 2.5 MHz band, providing time resolution 0.2 µs. From 30 observation sessions, 570 strong pulses were selected for the subsequent analysis of microstructure parameters. The analysis was performed by computing autocorrelation functions separately for the three components of the mean profile: two extreme main components I and II and for the central weak component in the profile saddle. For the component , microstructure analysis was performed for the first time. Distributions have been constructed by the following parameters: time scales , modulation depth , and parameter , which characterizes the shape of the micropulses. Noticeable differences were found in some parameters for different profile components. The discovered features were interpreted in the model of hollow cone with a central component. It was believed that the radio emission of the extreme components (I and II) is generated by ordinary mode O, and the radio emission of the central component is provided by extraordinary mode X. Under this interpretation the radio emission output heights above the polar cap, were estimated to be 45 and 280 km for the X and O modes, respectively. A noticeable deformation of the X mode emission cone relative to the central component S was mentioned. Considerations are presented that point to the spatial structure of the secondary plasma flow, elongated along the meridians of the magnetic field. [ABSTRACT FROM AUTHOR]

A new elasmobranch assemblage including 14 shark taxa, mainly lamniformes (9 taxa), is described from the Lower Eocene (NP 10–11) Kalinino Formation of the Alai River Basin, Baltai District, Saratov Region of Russia. The Nikulinka elasmobranch assemblage may have characterised inner neritic environments of the eastern part of the sub-boreal European paleobiogeographic region, being closely related to assemblages from the south-most sector of the boreal Western Siberian Province (southern Trans-Urals and Turgay straight). The absence of myliobatids in Nikulinka and Trans-Uralian localities may have been caused by the influence of Arctic water masses through meridional straits in early Ypresian. This is the first chondrichthyan assemblage from the Palaeogene of the Middle Volga Region, European Russia. [ABSTRACT FROM AUTHOR]

Coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats in vivo, as well as total ischemia (45 min) of an isolated rat heart followed by reperfusion (30 min) were reproduced. The selective δ2-opioid receptor agonist deltorphin II (0.12 mg/kg and 152 nmol/liter) was administered intravenously 5 min before reperfusion in vivo or added to the perfusion solution at the beginning of reperfusion of the isolated heart. The peripheral opioid receptor antagonist naloxone methiodide and δ2-opioid receptor antagonist naltriben were used in doses of 5 and 0.3 mg/kg, respectively. It was found that the infarct-limiting effect of deltorphin II is associated with the activation of δ2-opioid receptors. We have demonstrated that deltorphin II can improve the recovery of the contractility of the isolated heart after total ischemia. [ABSTRACT FROM AUTHOR]

Using ground-space VLBI data from the RadioAstron project archive, the phase distortions of the cross-spectrum caused by the ionosphere have been calculated and their influence on the results of determination of the visibility function has been studied. The Arecibo Observatory's 300-m antenna served as the ground station for the interferometer. The separation of ionospheric phase distortions from the influence of the interstellar and interplanetary medium and instrumental errors is based on different frequency dependencies of these effects. The amplitude of ionospheric phase variation caused by electron density fluctuations in the ionosphere above the Arecibo radio telescope is several radians per observation session of about one hour. The structure function of phase variations indicates a continuous spectrum of electron density fluctuations at typical times of 2–5 min with no pronounced signs of quasi-periodic processes. Ionospheric phase f-luctuations during pulsar observations increase the width of the maximum of the amplitude of the visibility function as a function of the residual fringe rate by 5–10 mHz with a decrease in the value at the maximum of . When constructing images of radio galaxies and quasars from ground-based VLBI observations, these phase shifts can significantly distort the final results. [ABSTRACT FROM AUTHOR]

Hypoxia (20 min) and reoxygenation (30 min) were simulated on isolated rat cardiomyocytes to evaluate the cytoprotective effect of selective δ2-opioid receptor agonist deltorphin II, opioid receptor antagonist naloxone methiodide, μ-opioid receptor antagonist CTAP, κ-opioid receptor antagonist nor-binaltorphimine, ε1-opioid receptor antagonist BNTX, and δ2-opioid receptors naltriben. Deltorphin II was administered 5 min before reoxygenation, antagonists were administered 10 min before reoxygenation. The cytoprotective effect of deltorphin II was assessed by the number of cardiomyocytes survived after hypoxia/reoxygenation, as well as by the lactate dehydrogenase content in the incubation medium. It has been established that the cytoprotective effect of deltorphin II occurs at a concentration of 64 nmol/liter and is associated with activation of δ2-opioid receptors. [ABSTRACT FROM AUTHOR]

The B1133+16 pulsar was observed at a frequency of 111 MHz with the BSA radio telescope of the Pushchino Radio Astronomy Observatory from October 2022 to March 2023. Observations were conducted twice a week for two consecutive days. In total, 38 measurements of the scintillation parameters were carried out with a high frequency resolution (up to 65 Hz). We used continuous signal recording in the frequency band of 2.5 MHz. The signal was reconstructed using the coherent dedispersion method. The pulsar's dynamic spectra (DSP) were analyzed using the two-dimensional autocorrelation function (2DACF). The fine frequency structure of the pulsar's scintillation was investigated both through the analysis of time and frequency sections of 2DACF from DSP and through the spectra of individual pulses. The analysis of the frequency sections of the 2DACF showed that the true form of diffractive frequency distortions can be represented by a generalized exponential function with a characteristic frequency width of 1.2 kHz and an index of 0.57. Comparison of scintillation parameters separately for two components of the average profile showed that they are identical for both components. [ABSTRACT FROM AUTHOR]

A new chondrichthyan assemblage comprising 27 genera is described from the Middle Eocene Osinovaya Formation of the Bystraya River Basin, Morozovsk District of Rostov Region, in the southern part of European Russia. The Morozovsk assemblage consists of 21 genera and 24 species of shark, 5 genera and species of batoid and a single genus and species of chimaeroid fish (Edaphodon sp.). A composition of the assemblage is characterised by the coexistence of Otodus sokolovi, O. auriculatus, Isurolamna bajarunasi, Macrorhizodus praecursor, Jaekelotodus trigonalis and Brachycarcharias lerichei and indicates the Lutetian age of the deposits (possibly middle – upper Lutetian because of the presence of O. sokolovi together with O. auriculatus). This corresponds to the previous dating of the Osinovaya Formation. Lamniformes (12 taxa) and Myliobatiformes (5 taxa) are dominated in assemblage between elasmobranchs, characterising the inner to middle neritic warm-water environments. The Morozovsk elasmobranch assemblage belongs to the European paleobiogeographic region and shows a great similarity with the previously known coeval assemblages from the Western Europe, as well as with Uzbek assemblages from the adjacent Crimean-Caucasian paleobiogeographic region. Scarce data on chimaeroid fishes show that only the genus Edaphodon is rarely present in shallow-water environments and only in the European paleobiogeographic region. [ABSTRACT FROM AUTHOR]

This study discusses the transition toward the use of environmentally friendly refrigerants in low-temperature technology. It also considers a new environmentally friendly fourth-generation refrigerant trans‑1,3,3,3-tetrafluoropropene R1234ze(E) as an alternative to the R134a refrigerant common in chillers and heat pumps, as well as the R22 refrigerant in air conditioning systems. A technique has been developed for constructing a unified fundamental equation on the states of liquid and gas for trans‑1,3,3,3-tetrafluoropropene. Around the critical point, the proposed fundamental equation satisfies the requirements of the scale theory for asymmetric systems, and in the region of a rarefied gas, it is reduced to the virial equation of state. Based on this fundamental equation, tables of standard reference data on pressure, density, enthalpy, isobaric and isochoric heat capacities, entropy, heat of vaporization, and sound velocity of trans‑1,3,3,3-tetrafluoropropene in the region of state parameters in the temperature ranges of 169–420 K and pressure of 0.1–100 MPa were calculated. Several statistical characteristics have been calculated, namely, absolute mean deviation, systematic deviation, standard deviation, and root mean square deviation, characterizing the accuracy of the proposed fundamental equation in describing the experimental values of the equilibrium properties obtained in recognized international thermophysical centers. Evidently, the values of these statistical characteristics are significantly lesser than those of the corresponding characteristics of the international fundamental equations of state, provided in the literature, when describing the thermal and caloric experimental data of trans‑1,3,3,3-tetrafluoropropene. The estimated expanded uncertainties of the tabulated data based on the proposed fundamental equation were 0.26% for density, 0.57% for pressure, 1.7% and 1.2% for isochoric and isobaric heat capacities, respectively, and 0.38% for sound velocity. The results suggest that the proposed unified fundamental equation of state adequately conveys the thermodynamic characteristics of trans‑1,3,3,3-tetrafluoropropene over the specified range of temperatures and pressures. [ABSTRACT FROM AUTHOR]

Simple Summary: Little is known about bat diversity in mountains above 2000 m a. s. l. in Europe. Here, we report data from a study carried out in the high-alpine karst landscape of Pirin Mountain, Bulgaria at an altitude ranging from 2300 to 2600 m a. s. l. Twenty bat species were detected using three inventory methods. Furthermore, we describe the highest bat swarming site in Europe, located at an altitude of 2600 m a. s. l. The study describes a pilot survey on bats in the highest areas of Pirin Mountain. The methods included examining subfossil bone remains, mist-netting, and recording echolocation calls. The study was conducted in August 2002 and 2013 and from 2019 to 2020. While in general, bat diversity tends to decrease with increasing altitude due to harsher environmental conditions, the present study, despite a short period, reveals high diversity. Twenty species, more than half of the Bulgarian bat fauna, were detected. The recording and analysis of vocal signatures proved to be the best way to inventory bat diversity. At least 13 species were detected by this method. Vespertilio murinus and Tadarida teniotis together make up more than 60% of all reliably determined echolocation sequences. Significant activity was found for Myotis myotis/blythii, Plecotus auritus, Eptesicus serotinus, and E. nilssonii. The registration of the latter species is of considerable faunistic interest. It was previously only known from a single specimen at one location in the country. The sex and age structure of the bat assemblage suggests that it is likely a swarming assemblage. The area is the highest swarming location in Europe. The results provide valuable information on bat ecology and behaviour, which can be used to inform management and protection efforts. [ABSTRACT FROM AUTHOR]

A comparative analysis of the infarct-limiting activity of δ- and κ-opioid receptors (OR) agonists was carried out on a model of coronary occlusion (45 min) and reperfusion (120 min) in male Wistar rats. We used selective δ2-OR agonist deltorphin II (0.12 mg/kg), δ-OR agonists BW373U86 and p-Cl-Phe DPDPE (0.1 and 1 mg/kg), selective agonists of δ1-OR DPDPE (0.1 and 0.969 mg/kg), κ1-OR U-50,488 (0.1 and 1 mg/kg), κ2-OR GR-89696 (0.1 mg/kg), and κ-OR ICI-199,441 (0.1 mg/kg). All drugs were administered intravenously 5 min before reperfusion. Deltorphin II, BW373U86 (1 mg/kg), p-Cl-Phe DPDPE (1 mg/kg), U-50,488 (1 mg/kg), and ICI-199,441 had a cardioprotective effect. The most promising compounds for drug development are ICI-199,441 and deltorphin II. [ABSTRACT FROM AUTHOR]

For the first time, all three types of play (locomotor, object, and social) have been recorded and described for wild representatives of the family Ochotonidae of the order Lagomorpha. Observations have been carried out at a separate settlement of pikas in the Irkutsk district of Irkutsk oblast (Russia). A total of 15 episodes of play were recorded for seven of the 14 animals observed, including ones of different sex and age. Eight episodes have been filmed and subjected to frame-by-frame analysis. We consider the recorded pika behavior to be play because it meets Burghardt's criteria for play. The play of pikas includes elements (jumping, spinning, and falling on the back) that are easily associated with a temporary loss of control over the body. [ABSTRACT FROM AUTHOR]

Abstract—The abundance of the common nettle on taluses was found to be strongly correlated with the abundance of signs of Turuchan pika occurrence such as feces, latrines, and haypiles collected by pikas in the crevices between and under the stones. We believe this activity of pikas provides nitrates and thus facilitates the growth of the common nettle, a ruderal nitrophilous plant, on taluses. On the other hand, pikas selectively store nettles. As a result, pikas can be considered as both "ecosystem engineers" and "niche constructors." [ABSTRACT FROM AUTHOR]

This review paper summarizes a new analytical approach to the theory of waves in periodic media developed in relation with the problems of fiber optics. An adequate definition of the oscillation phase used as an independent variable allows us to construct an infinite set of exact solutions describing excitation and damping of parametric oscillations beyond perturbation theory. [ABSTRACT FROM AUTHOR]

The problem of registration and recognition of thermal (3–15 µm) or ultraviolet (0.15–0.25 µm) objects in their surrounding area (0.8–1.1 µm) is solved by using two-channel two-spectrum optical systems. In order to implement innovative single-channel dual-spectrum emission image detectors, implemented in the image intensifier tube's architecture that make it possible to link the images of a thermal or ultraviolet object to an image of a terrain, it is necessary to develop a unified optical-mechanical system. In this paper, an approach for the development of a unified optical system for single-channel dual-spectrum emission image detectors of the image intensifier tube's architecture is proposed and theoretically studied. The proposed optical system makes it possible to form images of objects emitting in the thermal or ultraviolet range in relation to the image of the surrounding area. The choice of the base material, barium fluoride (BaF2), and geometry is based on a significant dispersion of the refractive index of the lens material. When performing calculations of the optical system, Newton's method and the Python language (SciPy library) were used. The optimal values of the thickness of the lenses and the input window of the image intensifier tube, the distance between them, and the radii of curvature of the lens surfaces are calculated. The calculation results can be used in the practical work on the creation of single-channel dual-spectrum emission receivers for images of the image intensifier tube architecture for the images of thermal and ultraviolet objects in relation to images of their surroundings. [ABSTRACT FROM AUTHOR]

Background: The use of percutaneous coronary intervention (PCI) in patients with ST‐segment elevation myocardial infarction (STEMI) is associated with a mortality rate of 5%–7%. It is clear that there is an urgent need to develop new drugs that can effectively prevent cardiac reperfusion injury. ATP‐sensitive K+ (KATP) channel openers (KCOs) can be classified as such drugs. Results: KCOs prevent irreversible ischemia and reperfusion injury of the heart. KATP channel opening promotes inhibition of apoptosis, necroptosis, pyroptosis, and stimulation of autophagy. KCOs prevent the development of cardiac adverse remodeling and improve cardiac contractility in reperfusion. KCOs exhibit antiarrhythmic properties and prevent the appearance of the no‐reflow phenomenon in animals with coronary artery occlusion and reperfusion. Diabetes mellitus and a cholesterol‐enriched diet abolish the cardioprotective effect of KCOs. Nicorandil, a KCO, attenuates major adverse cardiovascular event and the no‐reflow phenomenon, reduces infarct size, and decreases the incidence of ventricular arrhythmias in patients with acute myocardial infarction. Conclusion: The cardioprotective effect of KCOs is mediated by the opening of mitochondrial KATP (mitoKATP) and sarcolemmal KATP (sarcKATP) channels, triggered free radicals' production, and kinase activation. [ABSTRACT FROM AUTHOR]

The study examined eating timing, diet, and sleep phases in people with social jetlag (SJL). SJL was associated with a higher incidence rate of eating jetlag, eating phase delays, an increase in calorie intake after 9 p.m., a decrease in dietary fiber intake for brakfast, and melatonin-containing product consumption for dinner. People with SJL had a reduction in total sleep and light sleep phase duration by 60 and 36 min on work/school days and an increase in total sleep and rapid eye movement sleep duration by 66 and 60 min on weekends, respectively. People consuming foods with more melatonin for dinner showed a decrease in SJL by 54 min and an increase in total sleep and the deep sleep phase duration by 66 and 30 min, respectively. Thus, the consumption of melatonin-containing foods for dinner is associated with a decrease in circadian misalignment and an improvement in sleep quality. [ABSTRACT FROM AUTHOR]

The surface of the Kulunda Plain is dissected by a system of ancient wide valleys, former runoff hollows with a very small slope (less than 1°). Rivers flow through these weakly expressed valleys, redistributing soluble salts throughout the territory. The regime of these rivers is characterized by a high flood wave and low (up to complete drying) runoff in the summer. The purpose of this work is to study the ion-salt system of soils of ancient runoff hollows of the Kulunda Plain, their groundwater and river water flows in order to identify modern soil salinization processes. During floods, river water recharges nearby groundwater influencing its chemical composition. Studies of three key sites in the valleys of the Bagan (Novosibirsk oblast), Burla, and Kulunda (Altai region) rivers were conducted in 2021–2022. Groundwaters of various degrees of salinity (from 3.4 to 63.0 g/L) occur close to the surface (2–5 m), which determines the wide distribution of saline hydromorphic soils in the study area. Differences in the salt status of soils, groundwater, and river water in different valleys are considered. The degree of soil salinity depends on the soil texture. The high content of physical clay (<0.01 mm) particles contributes to the rise of salts with groundwater and their accumulation in the soil profile. A high content of exchangeable sodium in the soil adsorption complex (more than 3–5 cmol(c)/kg), the predominance of soluble sodium salts in the soil solution with its low mineralization, as well as the alkaline reaction of the soil medium are indicative of the development of solonetzic features in the studied soils. [ABSTRACT FROM AUTHOR]

A double perovskite Sr2CrNbO6 powder compound was studied by using X-ray diffraction, AC and DC magnetization, and ESR measurements. Two transitions in antiferromagnetically ordered regimes were observed through magnetization measurements at T = 5 and 2 K and were confirmed by the linear dependence of the magnetization on the applied magnetic field at these temperatures, approximations of the temperature dependence of the ESR linewidth, and AC magnetization. The zero field cooling curve was approximated by Bonner–Fisher law for quasi one dimensional chain with the exchange integral J/kB = 1 K between chromium spins. An approximation of linear part of magnetic susceptibility temperature dependence was performed using Curie–Weiss law. To describe the obtained effective moment μeff = 3.577μB, the presence Cr3+ and Cr4+ ions is estimated at a respective ratio about 0.8 : 0.2. [ABSTRACT FROM AUTHOR]

Scintillation of pulsar radio signals caused by the interstellar medium can in principle be used for interstellar interferometry. Changes in the dynamic spectra as a function of pulsar longitude were in the past interpreted as having spatially resolved the pulsar magnetosphere. Guided by this prospect we used very long baseline interferometry observations of PSR B1237+25 with the Arecibo and Green Bank radio telescopes at 324 MHz and analyzed such scintillation at separate longitudes of the pulse profile. We found that the fringe phase characteristics of the visibility function changed quasi-sinusoidally as a function of longitude. Also, the dynamic spectra from each of the telescopes shifted in frequency as a function of longitude. Similar effects were found for PSR B1133+16. However, we show that these effects are not signatures of having resolved the pulsar magnetosphere. Instead, the changes can be related to the effect of low-level digitizing of the pulsar signal. After correcting for these effects the frequency shifts largely disappeared. Residual effects may be partly due to feed polarization impurities. Upper limits for the pulse emission altitudes of PSR B1237+25 would likely be well below the pulsar light cylinder radius. In view of our analysis, we think that observations with the intent of spatially resolving the pulsar magnetosphere need to be critically evaluated in terms of these constraints on interstellar interferometry. [ABSTRACT FROM AUTHOR]

A method for the efficient analysis and solution of conditionally well-posed problems with a unique solution in the subspace is proposed. The use of the discrete finite-element model in the entire space to obtain a unique solution on the subspace of the original variational problem is substantiated. To find a normal pseudo-solution to the discrete problem (a system of linear algebraic equations with a sparse symmetric semi-definite matrix), a three-stage regularization method is proposed. This method makes it possible to obtain approximations of these solutions with a predetermined accuracy. Efficient adaptive high-performance algorithms of the method have been developed to solve systems of linear algebraic equations with sparse symmetric semi-definite matrices using modern computers with parallel computing. [ABSTRACT FROM AUTHOR]

Coronaviruses (CoVs) pose a huge threat to public health as emerging viruses. Bat-borne CoVs are especially unpredictable in their evolution due to some unique features of bat physiology boosting the rate of mutations in CoVs, which is already high by itself compared to other viruses. Among bats, a meta-analysis of overall CoVs epizootiology identified a nucleic acid observed prevalence of 9.8% (95% CI 8.7–10.9%). The main objectives of our study were to conduct a qPCR screening of CoVs' prevalence in the insectivorous bat population of Fore-Caucasus and perform their characterization based on the metagenomic NGS of samples with detected CoV RNA. According to the qPCR screening, CoV RNA was detected in 5 samples, resulting in a 3.33% (95% CI 1.1–7.6%) prevalence of CoVs in bats from these studied locations. BetaCoVs reads were identified in raw metagenomic NGS data, however, detailed characterization was not possible due to relatively low RNA concentration in samples. Our results correspond to other studies, although a lower prevalence in qPCR studies was observed compared to other regions and countries. Further studies should require deeper metagenomic NGS investigation, as a supplementary method, which will allow detailed CoV characterization. [ABSTRACT FROM AUTHOR]

The parameters of the synthesis of catalysts by the solution combustion method using oxalic acid as a reducing agent were investigated. The activity of the catalysts was determined in the production of hydrogen and carbon nanofibers by the catalytic decomposition of methane. The efficiency of oxalic acid was demonstrated in the preparation of a nickel catalyst (90% Ni/10% Al2O3), which does not require the preliminary reduction with hydrogen. Regression analysis identified that the yields of carbon and hydrogen are most strongly affected by temperature among other synthesis parameters. [ABSTRACT FROM AUTHOR]

This paper was stimulated by the experimental studies of solid-state lasers initiated by N. G. Basov and carried out at the Laboratory of Luminescence of the P. N. Lebedev Physical Institute under the direction of M. D. Galanin and A. M. Leontovich in the 1960-ies. Here, the classical parabolic equation method is extended in order to calculate complex eigenfrequencies of optical oscillations in a dielectric-filled open resonator. Accurate estimates confirm a high quality factor of ruby lasers. The developed approach can be used to find complex eigenfrequencies of other dielectric optical objects in laser systems of current interest. [ABSTRACT FROM AUTHOR]

Approximately 13% of the Russian population suffers from chronic kidney disease (CKD). Such a high prevalence of the disease, as well as the complexity and high cost of renal replacement therapy, explain the need for developing and implementing new approaches to treat patients at the pre-dialysis stages. The data collected in recent decades highlight the importance of gut microbiota in the progression of CKD. This review provides information about the microbiota composition in healthy individuals and patients with CKD and discusses the mechanisms of interaction in the intestine-kidney system. The article also presents the specifics of the violation of gut microbiota (GM) and correction thereof in CKD. [ABSTRACT FROM AUTHOR]

The authors propose software for the analysis and solution to the algebraic eigenvalue problem using an MIMD computer with GPUs, which includes parallel algorithms and programs with the functions of automatic adaptive configuration of the variable computer environment (multilevel parallelism, variable topology of interprocessor communications, mixed word length, caching, etc.) on the mathematical properties of the problem identified in the computer and the architectural features to ensure the reliability of the solution results and the efficient use of computing resources. [ABSTRACT FROM AUTHOR]

In male Wistar rats, coronary occlusion (45 min) and reperfusion (120 min) were modeled. Selective δ2-opioid receptor agonist (deltorphin II, 0.12 mg/kg) was administered intravenously 5 min before reperfusion; NO synthase inhibitor (L-NAME, 10 mg/kg), MPT pore blocker (atractyloside, 5 mg/kg), and protein kinase A inhibitor (H-89, 10 μg/kg) were administered intravenously 10 min before reperfusion. Deltorphin II administered before reperfusion led to a 2-fold decrease in the infarct size. The infarct-limiting effect of deltorphin II was associated with blockade of MPT pore. Protein kinase A and NO synthase were not involved in the cardioprotective effect of deltorphin II. [ABSTRACT FROM AUTHOR]

In-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is 5–6%. Consequently, it is necessary to develop fundamentally novel drugs capable of reducing mortality in patients with acute myocardial infarction. Apelins could be the prototype for such drugs. Chronic administration of apelins mitigates adverse myocardial remodeling in animals with myocardial infarction or pressure overload. The cardioprotective effect of apelins is accompanied by blockage of the MPT pore, GSK-3β, and the activation of PI3-kinase, Akt, ERK1/2, NO-synthase, superoxide dismutase, glutathione peroxidase, matrix metalloproteinase, the epidermal growth factor receptor, Src kinase, the mitoKATP channel, guanylyl cyclase, phospholipase C, protein kinase C, the Na+/H+ exchanger, and the Na+/Ca2+ exchanger. The cardioprotective effect of apelins is associated with the inhibition of apoptosis and ferroptosis. Apelins stimulate the autophagy of cardiomyocytes. Synthetic apelin analogues are prospective compounds for the development of novel cardioprotective drugs. [ABSTRACT FROM AUTHOR]

We propose a concept of terahertz waveguide plasmon amplifier based on a metal groove with active graphene. It is shown that the power amplification factor of the longitudinal-section magnetic (LSM) waveguide plasmon (normalized to its wavelength) near the cut-off frequency of this mode can exceed the amplification factor of the transverse magnetic (TM) plasmon in a layered graphene structure by more than four orders of magnitude for the same frequency. This is caused by the increase of the LSM plasmon wavelength near the cut-off frequency, smaller energy velocity of the LSM mode, and greater energy release from graphene for the LSM plasmon due to stronger lateral confinement of the LSM waveguide plasmon as compared to the TM plasmon in a layered graphene structure. We show that the enhancement of the LSM plasmon amplification factor near the cut-off frequency is a stronger effect than that due to screening of graphene. [ABSTRACT FROM AUTHOR]

The regularities of completely reversible valence transition Eu3+ → Eu2+ → Eu3+ in complex europium oxides have been investigated using a combination of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XANES + EXAFS) synchrotron methods. The influence of the type of M4+ cations on the reduction and oxidation, as well as the formation and evolution of the crystalline and local structure of the (M = Ti, Zr, Hf) compounds is established. It is shown that oxidation of initially reduced Eu2+MO3 samples leads to the formation of mixed-valence (MV) state Eu2+/Eu3+ with inhomogeneous charge distribution, causing a phase transition with formation of partially amophized intermediate metastable phases Eu3+MO3.5 having a monoclinic structure (sp. gr. Р1211). An increase in the oxidative annealing temperature to 1000°С facilitates further phase transition with the formation of stable cubic phases Eu M2O7. [ABSTRACT FROM AUTHOR]

We study 6000 author-publication observations to investigate predictors of early career success in six fields of economics. Concentrating on top researchers enables us to control for the effects of ability and effort, and focusing on the start of their careers minimizes distortions from reputation feedback. Our results reveal that the most important predictor for early career success is the ranking of an author's PhD granting institution, followed by his first placement. Our insights suggest that a counterfactual decrease in the Alma mater of a high ability author, who graduated from a top 10 university, by as little as 10 to 20 ranks, reduces his probability of getting a top 5 publication significantly by 13 percentage points. Lowering the ranking of his Alma mater by another 80 ranks decreases his chances of getting a top publication by a factor of three. Our findings suggest that the economics publication market values Alma mater signals, discounting newcomers graduating from- or working at lower ranked departments. [ABSTRACT FROM AUTHOR]

It is proposed to approximate the frequency and time sections of the two-dimensional autocorrelation functions of the dynamic spectra of pulsar scintillations by a universal exponential function with an arbitrary exponent . This approximation describes the shape of the correlation function much better than the Gaussian or simple exponential function. The relationship between the shape of autocorrelation functions and the initial profile of the average frequency structure of diffractive scintillations is studied by numerical simulation. It is shown that the true width of this average frequency profile differs significantly from the width of the autocorrelation function, which leads to a shift in estimates of some effects caused by scintillations. Examples of such distorted estimates for the pulsar velocity () and for the transition from the decorrelation bandwidth to the scattering time are presented. [ABSTRACT FROM AUTHOR]

Background: Current assessment methods of penile cavernous fibrosis in animal models have limitations due to the inability to provide complex and volume analysis of fibrotic alterations. Objective: The aim was to evaluate micro‐computed tomography for assessment of cavernous fibrosis and compare it with histological, histochemical, immunohistochemical, and RT‐PCR analysis. Materials and methods: A controlled trial was performed involving 25 New Zealand male rabbits with induced testosterone deficiency by orchidectomy. Penile samples were obtained before and after 7, 14, 21, and 84 days from orchidectomy. We consistently performed (a) gray value analysis of corpora cavernosa 3D models reconstructed after micro‐computed tomography, (b) morphometry of smooth muscles/connective tissue ratio, collagen type I/III ratio, and area of TGF‐beta‐1 expression in corpora cavernosa, and (c) RT‐PCR of TGF‐beta‐1 expression. Results: Micro‐computed tomography allowed visualization of penile structures at a resolution comparable to light microscopy. Gray values of corpora cavernosa decreased from 1673 (1512–1773) on the initial day to 1184 (1089–1232) on the 21st day (p < 0.005). However, on the 84th day, it increased to 1610 (1551–1768). On 21st and 84th days, there was observed a significant decrease in smooth muscle/connective tissue ratio and a significant increase in collagen type I/III ratio (p < 0.05). TGF‐beta1 expression increased on the 84th day according to immunohistochemistry (p < 0.005). RT‐PCR was impossible to conduct due to the absence of RNA in obtained samples after micro‐CT. Discussion and conclusions: Micro‐computed tomography provided 3D visualization of entire corpora cavernosa and assessment of radiodensity alterations by gray value analysis in fibrosis progression. We speculate that gray value changes at early and late fibrosis stages could be related to tissue reorganization. RT‐PCR is impossible to conduct on tissue samples studied by micro‐CT due to RNA destruction. We also suggest that micro‐computed tomography could negatively affect the immunohistochemical outcome, as a significant increase of TGF‐beta‐1 expression occurs later than histological fibrotic signs. [ABSTRACT FROM AUTHOR]

There are numerous studies which show that an early school start time has a negative impact on the sleep, well-being, and academic performance of students. There is not enough information on the association between school start time and eating disorders, however: the disruption of the circadian rhythm is known to be a risk factor for eating disorders. The aim of this study is to analyze the relationship between school start time (SST) and the sleep, well-being, academic performance, and eating behavior of children and adolescents. The study was conducted in April and May 2021 in two regions of Russia: the Komi Republic and Yekaterinburg. The online study involved the anonymous and voluntary participation of 6571 students in grades 6–11 (mean age: 14.5 ± 1.6 years, 60.1% female), who have morning classes. All participants were divided into three groups according to SST: 08:00 (n = 3661), 08:30 (n = 2020), and 09:00 (n = 890). Each participant of the study indicated their place of residence, SST, age, sex, height, weight, academic performance, and filled out the Munich Chronotype Questionnaire, the Zung Self-Rating Depression Scale, and the Yale Food Addiction Scale for Children. As a result of multiple regression analysis, it was shown that schoolchildren with SST of 09:00 wake up at a later time on school days (B = 0.432; ΔR2 = 0.039), sleep more (B = 0.293; ΔR2 = 0.004), have less pronounced social jetlag (B = −0.223; ΔR2 = 0.005) and sleep loss (B = −0.292; ΔR2 = 0.005), and higher academic performance (B = 0.113; ΔR2 = 0.003) than schoolchildren with SST of 08:00. As a result of logistic regression analysis, it was found that the frequency of the detection of food addiction is ~30% lower in schoolchildren with SST of 09:00 (OR = 0.690; 95% CI = 0.485–0.981) than in their peers with SST of 08:00. Thus, an overly early SST in Russia has a negative impact on the sleep function, academic performance, and eating behavior of children and adolescents. [ABSTRACT FROM AUTHOR]

Forward masking was investigated by the auditory evoked potentials (AEP) method in a bottlenose dolphin Tursiops truncatus using stimulation by two successive acoustic pulses (the masker and test) projected from spatially separated sources. The positions of the two sound sources either coincided with or were symmetrical relative to the head axis at azimuths from 0 to ± 90°. AEPs were recorded either from the vertex or from the lateral head surface next to the auditory meatus. In the last case, the test source was ipsilateral to the recording side, whereas the masker source was either ipsi- or contralateral. For lateral recording, AEP release from masking (recovery) was slower for the ipsi- than for the contralateral masker source position. For vertex recording, AEP recovery was equal both for the coinciding positions of the masker and test sources and for their symmetrical positions relative to the head axis. The data indicate that at higher levels of the auditory system of the dolphin, binaural convergence makes the forward masking nearly equal for ipsi- and contralateral positions of the masker and test. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate the associations among time perspective, sleep-wake rhythm characteristics, and psycho-emotional state during COVID-19 isolation. The study was carried out from April 17 to 14 June 2020and involved 844 people aged 17 to 26 years (average age: 19.4 ± 1.8 years, women: 79.4%). Each study participant filled out the Zimbardo Time Perspective Inventory, the Munich ChronoType Questionnaire, and Beck Depression Inventory. There were significant changes in the sleep characteristics during isolation: sleep duration increased by 56 minutes, sleep efficiency decreased by 2.4%, sleep phase delayed by 53 minutes, while social jetlag decreased by 77 minutes. Individuals with balanced, future, and past positive time perspective had better sleep characteristics, and were less likely to exhibit symptoms of depression. Persons with past negative, present hedonistic and present fatalistic time perspective were more likely to have worse sleep characteristics, and exhibited signs of depression. The results of the study indicate that persons focused on long-term planning for their lives generally endured the COVID-19 isolation more easily. [ABSTRACT FROM AUTHOR]

Intestinal microbiota is a topical subject of modern research. The maintenance of a healthy intestinal microbiota is an important component of homeostasis, and violations of its composition and functions, called dysbiosis, are associated with a number of diseases, including urinary tract infections. Antimicrobial therapy leads to significant changes in the intestinal microbiota and causes the possibility of urinary tract infection recurrence. In this regard, it is important to study methods of microbiota correction in order to restore its structural and functional integrity. [ABSTRACT FROM AUTHOR]

An original technique for describing excited states of electrons in crystal structure has been considered by an example of lithium. It is shown that the electron spectrum in lithium changes only slightly at large values of lattice parameter (up to 8.77 Bohr radii). The lifetimes of excited electrons of external s and p states differ significantly at lattice parameters d < 8.77 Bohr radii. A metastable crystalline state of bcc lithium is found, which barely depends on the excitation power at a lattice constant equal to 6.55 Bohr radii, corresponding to the bcc lattice constant of lithium in the ground state. [ABSTRACT FROM AUTHOR]

In our experiments, we develop and test portable multi-element receiver antenna arrays, electrically scanned in order to immediately obtain a recognizable image of subsurface objects. Two quadrature components of the radar return signal are processed with a Kirchhoff backward migration algorithm. Physical theory is used to assess the quality of the holographic image, and the synthetic aperture approach is developed and tested. The parabolic wave equation and Gaussian beam technique are used in order to take into account refraction effects and to suppress specular reflection from the air-ground interface. Laboratory and field tests confirmed the predicted device parameters. [ABSTRACT FROM AUTHOR]