bluuebunny/crossref_metadata_2025 huggingface dataset:
Combinational Overexpression of Foxa3 and Hnf4a Enhance the Proliferation and Prolong the Functional Maintenance of Primary Hepatocytes
Authors: Fan J. Y. , Dama G. , Liu Y. L. , Guo W. Y. , Lin J. T.
Published: April 2024

In an in vitro culture system, primary hepatocytes usually display a low proliferation capacity, accompanied with a decrease of viability and a loss of hepatocyte-specific functions. Previous studies have demonstrated that the combination introductions of certain hepatocyte-specific transcription factors are able to convert fibroblasts into functional hepatocyte-like cells. However, such combinational usage of transcription factors in primary hepatocytes culture has not yet sufficiently studied. The forkhead box protein A3 (FoxA3) and hepatocyte nuclear factor 4α (Hnf4α) are liver-enriched transcription factors that play vital roles in the differentiation, and maintenance of hepatocytes. Thus, we simultaneously overexpressed the two genes, Foxa3 and Hnf4a, in rat hepatocytes and observed that the combinational augmentation of these two transcription factors have enhanced the proliferation and stabilized the hepatocyte-specific functions of primary hepatocytes over a long-term culture period.
DNA-Phenotyping of Remains from Elite Burials in the South of Russia in the Khazar Period
Authors: Fesenko D. O. , Aramova O. Yu. , Vdovchenkov E. V. , Ivanovsky I. D. , Fesenko O. E. , Polyakov S. A. , Faleeva T. G. , Filippova M. A. , Florinskaya V. S. , Kornienko I. V.
Published: April 2024

The study of the past through the analysis of ancient DNA allows us to solve scientific problems related to the genogeographic origin and patterns of population migration. The Khazar Khaganate is a subject of controversy among scientists in various fields of science: its complex historical formation, the lack of a sufficient number of artistic and written sources, together with the disappearance of representatives of the Khazar culture, leaves open the question of the appearance of the Khazars. In this work, DNA-phenotyping of bone remains from the elite burials of the South of Russia of the Khazar period was carried out on the basis of the color of eyes, hair, skin, and blood groups according to the AB0 system. It was established that 8 out of 10 buried had brown eyes, dark hair (to varying degrees), and predominantly dark skin during their lifetime. People from two burials had gray-blue eyes, and one person had blond hair. In 8 individuals, the most probable blood type was established according to the AB0 system: 5 people had 0 (I) group, 4 people had A (II) group and one B (III). Assessment of allele distribution of ten autosomal markers with population specificity indicates high heterogeneity of ethnogeographic origin of the studied Khazars. The obtained results are evidence of the ethnocultural, genetic and phenotypic diversity of the Khazar Khaganate.
Interaction of DNA Methyltransferase Dnmt3a with Phosphorus Analogues of S-Adenosylmethionine and S-Adenosylhomocysteine
Authors: Filonov V. L. , Khomutov M. A. , Sergeev A. V. , Khandazhinskaya A. L. , Kochetkov S. N. , Gromova E. S. , Khomutov A. R.
Published: April 2024

Enzymatic methylatransferase reactions are of crucial importance for cellular metabolism, and S-adenosyl-L-methionine is the main donor of the methyl group. DNA, RNA, proteins, and low-molecular-weight compounds are the substrates of methyltransferases. In mammals, methylation of the C5 position of cytosine residues in CpG sequences in DNA is performed de novo by DNA methyltransferase Dnmt3a. “Methylation pattern” is one of the factors determining the epigenetic regulation of gene expression. In the present work, we investigated the interaction of phosphonous and phosphonic analogues of S-adenosyl-L-methionine and S-adenosyl-L-homocysteine with the catalytic domain of Dnmt3a. The phosphonous and phosphonic analogs of S-adenosyl-L-methionine were shown to be substrates of Dnmt3a, and the efficiency of the methylation was only two times less than that of natural S-adenosyl-L-methionine. Both phosphorus-containing analogs of S- adenosyl-L-homocysteine, a natural methyltransferase inhibitor, exhibited similar inhibitory activity against Dnmt3a and were approximately four times less active than S-adenosyl-L-homocysteine. The activities of the phosphonous and phosphonic analogs turned out to be close that was quite unexpected, since the geometry and charge of the phosphorus-containing groups differ significantly. The possibilities of using phosphorus-containing analogs of S- adenosyl-L- methionine and S-adenosyl-L-homocysteine as promising tools for the investigation of methyltransferases are discussed.
Inactivation of Ras1 in Fission Yeast Aggravates the Oxidative Stress Response Induced by Tert Butyl Hydroperoxide (tBHP)
Authors: Masood N. , Anjum S. , Ahmed S.
Published: April 2024

Ras proteins are small GTPases and function as molecular switches to regulate cellular homeostasis. Ras-dependent signalling pathways regulate several essential processes such as cell cycle progression, growth, migration, apoptosis, and senescence. The dysregulation of Ras signaling pathway has been linked to several pathological outcomes. A potential role of RAS in regulating the redox signalling pathway has been established that includes the manipulation of ROS levels to provide a redox milieu that might be conducive to carcinogenesis. Reactive oxygen species (ROS) and mitochondrial impairment have been proposed as major factors affecting the physiology of cells and implicated in several pathologies. The present study was conducted to evaluate the role of Ras1, tert Butyl hydroperoxide (tBHP), and antimycin A in oxidative stress response in Schizosaccharomyces pombe cells. We observed decreased cell survival, higher levels of ROS, and mitochondrial dysfunctionality in ras1Δ cells and tBHP as well as respiratory inhibitor, antimycin A treated wild type cells. Furthermore, these defects were more profound in ras1Δ cells treated with tBHP or antimycin A. Additionally, Ras1 also has been shown to regulate the expression and activity of several antioxidant enzymes like glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST), and catalase. Together, these results suggest the potential role of S. pombe Ras1 in mitigating oxidative stress response.
JMJD3 Exerts Oncorepressor Activity in Acute Promyelocytic Leukemia by Promoting PU.1 Expression
Authors: Wang M.-X. , Yu S.-H. , Xiao M. , Chen J.
Published: April 2024

All-trans retinoic acid (ATRA) in acute promyelocytic leukemia (APL) has been the most famous differentiation induction therapy during which the expression of PU.1, a key transcription factor (TF) for myeloid lineage determination in normal hematopoiesis is restored. In our previous studies, we found a stress-inducible H3K27 demethylase, JMJD3, to directly upregulate PU.1 expression to promote myeloid commitment during normal myelopoiesis. In addition, JMJD3 acts as an oncorepressor and plays a critical regulatory role in the initiation and progression of malignant hematopoiesis. In this study, we further resolved the relationship between JMJD3 and PU.1 in APL therein JMJD3 exerts oncorepressor activity via promoting PU.1 expression.
Apatinib Suppressed Macrophage-Mediated Malignant Behavior of Hepatocellular Carcinoma Cells via Modulation of VEGFR2/STAT3/PD-L1 Signaling
Authors: Yin T. , Fu C. B. , Wu D. D. , Nie L. , Chen H. , Wang Y.
Published: April 2024

Hepatocellular carcinoma (HCC) is the most frequently diagnosed primary liver tumor worldwide. Tumor-associated macrophages (TAMs) usually have a similar phenotype to M2-like macrophages and can participate in tumor progression by secreting cytokines to suppress the immune response of tumor-infiltrating lymphocytes. We investigated the role of M2 macrophages in HCC progression and explored the effects of vascular endothelial growth factor receptor 2 inhibitor – apatinib . As a cellular model of HCC, Hepb3 cell line was used. M2 macrophages were obtained by differentiation of THP-1 cells. The Transwell chamber was used to co-culture M2 macrophages and Hepb3 cells. CCK-8 assay and EdU assay were conducted to measure cell viability and proliferation capacity. Transwell migration assay was conducted to estimate cellular metastatic potential. Cytokine expression levels were assessed by ELISA. Western blot was used to quantify the activation of the VEGFR2/STAT3/PD-L1 axis. It has been shown that co-culture with M2 macrophages increased, proliferation, viability, cytokine production, invasion, and migration of Hepb3 cells. The secretion of TGF-β1, IL-6, MMP-9, and VEGF was significantly increased after co-culture. Apatinib suppressed M2 macrophage-induced proliferation, cell viability, invasion, and migration of Hepb3 cells. Moreover, apatinib remarkedly decreased expression levels of p-VEGFR2, p-STAT3, and PD-L1 in Hepb3 cells under the co-culture conditions. In conclusion, apatinib treatment could suppress TAMs-mediated cancer cell behaviors of HCC cells via modulation of the VEGFR2/STAT3/PD-L1 signaling pathway.
Dynamic Changes in the Activity and Content of Particular Proteasome Forms in Cerebral Cortex of C57BL/6 Mice during Aging
Authors: Burov A. V. , Funikov S. Yu. , Astakhova T. M. , Teterina E. V. , Nebogatikov V. O. , Erokhov P. A. , Ustyugov A. A. , Karpov V. L. , Morozov A. V.
Published: April 2024

Proteasomes are key components of the ubiquitin-proteasome system. Various forms of proteasomes are known. During aging, disturbances in the functioning of proteasomes were revealed, as well as an increased expression of their individual forms. Considering these data, we studied the expression of genes encoding the constitutive and immune subunits of proteasomes in the cerebral cortex samples from C57BL/6 mice at the age of 60, 190, 380, and 720 days. In addition, the content of constitutive and immune proteasome subunits, chymotrypsin-like and caspase-like activities of proteasome pools, as well as the activity of the β5i immune subunit were studied in tissue homogenates. The chymotrypsin-like activity and the activity of the β5i subunit of different forms of proteasomes separated by electrophoresis under native conditions were characterized. Compared with samples from young animals, in the cerebral cortex of animals aged 720 days the following changes in the expression patterns of proteasome genes were revealed: a decrease in the expression of PSMB5 gene encoding the constitutive proteasome subunit β5; activation of genes encoding immune subunits β5i and β1i. In clarified tissue homogenates of aged mice, an increase in the content of immune subunits β1i and β2i was shown. In samples from old animals, decreased chymotrypsin-like activity and a tendency to a decrease in caspase-like activity of proteasomes as well as the β5i subunit activity were also revealed. Analysis of the activity of native complexes in the tissues of old animals revealed decreased chymotrypsin-like activity of both 26S and 20S proteasomes containing the β5i subunit. Based on the data obtained, it can be assumed that changes in the pool of non-constitutive proteasomes reflect aging-associated adaptive processes in mouse brain.
Hepatitis C Virus Nonstructural Protein 3 Increases Secretion of Interleukin-1beta in HEK293T Cells with Reconstructed NLRP3 Inflammasome
Authors: Latanova А. A. , Tuchinskaya K. K. , Starodubova E. S. , Karpov V. L.
Published: April 2024

Infections caused by Flaviviridae pose a threat in the modern world. The pathology of diseases arising from these infections is largely determined by the development of systemic inflammation. The cytokines interleukin-1 beta and interleukin-18 play a key role in triggering inflammation. Their secretion from cells, in its turn, is induced upon activation of inflammasomes. Activation of NLRP3 (NLR family pyrin domain-containing 3) inflammasomes was detected in the cells infected with Flaviviridae. Some nonstructural proteins of these viruses have been shown to be able to activate or inhibit the NLRP3 inflammasome, in particular, through interaction with its components. In this study, the functional NLRP3 inflammasome was reconstructed in human HEK293T cells and the effect of some nonstructural proteins of individual Flaviviridae viruses on it was studied. This model did not reveal any impact of nonstructural proteins NS1 of West Nile virus, NS3 of hepatitis C virus, NS5 of tick-borne encephalitis virus on the inflammasome components content. At the same time, in the presence of the NS1 of the West Nile virus and NS5 of the tick-borne encephalitis virus, the level of secretion of interleukin-1 beta did not change, whereas in the presence of the NS3 protein of the hepatitis C virus, it increased by 1.5 times. Thus, NS3 can be considered as one of the factors of NLRP3 inflammasome activation and inflammatory pathogenesis in chronic hepatitis C virus infection.
Comparative Analysis of Mitochondrial Genome Mutation Spectra in Human Populations
Authors: Malyarchuk B. A.
Published: April 2024

Nucleotide sequence variability of whole mitochondrial genomes (mtDNA) was analyzed and mutation spectra were reconstructed (by L-chain of mtDNA) in four regional groups of indigenous populations representing Northeastern and Southern Siberia, Western Asia, and the Americas. The pyrimidine transitions were found to be predominant in all groups, and of these, the substitutions T→C were most frequent. The second most common in all regional groups (except Northeastern Siberia) are substitutions A→G. Of the transversions, in all the populations studied the substitutions C→A prevail. Between-regional differences in the distribution of nucleotide substitutions in mtDNA mutation spectra were not detected. However, a significant (4-fold) decrease in the number of mutations in mitochondrial gene pools was detected in the indigenous population of Northeastern Siberia compared to other regions. This may be due to the increased effect of negative selection on mtDNA in the Far North environment, which prevents the accumulation of new mutations, and gene drift, which is most pronounced in isolated and small populations of Northeastern Siberia. Because of the lack of between-regional differences in mtDNA mutation spectra, the results obtained do not allow us to confirm the hypothesis that the T→C substitution frequency appears to be a molecular marker of the level of oxidative stress in mitochondria (at least for generative mutations).
The Role of the WGR Domain in the Functions of PARP1 and PARP2
Authors: Maluchenko N. V. , Korovina A. N. , Saulina A. A. , Studitsky V. M. , Feofanov A. V.
Published: April 2024

PARP1 and PARP2 proteins are members of the poly(ADP-ribose) polymerase family involved in the regulation of DNA repair and replication, RNA processing, ribosome biogenesis, transcription, and cell division and death. PARP1 and PARP2 are promising targets for the development of anticancer and can be used in treatment of cardiovascular and neurodegenerative diseases, as well as other disorders. WGR domain was shown to play a central role in functioning of PARP1 and PARP2 proteins. This review considers the mechanisms of functioning of WGR domains in PARP1 and PARP2 proteins, which have a number of similar and specialized properties. Understanding these processes is of great interest for fundamental science and will contribute to the development of more effective and selective inhibitors of PARP1 and PARP2.
Association of Polymorphic Genome Variants in the 2q32.1 Locus with the Development of Vasovagal Syncope
Authors: Matveeva N. A. , Titov B. V. , Bazyleva E. A. , Kuchinskaya Е. А. , Kozin M. S. , Favorov A. V. , Pevzner A. V. , Favorova O. O.
Published: April 2024

Vasovagal syncope (VVS) is the most common form of syncope. The mechanisms of VVS development are not entirely clear. It is known that there is a genetic predisposition to this disease, but the data on the role of individual genes are quite contradictory. Recently, a genome-wide association study identified a locus at chromosome 2q32.1 associated with a united group of diseases – syncope and collapse; among the single nucleotide polymorphisms (SNPs) of this locus, the most significant association was observed for rs12465214. In a homogeneous sample of patients according to the diagnosis of VVS, we analyzed the association of rs12465214, rs12621296, rs17582219 and rs1344706 located on chromosome 2q32.1, with this form of syncope. In the enrolled set, only rs12621296 was associated with VVS by itself, whereas associations of other SNPs were observed only in biallelic combinations. An epistatic interaction between the components of the combination rs12621296*A + rs17582219*A was revealed. The possible involvement of individual genes localized in the 2q32.1 locus in the genetic architecture of the VVS is discussed.
Efficiency of Escherichia coli and Bacillus subtilis Expression Systems for Production of Binase Mutants
Authors: Nadyrova A. I. , Kosnyrev A. S. , Ulyanova V. V. , Dudkina E. V. , Vershinina V. I. , Ilinskaya O. N.
Published: April 2024

Bacillus pumilus ribonuclease (binase) exhibits cytotoxic and oncolytic properties, while at high concentrations it causes genotoxic effects. The use of mutants with reduced catalytic activity preserving the antitumor properties of the native enzyme could reduce the toxic side effects of the enzyme. Here, mutant forms of binase with Lys26Ala and His101Glu single substitutions were obtained by site-directed mutagenesis. A comparative analysis of Escherichia coli and Bacillus subtilis-based expression systems demonstrated the feasibility of using a bacilli-based heterologous system for production binase mutants. Binase mutants with reduced catalytic activity were isolated and purified with ion exchange chromatography in a homogeneous state with 25 mg/L yield. The catalytic properties of obtained mutants toward natural RNA-substrates in comparison with those for native binase were analyzed. The catalytic activity of the Lys26Ala and His101Glu mutants was 11 and 0.02%, respectively. It was found that the Lys26Ala mutant as well as the native binase exhibits selective cytotoxicity toward A549, BT-20 and HuTu 80 tumor cell lines, without causing toxic effects toward normal WI-38 cells. The mutant His101Glu did not exhibit cytotoxicity.
Cytochrome bd as Antioxidant Redox Enzyme
Authors: Borisov V. B. , Nastasi M. R. , Forte E.
Published: April 2024

One of the main functions of enzyme complexes that constitute electron transport (respiratory) chains of organisms is to maintain cellular redox homeostasis by oxidizing reducing equivalents, NADH and quinol. Cytochrome bd is a unique terminal oxidase of the chains of many bacteria including pathogenic species. This redox enzyme couples the oxidation of ubiquinol or menaquinol by molecular oxygen to the generation of proton motive force, a universal energy currency. The latter is used by the organism to produce ATP, another cellular energy currency, via oxidative phosphorylation. Escherichia coli contains two bd–type oxidases, bd-I and bd-II, encoded by the cydAB and appCB operons, respectively. Surprisingly, both bd enzymes make a further contribution to molecular mechanisms of maintaining the appropriate redox balance in the bacterial cell by means of elimination of reactive oxygen species, such as hydrogen peroxide. This review summarizes recent data on the redox-modulated H2O2-scavenging activities of cytochromes bd-I and bd-II from E. coli. The possibility of such antioxidant properties in cytochromes bd from other bacteria is also discussed.
The Thymic Hormone Thymosin-1 α Reduces the Pro-Inflammatory Response of RAW 264.7 Cells Induced by Endotoxin
Authors: Novoselova E. G. , Glushkova O. V. , Khrenov M. O. , Lunin S. M. , Sharapov M. G. , Goncharov R. G. , Mubarakshina E. K. , Novoselova T. V. , Parfenyuk S. B.
Published: April 2024

The aim of this work was to study effects of thymosin-1 alpha (Tα1) on the anti-inflammatory response of RAW 264.7 macrophages cultured in the presence of lipopolysaccharide (LPS) from the walls of gram-negative bacteria. Also we evaluated production of pro-inflammatory cytokines and activity of the NF-κB and SAPK/JNK signaling pathways. In addition, the level of expression of a number of genes that regulate cell apoptosis, as well as the activity of receptors involved in the pro-inflammatory response, was determined. Firstly, the addition of Tα1 normalized the level of cytokine production to varying degrees, with a particularly noticeable effect on IL-1β and IL-6. Secondly, the addition of Tα1 normalized activity of the NF-κB and SAPK/JNK signaling cascades and the expression of the Tlr4 gene. Thirdly, Tα1 significantly reduced p53 and the activity of the P53 gene, which is a marker of cell apoptosis. Fourthly, it was shown that an increase in Ar-1 gene expression under the influence of LPS was significantly reduced using Tα1. Thus, it was found that the presence of Tα1 in the RAW 264.7 cell culture medium significantly reduced the level of the pro-inflammatory response of cells.
Changes in Activity of Antioxidant Systems of Escherichia coli under Phosphate Starvation
Authors: Smirnova G. V. , Tyulenev A. V. , Muzyka N. G. , Sutormina L. V. , Oktyabrsky O. N.
Published: April 2024

Changes in the activity of antioxidant systems in Escherichia coli during phosphate starvation were studied. It was shown that starvation was accompanied by a decrease in the intensity of respiration, an increase in the rate of superoxide production, and a decrease in the level of ATP. Simultaneously, there was a decrease in H2O2 in the medium and a significant increase in the expression of the katG and katE genes encoding the HPI and HPII catalases, respectively. At the same time, there was no drop in the membrane potential, which may indicate the retention of normal membrane activity in starving cells. It has been shown for the first time that the transition of E. coli to phosphate starvation is accompanied by significant changes in the status of glutathione. The most important of them are associated with a decrease in the level of glutathione reductive form (GSH) in the medium (GSHout) and with a simultaneous increase in its content in the cytoplasm (GSHin), as well as a shift in the GSHin to oxidized glutathione form (GSSGin) ratio towards reductive values, and GSHout/GSSGout towards oxidative values. Among the mutants used in the work, the double mutant gor trxB, deficient in the synthesis of glutathione reductase and thioredoxin reductase, showed the most pronounced distinctive features. Compared to the parental strain, this mutant showed a multiple higher expression of katG::lacZ, the highest level of oxidized intra- and extracellular glutathione, and, accordingly, the lowest GSH/GSSG ratio in both compartments. In general, the data obtained indicate that during phosphate starvation the interaction of the glutathione redox-system and regulons that control protection against reactive oxygen species creates conditions that allow maintaining the concentration of ROS below the toxic level. As a result, phosphate-starved E. coli cells can maintain a high viability for a long time that allows them quickly to resume growth after the addition of phosphate.
The Role of Heat Shock Proteins in Plant Protection from Oxidative Stress
Authors: Yurina N. P.
Published: April 2024

The review considers the recent progress on the role of heat shock proteins (HSPs), as well as transcription factors of heat shock proteins (HSFs) in protecting plants from oxidative stress induced by various types of abiotic and biotic stresses. HSPs are pleiotropic proteins involved in various intracellular processes and performing many important functions. In particular, HSPs increase plant resistance to stress by protecting the structure and activity of proteins of the antioxidant system. Overexpression of Hsps genes under stressful conditions, leading to an increased content of HSP, can be used as a marker of oxidative stress. Plant HSFs are encoded by large gene families with variable sequences, expression and function. Plant HSFs regulate transcription of a wide range of stress-induced genes, including HSPs and other chaperones, reactive oxygen species scavengers, enzymes involved in protective metabolic reactions and osmolytic biosynthesis, or other transcriptional factors. Genome-wide analysis of Arabidodpsis, rice, poplar, lettuce and wheat revealed a complex network of interaction between Hsps and Hsfs gene families that form plant protection against oxidative stress. Plant protection systems are discussed, with special emphasis on the role of HSPs and HSFs in plant response to stress, which will be useful for the development of technologies to increase productivity and stress resistance of plant crops.
Metabolic Stress of Red Blood Cells Induces Hemoglobin Glutathionylation
Authors: Zaripov P. I. , Kuleshova Iu. D. , Poluektov Yu. M. , Sidorenko S. V. , Kvan O. K. , Maksimov G. V. , Mitkevich V. A. , Makarov A. A. , Petrushanko I. Yu.
Published: April 2024

Metabolic stress caused by a lack of glucose significantly affects the state of red blood cells, where glycolysis is the main pathway for the production of ATP. Hypoglycemia can be both physiological (occurring during fasting and heavy physical exertion) and pathological (accompanying a number of diseases, such as diabetes mellitus). In this study, we have characterized the state of isolated erythrocytes under metabolic stress caused by the absence of glucose. It was established that 24 h of incubation of the erythrocytes in a glucose-free medium simulating blood plasma led to a twofold decrease in the ATP level into them. Besides, the cell sizes as well as intracellular sodium concentration were increased. These findings could be the result of a disruption in ion transporters` functioning because of a decrease in the ATP level. The calcium level remained unchanged. With a lack of glucose in the medium of isolated erythrocytes, there was no increase in ROS and significant change in the level of nitric oxide, while the level of the main low-molecular weight thiol of cells, glutathione (GSH), decreased by almost 2 times. It was found that the metabolic stress of isolated red blood cells induced hemoglobin glutathionylation despite the absence of ROS growth. The reason was the lack of ATP, which led to a decrease in the level of GSH because of the inhibition of its synthesis and probably, by decrease in the NADPH level required for glutathione (GSSG) reduction and protein deglutathionylation. Thus, erythrocyte metabolic stress induced hemoglobin glutathionylation, which is not associated with an increase in ROS. This may have an important physiological significance, since glutathionylation of hemoglobin changes its affinity for oxygen.
An Industrial Data-Based Model to Reduce Octane Number Loss of Refined Gasoline for S Zorb Process
Authors: Bo Chen , Jie Wang , Song Liu , Fusheng Ouyang , Da Xiong , Mingyang Zhao
Published: April 2024

S Zorb process is one of the main technologies for deep desulfurization of gasoline from fluid catalytic cracking (FCC) process, which by the process will also cause some research octane number (RON) loss of gasoline. Establishing a data-driven model with data mining technologies to optimize production is one of the development directions in petrochemical field. Based on the industrial data from a 1.20 Mt/a S Zorb unit in China in recent three years, 422 modeling samples and 22 modeling variables were screened out and then three data-driven models were established by back propagation neural network (BPNN), radial basis function neural network (RBFNN) and generalized regression neural network (GRNN) to predict RON of refined gasoline (r-RON). The results show that the BPNN model has the best prediction effect and generalization ability. Genetic algorithm (GA), particle swarm optimization algorithm (PSO) and simulated annealing algorithm (SA) in combination with the BPNN model respectively were used to optimize the operation variables to reduce the r-RON loss. The results indicate that the optimized performance of PSO-BPNN model is best because of its largest reduction in r-RON loss at 48.55%. The validity of the PSO-BPNN model was verified in the S Zorb unit and the research methods to establish a data-driven model for reducing r-RON loss are also worthy of reference for other S Zorb units.
Epoxidation of Olefins in the Presence of Molybdenum Catalysts based on Porous Aromatic Frameworks
Authors: Yarchak V. A. , Kulikov L. A. , Maksimov A. L. , Karakhanov E. A.
Published: April 2024

A porous aromatic framework, namely PAF-30, was structurally modified by the introduction of complexing groups based on dipyridylamine, dipicolylamine, and acetylacetone. The materials synthesized in this manner were used as supports of molybdenum catalysts for epoxidation: PAF-30-dpa-Mo, PAF-30-dpcl-Mo, and PAF-30-AA-Mo. All the materials were examined by various analytic methods, such as IR spectroscopy, low-temperature nitrogen adsorption/desorption, X-ray photoelectron spectroscopy, elemental analysis, and transmission electron microscopy. The catalytic activity was tested in epoxidation of cyclohexene, 1-hexene, 1-octene, and styrene. The reusability of the catalysts was assessed using the case of cyclohexene epoxidation.
tert-Butyl Ethers of Renewable Diols as Oxygenated Additives for Motor Gasoline. Part I: Glycerol and Propylene Glycol Ethers
Authors: Samoylov V. O. , Stolonogova T. I. , Ramazanov D. N. , Tyurina E. V. , Lavrent'ev V. A. , Porukova Yu. I. , Chernysheva E. A. , Kapustin V. M.
Published: April 2024

The study investigates tert-butoxy alkanols (otherwise defined as polyol tert-butyl ethers) that have vicinal tert-butoxy and hydroxy groups in their molecules from the perspective of their usability as oxygenated additives for motor gasoline. A series of propylene glycol mono-tert-butyl ether (PTBE) and glycerol di-tert-butyl ether (di-GTBE) samples were prepared: PTBE by direct acid-catalytic alkylation of diols with tert-butanol, and di-GTBE by alkylation of epichlorohydrin. Adding PTBE and di-GTBE to base motor gasoline was found to improve its antiknock performance: the average blending research octane number to blending motor octane number ratios (bRON/bMON) equaled 120/111 and 124/104 for PTBE and di-GTBE, respectively. Furthermore, the effects of the ether additives on the properties of ethanol-blended base gasoline were characterized. Finally, the study describes the effect of polyol tert-butyl ether additives on the cloud point depression of ethanol-blended gasoline (low-temperature phase stabilization) and demonstrates a positive synergistic effect of adding the ethers mixed with ethanol
Partial Oxidation of Propane: Single-Site Pd/γ-Al2O3 Catalysts
Authors: Chepaykin E. G. , Menchikova G. N. , Pomogaylo S. I. , Tkachenko O. P. , Kustov L. M.
Published: April 2024

The paper proposes a method for synthesizing a heterogeneous catalyst that contains single Pd sites on γ-Al2O3 surface. This method involves preliminary heterogenization of a Pd complex with a hydroxyquinone (e.g., alizarin) on the γ-Al2O3 surface, followed by hydrogenolysis of the Pd–alizarin bond, reduction of Pd(II) into Pd(0), and removal of alizarin. The catalyst was examined by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and tested in propane oxidation into key petrochemicals. During the test, the catalyst exhibited high activity (242 mol of the product per g-at Pd per hour).
Synthesis of New Hydrazone Compounds from Natural Grease and Investigation as Flow Improver for Crude Oil
Authors: Shu Zhang , Longyu Wang , Pengzhang Cao , Xuefan Gu , Huani Zhang , Gang Chen
Published: April 2024

n this work, salicylaldehyde hydrazone (SAH), different from the traditional polymers, was synthesized from natural oils (castor, SAСH, rapeseed, SARH and soybean, SASH), hydrazine hydrate and salicylaldehyde. Firstly, natural grease reacts with hydrazine hydrate to produce hydrazide, and then salicylaldehyde reacts with hydrazide to synthesis salicylaldehyde hydrazone. In this work, SAH were evaluated as viscosity-reducers and pour point depressors for crude oil. The results show that the SAH can significantly reduce the pour point and viscosity of crude oil, with the increase of crude oil fluidity, the viscosity reduction rate of сrude oil from Jinghe Oilfield (QHO) reaches to 80.1% (40°С), the pour point decreases by 12.1°С, the viscosity reduction rate of сrude oil from Xinjiang Oilfield (STO) reaches to 87.5% (15°С), and the pour point decreases by 6.2°С. Based on the efficiency of different SAH, structure-function relationship was discussed. The mechanism of SAH effecting on crude oil is that the long alkyl chain is conducive to inhibiting the growth of crystals when eutectic with wax nuclei in heavy oil, and plays the role of pour point and viscosity reduction.
Hydrogenation of Light Cycle Oil to Produce Components of Winter and Arctic Diesel Fuels
Authors: Sultanova M. U. , Samoylov V. O. , Ziniatullina A. F. , Utepbergenova A. Sh. , Ramazanov D. N. , Knyazeva M. I.
Published: April 2024

This study proposed and experimentally investigated a novel approach to hydrogenation of light cycle oil (LCO) into components of winter and arctic diesel fuels (DF) environmentally classified as K5 as per the Technical Regulation of the Customs Union (TR CU) 013/2011 “On the requirements for automotive and aviation gasoline, diesel and marine fuels, jet fuels, and heating oils”. The process design involves atmospheric distillation of LCO with EBP 300˚C followed by hydrotreating. Hydrogenates with low concentrations of total sulfur (10 mg/kg) and arenes (28.6–38.0 wt %) and adequate low-temperature properties (CFPP≤–43˚C) were produced. An assessment of the physicochemical properties of the hydrogenates against applicable regulations for DF properties suggested that these hydrogenates can be effectively used as components of winter and arctic fuels by blending them into hydroisomerization diesel fractions (HIDF) and winter diesel fuels (WDF). An analysis of the main quality characteristics confirmed the feasibility of blending the LCO-derived hydrogenates into winter and arctic diesel fuels. Using GC×GC/MS examination, correlations were found between the hydrogenation process conditions, the physicochemical properties of the hydrogenates, and their detailed hydrocarbon compositions.
Comparison of the Hydrocarbon Distribution in Thermolysis Products of Asphaltenes, Resins, and Acids Isolated from Weakly Transformed Crude Oil from the Anastasievsko-Troitskoe Oil Field (Horizon IV)
Authors: Gordadze G. N. , Vasil'eva A. V. , Vylekzhanina D. S. , Gadzhiev G. A. , Stokolos O. A.
Published: April 2024

Regular trends in the distribution of hydrocarbon biomarkers (n-alkanes, isoprenanes, steranes, and terpanes) and hydrocarbons of the adamantane series in low-maturity crude oil from the Anastasievsko-Troitskoe oil field (horizon IV) and in products formed by thermolysis of asphaltenes, resins, and acids from this oil were studied by gas chromatography–mass spectrometry. Thermolysis of high-molecular-mass oil precursors yields the same hydrocarbons (HCs) as those present in the initial oil, and also protoadamantanes (precursors of adamantanes). HCs of the adamantane series are not formed, and their presence in this crude oil is due to their supply from other oil source strata. The experiments show that the n-alkanes present in the initial oil in small amounts are released under more severe conditions.
Effect of Quinoline Additions on the Activity of In Situ Formed NiWS Catalysts
Authors: Ziniatullina A. F. , Kuchinskaya T. S. , Knyazeva M. I. , Maksimov A. L.
Published: April 2024

The effect of quinoline additions and amount of the sulfiding agent added on the activity of the in situ prepared NiWS catalyst in naphthalene hydrogenation was studied. In the presence of 1 wt % quinoline, the obtained catalyst shows high activity (95% naphthalene conversion). The physicochemical properties of the catalyst were studied by XPS, X-ray diffraction analysis, and TEM. At the W : substrate molar ratio of 1 : 40 and 360°С, an increase in the amount of the sulfiding agent from 1 to 5 wt % leads to a decrease in the selectivity with respect to decalins from 68 to 39%, respectively. The degree of decoration with nickel on adding 1 wt % sulfiding agent is 0.1. As the amount of the sulfiding agent added is increased to 5 wt %, the degree of decoration with nickel increases to 0.3.
Influence of Synthesis Conditions on the Performance of Palladium–Copper Ethanol-to-Butanol Conversion Catalysts
Authors: Nikolaev S. A. , Ezzhelenko D. I. , Chistyakov A. V. , Chistyakova P. A. , Tsodikov M. V.
Published: April 2024

The influence of the synthesis conditions on the performance of Pd–Cu ethanol-to-butanol conversion catalysts was studied. The optimum conditions for forming the most active system 0.2%Cu/0.3%Pd/Al2O3 are as follows: sample synthesis by Al2O3 impregnation from aqueous solutions of Pd and Cu nitrates; deposition of the metal precursors in succession; total content of Pd and Cu in the sample 0.5 wt %; Pd : Сu molar ratio 1 : 1; catalyst reduction temperature 200○С. As shown by TEM, XPS, TPD-NH3, TPR-H2, XRD, and N2 adsorption, the surface of the most active catalyst contains Pd0Cu0 particles with the mean size of 4 ± 2 nm. The bimetallic particles are an alloy with the fcc structure and Pd : Cu ratio of 40 : 60. At 275○C, the performance of 0.2%Cu/0.3%Pd/Al2O3 is 182 × 10–4 mol h–1 g–1. The value obtained is higher by several orders of magnitude than the performance of the reference catalysts M1/Al2O3 (M1 = Fe, Ni, Co) and by an order of magnitude than that of the reference catalysts M2/Al2O3 (M2 = Ru, Rh, Pt, Pd, Pt–Re, Ni–Mo).
Quantification of C10–C14 Adamantanes in High-Viscosity Naphthenic Oils
Authors: Kul'kov M. G. , Salakhidinova G. T. , Vtorushina E. A. , Butyrin R. I. , Aliev A. E.
Published: April 2024

The paraffin–naphthenic fractions (with boiling points below 310°C) prepared from three high-viscosity naphthenic crude oils, classified as types B1 and B2 (according to Petrov’s classification), were subjected to thiocarbamide complexation. The molecular composition of polycyclic hydrocarbon biomarkers and C11–C13 adamantanes in the oil samples suggested a predominantly marine genotype of the precursor organic matter (OM). The molecular composition also suggested source rocks of a clayey type. Nonetheless, the biomarkers detected in one sample indicated some contribution of terrigenous components to the precursor OM. All the oils were generated under the conditions of the main oil generation zone and, presumably, underwent microbial transformations in the deposits. The compositions of C10–C14 adamantanes in the initial paraffin–naphthenic fraction, in the thiocarbamide adduct, and in the filtrate that remained after the adduction were comparatively characterized for each oil sample. The test conditions allowed us to have adamantane more than 100-fold concentrated (in the adduct), to quantify it in the oils, and to evaluate the concentrations of C11–C14 alkyladamantanes in the oils using adamantane as an internal standard. C10–C14 adamantanes exhibited selective adduction ability, with the extraction ratios of individual components being different. Taking into account these extraction ratios, the component concentrations were evaluated on crude oil basis: 2.7 to 7.6×10–3 wt % for adamantane and 87 to 267×10–3 wt % for total C10–C14 adamantanes. The identification of adamantanes in the initial paraffin–naphthenic fractions, adducts, and filtrates revealed the presence of some other tricyclanes (probable precursors of alkyladamantanes) as well as decaline homologues. Like adamantanes, these compounds exhibited selective ability to complex with thiocarbamide.
Рt/SAPO-11 Catalytic Systems Differing in Acidity and Secondary Pore Structure in n-Hexadecane Hydroisomerization
Authors: Agliullin M. R. , Serebrennikov D. V. , Khazipova A. N. , Malunov A. I. , Dement'ev K. I. , Kutepov B. I.
Published: April 2024

SAPO-11 molecular sieve samples differing in the acid properties, crystal morphology and size, and secondary pore structure characteristics were obtained by crystallization of reaction gels with the SiO2/Al2O3 molar ratios of 0.1 and 0.3, prepared using aluminum isopropoxide or boehmite as an aluminum source. Platinum (0.5 wt %) was deposited onto the molecular sieves prepared, and the catalytic properties of the resulting samples in n-hexadecane hydroisomerization were studied. The hydrocarbon conversion on these samples varies from 76.8 to 87.7 wt %, and the isoparaffin formation selectivity, from 76.7 to 91.2 wt %.
Application of High-Temperature Combustion Method for Measuring Content of Organic Carbon in Faecal Pellets and Small-Sized (≤1 mm) Zooplankton
Authors: Drits A. V. , Belayev N. A. , Karmanov V. A. , Flint M. V.
Published: April 2024

Organic carbon of fecal pellets and small-sized (≤ 1mm) zooplankton was measured using a high- temperature combustion method. The method was adapted for measurements with Shimadzu TOC-VCPH analyzer equipped with a manual injection module. The range of carbon content values was 30–10 000 ng ind–1. The samples for analysis were collected during the cruises of the R/V “Akademik Mstislav Keldysh”in the Kara Sea in 2019-2021. Relationship between body carbon (C, µg ind-1) and prosome length (L, mm) of zooplankton describes by the equation С = 4.24 L1.84, r2 = 0.85, n = 46. Carbon of field collected fecal pellet varied from 9.4 до 102.9 µg С mm–3. The carbon to chlorophyll a ratio of fecal pellets differed by more than two orders of magnitude. The highest values (542 and 736) were obtained in the bays of the Novaya Zemlya archipelago, the lowest (3–6) on the Kara sea shelf in June 2021 soon after ice melting. The perspectives of implication of high temperature combustion method for studies of zooplankton in situ feeding and to estimate the contribution made by pellets to POC vertical flux are discussed.
Surface Bottom Sediments of the North Atlantic on the Transect along 59.5° N
Authors: Matul A. G. , Novichkova E. A. , Kazarina G. Kh. , Tikhonova A. V. , Kozina N. V. , Behera P. , Sahoo N. , Tiwari M. , Mohan R.
Published: April 2024

An analysis of the lithological, isotope-geochemical, and micropaleontological parameters of the surface layer of bottom sediments in the North Atlantic was made at 26 stations on the profile along 59.5° N. The distribution of humidity and granulometric composition of sediments reflects vertical/circumcontinental zonality, since fine-grained and water-saturated material accumulates in the deepest parts of the Iceland Basin and the Labrador and Irminger seas, which are farthest from land. Larger masses of calcium carbonate are also formed there, but organic carbon is unevenly distributed. Both vertical/circumcontinental and climatic (circulation of the warm North Atlantic water) zonalities affect the mineral composition of the sediment fraction 0.063 mm. The accumulation of diatoms, radiolarians, and planktic foraminifers in sediments reflects both vertical/circumcontinental and, to a greater extent, climatic zonality. Variations in the isotopic oxygen and carbon ratios in the shells of benthic and planktic foraminifers require a complex interpretation involving data on the parameters of various surface and bottom water masses. The distribution of planktic microfossil assemblages according to cluster analysis shows areas of distribution of different water masses with a clear boundary along the eastern margin of the Subpolar Gyre. The distribution of “cluster” assemblages of benthic foraminifers does not correspond much to that of planktic microfossils, reflecting the division of the water area into abyssal and shallow water areas.
Pleistocene Paleoceanographic Conditions in the Ioffe Drift Area (South Atlantic) Based on Benthic Foraminiferal Assemblages
Authors: Ovsepyan E. A. , Grechikhina N. O.
Published: April 2024

The Ioffe Drift located in the western South Atlantic to the north-east to the Vema Channel was discovered in the 32nd cruise of the R/V “Akademik Ioffe” in 2010. The analysis of the seismoacoustic, biostratigraphic, lithological, grain-size, geochemical and X-ray fluorescence data allowed to estimate the Pleistocene age of the upper part of the drift as well as to confirm contourite genesis of the sediments. Quantitative analyses of benthic foraminiferal assemblages are carried out in the sediment core AI-2436 (26°51.6′ S, 34°01.40′ W, 3800 m water depth) collected near the drift summit. The obtained results allowed reconstructing relative changes of the organic matter flux to the seafloor, its periodicity and bottom current intensity as well as suggesting interplay of the deep-water masses during the Pleistocene. Visual evaluation of benthic foraminiferal tests allowed distinguishing three groups of damages of presumably variable genesis. First group includes damages possibly resulted from impacts of particles transporting by bottom currents. Second group consists of damages that appeared due to movement of the tests by strong bottom currents. Third group contains deformations caused by dissolution in carbonate-aggressive bottom-water environment. Thus, specific features of the tests in combination with traditional methods may serve as a supporting technique for diagnostics of contourites. However, this method demands a development of application criteria and should be verified on reliable material.
Geological Investigations of the Mid-Atlantic Ridge between the Charlie Gibbs and Maxwell Transform Faults during Cruise 53 of the R/V “Akademik Nikolaj Strakhov”
Authors: Peyve A. A. , Sokolov S. Yu. , Ivanenko A. N. , Razumovskii A. A. , Patina I. S. , Bogolyubskii V. A. , Veklich I. A. , Denisova A. P. , Dobrolyubov V. N. , Dokashenko S. A. , Ivanova E. S. , Lapina S. A. , Naumov I. A. , Nikitin N. S. , Urazmuratova Z. F.
Published: April 2024

We provide information on geological and geophysical studies of the structure of the Mid-Atlantic Ridge between the Charlie Gibbs and Maxwell transform faults in the North Atlantic during the 53-th cruise of the R/V Akademik Nikolaj Strakhov in July–August 2022. The preliminary results of the expedition are discussed.
Seasonal Meridional Displacement of the Jet Structure of the Antarctic Circumpolar Current South of Africa
Authors: Tarakanov R. Yu.
Published: April 2024

This paper describes a method for analyzing the seasonal variability of the structure of the gradient field of Absolute Dynamic Topography (ADT) based on the satellite altimetry data. This structure is understood as the alternation in the meridional direction of the zones of increased values of the absolute values of the ADT gradient and the zones of their lower values, i.e. jets and inter-jet gaps. The technique uses linear and harmonic regression analyzes and makes it possible to calculate the amplitudes and phases of stationary harmonic oscillations that approximate the seasonal variations in the meridional shift of the structure of the ADT gradient field and in the absolute values of the ADT gradient, as well as to estimate the calculation error. Based on this technique, corresponding calculations were made for the Antarctic Circumpolar Current (ACC) band south of Africa (from 10 ° W to 25 ° E). In particular, the amplitude of the seasonal variation of the meridional shift of the ADT gradient field for the ACC as a whole was 0.009 ± 0.013° latitude with a maximum northward shift in December. At the same time, there are zones within the ACC band where this amplitude reaches 0.12°, 0.16° and 0.28° latitude. The amplitude of the shift of the indicated field relative to the scale of the ADT itself within the ACC band at different scales is 0.6–2.5 cm. It is shown that this shift is mainly due to the seasonal variation of the ADT at geographic points. The amplitude of the seasonal variation of the ADT gradient modulus relative to both latitude and the ADT scales increases from 1 × 10–3 cm/km in the central part of the ACC to 6–7 × 10–3 cm/km at the southern and northern peripheries.