In this article we showed the characteristic structural features of the groups of interacting alpha-helices and beta-strands (blocks) in four sets of nonhomologous proteins from different structural classes. Stability of each element of secondary structure has been checked with help of the PentaFOLD algorithm that finds intrinsic alpha-helical and beta-structural sequences of amino acid residues. We proved that the most frequent blocks of “alpha + beta” and “alpha/beta” proteins are 2 interacting alpha helices, and they demonstrate the highest level of stability. In alpha-helical proteins the most frequent blocks contain 4 alpha-helices. In beta-structural proteins alpha-helices most frequently do not interact with other helices and demonstrate the lowest level of stability. The most stable type of beta-structure is a block made from three interacting beta-strands, while the less stable one is a beta-hairpin. There is a characteristic distribution of stable alpha-helices in “alpha + beta” proteins: they are usually situated in the beginning of a block while stable beta-strands are usually situated in the end of the block. This type of distribution of stable alpha-helices and beta-strands helps the protein to form its stable three-dimensional structure in case  it begins from beta-structural domain which is the most frequent case for the structural class of proteins. 

The results of studies of macrozoobenthos and pleustonic aquatic invertebrates complexes  of the Viliya River have been considered in the article. 92 species and forms related to 3 types of aquatic animals which are Mollusca – 15 species and forms; Annelida – 2 and Arthropoda –75 have been detected. The analysis of the species composition has shown in all studied sites that the species richness was within the range of 29–30 species. At the place of wastewater discharge from the town of Vileika, a species richness decrease and the number of Diptera and Oligochaeta increase has been observed. The relatively high number of species with rheophilic and oxyphilic properties such as representatives of the Plecoptera, Ephemeroptera, and Trichoptera orders groups indicates a fairly high water quality in the investigated sites of the Viliya River. Rare and protected for Belarus and Europe.species have been found.

Antioxidant, antimutagenic and antigenic properties of partial hydrolysates of whey and colostrum obtained using bacterial endopeptidase (alcalase) have been investigated. It was found that the depth of proteolysis, qualitative and quantitative composition of protein component of samples determined the level of their antiradical and antimutagenic activity. According to SDS-electrophoresis whey hydrolysate contains cleaved allergen proteins, whereas colostrum hydrolysate possesses a high molecular weight fraction (>10 kDa) of partially digested immunoglobulins. Proteolysis of β-lactoglobulin, which has a high allergenic potential, is confirmed by results of immunoprecipitation reaction. In accordance with the ORAC method antioxidant action of hydrolysed whey and colostrum increased by 2.8 and 5.0 times, respectively. Antimutagenic effect for whey hydrolysate was 15.7–49.2 % when tested on the strain Salmonella typhimurium TA 98 and 18.8–52.1 % for strain TA 100. It exceeded values of colostrum hydrolysate. Samples of whey and colostrum hypoallergenic hydrolysates with confirmed antioxidant and antimutagenic properties have been obtained.

The porcine reproductive and respiratory syndrome (PRRS) caused the serious economic damage to swine breeding around the world. It is a viral infective disease against which live attenuated and inactivated vaccines are not always successful. Development of new types of drugs such as DNA vaccines is necessary for improving the protection against the virus. DNA vaccines induce the development of both a cellular and humoral immune response. Such vaccines consist of a plasmid or viral vector with genes of potentially immunogenic proteins. The expression of these genes realized in cells of the vaccinated animal. It leads to the synthesis of antigen proteins triggering the immune response. The purpose of this work is to create a genetic construction that can be used as DNA vaccine against PRRS virus. The construction consists of the commercial vector pVAX1 and open reading frame of two structural proteins of PRRS virus, a lysosomal localization signal sequence of the invariant chain gene and regulatory elements necessary for the expression of cloned genes in mammalian cells.

Spirulina (Arthrospira) platensis biomass has a wide range of applications in several industries. One of the key issues for its production is the reduction of the culture medium cost. Here we have shown the possibility of a single recycling (repeated usage) of the modified Zarrouk nutrient medium (MZM; which contains 8.4 g/l of NaHCO₃ and 0.1 g/l of NaOH instead of 16.8 g/l of NaHCO₃ ) for spirulina cultivation without altering culture productivity, photosynthetic pigments and protein contents in its biomass  given that technological approach consisting in application of a mixture of a freshly prepared and once recycled modified Zarrouk medium in a ratio of 1:1 by volume is used. The obtained results can be applied for further reduction of costs of spirulina biomass production compared to methods described in previous studies.

There is a review of floral studies of the water bodies in Minsk Region and National Park “Belovezhskaya Pushcha”. 75 new locations of 20 rare aquatic and riverside plant species coming at the water and 1 hybrid were found. 7 of these species are listed in the Red Book of the Republic of Belarus, 5 species are included into the category of Least Concern and Data Deficient. Potamogeton berchtoldii Fieber, Utricularia minor L., Potamogeton acutifolius Link, P. nodosus Poir., Salvinia natans (L.) All. are reported for the first time from National Park «Belovezhskaya Pushcha». The spreading of Berula erecta (Huds.) Coville on the territory of National Park is considered in detail. New locations of Nuphar pumila (Timm) DC., Ranunculus kauffmannii Clerc., Najas major All., Berula erecta, Glyceria lithuanica (Gorski) Gorski, Conioselinum tatari­ cum Hoffm. in Minsk Region, which were not included in 4th edition of the Red Book, have been described. A brief description of habitat environmental conditions is given for the revealed species of aquatic plants, and their phytocoenotic confinement is also pointed out. New information on the locations of protected aquatic plant species should be used to monitor their populations and prepare the documents of protection.

Currently, there are critical ecosystems that accumulate radionuclides and determine the duration of radiation exposure on biota. The dose of external exposure caused by two factors – radioactive contamination of forest stands and the human behavior mode. In this work, authors represent the analysis of structure of ionizing radiation sources in forest stands at the territory with radioactive contamination. A method for estimating values of external radiation dose is based on calculation of protection against extended sources of ionizing radiation. A calculation data source is information on contamination density, wood species and forest type. We used taxation characteristics of pine stands to determine configuration and radiation sources composition. Calibration and verification of proposed model were carried out by dose rate in situ measurements by different methods. The results of comparison of the exposure dose rate in the meadow-forest areas confirmed the existence of the so-called “edge effect”. Experimental data is in a good agreement with the model calculations. A forecast of external exposure dose in pine forests for a remote period after the accident at ChNPP has been obtained. The method allows to improve radiation safety measures of forestry engineers, worked at forest sites.

The article provides information about biological properties (taxation characteristics, dynamics of the current average period growth in diameter, seed production, natural renewal) of 8 species and 12 decorative forms from the genus Abies Mill.

Under the conditions of introduction, the explored species of fir and their decorative forms showed a sufficiently high winter hardiness, resistance to diseases and pests, they successfully seed, and some of them give self-seeding. In the cultural dendroflora, fir trees are rare. Among the species, the most common fir on the territory of the republic is Abies concolor Lindl. et Gord, and among the decorative forms cultivars it is Abies koreana Wils.

Data on a genus of the Daffodils have been given in the article. The areas of species have been designated. Dates of selection work for the Daffodils have been determined. Countries and number of plant breeders of the Daffodils have been presented. The first cultivar of the Daffodil with pink crown has been specified, too.

Group accessory for the 55 Daffodils from the collection of the Central Botanical Garden of NAS of Belarus has been defined. The age and authorship of the studied cultivars have been established. Assessment of their biological features in the conditions of the Central area of Belarus has been carried out. Periods and duration of some phenological phases have been established. Height of plants and sizes of flowers have been estimated. Periods of the Daffodils with a pink crown blossoming have been established. The abundance of blossoming depends on cultivar’s features and duration of their cultivation without grafting. The flowers of Daffodils with a pink crown have been measured from 6.5 to 11.5 cm. For the long-cupped Daffodils sizes and forms of crowns are various. The multiplication factor during the three years cultivation fluctuates from 5 to 16 units. Grades are rather steady in local conditions against diseases and pests.

From studied cultivars the 13 best ones have been recommended for cultivation.

Based on the data of seven-year observations of the rhythms of seasonal growth and development, the features of the passage of the phases of phenological development of 15 cultivars of highbush blueberry and 1 cultivar of lowbush blueberry have been presented in the article. The rhythmic plasticity of the blueberry cultivars introduced in Belarus appeared in the ability to change phenorhythmics by the reason of different weather conditions during the years of observation. It was reflected in the variation of dates of the main phenological phases onset. At the same time, inter-branch differences in the early phases of development (vegetative) were insignificant, they became much more pronounced in terms of the passage of the phenological phases associated with the development of the generative sphere of the highbush blueberry. The investigated blueberry cultivars under the conditions of the introduction point retain their inherent order of fruit ripening, characteristic of their homeland.

The climatic conditions of the Belarusian Polesie ensure the passage of a full cycle of seasonal development by the investigated highbush blueberry of the entire spectrum of ripening of the crop. At the same time, inter-branch differences in the duration of the growing season are insignificant. The obtained results testify to the prospects of the investigated blueberry cultivars of different maturation periods for homestead and industrial gardening in the Belarusian Polesie and determine the expediency of carrying out further introductory research.

The features of entering into the stage of generative development, industrial fruiting, productivity, the variability of fruiting of 20 cultivars of blueberry and a large variety of blueberry, introduced in Belarus have been shown on the base of results during many years of researches. All the investigated blueberry cultivars in conditions of Belarus fulfill their target functions – they form fruits. It indicates successful implementation of their adaptive potential at the introduction point. The introduction into the generative phase of the development of blueberry plants occurs at the age of 4, in the stage of industrial fruiting – in the 6-year-old. . In different years of fruiting, the yield of blueberry cultivars varies greatly. While the cultivars Bluecrop, Bluetta, Denise Blue, Duke, Earliblue, Elizabeth, Jersey, Northblue, Northcountry, Northland, Patriot, Weymouth are characterized by a higher berry productivity then other ones, Blueray, Northland and Jersey are characterized by more regular fruit bearing. The variability  of fruiting of blueberry plants mainly is caused by the death of flowering buds in winter and/or by the drought during the period of their forming. The weight of the blueberry fetus is very variable, depending on the varietal characteristics and the year. A close size of berries correlation dependence has been established concerning to the moisture content in the period of their growth, and to its temperature regime especially.

Quercetin (3,3ʹ,4ʹ,5,7-pentahydroxyflavon), one of the most common and studied flavonoids, possesses the antioxidant activity  and demonstrates the pronounced therapeutic potential under a number of pathological conditions. The purpose of this work is to estimate the electronic structure of the quercetin and its semi-quinone radical molecules and to compare the antioxidant activities of quercetin and its inclusion complex with hydroxypropyl-β-cyclodextrin. Generation of maps of the electron density distribution in quercetin and quercetin semi-quinone radical molecules showed that the active electron orbitals (HOMO and LUMO) are delocalized over all phenolic rings providing the radical stabilization. We have showed that quercetin prevents the tert-butyl hydroperoxide-induced lipid peroxidation of erythrocytes (IC₅₀ = 25 ± 3 μM) and mitochondrial membranes (IC₅₀ = 31 ± 4 μM). The efficiency of quercetin inhibition the reduced glutathione oxidation in erythrocytes and mitochondria is much lower reflecting the lipophilicity  of polyphenol. Quercetin also prevented the hypochlorite-induced lysis of red blood cells (IC₅₀ = 3 ± 0.5 μM). Our data revealed that the quercetin-hydroxypropyl-β-cyclodex-trin complex is more effective inhibitor of the membrane lipids peroxidation and glutathione oxidation processes.