Background: An urgent problem of modern biomedicine is the search for potential ways to reduce the spread of coronavirus infections in human and animal populations and eliminate the impact of coronavirus on their bodies. Aim of the work was to determine the structural organization of C60 fullerenes in a model cell medium, to assess their potential ability to penetrate the model lipid envelope of a coronavirus, thus destroying its integrity, as well as the effectiveness of the anticoronavirus action in the in ovo system. Methods: The research was conducted using the Gromacs 2020 software package and the Charmm36 force field. The CHARMM-GUI web resource was used to construct the lipid envelope of a coronavirus. Virological and toxicological methods were used in the in ovo experiments. Results: It is shown that at the initial stages of molecular dynamics C60 fullerene forms small nanoclusters in the amount of 7–16 molecules, which is affected by the initial concentration of C60 fullerene in a model cell medium. At the same time, the shape of nanostructures for the number of molecules over 16 may differ from the correct spherical shape. It was established that C60 fullerene and its nanoclusters are able to penetrate inside the lipid envelope of a coronavirus. In particular, a single C60 molecule can migrate, completely embed itself in the lipid envelope, or move within it. It was found that C60 fullerene aqueous solution, at the maximum permissible concentration (MPC) of 30 μg/embryo, reduces the infectious activity of the chicken infectious bronchitis (CIB) coronavirus when it is used 1, 2 and 4 h after the infection of a sensitive biological system with a coronavirus. Conclusions: It is shown that aggregation of C60 fullerene in a model cell medium can occur in different ways: either before penetration into the lipid envelope of a coronavirus, or inside it. C60 fullerenes, both individually and as part of nanoclusters, are able to form pores in the envelope of a coronavirus, destroying its integrity, which possibly leads to disruption of the corresponding stages of its replication cycle and attachment to cell receptors. It was established that C60 fullerene aqueous solution, when used in the MPC value, shows antiviral activity against the CIB coronavirus in its early stages of interaction with the cell (1–4 h).

Background: Light is a multifaceted exogenous factor that plays an important role in plant growth and development. The spectral composition of light is determinative for the regulation of photomorphogenetic processes in plants. Nowadays plants have several groups of photoreceptors that include receptors of red (RL) and far red light (FRL) — phytochromes; receptors of UV-A, blue (BL) and green (GL) light — cryptochromes, phototropins, proteins of the ZEITLUPE family, as well as the UV-B receptor — UVR8 protein. One of the possible mechanisms that realize an activation of photoreceptor systems in the plant may be concerned with carbohydrate metabolism. The research of morphogenetic reactions of seedlings under the action of selective light irradiation by activating photoreceptor systems is important for understanding the mechanisms of regulation of the program of plant organism`s ontogenesis. The aim of this study was to investigate the effect of selective light of different spectrum: RL (660 nm), GL (530 nm) and BL (450 nm) on growth reactions, morphogenesis and content of soluble carbohydrate in axial organs of seedlings of long-day plants. Materials and methods: 10-day etiolated seedlings of pea Maecenat variety were used for experiments. Activation of photoreceptor systems by red (RL, 660nm), green (GL, 530nm) and blue (BL, 450nm) light was performed for 5 days for 30 minutes using LED matrices. The growth reaction, morphogenesis and the content of soluble mono- and oligosugars in the axial organs of seedlings were analyzed. Results: The axial organs of seedlings differ in their response to irradiation with selective light. The root system is more sensitive to the action of selective light than the shoot of the seedlings of the long-day plants of the pea Maecenat variety. Activation of photoreceptor systems stimulates growth processes, activates the processes of photomorphogenesis and the biosynthesis of oligosugars de novo, most likely sucrose. Among the spectra of selective light, the maximum stimulating effect is shown by irradiation of the GL (530 nm) in the reactions of the aboveground part and roots. RL (660 nm) and BL (450 nm) show opposite effects: RL initiates a photomorphogenetic program of shoot part, and BL has a greater effect on photomorphogenesis of root system. Conclusions: Different levels of growth, morphogenetic processes and changes in the content of soluble carbohydrates are probably related to the ability of photoreceptor systems to activate the realization of different ways of photomorphogenesis in the axial organs of seedlings under the influence of selective light of a certain spectrum.

Background: Biophysical research methods as a powerful tool for studying small quantities of samples, are successfully used in related fields — forensic medicine, agriculture, archeology. The use of infrared spectroscopy is a progressive method due to the possibility of non-destructive analysis, easy sample preparation and high sensitivity, allowing to supplement historical reconstruction. It is possible to identify individual organic molecules by infrared spectroscopy. It is important to study the soil from the excavation site because all the anthropogenic processes that took place in the appropriate place are reflected in the composition of the soil. Objectives: Discover of organic remains in the soil from the object of archeological site and to identify organic molecules. Materials and methods: The object of research is the soil from 3 different objects (2 buildings and a ditch), which were identified within one excavation, Novgorod-Siversky, Chernihiv region. According to preliminary data, the objects are ancient Russian. For the study, 3 incremental samples were collected from each object. Further, the physicochemical properties of the selected soil were studied and spectroscopic studies were performed to determine the presence of low- and high-molecular compounds in the material. Results: It was determined that the pH level of the test samples ranges from weakly acidic to alkaline. The pH of the parent breed is slightly alkaline. FT-IR spectroscopy revealed DNA molecules, proteins, and lipids at the second site in soil samples from sites 1 and 2 (buildings). Only proteins are present in the ditch (№3). Instead, only mineral components were observed in the parent rock. Microscopy of soil samples revealed that the grains of sand from the ditch (№3) have a rounded shape, which is typical for places that have been in prolonged contact with water. Also, microscopy revealed traces of charcoal from the second site. Conclusions: The presence of organic components in the studied soils may be the result of human habitation and long-term activity. The presence of charcoal residues and identified lipid molecules in the №2 samples may indicate that this site was associated with cooking. In this case, the soil from place № 3 (ditch) is depleted of organic residues and sand grains, which have a rounded shape, may indicate that this place has been in contact with water for a long time.

Background: The technological developments for nanocellulose production from cheaper plant materials compared to wood, in particular, agricultural waste is an urgent task of nanobiophysics. The discovery of possibility of expanding the functional characteristics of materials in compositions with modified cellulose particles essentially stimulated the interest of researchers in cellulose composites. Surface modification of cellulose particles by functional materials, such as dyes, metal oxides, silicon, allows applying composites with modified cellulose in various areas of modern industry. A significant improvement in the operational performances of functionalized cellulose particles can be achieved by using them as filler in polymers. Epoxy resin compositions with modified and unmodified cellulose particles, studied in present work, are an example of hybrid biosystem. The interfacial interaction of filler particles with the epoxy matrix, their concentration and dispersion can change the physical and chemical properties of the biopolymer and the functional parameters of biocomposites. Studying the influence of external fields on the physical and chemical properties of epoxy resin-based biosystems and their influence on operational parameters seems to be an urgent problem of advanced and sustained materials science. Objectives: The purpose of this work was to develop an effective nanocellulose synthesis from plant materials and surface functionalization of micro- and nanocellulose particles with clathrochelate iron (ΙΙ) dye as well obtaining biocompositions of epoxy resin with functionalized and non-functionalized micro- and nanocellulose, and to explore of the morphology, chemical resistance, mechanical and thermal properties of epoxy composites with cellulose micro and nanoparticles. Materials and methods: The studying objects were the composites of epoxy resin Eposir-7120 with a polyethylene polyamine “PEPA” hardener in a ratio of 6.2:1 and 10% cellulose micro and nanoparticles. The microcellulose obtained from wood has been a commercial product. Nanocellulose has been synthesized from organosolv cellulose obtained from Miscanthus x giganteus stalks. Surface modification of micro- and nanocellulose was performed using the clathrochelate iron (ΙΙ) dye. The specific surface area of cellulose particles was determined using low-temperature nitrogen adsorption-desorption according to the Brunauer-Emmett-Teller method. Mechanical parameters were determined using universal Shopper and UMM-10 machines. Thermal analysis was performed using Q1500 analyzer. Swelling was determined by the gravimetric method. Results: Elastic modulus E, compressive strength σ and thermogravimetric parameters were determined. It was shown that in composites with micro and nanocellulose the E rises in 7.0–12.2% while the σ increases in 9.1% for composites with cellulose micro particles. The loading resin with nanocellulose and modified cellulose microparticles no affects the σ value of composites. The thermal stability of epoxy polymer (310°C) reduces after loading with micro and nanocellulose to 290 and 300°C, respectively. Chemical resistance of composites with both celluloses to 20% nitric acid reduces. In neutral medium swelling characterizes by rapid sorption to saturation of 15–20% acetone in 36 hours. Conclusions: Thus, the synthesis method of nanocellulose from plant materials and functionalization of its surface with clathrochelate iron (ΙΙ) were developed. Light response of dye was detected in visible spectral range. Epoxy resin composites with 10% micro and nanocellulose were obtained. The filling effect with micro- and nanocellulose at elastic modulus, compressive strength, and thermal stability of epoxycomposites was studied. The swelling processes run similarly in composites with cellulose micro and nanoparticles.

Актуальність.При розробці методів низькотемпературного зберігання клітин серйозною проблемою є рекристалізація, яка призводить до пошкодження клітин при відігріві.Раніше була показана перспективність використання полівінілового спирту (ПВС) в якості інгібітора рекристалізації.Але механізми захисної дії ПВС з'ясовані недостатньо.Зокрема невідомо, які структурні особливості сприяють реалізації антирекристалізаційних властивостей ПВС в кріозахисному діапазоні концентрацій

Background: The membrane protein-pigment complexes of photosynthetic isolated reaction centers (RC) Rhodobacter Sphaeroides are macromolecular systems for studying the physical mechanisms of electron and proton transport in biological structures, the role of molecular dynamics. The experimental kinetics of cyclic electron transfer in molecular complexes has a multiexponential character with negative values of decrements. For their description, a system of balance equations is used. Objective of the work is to determine the features of the kinetics of cyclic electron transfer in the RC using two models of electron transfer and the connection of such features with space-time motions in the RC. Materials and methods: Measurement of the absorption kinetics was performed at 865 nm using a two-channel diode spectrometer. The experimental kinetics of RC absorption (the main reaction of the system) was represented by the fitting method in the form of a sum of three exponential functions. In the first model with time-variable rate constants of the balance equations, the wavelet transform method of the logarithmic derivative of the electron transfer kinetics was used. In the second model, the equation of state and three differential equations with constant coefficients were used as the algebraic sum of the rate constants. To determine the values of the rate constants in the balance equation, an optimization problem was solved. The solution of the system of balance equations by the matrix method made it possible to determine the features of the kinetics of the population of substates of the RC. Results of calculations showed that the features of the wavelet spectrum of the logarithmic derivative of the electron transfer kinetics in the first model coincided with the features of the population kinetics of substates of the RC of the second RC model. These features were in the bands 1 s, 3 s, 60 s from the moment of switching on (off) the light and depend on the photoexcitation parameters. Conclusions: The features of the kinetics of the populations of substates in the RC both at the stage of illumination and at the relaxation stage are determined by changes in the structure of the RC in the form of effects of hidden parameters of the structural self-regulation of the RC (feedback through the RC structure).

Background: Investigation of the specific protein-DNA complexation mechanisms allows to establish general principles of molecular recognition, which must be taken into account while developing artificial nanostructures based on DNA, and to improve the prediction efficiency of the protein binding sites on DNA. One of the main characteristics of the protein-DNA complexes are the number and type of contacts in the binding sites of DNA and proteins. Conformational changes in the DNA double helix can cause changes in these characteristics. Objectives: The purpose of our study is to establish the features of the interactions between nucleotides and amino acid residues in the binding sites of protein-DNA complexes and their dependence on the conformation of deoxyribose and the angle γ of the polynucleotide chain. Materials and methods: At research of protein-DNA recognition process we have analyzed the contacts between amino acids and nucleotides of the 128 protein-DNA complexes from the structural databases. Conformational parameters of DNA backbone were calculated using the 3DNA/CompDNA program. The number of contacts was determined using a geometric criterion. Two protein and DNA atoms were considered to be in contact if the distance between their centers is less than 4.5 A. Amino acid residues were arranged according to hydrophobicity scale as hydrophobic or nonpolar and polar. Results: The analysis of contacts between polar and hydrophobic residues and nucleotides with different conformations of the sugar-phosphate backbone showed that nucleotides form more contacts with polar amino acids in both grooves than with hydrophobic ones regardless of nucleotide conformation. But the profile of such contacts differs in minor and major grooves and depends on the conformation of both deoxyribose and γ angle. The contact profiles are characterized by the sequence-specificity or the different propensity of nucleotides to form contacts with the residues in both grooves. Conclusions: Our analysis have shown, that the amount and type of protein-nucleic contacts and their distribution in the grooves depend on the conformation of the sugar-phosphate backbone, the nucleotide sequence and the type of amino acids in the binding sites.