Steel Micro-alloying with Boron: A Perspective Direction to Reduce the Consumption of Manganese Ferroalloys

Manganese ferroalloys occupy a strategically important place in the total production of ferroalloys, since no steel grade can be made without the manganese addition. Today, the metallurgical complex of Russia is fully dependent on imports of manganese products (raw ore and ferroalloys), so special attention should be paid to the issues of more rational use of manganese. In particular, one should more widely use the methods of direct micro-alloying of steel with manganese in steel-smelting units and ladle-furnaces unit (LFU) and expand the range of high-strength steel with reduced manganese content, micro-alloyed with high-performance elements. Among the micro-alloying elements, a special place is occupied by boron. Its introduction into the metal in the amount of 0.001–0.005% makes it possible to save expensive and scarce alloying elements, in particular manganese, and to provide an increase in the strength of steel without reducing ductility. The results of the studies of the physicochemical properties of slags of the system CaO–SiO2–B2O3–Al2O3–MgO had formed the basis for the technology development for the formation of basic boron-containing slags, that implementation at the LFU in the converter shop of JSC “ArcelorMittal Temirtau” provided the smelting of boron-containing steel economically doped with manganese with low-content of sulfur and high strength and plastic properties. The developed technology provided, depending on the steel grade, a boron content of 0.001–0.008% by weight, low concentration of sulfur in the metal, not more than 0.004–0.014% by weight, and reducing the manganese ferroalloys consumption from 0.5 to 1.4 kg/ton of steel. Keywords: pipe steel, manganese, sulfur, boron, mechanical properties, structur

Influence of boric anhydride upon the physical and chemical properties of ferrosilicon slag

The authors study the influence of boric anhydride upon the physical and chemical properties of slag in the manufacture of ferrosilicon. It is established that adding boric anhydride to the slag changes its refractory quality and its viscosity and eases pouring slag and metal. Slags with optimal composition and properties are described

Metabolic role of pyrophosphate-linked phosphofructokinasepfkfor C1 assimilation inMethylotuvimicrobium alcaliphilum20Z

Background Methanotrophs is a promising biocatalyst in biotechnological applications with their ability to utilize single carbon (C1) feedstock to produce high-value compounds. Understanding the behavior of biological networks of methanotrophic bacteria in different parameters is vital to systems biology and metabolic engineering. Interestingly, methanotrophic bacteria possess the pyrophosphate-dependent 6-phosphofructokinase (PPi-PFK) instead of the ATP-dependent 6-phosphofructokinase, indicating their potentials to serve as promising model for investigation the role of inorganic pyrophosphate (PPi) and PPi-dependent glycolysis in bacteria. Gene knockout experiments along with global-omics approaches can be used for studying gene functions as well as unraveling regulatory networks that rely on the gene product. Results In this study, we performed gene knockout and RNA-seq experiments inMethylotuvimicrobium alcaliphilum20Z to investigate the functional roles of PPi-PFK in C1 metabolism when cells were grown on methane and methanol, highlighting its metabolic importance in C1 assimilation inM. alcaliphilum20Z. We further conducted adaptive laboratory evolution (ALE) to investigate regulatory architecture inpfkknockout strain. Whole-genome resequencing and RNA-seq approaches were performed to characterize the genetic and metabolic responses of adaptation topfkknockout. A number of mutations, as well as gene expression profiles, were identified inpfkALE strain to overcome insufficient C1 assimilation pathway which limits the growth in the unevolved strain. Conclusions This study first revealed the regulatory roles of PPi-PFK on C1 metabolism and then provided novel insights into mechanism of adaptation to the loss of this major metabolic enzyme as well as an improved basis for future strain design in type I methanotrophs

Delay-differential SEIR modeling for improved modelling of infection dynamics

Abstract SEIR (Susceptible–Exposed–Infected–Recovered) approach is a classic modeling method that is frequently used to study infectious diseases. However, in the vast majority of such models transitions from one population group to another are described using the mass-action law. That causes inability to reproduce observable dynamics of an infection such as the incubation period or progression of the disease's symptoms. In this paper, we propose a new approach to simulate the epidemic dynamics based on a system of differential equations with time delays and instant transitions to approximate durations of transition processes more correctly and make model parameters more clear. The suggested approach can be applied not only to Covid-19 but also to the study of other infectious diseases. We utilized it in the development of the delay-based model of the COVID-19 pandemic in Germany and France. The model takes into account testing of different population groups, symptoms progression from mild to critical, vaccination, duration of protective immunity and new virus strains. The stringency index was used as a generalized characteristic of the non-pharmaceutical government interventions in corresponding countries to contain the virus spread. The parameter identifiability analysis demonstrated that the presented modeling approach enables to significantly reduce the number of parameters and make them more identifiable. Both models are publicly available

THE NUMBER OF HOMOLOGS OF SOME ENZYMES IN THE TRYPTOPHAN BIOSYNTHESIS PATHWAY CORRELATES WITH THE PROPORTION OF PROTEINS ASSOCIATED WITH TRANSCRIPTION IN PLANTS

The tryptophan biosynthesis pathway (TBP) is ubiquitous in most known organisms, being absent only from animals and some bacteria. It is conserved in plants, although various species differ in the number of TBP enzyme paralogs. In the current work we investigated a putative possible role of changes in the number of paralogs of TBP enzymes in the course of plant evolution. We identified TBP enzyme paralogs in plant species with fully sequenced genomes and estimated the relationship between its number and organismal complexity. It is shown that organismal complexity significantly correlates with the total number of TBP paralogs and for some enzymes specifically (ASA/ASB, PAI, and IGPS). We suggest that such a relationship arises because both organismal complexity and the increasing number of paralogs may be important for the evolutionary adaptation of land plants to variable environmental conditions

RECOMBINANT STRAINS OF SACCHAROMYCES CEREVISIAE FOR ETHANOL PRODUCTION FROM PLANT BIOMASS

Saccharomyces cerevisiae is the most appropriate and the most widely used model organism for industrial production of ethanol from sugars, because yeasts (1) have high rates of growth, fermentation and  biosynthesis of ethanol under anaerobic conditions and (2) are tolerant of high concentrations of ethanol and low pH values. Currently, the most promising source of sugar is lignocellulosic biomass. Sugars derived from it are a mixture of hexoses and pentoses. However, S. cerevisiae strains in current use are poorly adapted to pentasaccharide fermentation. Therefore, it is necessary to optimize the metabolism of currently available bioethanol producers for pentasaccharide consumption. The article presents an overview of existing approaches designed to solve this problem by using recombinant S. cerevisiae strains

A MATHEMATICAL MODEL FOR THE INFLUENZA VIRUS LIFE CYCLE

Motivation: The Influenza virus (InfV) is a widespread infectious agent causing contagious disease in humans and animals. Its prominent feature is high and functional genetic variability. The mechanisms underlying virus give rise to strains possessing novel unpredictable properties. Their analysis and reliable prediction are the tasks of basic and applied biogenetics and virology. The pressing question is: What may be the replication pattern of the InfV within the infected host cell? There is, as yet, no clarity. This is a stumbling block for advancement in this research area. Results: Here, we have reconstructed the gene network and develop a mathematical model for the InfV. They incorporate the processes of replication, transcription, translation, regulation them and assembly within the InfV infected cell. Based on the mathematical model, we followed the dynamics of the developed gene network and analyzed the key regulatory stages of the InfV replication. Availability: The schematic presentation of the gene network “Influenza (life cycle) ” is available through the GeneNet viewer a

NEW FACILITIES OF THE MGSmodeller

Mathematical modeling and analysis of complex molecular-genetic systems (MGS) are the key challenges in the systems biology era. To solve this task the special technologies and programming approaches considering the MGS as an ensemble of dynamic interconnected subsystems with a more simple structure are necessary to be developed. We have presented the approach that is aimed at acceleration of reconstruction of the complex MGS mathematical models and complex analysis using high performance computation techniques

The Phylogeny of Class B Flavoprotein Monooxygenases and the Origin of the YUCCA Protein Family

YUCCA (YUCCA flavin-dependent monooxygenase) is one of the two enzymes of the main auxin biosynthesis pathway (tryptophan aminotransferase enzyme (TAA)/YUCCA) in land plants. The evolutionary origin of the YUCCA family is currently controversial: YUCCAs are assumed to have emerged via a horizontal gene transfer (HGT) from bacteria to the most recent common ancestor (MRCA) of land plants or to have inherited it from their ancestor, the charophyte algae. To refine YUCCA origin, we performed a phylogenetic analysis of the class B flavoprotein monooxygenases and comparative analysis of the sequences belonging to different families of this protein class. We distinguished a new protein family, named type IIb flavin-containing monooxygenases (FMOs), which comprises homologs of YUCCA from Rhodophyta, Chlorophyta, and Charophyta, land plant proteins, and FMO-E, -F, and -G of the bacterium Rhodococcus jostii RHA1. The type IIb FMOs differ considerably in the sites and domain composition from the other families of class B flavoprotein monooxygenases, YUCCAs included. The phylogenetic analysis also demonstrated that the type IIb FMO clade is not a sibling clade of YUCCAs. We have also identified the bacterial protein group named YUC-like FMOs as the closest to YUCCA homologs. Our results support the hypothesis of the emergence of YUCCA via HGT from bacteria to MRCA of land plants

SUPPRESSION OF SUBGENOMIC HEPATITIS C VIRUS RNA REPLICON REPLICATION IN Huh-7 CELLS BY THE NS3 PROTEASE INHIBITOR SCH5030334: A STOCHASTIC MATHEMATICAL MODEL

Hepatitis C virus (HCV) causes a severe liver disease frequentlyassociatedwith cirrhosis andhepatocellular carcinoma. No effective anti-HCVtherapyis available so far. Thus, it is pertinent to applymathematical modelingto prediction ofthe efficiencyofnew candidate pharmaceuticals. Astochastic mathematical model for subgenomic HCVreplicon replication in Huh-7 cells with the presence ofthe HCVNS3 protease inhibitor SCH 503034 is proposed. The model describes the experimental kinetic curves ofviral RNAsuppression at various SCH 503034 concentrations. It is applicable to the development ofapproaches to HCVRNAsuppression in Huh-7 cells