The tick-borne encephalitis virus (TBEV), a member of the Flaviviridae family, is currently subdivided into three main subtypes-the European (TBEV-Eu), the Far-Eastern (TBEV-FE), and the Siberian (TBEV-Sib). The TBEV-Sib is the most common subtype and found in all regions where TBEV was detected, except for Central and Western Europe. Currently, four genetic lineages have been described within TBEV-Sib. In this study, detailed analysis of TBEV-Sib genetic diversity, geographic distribution, phylogeography and divergence time of different TBEV-Sib genetic lineages based on E gene fragments, complete genome sequences, and all currently available data in the GenBank database was performed. As a result, a novel Bosnia lineage within the TBEV-Sib was identified. It was demonstrated that the Zausaev lineage is the most widely distributed among the TBEV-Sib lineages, and was detected in all studied regions except the Far East. The Vasilchenko lineage was found from Western Siberia to the Far East. The Baltic lineage is presented from Europe to Western Siberia. The Obskaya lineage was found only in Western Siberia. TBEV strains from a newly described Bosnia lineage were detected in Bosnia, the Crimean peninsula, Kyrgyzstan and Kazakhstan. The greatest divergence of the TBEV-Sib genetic variants was observed in Western Siberia. Within the TBEV-Sib, the Obskaya lineage diverged from the common ancestor the earliest, after that the Bosnia lineage was separated, then the Baltic lineage, and the Zausaev and Vasilchenko lineages diverged most recently.

Background. During the study of the genetic variability of the tick-borne encephalitis virus (TBEV) in Eastern Siberia, a group of 22 strains with a unique genetic structure significantly different from all known TBEV subtypes was identified. This TBEV variant was tentatively called “group 886”. Therefore, for this original TBEV variant it was necessary to study the genetic, biological properties of the “group 886” strains, clarify its TBEV taxonomic status, its range, evolutionary history, etc.Aim. The generalization of the currently available data on genetic and biological properties of TBEV “886” group.Materials and methods. The genetic structure of “group 886” strains was studied by the complex of molecular-genetic methods (MHNA, sequencing of fragments or the complete genome).Results. It was shown that “group 886” strains form a separate cluster on phylogenetic tree, and the level of genetic differences from other genotypes is more than 12 %. It was defined that this TBEV variant has its own area (Irkutsk region, Republic of Buryatia, Trans-Baikal region, Northern Mongolia). Its ecological connection with all links of the transmissive chain (ixodid ticks, small mammals, human), participation in human pathology, stability and duration of circulation in the Baikal region, individual evolutionary history were proved. Some phenotypic characteristics of the “group 886” strains were considered.Conclusion. The presented data testify to the validity of the “886 group” isolation as an independent genetic type. Taking into account the geographical distribution of this TBEV genotype, we propose to assign it the name “Baikal genotype/subtype”.

Tick-borne encephalitis virus (TBEV) is classified into three subtypes: Far Eastern (TBEV-FE), European (TBEV-EU) and Siberian (TBEV-SIB). In Russia, these are also called genotypes 1, 2 and 3, respectively. Geographically, TBEV-EU dominates in Central and Northern Europe, but its representatives are also found to the east - along the southern part of the forest zone of extratropical Eurasia - up to Eastern Siberia and South Korea. However, the strains isolated outside Europe remain poorly investigated. In the proposed study, eight full genomes of the Siberian isolates of TBEV-EU were determined and 13 complete genomes were compared. The analysis of 152 full-genome TBEV sequences showed that the TBEV-EU has a higher degree of stability of the genome-coding region in the entire Eurasian area (3.1% of differences) compared to TBEV-FE (6.6%) and TBEV-SIB (7.8%). At the same time, the maximum differences are observed not between European and Siberian strains, as one could expect, but between the representatives from Europe - TBEV strains Mandl-2009 from Norway and Hypr from the Czech Republic. The studied strains from Siberia form the compact genetic cluster of 42 TBEV-EU strains and are divided into two subclusters - West Siberian and East Siberian variants. These variants differ in the combinations of amino acid substitutions in all proteins except NS2B. The West Siberian variant mostly circulates in the territory of Altai, and the closest relative of its representatives is Absettarov strain from the European part of Russia. The strains similar to the East Siberian variant of the European subtype were recorded in the Altai (strain 84.2, 2007) and in Belarus (N256, about 1940).

The joint crystallization of the stable phase (a number of solid solutions of chromium-containing beryllian indialite) and metastable phases (crystalline modifications) of the compound with β-quartz structure (Si0.64Al0.28Mg0.21Be0.09)IVO2 ~ Mg1.89Be0.81Al2.52Si5.76O18 admixed with Cr2O3 phases of khmaralite Mg1.21Cr0.01Be0.46Al1.78Si3.38O20 and spinel {(Mg0.95Be0.045Si0.005)IV(Al1.31Cr0.67Mg0.02)VI}O4 is performed using melted chromium–beryllian indialite preliminarily obtained by solid-phase synthesis as a precursor. Simultaneously, the residual X-ray amorphous melt of composition Mg1.83Cr0.01Be1.04Al2.64Si5.57O18 is hardened. Thus, a reconstructive transition from the beryllian indialite melt to a phase with the β-quartz structure is implemented, and the chemical similarity of these compounds is demonstrated. The rate of change in the crystallization isotherm of 2°С/h and increased heat outflow through the highly heat-conducting walls of the Pt–Rh crucible (taper) contribute to this process.

The results of examining high-purity quartzites retrieved from the Eastern Sayan Mountains (namely, the Bural–Sardag deposit), extracting ultra-high purity quartz concentrates from them, and depositing silica glass using the vacuum-compression method are reported. The flowsheet for their beneficiation is elaborated. The characteristics of quartz concentrates and silica glass based on them are provided.

The aim of the study was to determine the ecology features of tick-borne encephalitis virus (TBEV) of European subtype circulating in Siberia. The strains of European subtype TBEV from Siberia were isolated in areas with different terrain types - from the plains to the midlands. The strains isolation areas differed in variety of landscapes, flora and fauna and were characterized by the presence of sharp-continental, or in some places - quite harsh climate. The composition of the main vectors and reservoir hosts of TBEV of European subtype in Siberia has its own features and is significantly different from that one in Europe. However, in spite of this, the homology of TBEV strains of European subtype isolated in different parts of habitat range of the virus from the Scandinavian countries in the West to its Eastern borders is much higher than the homology level degree of TBEV strains of FarEastern and Siberian subtypes.

Tick-borne encephalitis virus (TBEV) is divided into three subtypes: European (TBEV-Eu), Siberian (TBEV-Sib), and Far Eastern (TBEV-FE) subtypes. The geographical range of TBEV-Eu dominates in Europe, but this subtype is present focally across the whole non-tropical forested Eurasian belt, through Russia to South Korea. However, the TBEV-Eu strains isolated outside Europe remain poorly characterized. In this study, full-genome sequences of eight TBEV-Eu isolates were determined. These strains were isolated from Ixodes persulcatus ticks, long-tailed ground squirrel (Spermophilus undulatus), and human blood in the natural foci of Western and Eastern Siberia, Russia. A phylogenetic analysis of all available TBEV-Eu genomic sequences revealed that strains from Siberia were closely related to other strains from Europe and South Korea. The closest relation was identified between the Siberian strains and strains from Zmeinogorsk (Western Siberia, Russia) and strain Absettarov (Karelia, Russia), and were most divergent from strains from the Czech Republic and Norway. TBEV-Eu strains isolated in Eastern Siberia were more closely related phylogenetically to strains from South Korea, but strains from Western Siberia grouped together with the strains from Europe, suggesting two genetic TBEV-Eu lineages present in Siberia.

The aim of the study was to obtain the complex characteristics of tick-borne encephalitis virus (TBEV) of European subtype circulating in Western and Eastern Siberia. Using full-genome sequencing approach it was demonstrated that TBEV strains of European subtype isolated in Siberia are genetically similar to the strains from European part of its habitat range, and with the representatives from South Korea. It was confirmed that the homology of TBEV strains of European subtype isolated in different parts of the virus habitat area from Scandinavian countries in the west to the eastern borders of the area (South Korea) is much higher than the homology level of TBEV strains of Far Eastern and Siberian subtypes. The Siberian population of TBEV of European subtype is presented with two groups of strains called as Eastern Siberian and Western Siberian variants, which differ in the combinations of amino acid substitutions in all proteins except NS2B protein. It is found that TBEV strains of European subtype from Siberia possess high neurovirulence, but some of them, like strains from Europe, demonstrate low invasiveness. It is shown that TBEV strains of European subtype have good adaptive capacity, and therefore, can easily adapt to the circulation in various biocenoses in the territory of different landscape-geographical zones. It was found that the circulation of TBEV of European subtype is fixed in Siberia territory for over 40 years. It was emphasized that in spite of circulation of TBEV of European subtype in the significantly different areas by climatic conditions, topography, landscape, habitat characteristics it possesses a high degree of genome stability.

The aim of the study was to obtain the complex characteristics of tick-borne encephalitis virus (TBEV) of European subtype circulating in Western and Eastern Siberia. Using full-genome sequencing approach it was demonstrated that TBEV strains of European subtype isolated in Siberia are genetically similar to the strains from European part of its habitat range, and with the representatives from South Korea. It was confirmed that the homology of TBEV strains of European subtype isolated in different parts of the virus habitat area from Scandinavian countries in the west to the eastern borders of the area (South Korea) is much higher than the homology level of TBEV strains of Far Eastern and Siberian subtypes. The Siberian population of TBEV of European subtype is presented with two groups of strains called as Eastern Siberian and Western Siberian variants, which differ in the combinations of amino acid substitutions in all proteins except NS2B protein. It is found that TBEV strains of European subtype from Siberia possess high neurovirulence, but some of them, like strains from Europe, demonstrate low invasiveness. It is shown that TBEV strains of European subtype have good adaptive capacity, and therefore, can easily adapt to the circulation in various biocenoses in the territory of different landscape-geographical zones. It was found that the circulation of TBEV of European subtype is fixed in Siberia territory for over 40 years. It was emphasized that in spite of circulation of TBEV of European subtype in the significantly different areas by climatic conditions, topography, landscape, habitat characteristics it possesses a high degree of genome stability.

Установлено, что твердофазная кристаллизация бериллиевого индиалита (БИ), полученного нагревом золь-гель-прекурсора исходного соединения нестехиометрического состава Mg1.81Be1.09Al2.27Si5.85O18, происходит путем последовательного реконструктивного преобразования: фаза со структурой кварца фаза со структурой петалита БИ. Обнаружено, что в этом процессе метастабильные фазы со структурами кварца и петалита, “начиненные” избыточными катионами, трансформируются в равновесный БИ, не имеющий катионного избытка. Выявлено, что структурный аспект родства участников преобразования состоит в наследовании полого кольца Si6O18 предыдущей фазы последующими фазами и в реберном объединении полиэдров. Химическое родство заключается в примерно одинаковом количестве всех видообразующих компонентов в составах фаз.

The work deals with the quartz raw materials of industrial type of deposits Kyshtym (Southern Ural), Bural-Sarjdag (Eastern Sayan). Quartz raw materials of three types: granular vein quartz, superquartet and fine-grained quartzite were investigated. The main typomorphic properties of quartz: structural and textural char­acteristics, presence of impurity phases, and impurity elements were described. The main form of occurrence of impurity phases in the studied quartzites was identified. It is ascertained that each type of quartz has its own individual characteristics that affect the degree of efficiency of the starting material during processing of raw materials.

The results of the bioinformatic search for the potential sites of the recombination in the genome-wide structures of the tick-borne encephalitis virus (TBEV) through a series of software techniques were presented in this work. The genomes of the 55 TBEV strains were assayed, 21 of them showed the presence of the recombination sites. Recombinant strains belonged to the Far Eastern (19 strains) and European (2 strains) genotypes. 22 sites of the recombination attributed were identified to five types based on position, strain, and regional characteristics. The parental strains were identified based on the genotypic and geographical parameters, which do not contradict the possibility of the formation of the recombinants. Nearly two-thirds of the sites are located in the regions of NS4a and Ns4b genes, which are the "hot spots" of the recombination, most of them being concentrated in the gene NS4. it was shown that the recombination processes did not occur at the level of the genotypes (European genotype) or certain groups within the genotype (Far East) and were typical of the peripheral populations.

The work deals with the quartz raw materials of industrial type of deposits Kyshtym (Southern Ural), Bural-Sarjdag (Eastern Sayan). Quartz raw materials of three types: granular vein quartz, superquartet and fine-grained quartzite were investigated. The main typomorphic properties of quartz: structural and textural characteristics, presence of impurity phases, and impurity elements were described. The main form of occurrence of impurity phases in the studied quartzites was identified. It is ascertained that each type of quartz has its own individual characteristics that affect the degree of efficiency of the starting material during processing of raw materials.

The results of the bioinformatic search for the potential sites of the recombination in the genome-wide structures of the tick-borne encephalitis virus (TBEV) through a series of software techniques were presented in this work. The genomes of the 55 TBEV strains were assayed, 21 of them showed the presence of the recombination sites. Recombinant strains belonged to the Far Eastern (19 strains) and European (2 strains) genotypes. 22 sites of the recombination attributed were identified to five types based on position, strain, and regional characteristics. The parental strains were identified based on the genotypic and geographical parameters, which do not contradict the possibility of the formation of the recombinants. Nearly two-thirds of the sites are located in the regions of NS4a and Ns4b genes, which are the "hot spots" of the recombination, most of them being concentrated in the gene NS4. it was shown that the recombination processes did not occur at the level of the genotypes (European genotype) or certain groups within the genotype (Far East) and were typical of the peripheral populations.

It is established that solid-phase crystallization of beryllian indialite (BI), obtained by heating a sol-gel precursor of the initial compound of nonstoichiometric composition Mg 1.81 Be 1.09 Al 2.27 Si 5.85 O 18 , occurs through the following successive reconstructive transformation: phase with a quartz structure → phase with a petalite structure → BI. It is found that metastable phases with quartz and petalite structures, filled with excess cations, are transformed into equilibrium BI, which has no cationic excess, during this process. It is revealed that the structural aspect of the relationship between the phases involved in the transformation is in the inheritance of a hollow Si 6 O 18 ring of preceding phase by subsequent phases and in the edge aggregation of polyhedra. The chemical relationship is in the approximately identical amounts of all species-forming components in the phase compositions.

The causative agent of this infection is tick-borne encephalitis virus (TBEV). According to the modern classification it belongs to the group of mammal viruses transmitted by ticks, and is a member of the genus Flavivirus of the family Flaviviridae [23]. As a result of nu‐ merous studies devoted to TBEV genetic variability it was divided into three genotypes (subtypes): 1) genotype 1 (Far-Eastern (FE) subtype); 2) genotype 2 (European subtype); 3) genotype 3 (Siberian subtype). Each genotype is believed to distribute in its certain area where its absolute domination is observed [10, 20].

1 ФГБУ «Научный центр проблем здоровья и семьи и репродукции человека» СО РАМН, (Иркутск) 2 ФБУЗ «Центр гигиены и эпидемиологии в Иркутской области» (Иркутск) 3 ГБОУ ВПО «Иркутский государственный медицинский университет» Минздрава РФ (Иркутск) Получены новые данные об оригинальном варианте вируса клещевого энцефалита (ВКЭ), циркулирующем на территории Восточной Сибири. С помощью молекулярной гибридизации нуклеиновых кислот (МГНК) и секвенирования геномов выявлена группа из 13 штаммов, имеющих генетическую структуру, аналогичную штамму 886-84, который был описан нами ранее как единственный вероятный представитель генотипа 5. Формирование отдельного кластера на филогенетическом древе, дифференцирующий уровень генетических отличий от других генотипов - более 12 %, наличие собственного ареала, экологическая связь со всеми звеньями трансмиссивной цепи, участие в патологии человека, стабильность и длительность циркуляции в природе подтверждают правомерность аттестации «группы 886» в качестве самостоятельного генотипа 5 ВКЭ. Показано, что для мест изоляции штаммов «группы 886» характерно совмещение нескольких ландшафтных формаций, значительное разнообразие флоры и фауны.