Search

The first data on the diversity and structure of bacterial communities in the Selenga River, its tributaries, and delta waters (Selenga shallows) during the summer high-water period of 2021 were obtained. The chemical indices (alkalinity, mineralization, as well as concentrations of sulfate and chloride ions) in the Russian part of the Selenga River exhibited a tendency to decrease gradually in the downstream direction. As before, the chemical composition of the Selenga River waters was determined by water content and anthropogenic pressures, while the effect of tributary waters was local. At a distance of 1 km from the mouths in the mixing zone of river water and lake water, the chemical composition and taxonomic structure of bacterial communities were close to those observed in the pelagic zone of Lake Baikal. In all analyzed 16S rRNA gene libraries, nine common bacterial phyla were identified, with a predominance of Pseudomonadota (51.71–76.83%) in river communities and Actinomycetota (17.28–66.32%) in the communities of the Selenga shallows. The most significant differences in the taxonomic composition of bacterial communities were noted at the genus level. We suggest that a stable bacterial community exists throughout the Selenga River course, with dominant members representing the bacterial genera Limnohabitans, Pseudarcicella, Rhodoluna, and Polynucleobacter. The same genera also predominated in the small rivers of South Baikal. A comparative analysis of the diversity of tributary communities did not reveal any significant impact on the microbiomes of the Selenga River and Lake Baikal. Only a few riverine bacterial taxa were identified in the littoral and pelagic zones of the lake. [ABSTRACT FROM AUTHOR]

Monitoring wildlife exposure to biological hazards is a critical component of the wildlife risk assessment. In this study 38 hair samples were collected from 8 different species from ten districts of Russian Far East and Siberia and analysed for the presence of organochlorine pesticides (OCP). 50% of the samples were contaminated with - p, p’-DDT, α-HCH and DDD. DDT was the main contaminant found in 13 sample at concentrations range of 14.3 to 369.5 pg/mg hair, mean 91.9 ± 89.7 pg/mg. α-HCH was detected in three samples with the concentrations range 29.9–180.2 pg/mg. The p, p’-DDD was found only in one hair sample of Siberian roe deer from Altai region at 52.6 pg/mg. The exposure level is depended on animals habitat location. The most contaminated region is Terney district which is in the proximity to the borders with China and North Korea where OCP are still in use. [ABSTRACT FROM AUTHOR]

The international sanctions on Russian industry necessitate the study of consumer behavior in such conditions. Legal aspects of economic regulation are reviewed. Analysis of what is entailed in protecting the social and economic rights of Russian citizens permits clearer understanding of the sanctions' influence on consumer behavior. Measures to stabilize the Russian economy are evaluated, and the current circumstances of industry and citizens are discussed. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a DNA repair enzyme that can reduce the efficacy of some anticancer drugs targeting topoisomerase 1 (TOP1) making it a promising target for antitumor therapy when combined with TOP1 poisons. Here we describe the synthesis of a number of adamantane-monoterpene conjugates 20a–g and 21a–g connected through a 1,3,4-thiadiazol-2(3H)-imine linker, where acyclic, monocyclic, and bicyclic structural types of monoterpenes were used. All the synthesized compounds demonstrated activity against TDP1 in micromolar range, with the most potent inhibitor being compound 21a (IC50 1.2 μM). The cytotoxic effects of these compounds determined in the HEK293A and HeLa cell lines were low to moderate. These findings imply that such compounds are promising for further development of new TDP1 inhibitors with favorable physicochemical properties. [ABSTRACT FROM AUTHOR]

The purpose of this research was to investigate and identify by tandem mass spectrometry the polyphenolic complexes and other biologically active compounds present in the leaves and stems of Ledum palustre L. Carbon dioxide, compressed to a supercritical state, was used for the most environmentally friendly extraction of polyphenolic complexes and other biologically active compounds from Ledum palustre L. The most effective extraction characteristics (pressure 350 bar, temperature 60°C, extraction time 1 h, co-solvent MeOH 3.5%) of supercritical CO2 extraction of L. palustre were determined empirically. To identify target analytes in the supercritical extracts, high performance liquid chromatography (HPLC) in combination with a BRUKER DALTONIKS ion trap was used. The results showed the presence of 61 biologically active compounds corresponding to the Rhododendron species, of which 32 were identified for the first time in L. palustre. These are flavanols dihydrokaempferol, quercetin arabinoside, myricetin galactoside; flavones diosmetin, nevadensin, cirsimaritin; flavanone naringenin; anthocyanins delphinidin, petunidin, cyanidin pentoside, delphinidin pentoside, peonidin 3-(6-O-acetyl) glucoside, peonidin-3-O-malonylglucoside, cyanidin-3-rutinoside, peonidin 3-O-glucoside; ellagic acid; lignan medioresinol; a type A procyanidin dimer; sterols fucosterol and avenasterol, etc. [ABSTRACT FROM AUTHOR]

This is the first report on the application of metagenomic analysis of the microbiome of Lake Baikal bottom sediments in order to assess the community structure and metabolic potential of the microorganisms inhabiting the upper sediment horizon at the site of a deep-water station. Compared to the metagenome of near-bottom water, relative abundance of the phyla Methylomirabilota, Chloroflexota, and Acidobacterota was found to increase, as well as that of the genes for the pathways of methane, sulfur, and thiosulfate oxidation and of nitrate reduction. Genomes of members of 12 phyla forming the basis of the studied microbiome were assembled. Reconstruction of the metabolic pathways indicated the possible coexistence of microorganisms capable of gaining carbon and energy due to oxidation of carbohydrates, methane, thiosulfate, and ammonia, as well as via anaerobic processes of fermentation, denitrification, and (to a lesser degree) sulfate reduction. [ABSTRACT FROM AUTHOR]

We introduce eco4cast,1 an open-source package aimed to reduce carbon footprint of machine learning models via predictive cloud computing scheduling. The package is integrated with machine learning models and employs an advanced temporal convolution neural network to forecast daily carbon dioxide emissions stemming from electricity generation.The model attains remarkable predictive accuracy by accounting for weather conditions, acknowledged for their robust correlation with carbon energy intensity. The hallmark of eco4cast lies in its capability to identify periods of temporal minimal carbon intensity. This enables the package to manage cloud computing tasks only during these periods, significantly reducing the ecological impact. Our contribution represents a compelling fusion of sustainability and computational efficiency. The code and documentation of the package are hosted on GitHub under the Apache 2.0 license. [ABSTRACT FROM AUTHOR]

Clinical blood analysis, combined with cytomorphological examination is an important diagnostic tool for assessing the physiological state of animals. The cytomorphological features of blood cells have been described for terrestrial mammals, and well-illustrated veterinary atlases have been created, in which normal and pathological forms of animal blood cells are displayed. However, such information is virtually nonexistent for marine mammals. In this article, we present the results of a study of the morphology of the blood cells of the beluga (also known as "white") whale Delphinapterus leucas, obtained by supravital staining of blood smear preparations with Brilliant Cresyl Blue, Methylene Blue, and utilizing the standard Romanowsky–Giemsa staining technique. We describe the main types of blood cells of marine mammals: erythrocytes, segmented neutrophils, eosinophils, monocytes, lymphocytes, and band neutrophils, as well as rare basophils. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a DNA repair enzyme that removes various adducts from the 3' end of DNA. Such adducts are formed by enzymes that introduce single-strand breaks in DNA during catalysis (for example, topoisomerase 1) and a number of anticancer drugs with different mechanisms of action. Poly(ADP-ribose) polymerase 1 (PARP1) is an enzyme that catalyzes posttranslational modification (PARylation) of various targets and thus controls many cell processes, including DNA repair. Tdp1 is a PARP1 target, and its PARylation attracts Tdp1 to the site of DNA damage. Olaparib is a PARP1 inhibitor used in clinical practice to treat homologous recombination-deficient tumors. Olaparib inhibits PARylation and, therefore, DNA repair. The Tdp1 inhibitor OL7-43 was used in combination with olaparib to increase the antitumor effect of the latter. Olaparib cytotoxicity was found to increase in the presence of OL7-43 in vitro. OL7-43 did not exert a sensitizing effect, but showed its own antitumor and antimetastatic effects in Lewis and Krebs-2 carcinoma models. [ABSTRACT FROM AUTHOR]

Cases of horizontal transfer of transposable elements (TEs) between species are known for the Drosophilidae family. In the middle of the last century, the case of horizontal transfer of the P-element from the Drosophila willistoni to the D. melanogaster was described. A novel P-element invasion into the D. simulans genome from D. melanogaster occurred approximately 10 years ago. Currently, the P-element has spread across all D. melanogaster population and 30% of D. simulans populations in Europe, Africa and America. In this paper, we investigated the presence of the P-element in D. simulans lines caught in different years in three Asian populations (Tashkent, Nalchik and Sakhalin Island). We also examined the physiological characteristics (cytotype, lifespan, fecundity and locomotor activity) of D. simulans lines with and without the P-element to determine the significance of this new mobile element in the genome. The P-element was found in lines isolated from nature after 2012. The number of P-element copies per genome (two-to-three dozen according to fluorescence in situ hybridization data) was greater than in the American and comparable to the African populations. There were signs of intraspecific hybrid dysgenesis for some pairs of lines. However, in general the presence of the P-element did not adversely affect the physiological characteristics. Either adaptation to the new TE occurs very quickly, or the rate of movement of the P-element is so insignificant that its appearance in the genome remains unnoticed. [ABSTRACT FROM AUTHOR]

To date, various strategies have been proposed to increase the efficiency of cancer therapy. It is known that the action of DNA repair system can determine the resistance of cancer cells to DNA-damaging chemotherapy and radiotherapy, and one of these ways to increase therapeutic efficiency is the search for inhibitors of enzymes of the DNA repair system. Inhibition of the DNA repair enzyme tyrosyl-DNA phosphodiesterase1 (Tdp1) leads to an increase in the effectiveness of the topoisomerase 1 (Top1) inhibitor, the anticancer drug topotecan. Covalent complexes Top1-DNA, which are normally short-lived and are not a threat to the cell, are stabilized under the influence of topotecan and lead to cell death. Tdp1 eliminates such stabilized complexes and thus weaken the effect of topotecan therapy. We have previously shown that the use of the usnic acid hydrazonothiazole derivative OL9-119 in combination with topotecan increased the antitumor and antimetastatic efficacy of the latter in a mouse model of Lewis lung carcinoma. In this work, it was shown that the combined use of topotecan and Tdp1 inhibitor, the hydrazonothiazole derivative of usnic acid OL9-119, leads to an increase in the DNA-damaging effect of topotecan which is used in the clinic for the treatment of cancer. The study of the proapoptotic effect of the compound OL9-119 showed that the compound itself does not induce apoptosis, but increases the proapoptotic effect of topotecan. The results of the study could be used to improve the effectiveness of anticancer therapy and/or to reduce the therapeutic dose of topotecan and, therefore, the severity of side effects. [ABSTRACT FROM AUTHOR]

The effect of PARP1 knockout in HEK293 cells on the gene expression of DNA base excision repair (BER) proteins was studied. It was shown that the expression of all differentially expressed genes (DEGs) of BER was reduced by knockout. The expression of the DNA glycosylase gene NEIL1, which is considered to be one of the common "hubs" for binding BER proteins, has changed the most. The expression of genes of auxiliary subunits of DNA polymerases δ and ε is also significantly reduced. The PARP1 gene knockout cell line obtained is an adequate cell model for studying the activity of the BER process in the absence of PARP1 and testing drugs aimed at inhibiting repair processes. It has been found for the first time that knockout of the PARP1 gene results in a significant change in the level of expression of proteins responsible for ribosome biogenesis and the functioning of the proteasome. [ABSTRACT FROM AUTHOR]

Perturbations of attenuation coefficients and group velocities of acoustic modes is considered in a shallow-water waveguide with an inhomogeneous bottom relief. Explicit formulas are constructed for calculating the first and second derivatives of the aforementioned quantities with respect to the sea depth on the basis of the perturbation theory developed by the authors in previous publications. Application of the proposed formulas is illustrated by a model example. It is shown that they allow highly accurate approximation of depth dependences for group velocities and modal attenuation coefficients. The proposed formulas can be used to obtain simple analytic estimates of acoustic propagation loss in irregular waveguides, as well as to allow for inhomogeneities of the bottom relief in geoacoustic inversion according to the data on waveguide dispersion of signals. [ABSTRACT FROM AUTHOR]

The size and complexity of deep neural networks used in AI applications continue to grow exponentially, significantly increasing energy consumption for training and inference by these models. We introduce an open-source package eco2AI to help data scientists and researchers to track the energy consumption and equivalent CO2 emissions of their models in a straightforward way. In eco2AI we focus on accurate tracking of energy consumption and regional CO2 emissions accounting. We encourage the research for community to search for new optimal Artificial Intelligence (AI) architectures with lower computational cost. The motivation also comes from the concept of AI-based greenhouse gases sequestrating cycle with both Sustainable AI and Green AI pathways. The code and documentation are hosted on Github under the Apache 2.0 license https://github.com/sb-ai-lab/Eco2AI. [ABSTRACT FROM AUTHOR]

An analysis of the advantages of laser marking is carried out in comparison with other methods of forming a given surface relief of structural materials, forming barcodes, and reading them. The necessary conditions for stable reading of barcodes, described by the value of the contrast ratio, are formulated. The elements of the prints of the laser exposure pattern that make up the barcode are classified, and an example of measuring and calculating the contrast ratio of samples using spectrophotometry is given. The parameters of the surface relief in the areas of the applied barcode are measured using scanning probe microscopy. The analysis of the influence of the parameters of laser radiation on the geometric characteristics of the elements of the barcode and the value of its contrast ratio is carried out. [ABSTRACT FROM AUTHOR]

The biological traits of invertebrates inhabiting freshwater methane seeps are poorly understood. We analysed the relationship between invertebrate abundance and environmental factors such as methane concentration, location of gas hydrates in sediments, sediment composition, and the total number of microorganisms (TNMs), including methanotrophs. The abundance of invertebrates varied greatly (CV 10–136%) across box core samples and stations. No significant differences (P > 0.05) in the abundance of invertebrates were found between stations with sluggish methane discharge, methane concentrations, and gas hydrates located deep in sediments (> 70 cm) and the reference stations. The abundance of meio- and macrobenthic invertebrates reached ~ 130,000 ind. m−2 around gas hydrates ~ 30 cm deep in the sediments. The abundance of nematodes significantly depended on the presence of sulfur bacteria and copepod detritus, while oligochaetes were correlated with the TNMs. Amphipod abundance was dependent on the number of methanotrophic bacteria, while ostracods and copepods showed no dependence on the studied biotic factors. Stable isotope analysis of δ13C and δ15N indicated that oligochaetes and chironomids consumed different proportions of chemosynthetic carbon. Most benthic invertebrates also formed aggregates, possibly enabling the complete utilization of food resources. [ABSTRACT FROM AUTHOR]

MRK 421 is a giant elliptical galaxy in the Ursa Major constellation whose core has all the properties of a BL Lac object. It manifests a high activity and variability from the radio to gamma-ray ranges on time scales from a few hours to more than 10 years. MRK 421 has a large companion— a spiral, probably, also active galaxy (MRK 421-5). This paper presents the results of an analysis of observations (in the V, R, and I bands) as part of a joint Latvian-Ukrainian project for study of the variability of bright AGN. In addition, the light curves of MRK 421 from the AAVSO data base (American Association of Variable Star Observers) are analyzed to confirm the results of periodogram analysis. Ultimately, over the time interval studied here, MRK 421 is suspected of having a cyclical variability with a characteristic time in the range of 9.3-13.4 days determined by two different methods (approximation of the data by sinusoids and the CLEANest method), which is confirmed by an analysis of longer observations of MRK 421 in the V band (with AAVSO data). The longer variability of MRK 421 was also analyzed. It was found that in the V, R, and I light curves from AAVSO the maxima of the LS-periodograms correspond to periods of 1.6-1.7 years. This is close to earlier results from an analysis of historical light curves of MRK 421 obtained by other authors. The AAVSO data also indicate the presence in MRK 421 of a longer cycle of brightness variation with a characteristic time of 20-30 years. [ABSTRACT FROM AUTHOR]

A comparative analysis of molecular genetic phenotypes of mucous membrane cells has been carried out in five anatomical regions of the large intestine in a group of healthy donors. The mRNA expression profiles of 62 genes involved in the regulation of vital cellular function were investigated in 181 biopsy samples of morphologically unchanged colon mucosa, obtained from the colon (ascending, transverse, descending, sigmoid) and rectum sections during prophylactic colonoscopy of 58 donors without large intestine pathology. The mRNA levels for 62 genes involved in the regulation of apoptosis, proliferation, transcription, differentiation, cell-cell adhesion, and immune response were assessed by RT-PCR. Statistically significant differences were found for the molecular phenotypes of five sections of the large intestine. The results of the study can serve as a basis for creating a reference database (values of expression profiles), developing methods of differential diagnostics and screening of various pathologies of the large intestine. [ABSTRACT FROM AUTHOR]

The review analyzed the validity of using unstable alleles of Drosophila melanogaster genes to assess the rate of movement of mobile genetic elements by the frequency of phenotype change. Several examples show that the instability of alleles with introduced transposons is determined to a greater degree by recombination between them than by the true movement of transposons with the participation of transposase. [ABSTRACT FROM AUTHOR]

We studied the microbial communities associated with the Baikal ostracods, Candona sp. (Candonidae). Bacterial biofilms were identified on the shell valves of the ostracods localized near epibiotic ciliates of the genus Lagenophrys (Ciliophora: Lagenoprydae). In situ hybridization confirmed the presence of eubacterial cells in different parts of the ostracod's body. Bacteria of two morphotypes were detected in bacterial biofilms, including filamentous bacteria. Next-generation sequencing of 16S rRNA bacterial gene fragment allowed us to identify representatives of five bacterial phyla. Members of the phyla Proteobacteria and Bacteroidetes typical of non-marine epibiotic associations of ostracods were dominant taxa in the ostracod microbiomes. Members of other taxa (Actinobacteria, Gracilibacteria and Cyanobacteria) are likely facultative and consumed by ostracods together with detritus. In the ostracod microbiome, a significant proportion (20% of all reads) belonged to the sequences of the genus Rickettsia related to intracellular parasites. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (TDP1) is a DNA repair enzyme that plays a key role in repairing damage caused by various antitumor drugs. It is a promising target in medicinal chemistry for the creation of cancer adjuvant therapy. Inhibition of this enzyme together with the use of anticancer chemotherapy enhances the effect of the latter. The natural mutant of TDP1, TDP1(H493R), causes severe neurodegenerative disease spinocerebellar ataxia syndrome with axonal neuropathy (SCAN1). Inhibition of TDP1(H493R) appears to be useful in containment the progression of the disease. A library of compounds was synthesized starting from dehydroabietylamine including heterocyclic pharmacophore groups in the core. To obtain the desired products, the starting dehydroabietylamine was introduced sequentially in reaction with isothiocyanate and ethyl bromoacetate. Different classes of heterocyclic derivatives—2-iminothiazolidin-4-ons and 2-thioxoimidazolidin-4-ones—were obtained depending on the addition order of reagents. 2-Iminothiazolidin-4-thiones were obtained from 2-iminothiazolidin-4-ones under the action of the Lawesson's reagent. Effective TDP1 inhibitors were found among the obtained compounds that work in submicromolar concentrations. The inhibitor of TDP1(H493R) was also detected. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a repair enzyme for 3′-end DNA lesions, predominantly stalled DNA–topoisomerase 1 (Top1) cleavage complexes. Tdp1 is a promising target for anticancer therapy based on DNA damage caused by Top1 poisoning. Earlier, we have reported about usnic acid enamine derivatives that are Tdp1 inhibitors sensitizing tumor cells to the action of Top1 poison (Zakharenko in J Nat Prod 79:2961−2967, 2016). In the present work, we showed a sensitizing effect of an enamine derivative of usnic acid (when administered intragastrically) on Lewis lung carcinoma in mice in combination with topotecan (TPT, Top1 poison used in the clinic). In the presence of the usnic acid derivative, both the volume of the primary tumor and the number of metastases significantly diminished. The absence of acute toxicity of this compound was demonstrated, as was the importance of the method of its administration for the manifestation of the sensitizing properties. [ABSTRACT FROM AUTHOR]

The adsorption and photosorption properties of aerosol particles from zircon (ZrSiO4) have been studied under conditions similar to tropospheric. The physicochemical characteristics of the aerosol were determined by diffuse reflection spectroscopy. The composition of the adsorbed layer formed in the troposphere is analyzed. The kinetic dependences of CO2 desorption and O2 adsorption in the dark and under illumination are studied. The quantum yields and spectral dependences of the quantum yields of photodesorption and photoadsorption are determined. [ABSTRACT FROM AUTHOR]

Diversity of methano- and methylotrophic bacteria in enrichments from the oxidized sediment layer maintained at 10°C in mineral media with nitrogen compounds ( and ) and methanol was studied using high-throughput sequencing of the V2–V3 region of the 16S rRNA gene. Methanotrophs of the bottom sediment belonged to the order Methylococcales, with predominance of the genus Methylobacter (6.4 and 4.6% of the total number of sequences, respectively). Members of the methylotrophic community belonged to the genus Methylotenera (family Methylophilaceae). Enrichments in the medium with ammonium and methane were characterized by the highest diversity of methanotrophs, containing 22 OTUs of the family Methylococcaceae, nine of which were not detected under other cultivation conditions. Altogether, only six out of 28 OTUs of methanotrophic bacteria exhibited similarity to cultured members of Methylobacter, Metyloglobulus, and Methylomicrobium, while others showed different levels of similarity (94–99%) to uncultured members of the family Methylococcaceae. The presence of 0.01% methanol promoted preferential development of methylotrophic bacteria, while 0.5% methanol suppressed the growth of methanotrophic bacteria irrespective of the nitrogen source added. [ABSTRACT FROM AUTHOR]

Perturbations of acoustic normal modes by bathymetry variations in a shallow-water waveguide are considered. The problem is reduced to the case of a potential perturbation for the stationary Schrödinger equation. The derivatives of the modal functions and eigenvalues with respect to water depth are formally calculated. Applications of such derivatives in sound propagation models based on the normal mode theory are discussed. It is shown that the computational cost associated with the sound pressure field computation in a range-dependent waveguide can be reduced by a factor of 5-10 by using the proposed formulas. DOI 10.1134/S1061920821020102 [ABSTRACT FROM AUTHOR]

Topotecan is a cytostatic drug from the camptothecin group, it acts by inhibiting topoisomerase 1 (TOP1). Tyrosyl-DNA phosphodiesterase 1 (TDP1) is capable of interfering with the action of TOP1 inhibitors, reducing their therapeutic efficacy. Suppression of TDP1 activity may enhance the effects of topotecan. In this work, we investigated the effect of the antitumor drug topotecan alone and in combination with a TDP1 inhibitor, a hydrazinothiazole derivative of usnic acid, on Krebs-2 mouse ascites tumors. We have previously shown that this derivative efficiently inhibits TDP1. In the present work, we show that both topotecan and the TDP1 inhibitor have an antitumor effect when evaluated separately. The combination of topotecan and the TDP1 inhibitor additively reduces both the weight of the ascites tumor and the number of cells in ascites. In mice, the TDP1 inhibitor alone or in combination with topotecan eliminated the tumor cells. After the combined intraperitoneal administration of these two compounds, we observed cells in which lipid droplets occupied almost the entire cytoplasm and the accumulation of cell detritus, which was absent in the samples collected from mice treated with each compound separately. [ABSTRACT FROM AUTHOR]

Adsorption and photosorption properties of precipitated indium(III) oxide aerosol particles are studied under conditions close to those of ambient air. The composition of the adsorbed surface layer of precipitated aerosol particles is analyzed. The quantum yields and their spectral dependences of oxygen photosorption and carbon monoxide photocatalytic oxidation are determined. Photocatalytic activity in the reaction of carbon monoxide oxidation is detected during the absorption of light quanta from the region of indirect electron transitions (quantum energy of <2.9 eV). [ABSTRACT FROM AUTHOR]

We analysed the relationship between the chemical complex (concentration of dissolved ions, nutrients, pH) and biological parameters (primary production, biomass of phytoplankton, abundance and activity of bacterial communities) at estuaries of rivers and coastal waters of Southern Baikal during the under-ice period. Correlation network analysis revealed CO2 to be the main limiting factor for the development of algae and microbial communities in the coastal zone of Lake Baikal. This study indicates that primarily reverse synthesis of bicarbonate and carbonate ions associated with the development of phytoplankton and accumulation of dissolved CO2 during photosynthesis regulates pH in the Baikal water. We did not detect the anthropogenic factors that influence the change in pH and acidification. Near the Listvyanka settlement (Lake Baikal, Listvennichnaya Bay), there was a great number of organotrophs and thermotolerant bacteria with low bacterioplankton activity and high concentration of organic carbon. This evidences eutrophication due to the influx of organic matter having an anthropogenic source. Nutrients produced during the bacterial destruction of this matter may explain the changes in bottom phytocenoses of Listvennichnaya Bay. [ABSTRACT FROM AUTHOR]

The photocatalytic activity of indium(III) oxide in the oxidation of carbon monoxide upon absorption of light quanta from the region of indirect electronic transitions (quantum energies <2.9 eV) has been found. The quantum yields and spectral dependences of the quantum yields of photocatalytic oxidation of carbon monoxide and photoadsorption of oxygen have been determined. The adsorption, photoadsorption, and photocatalytic properties of indium oxide microparticles have been studied. [ABSTRACT FROM AUTHOR]

The results of studies aimed at creating a complex of high-precision hardware instruments for reproduction and transmission of the unit of length are described. The composition of the complex is described. The creation of the complex is intended to increase the scientific and technological level of the Russian Federation and support the uniformity of measurements of length. The complex will become the foundation for the further development of the standards base of the Russian Federation in the field of measurements of length and will make it possible to perform reproduction of the unit of length at two wavelengths, 633 and 532 nm, as well as measure the wavelength of laser sources of radiation in a vacuum in the range 500–1050 nm. [ABSTRACT FROM AUTHOR]

Lightning was detected by Voyager 2 at Uranus and Neptune, and weaker electrical processes also occur throughout planetary atmospheres from galactic cosmic ray (GCR) ionisation. Lightning is an indicator of convection, whereas electrical processes away from storms modulate cloud formation and chemistry, particularly if there is little insolation to drive other mechanisms. The ice giants appear to be unique in the Solar System in that they are distant enough from the Sun for GCR-related mechanisms to be significant for clouds and climate, yet also convective enough for lightning to occur. This paper reviews observations (both from Voyager 2 and Earth), data analysis and modelling, and considers options for future missions. Radio, energetic particle and magnetic instruments are recommended for future orbiters, and Huygens-like atmospheric electricity sensors for in situ observations. Uranian lightning is also expected to be detectable from terrestrial radio telescopes. [ABSTRACT FROM AUTHOR]

Progressive ventricular enlargement, a key feature of several neurologic and psychiatric diseases, is mediated by unknown mechanisms. Here, using murine models of 22q11-deletion syndrome (22q11DS), which is associated with schizophrenia in humans, we found progressive enlargement of lateral and third ventricles and deceleration of ciliary beating on ependymal cells lining the ventricular walls. The cilia-beating deficit observed in brain slices and in vivo is caused by elevated levels of dopamine receptors (Drd1), which are expressed in motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 results in Drd1 elevation, which is brought about by a reduction in Drd1-targeting microRNAs miR-382-3p and miR-674-3p. Replenishing either microRNA in 22q11DS mice normalizes ciliary beating and ventricular size. Knocking down the microRNAs or deleting their seed sites on Drd1 mimicked the cilia-beating and ventricular deficits. These results suggest that the Dgcr8–miR-382-3p/miR-674-3p–Drd1 mechanism contributes to deceleration of ciliary motility and age-dependent ventricular enlargement in 22q11DS. Schizophrenia is associated with brain ventricular enlargement. Here, the authors show in mice that 22q11 deletion, which is associated with schizophrenia, causes ventricular enlargement and motility abnormalities in cilia lining ventricle walls via a microRNA mechanism. [ABSTRACT FROM AUTHOR]

In March 2018, we analyzed water, ice, and snow cover in the estuaries and estuarine basins of the rivers of the southeastern and southwestern parts of Lake Baikal, as well as in two reference stations in the lake pelagic zone. The parameters determined in melted ice cores and estuarine waters were chemical composition, total microbial counts (TMC), dark CO2 assimilation (DCA) as well as the overall abundance of organotrophs and bacteria of sanitary importance. Our results indicated ice acidification in the basins of the Rivers Pereemnaya, Krestovka, and Bolshaya Cheremshanaya due to the effect of atmospheric precipitation enriched with the exhaust of nearby coal power plants and the river bottom. These processes had no negative effects on TMC, the abundance of organotrophic bacteria, and production characteristics. DCA measurements revealed the higher activity of ice microbial communities in the rivers and estuarine basins of the southeastern part of the lake (0.43 µg C L–1 day–1) compared to those of southwestern Baikal (0.26 µg C L–1 day–1). Microbiological parameters of the water samples exhibited a correlation with the levels of biogenic elements, total ions, and dissolved organic matter; a positive correlation was also observed between TMC and pH (r = 0.66). Low activity of microbial communities observed at high TMC at the estuaries of Lake Baikal rivers could result from the anthropogenic impact on microbial productive potential. [ABSTRACT FROM AUTHOR]

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is one of the important DNA repair enzymes responsible for the repair of DNA damage caused by anticancer drugs, such as topotecan. In this regard, enzyme activity is one of the possible causes of tumor resistance to chemotherapy, and the use of inhibitors of this enzyme is considered as a promising adjuvant therapy. We have obtained a number of new isomeric naphthyl derivatives of thiophenyl octahydro-2H-chromene, the structure of one of which is confirmed by X-ray structural analysis. Based on molecular modeling data, the structure of the ligand-Tdp1 complex has been proposed. All compounds obtained inhibit Tdp1 at a concentration of about 2 μM. Low toxicity of three compounds was shown, which makes them promising candidates for the development of accompanying cancer therapy. [ABSTRACT FROM AUTHOR]

We have assessed the diversity of bacteria near oil-methane (area I) and methane (area II) seeps in the pelagic zone of Lake Baikal using massive parallel sequencing of 16S rRNA, pmoA, and mxaF gene fragments amplified from total DNA. At depths from the surface to 100 m, sequences belonging to Cyanobacteria dominated. In the communities to a depth of 200 m of the studied areas, Proteobacteria dominated the deeper layers of the water column. Alphaproteobacteria sequences were predominant in the community near the oil-methane seep, while the community near the methane seep was characterized by the prevalence of Alpha- and Gammaproteobacteria. Among representatives of these classes, type I methanotrophs prevailed in the 16S rRNA gene libraries from the near–bottom area, and type II methanotrophs were detected in minor quantities at different depths. In the analysis of the libraries of the pmoA and mxaF functional genes, we observed the different taxonomic composition of methanotrophic bacteria in the surface and deep layers of the water column. All pmoA sequences from area I were type II methanotrophs and were detected at a depth of 300 m, while sequences of type I methanotrophs were the most abundant in deep layers of the water column of area II. All mxaF gene sequences belonged to Methylobacterium representatives. Based on comparative analyses of 16S rRNA, pmoA, and mxaF gene fragment libraries, we suggest that there must be a wider spectrum of functional genes facilitating methane oxidation that were not detected with the primers used. [ABSTRACT FROM AUTHOR]

The antimetastatic activity of combined or individual administration of topotecan and tyrosyl-DNA phosphodiesterase 1 (Tdp1) inhibitor was examined under various administration schedules in mice with Lewis lung carcinoma modeled by intravenous injection of 200,000 clone/mouse. The greatest antimetastatic effect was observed after combined use of topotecan and Tdp1 inhibitor as documented by macroscopic study of the lungs that revealed the decreased metastatic scores by 76, 91, or 74% at the respective inhibitor doses of 2, 4, or 6 mg/mouse, respectively, in parallel with inhibition of metastasis up to 98% (at inhibitor dose of 4 mg/mouse) and morphological and morphometric analyses of the lung sections, which revealed elevation of metastasis growth delay index to 86 and 63% at the respective inhibitor doses of 4 and 6 mg/mouse, respectively. The combined administration of topotecan and Tdp1 inhibitor is viewed as the most effective way to eliminate the metastatic formations with possible restitution of focal lesions. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs) constitute a wide range of chemicals. Their release into the environment has raised great concern due to their potentially harmful impact in humans and wildlife species. The aim of this current study was to detect selected POPs in hair samples of wild terrestrial mammals from Primorsky Krai, Russia, so as to assess potential environmental exposure. The tested wild species were leopard cat, musk deer, wolf, amur hedgehog, and raccoon dog. The targeted organochlorines were hexachlorobenzene (HCB) and DDTs (opDDE, ppDDE, and opDDD), polychlorinated biphenyl (PCB) congeners (28, 52, 101, 118, 138, 153, and 180), and polycyclic aromatic hydrocarbons (PAHs) (acenaphylene (ACEN), fluorene (FLU), anthracene (ANTH) phenathrene (PHEN), and pyrene (PYR)). The detection of POPs was conducted in hair samples by a one-step hair extraction method, by using a headspace solid-phase microextraction technique (HS-SPME) and analyzed then by GC-MS. The majority of the wild animal hair samples were found positive in all tested pollutants. More specifically, the percentage of positive hair samples for HCB was 93.3% and for DDTs, PCBs, and PAHs, 20.0 to 100.0%, 6.7 to 100.0%, and 75.0 to 100.0%, respectively. DDT, PCB, and PAH detection ranged from 1.26 to 52.06 pg mg−1, 0.73 to 31.34 pg mg−1, and 2.59 to 35.00 pg mg−1, respectively. The highest mean concentration levels of all tested pollutants were found for musk deer (PCBs 12.41 pg mg−1, DDTs 21.87 pg mg−1, PAHs 22.12 pg mg−1) compared to the other wild species. To the best of our knowledge, this is the first study that provides results regarding contamination in different terrestrial mammals by POP exposure. The use of hair as a matrix is proven to be an effective tool for nondestructive biological monitoring of POP contamination in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Six imines including four new ones were synthesized via the reaction of monoterpenoid aldehydes with aminoadamantanes. The inhibitory activities of the synthesized compounds against purified human recombinant DNA repair enzyme tyrosyl-DNA phosphodiesterase 1 (Tdp1) fell in the range IC50 = 5.5-7.1 μM. [ABSTRACT FROM AUTHOR]

Abstract: The characteristics of anomalously intense pulses of the pulsar J0242+6256 in the decameter wavelength range are studied in the paper. Observations were made using the Ukrainian T-shaped Radio telescope, second modification (UTR-2) in October 2014. The dispersion measure for the pulsar was refined. For the first time, such characteristics as the scattering time constant, scattering measure, and rotation measure towards the pulsar were determined. Also, the rapid changes in the rotation measure along the profiles of individual anomalously intense pulses were considered. The obtained characteristics show that, despite the small dispersion measure and the close arrangement to the Earth, the scattering measure towards the pulsar is large. Rapid changes in the rotation measure along the pulse profile of this pulsar are possibly due to the presence of a plasma with rapidly changing parameters near the pulsar. [ABSTRACT FROM AUTHOR]

Massive parallel sequencing of the 16S rRNA gene fragments was used to investigate the composition and diversity of microbial communities in sediments from Southern Baikal to a depth of 9 cm with 1-cm step. In the layers from the sediment surface to the lower border of oxygen penetration (2 cm), organotrophic bacteria with high similarity to the heterotrophic species Luteolibacter luojiensis constituted the largest fraction of the community. In the formation zone of Fe/Mn crusts (3-5 cm), Proteobacteria and Actinobacteria predominated in the community, while the share of Cyanobacteria was considerable. The lower reduced layers showed an increased contribution of the Bacteroidetes, while the shares of the taxa predominant in the higher layers remained significant. Analysis of archaeal 16S rRNA gene amplicons revealed predominance of the soil and aquatic Thaumarchaeota (Marine Group I lineage), which are involved in anaerobic ammonium oxidation, practically in all sediment layers. The buried oxidized layer (6-7 cm), where members of the uncultured Marine Benthic Group D lineage of the order Thermoplasmatales (Euryarchaeota) predominated, was an exception in this regard. Small numbers of archaea of the Baikal-1 lineages (below 1%) were observed in the communities from the 6-7 and 7-8 cm layers, while the archaea involved in anaerobic methane oxidation (including the ANME-2d group) were not detected. [ABSTRACT FROM AUTHOR]

We show for the first time that natural 2,5-diketopiperazines (cyclic dipeptides) can suppress the activity of the important anticancer target poly(ADP-ribose)polymerase (PARP). Cyclo(L-Ala-L-Ala) and cyclo(L-Ala-D-Ala) can interact with the key residues of the PARP-1 active site, as demonstrated using docking and molecular dynamics simulations. One of the amide groups of cyclo(L-Ala-L-Ala) and cyclo(L-Ala-D-Ala) forms hydrogen bonds with the Gly863 residue, while the second amide group can form a hydrogen bond with the catalytic residue Glu988, and the side chain can make a hydrophobic contact with Ala898. Newly identified diketopiperazine inhibitors are promising basic structures for the design of more effective inhibitors of PARP family enzymes. The piperazine core with two chiral centers provides many opportunities for structural optimization. [ABSTRACT FROM AUTHOR]

DNA repair is a complicated process that occurs due to a network of different pathways and mechanisms for correction of DNA damages during the normal DNA biosynthesis and under the influence of external and internal factors. The study of these mechanisms and their regulation is closely related to both diagnostics and the search for ways of treating various diseases, including oncological ones. Malignant neoplasms are one of the three most widespread diseases in the world, which unfortunately often become the reason for a lethal outcome. Traditional cancer therapy aims to the DNA damage in malignant cells, and its result depends on the efficiency of the repair systems. In many cancer cells, the individual DNA repair enzymes are overexpressed, which promotes the resistance of these tumors to the therapy. On the other hand, defects in the DNA repair systems in cancer cells allow researchers to find both appropriate biomarkers for diagnostics and targets for the development of the specific and effective therapy. Currently, DNA repair inhibitors are being actively developed in order to increase the sensitivity of the tumor cells to traditional chemotherapy. The principle of synthetic lethality is used to create cell-specific drugs and to improve the effectiveness of the treatment. In this review, we discuss the current state of research and prospects for the development of inhibitors for five important DNA repair enzymes. [ABSTRACT FROM AUTHOR]

Using the FISH method and PCR analysis, the presence of canonical P element was studied in the genomes of a number of laboratory lines isolated from nature in different years from the Zaprionus genus ( Z. indianus) and Drosophila genus, Sophophora subgenus ( D. ananassae, D. eugracilis, D. simulans, D. immigrans), Drosophila subgenus ( D. virilis, D. mercatorum, D. hydei, D. funebris, D. pseudoobscura), Lordiphosa subgenus ( L. magnipectinata), and Dorsilopha subgenus ( D. busckii) in a search for new cases of horizontal transfer. According to our data, the L. magnipectinata genome contains sequences homologous to terminal regions of canonical P element, as well as the sequence with a weak homology from the central part of canonical P element. The P-element hybridization sites adjacent to the chromocenter were found in the D. pseudoobscura genome; this can indicate an ancient origin of the sequences homologous to the P element. The P element is absent in old D. simulans lines, except for the line isolated from nature in 2014 (in which the P element was found); this confirms data of other researchers about recent cases of horizontal P-element transfer in this species. No new cases of horizontal transfer were detected in the analyzed lines. [ABSTRACT FROM AUTHOR]

The effect of humic substances of various origin on the behavior of heavy metals was investigated in a field model experiment on remediation of technogenic wastelands near the mining-metallurgical compplex Severonickel in the Subarctic Zone of the Kola Peninsula. Two distinct types of humates, coal and peat, were applied to the experimental sites in various doses and combinations with NPK fertilizer and lime. The combination of peat humates with lime proved the most effective for stabilizing heavy metals in a sixweek experiment. The application of coal humates in conditions of prolonged contamination, accompanied by suppression of vegetation and biota, is effective in small doses (0.5%) and, conversely, causes the mobilization of metals with an increase in humate concentration (1%). [ABSTRACT FROM AUTHOR]

MicroRNA-21 (miR-21) expression was quantified by real-time qRT-PCR in peripheral blood and saliva samples obtained from patients diagnosed with colorectal cancer (CRC) of varying degrees of malignancy and healthy volunteers. All patients had adenocarcinoma located in the distal colon at different stages. Significant differences were detected between the control group and the total experimental group of CRC patients (plasma, P = 0.0001; saliva, P = 5e-12). MiR-21 expression was also significantly different in certain subgroups of patients with CRC disease stages II-IV as compared to the control group. No correlation of miR-21 expression was found with regard to gender and age of patents. Also, there were no significant individual correlations and linear regression of miR-21 expression in the plasma and saliva. The estimated diagnostic sensitivity and specificity of miR-21 expression were respectively 65 and 85% in the plasma, and 97 and 91% in the saliva. Our data suggest that miR-21 in both the saliva and plasma could be a proper biomarker for CRC screening, although the saliva miR-21 expression test looks preferable due to its higher sensitivity, specificity, and technical simplicity. [ABSTRACT FROM AUTHOR]

A versatile strategy for the synthesis of $$\hbox {NAD}^{+}$$ mimetics was developed, involving an efficient pyrophosphate linkage formation in key conjugates containing a functional amino group which acts as useful reactive anchor for further derivatization. These $$\hbox {NAD}^{+}$$ mimetics consist of ADP conjugated through a diphosphate chain to an extended aliphatic linker bearing an aromatic acid residue. A number of conjugates containing aromatic carboxylic acids were found to inhibit poly(ADP-ribose) synthesis catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1). A new class of potential PARP-1 inhibitors mimicking $$\hbox {NAD}^{+}$$ , a substrate in the PARP-1 catalyzed reaction, was proposed. Graphical Abstract : [ABSTRACT FROM AUTHOR]

A convenient approach has been proposed to the synthesis of nicotinamide adenine dinucleotide (NAD) mimetics, which comprise morpholino analogues of nucleosides. The approach is based on the use of ADP conjugates containing an amino group, which is tethered to the terminal phosphate through the aliphatic linker by the phosphodiester bond. We have synthesized four series of the NAD mimetics, which differ in the type of the modified nucleoside (2-aminomethylmorpholine (Mor) or 2-aminomethyl-4-carboxymethylmorpholine (MorGly) derivatives), in the linker length, and in the manner of the nucleoside attachment to the ADP derivative. We have studied the efficiency of NAD mimetics in the inhibition of the auto-poly(ADP-ribosyl)ation by the PARP 1 enzyme. The linker length, the mode of the attachment of the morpholino nucleoside analogue, and the nature of the heterocyclic base of the modified nucleoside were shown to inf luence the inhibition efficiency. [ABSTRACT FROM AUTHOR]

The synthesis of (+)-usnic acid derivatives is described. The derivatives contain one or two cyano groups, connected to the acetophenone fragment of dibenzofuran core by linkers of different length and character, or some other modifications. The influence of these compounds on the activity of recombinant human tyrosyl-DNA phosphodiesterase 1 and MCF-7 tumor cells' viability has been estimated. The data indicate a distinct dependence of functional characteristics of the compounds on their structure. [ABSTRACT FROM AUTHOR]

An analysis of the literature on the cryopreservation of Drosophila melanogaster, the collections of which include hundreds of thousands of lines, was conducted. It was noted that the cryopreservation of D. melanogaster embryos is possible only at the 14th stage of development after permeabilization of the chorion, which prevents the penetration of cryoprotectants, and succeeds in 3% of cases. The successful cryopreservation of Drosophila larvae and imago was carried out so far only for the Chymomyza costata species. It was established that it is possible to save the cost of maintaining the collection of D. melanogaster by extending ontogenesis due to reducing the feed calorie content and the temperature, as well as due to shortening of the light period. [ABSTRACT FROM AUTHOR]