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Nowadays, civil engineering makes high demands on numeral modelling in geotechnical engineering, notably, to ensure reliability of a structure at minimum cost. Using of codes and standards supported with numerical calculations and soil constitutive models makes the design satisfying this requirement possible. But no matter how complex the model is its fidelity depends on input data. The article describes a method for determining the main characteristics of the Hardening Soil model (including calculating the power parameter m and reducing the deformation characteristics of the soil to the recommended value of the reference pressure). A comparison of two approaches was made: using a table of physical and mechanical characteristics; and the approach based on the analysis of the results of laboratory tests in accordance with the methodology given in the article and further verification of the obtained parameters. The result of the comparison was the complete inconsistency of the first approach for assigning the parameters of the nonlinear soil model and the need to refer to the test protocols was confirmed.

There is the opportunity to specify the nonlinear behavior of «Geogrid» element that is intended for modeling of geosynthetic materials and the opportunity to take into account creep in the latest version (2017) of the Plaxis program. The numerical modeling gives the possibility to make a calculation taking into account not only geosynthetic materials creep, but also soils creep. The rheological behavior of «Geogrid» element is based on the theory of the idealized creep of geosynthetic materials and the theory of Kelvin-Voigt. It is necessary for calculations to set the stiffness under short term tension and stiffness along the isochrone of estimated time and a specific parameter retardation time. An example of the calculation of an embankment on soft soils is presented in the report with respect to soils strengthening in the consolidation process, soils creep (model SoftSoil) and creep of geogrids. The required strength of a geosynthetic layer is determined in dependence on these factors.

This paper reports the results of a detailed study of the optical response of boron difluoride curcuminoids to radiation exposure. Two lines of the dyes fundamentally different in structure (namely, symmetrical and asymmetrical) were tested. If the absorption responses of their solutions in chloroform to X-rays turns out to be quite close quantitatively (note that it has a very indicative visual manifestation - a gradual discoloration is observed in the dose range up to 300 Gy), the fluorescence ones differ notably: among other things, the former demonstrate much more sensitive reactions (the corresponding limit of detection values ​​differ by up to 2.36-fold). Nevertheless, in both parameters, these dyes generally show good linearity of the response as in classical coordinates (up to ≈ 100-150 Gy), as in semi-logarithmic ones (up to 1000 Gy). Since the main reason for such behavior seems to be the radiation-induced decomposition of the dyes, its possible scheme and corresponding "weak links" in the structure of the molecules (in other words, radiosensitive elements) are proposed for each case. For example, these include N(CH 3 ) 2 fragments at the ends of dimethylaminostyryl groups. It is precisely their detachment that determines the observed optical response of asymmetrical dyes. Thus, the results obtained provide some insight into the possibilities of controlling the sensitivity of organic dyes to irradiation by changing their structure., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Molecular systems with intense exciplex luminescence are promising for the creation of OLEDs and light-transforming materials. The luminescent properties of difluoroboron meta- and para-nitrodibenzoylmethanates (1 and 2) were studied by the steady-state and time-resolved luminescence spectroscopy methods and quantum chemistry simulation. The influence of the position of the nitro group on the spectral properties of the complexes was revealed. The nitro group withdraws the electron density upon photoexcitation in the para-isomer in contrast to the meta-isomer. The bond order of the CC bond between the phenyl and chelate rings decreases in the excited relaxed state of 2, which leads to rotation of the substituent and a low quantum yield. Formation of exciplexes of 1 and 2 in benzene, toluene and polystyrene was found. The formation of the ground and excited-state electron donor-acceptor complexes based on difluoroboron nitrodibenzoylmethanates and benzene was revealed. The TDDFT method showed that the complexes are characterized by the presence of short contacts between the fluorine atom of the dye molecule and the hydrogen atoms of the aromatic hydrocarbon molecule. These contacts shorten during the transition from the ground state to the excited state. Polymeric compositions based on polystyrene (PS) and poly(methyl methacrylate) (PMMA) doped with 1 and 2 were obtained. The luminescence intensity of dyes 1 and 2 increases during the transition from PMMA to PS. A significant bathochromic shift of the luminescence maximum of 1 is observed, which is associated with the formation of exciplexes and triplexes. The obtained polymeric materials are promising for the development of optical smart materials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Curcuminoids of boron difluoride, 1-aryl(hetaryl)-5-phenylpenta-2,4-dien-1-onates of boron difluoride, have been synthesized. A comparative study of the electronic structure, luminescent properties and their potential for applications in bio-imaging has been carried out. The influence of the electronic structure of α-substituents on the luminescence of compounds was studied by the methods of stationary and time-resolved luminescence spectroscopy and DFT modeling. The introduction of π-donor substituents leads to a noticeable bathochromic shift and an increase in the Stokes shift in the luminescence spectra. On going from σ-donor substituents in the phenyl ring to π-donor substituents, the luminescence quantum yield increases from 0.03 to 0.22. The maximum Stokes shift and high quantum yield of luminescence is exhibited by the complex with a stilbene substituent, which has the longest π-system and the maximum efficiency of charge transfer. Dyes are able to penetrate into the cells of the model cell line and accumulate, moreover, accumulation occurs mainly in the cytoplasm of cells. The compounds penetrate into the cells by 12 h of incubation without damaging it's structure and without causing rapid cell death. The submicromolar range of non-toxic concentrations during long-term incubation for a model cell line was determined, which is a characteristic of fluorescent imaging. Due to uniform distribution in the cytoplasm of cells dye with naphtyl substituent is promising for visualization of the cell cytoplasm. This leader compound has the lowest cytotoxicity for cells from the synthesized series of dyes, which makes it promising for further studies as a fluorescent imaging agent. The leader compound has the lowest cytotoxicity for cells from the synthesized series of dyes, which makes it promising for further studies as a fluorescent imaging agent., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The spectral properties and solvatochromic behavior of boron difluoride ortho-hydroxydibenzoylmethanates in polymer matrices with different polarity (polystyrene, polyvinyl chloride, polycarbonate, poly(methyl methacrylate)) were investigated. The specific interaction of polystyrene, polycarbonate and poly(methyl methacrylate) with the investigated fluorophores was revealed. It was shown that the dyes are capable to form exciplexes with phenyl rings of polystyrene. The spectral properties of polystyrene films doped with boron difluoride ortho-hydroxydibenzoylmethanates, which were obtained by the pouring method, significantly depend on the solvent from which they were formed. This makes it possible to control the luminescence color of the films at the manufacturing stage., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Excessive salt intake is a risk factor for noncommunicable diseases, but salt iodization is the most effective method of population-based prevention of iodine deficiency. Therefore, an assessment of dietary iodine intake from the use of iodized salt in the food industry and potential reductions in salt intake is needed. Objective . To assess the feasibility of integrating iodine deficiency prevention and salt reduction programmes among the adult population in the Republic of Belarus. Material and methods . Using the thiocyanate-nitrite method, the determination of iodine in various types of foods was carried out. Taking into account the actual dietary intake, estimated using the frequency method among 583 respondents over 18 years old, living in Minsk, from various socioeconomic groups, alimentary iodine intake was assessed at different levels of salt use in households. The level of iodine sufficiency was additionally estimated on the base of urinary excretion data obtained by the cerium-arsenite spectrophotometric method in 100 healthy adults over the age of 18 living in Minsk (65 women and 35 men). Results . As part of the legal framework for the use of iodized salt in food production, there has been a steady increase in iodine levels in the target products (bakery and meat products to 42.0 and 133.3 μg/100 g respectively). The content of the discussed micronutrient in the diet of the adult population has raised at least 1.9-fold in recent decades, to 237.3 μg/day in the most realistic consumption model. The main source of iodine among this subpopulation is commercially produced foods with iodized salt, which forms 30-58% of the alimentary iodine exposure. Consumption of salt in Belarus averages 10.6 g per day, which poses a risk of developing noncommunicable diseases and necessitates programmes to reduce the level of salt in the diet. Modeling of scenarios with reduction of salt use in households in accordance with the recommendations of the World Health Organization (WHO) shows that the main contribution to dietary iodine exposure will be made by bread products (38%), about 1/3 will be formed by table salt, the value of non-target fortified products (milk and eggs) will increase (up to 21%). The contribution of table iodized salt to the dietary iodine exposure reaches 43% at actual consumption levels and will decrease to 18% if it is reduced to the WHO recommended values. The median of ioduria among those surveyed is 136.8 μg/l, indicating adequate iodine supply. Conclusion . In implementing joint programs on prevention of iodine deficiency and cardiovascular diseases associated with excessive salt intake, it is necessary to consider national conditions - mandatory use of iodized salt in food industry, its level of fortification, content of this micronutrient in foodstuffs and structure of their consumption among certain population groups., Competing Interests: The authors declare no overt and potential conflict of interest related to the publication of this article., (Copyright© GEOTAR-Media Publishing Group.)

The structural, luminescence and chemosensor properties of boron difluoride o-hydroxydibenzoylmethanate (1) have been investigated. In the concentrated solution, PE (polyethylene) matrix, and crystals of 1, one observes the formation of J-aggregates. The crystal structure of 1 is in compliance with that of J-aggregates of the "brickwork type" consisting of dimers that comprise excimer traps. In time-resolved luminescence spectra of 1 in PE films and crystals, one observes luminescence bands corresponding to the luminescence of excimer J-aggregates. At application of external stimuli on the crystals of 1 (heating, grinding), one observes changes in the luminescence spectrum caused by redistribution of intensities of excimer and J-aggregate bands. 1 could act as an optic chemosensor for probing amines vapors with different response rates and different sensitivities controlled by their morphologies., (Copyright © 2019 Elsevier B.V. All rights reserved.)

After removal of manganese ions responsible for light-driven water oxidation, redox-active tyrosine Y Z (tyrosine 161 of the D1 subunit) still remains the dominant electron donor to the photooxidized chlorophyll P 680 (P 680 + ) in the reaction center of photosystem 2 (PS2). Here, we investigated P 680 + reduction by Y Z under single-turnover flashes in Mn-depleted PS2 core complexes in the presence of weak acids and NH 4 Cl. Analysis of changes in the light-induced absorption at 830 nm (reflecting P 680 redox transitions) at pH 6.0 showed that P 680 + reduction is well approximated by two kinetic components with the characteristic times (τ) of ~7 and ~31 μs and relative contributions of ~54 and ~37%, respectively. In contrast to the very small effect of sodium formate (200 mM), addition of sodium acetate and NH 4 Cl increased the rate of electron transfer between Y Z and P 680 + approx. by a factor of 5. The suggestion that direct electron transfer from Y Z to P 680 + has a biphasic kinetics and reflects the presence of two different populations of PS2 centers was confirmed by the data obtained using direct electrometrical technique. It was demonstrated that the submillisecond two-phase kinetics of the additional electrogenic phase in the kinetics of photoelectric response due to the electron transfer between Y Z and P 680 + is significantly accelerated in the presence of acetate or ammonia. These results contribute to the understanding of the mechanism of interaction between the oxidized tyrosine Y Z and exogenous substances (including synthetic manganese-containing compounds) capable of photooxidation of water molecule in the manganese-depleted PS2 complexes.

The electronic structure and optical properties of the isomeric difluoroboron β-diketonates, 2,2-difluoro-4-methylnaphtho-[2,1-e]-1,3,2-dioxaborin (I) and 2,2-difluoro-4-methylnaphtho-[1,2-e]-1,3,2-dioxaborin (II), were studied by means of X-ray photoelectron, absorption and luminescence spectroscopies. The experimental results were interpreted using high-level ab initio quantum chemical computations, including the algebraic-diagrammatic construction method for the polarization propagator of the second and third orders (ADC(2) and ADC(3)), the outer-valence Green's function (OVGF) method, and the time-dependent density functional (TDDFT) approach. The X-ray photoelectron measurements were assigned in the entire energy range using the results of the Kohn-Sham orbital calculations which employed the B3LYP functional. Pronounced hypsochromic shift of crystal-state fluorescence was observed in I upon the lowering of temperature, which can be explained by the deterioration of the conditions for excimers formation. According to our results, remarkable feature of II, absent in I, is its phosphorescence at room temperature. Basing on our calculations, a decay mechanism for the S 1 state was proposed, explaining the observed differences in the phosphorescence of I and II., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Oral fluid is a unique biological environment, containing a wide range of substances, coming from local and systemic sources, which makes it possible to use it as an object for assessing pathological changes in the body both at the local and systemic levels. In comparison with the traditional method of blood analysis, the advantage of evaluating the parameters of the oral fluid is the non-invasive of this method of obtaining material. All patients underwent oral fluid sampling using special plastic containers with a swab, which facilitate the selection of material, eliminating the penetration of mucin into a clean test sample, which helps to obtain more accurate analysis results. The amount of secretory IgA, lipopolysaccharide-binding protein (LBP), TBA-active products, the level of total antioxidant activity in the oral fluid in individuals with a low level of 25(OH)D before and after taking the native solution of vitamin D "Aqua Trim" were determined. The concentrations of secretory immunoglobulin A, lipopolysaccharide, binding protein and the level of total antioxidant activity are reduced in the oral fluid of people with vitamin D deficiency, but the number of intermediate products of lyoperoxidation increases. The course intake of the native solution of vitamin D (International Nonproprietary Name - Colecalciferol) normalizes the functioning of the immunity of the oral cavity and restores the balance of the "lipid peroxidation-antioxidants" system., Competing Interests: The authors declare no conflict of interest.

A series of new nitrogen-containing analogues of boron difluoride benzoylacetonates with hydrogen and methyl substituents at the nitrogen atom have been synthesized. A comparative study of boron difluoride β-ketoiminates and their oxygen-containing analogues by means of luminescence and IR spectroscopic methods as well as quantum chemistry simulations was also performed., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Electronic structure and optical properties of boron difluoride dibenzoylmethanate and four of its derivatives have been studied by X-ray photoelectron spectroscopy, absorption and luminescence spectroscopy and quantum chemistry (DFT, TDDFT). The relative quantum luminescence yields have been revealed to correlate with charge transfers of HOMO-LUMO transitions, energy barriers of aromatic substituents rotation and the lifetime of excited states in the investigated complexes. The bathochromic shift of intensive bands in the optical spectra has been observed to occur when the functional groups are introduced into p-positions of phenyl cycles due to destabilizing HOMO levels. Calculated energy intervals between electronic levels correlate well with XPS spectra structure of valence and core electrons., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Electronic structure and optical properties of boron difluoride dibenzoylmethanate BF2Dbm and its four derivatives were studied using X-ray photoelectron spectroscopy, absorption and luminescence spectroscopy, and quantum chemistry (DFT and TDDFT). In a series of the studied compounds, the relationship of molecular design and optical properties has been revealed. At the transition from BF2Dbm to BF2Dbm(OCH3)2, the HOMO-LUMO energy gap decreases, resulting in a bathochromic shift of the optical spectra. Substitution of one methoxy group by the nitro group in BF2Dbm(OCH3)2 causes a decrease in the contribution of the chelate ring π-orbital in the LUMO, resulting in a lower value of charge transfer from the substituents to the chelate ring in the case of the first excited state, which determines the characteristics of the main absorption bands. The nitro group transition from the m- to p-position of the benzene ring causes a change in the nature of the main bands of the optical spectra due to the increase of the splitting value of the LUMO and LUMO+1 levels. The main band in the optical spectra of the complex containing the C10H7 group is associated with the charge transfer transitions.

Boron difluoride of 3-amino-1,3-diphenyl-2-propene-1-onate (1) has been synthesized and its crystal structure has been determined. The comparative studies of 1 and its oxygen analog 1,3-diphenyl-1,3-dionate (dibenzoylmethanate) of boron difluoride (2) have been performed using the methods of stationary and time-resolved spectroscopy and quantum chemical modeling. It was established that at the transition from solutions to crystals, a bathochromic shift of the spectra and a significant increase of luminescence intensity of 1 take place. The luminescent properties of solutions of 1 and 2 are similar. The peculiarities of crystal packings of 1 and 2 are responsible for differences in crystals luminescent properties. For crystals of 2, one observes the luminescence of J-aggregates and excimers, while for 1, in which a dimer is an elementary structural fragment, only the excimer luminescence is registered. A delayed excimer fluorescence of the P-type was observed for crystals of 1 and 2 at room temperature. The intensity of the delayed fluorescence of 1 is 300-fold higher than that of 2. Graphical Abstract Luminescence of J-aggregates and the formation of excimers in crystals of 1 and 2.

The problem of iodine deficiency is relevant to the Republic of Belarus. It’s confirmed by virtually commonly found geophysical iodine deficiency in soils and waters. Data on iodine deficiency initiated the development of a state strategy for the elimination of iodine deficiency in the population. This strategy determined the mandatory use of iodized salt only in the country in the food industry and catering as the main event for the elimination of iodine deficiency. The aim of this work was a comprehensive evaluation of the results of the implementation of the strategy for elimination of iodine deficiency among the population of the Republic of Belarus. Medical monitoring of the assessment of the efficacy showed the decrease in the incidence of simple non-toxic goiter in adolescents from 1215,23 per 100,000 population in 1998 to 341,25 in 2013 (3.6 times), and indices ofprimary morbidity rate in children fell by 2.9 times. Over the period from 1998 primary morbidity rate of simple nontoxic goiter decreased significantly in adults from 379.9 to 31,71 people per 100,000 of the population in 2013 respectively (almost 12 times). Data of the assessment of ioduria in Belarus indicate that 89.2% of children enrolled in the study have iodine excretion of more than 100 pg/L. Thus, in the Republic of Belarus there was achieved the level of an adequate intake of iodine with foodstuffs. This model ofprevention of iodine deficiency, as well as the traditional approach based on the adoption of the law, is a versatile and cost-effective mode.

Food-borne infectious diseases remain an actual problem of health care. In the Republic of Belarus the level of food-borne diseases persists to be stable, at the same time these diseases remain to be significant. Despite the insignificant number of nonconforming food samples the prevalence rates of food-borne acute infectious diseases of various etiology with dominantly food transmission pathway remain to be rather high. The mentioned fact determines the need for the development of approaches on the security of microbiological food safety based on the risk analysis. There are determined criteria for a hygienic assessment of the microbiological hazards (associated with the pathogen, food products and a consumer health state), there is presented the classification offood products in dependence on the grade of microbiological risk. There was performed the comparative analysis of requirements for the microbiological safety of food accepted in the Republic of Belarus and European Economic Union, in the European Union and at the international level, which testify to the presence of separate differences. Based on the international approaches there was substantiated the multilevel control system of management of microbiological risks, there is reported the characteristic of separate criteria. There are determined the directions of the improvement of the security of microbiological safety of food.

The concentration dependence of spectral-luminescence properties of solutions boron difluoride dibenzoylmethanate (DBMBF2) in benzene and chloroform has been studied through stationary and time-resolved emission spectroscopy methods. The formation of J-aggregates in the solution of DBMBF2 in chloroform has been revealed and a crystalline adduct of DBMBF2 with benzene has been obtained. A bright blue adduct luminescence is due only to the luminescence of J-aggregates, unlike the crystals of DBMBF2, for which the luminescence of excimers and J-aggregates has been observed. The quantum chemistry simulation of geometric and electronic structure of the DBMBF2 С6Н6 solvate has been performed, and the absorption spectra of DBMBF2 and it is adduct have been calculated., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Methodological approaches to the assessment of alimentary load of nutritional supplements (ALNS) have been based. Description for the different models for assessment of ALNS according to the allowable daily intake and the use of hygienic regulations is presented.

The study is aimed to investigate the distribution of alleles of HLA-DRB1 gene in patients with early rheumatoid arthritis and healthy individuals in Russian population, and evaluate their significance as molecular genetic markers of rheumatoid arthritis predisposition and protection. The association between alleles of HLA-DRB1 genes, antibodies to cyclic citrullinated peptides and IgM rheumatoid factor was also studied. Low and high resolution HLA-DRB1 genotyping were compared. In the cohort of patients with early rheumatoid arthritis, the alleles of HLA-DRB1 gene were found to be markers of rheumatoid arthritis protection/risk, especially in the homozygous state. They determined production of antibodies to cyclic citrullinated peptides but were not associated with rheumatoid factor IgM levels. These findings support different autoimmune mechanisms of rheumatoid arthritis pathogenesis.

The photomechanical effect was found in a polymer composition on the basis of polymethylmethacrylate with embedded molecules of the luminophor incapable to undergo photochemical isomerization (anthracenoylacetonate of boron difluoride and dibenzoylmethanatoeuropiate triethylammonium), unlike other compounds having the above effect. The possibility of the development of a simple upward-downward movement drive on the basis of the above compounds was demonstrated., (Copyright © 2010 John Wiley & Sons, Ltd.)

The photomechanical effect was found for the first time in a polymer composition on the basis of polymethylmethacrylate with embedded molecules of the luminophor dibenzoylmethanate of boron difluoride incapable of undergoing photochemical isomerization, unlike other compounds. A thermal mechanism of photochemical displacement was suggested., (Copyright © 2009 John Wiley & Sons, Ltd.)

Aim: To estimate potentialities of early diagnosis of rheumatoid arthritis (RA) diagnosis in clinical practice in the course of the RADICAL program., Material and Methods: Of 366 patients participating in the trial 61 (16.7%) were males and 305 (83.3%) were females at the age of 47.76 +/- 14.1 years. The longest duration of the symptoms before consulting a doctor was 51 weeks, mean duration--5.7 weeks, 55% patients had the symptoms for 3 weeks. All the patients have undergone laboratory examination including leukocyte count, platelet count, estimation of ESR, concentration of C-reactive protein (CRP), rheumatoid factor (RF) and antibodies to a cyclic citrullated peptide (ACCP); roentgenography of the wrists and feet. On demand, antinuclear factor (ANF) and HLA-B27 were investigated. RA was diagnosed on the basis of ACR classification criteria. If the criteria were not complete at the moment of the study, the patient was referred to the group of "undifferentiated arthritis" (UA). The patients were examined before the treatment, 6 and 12 months later. The treatment was made according to Russian clinical recommendations., Results: Prior to admission to hospital, 58% patients were suspected for RA, 18.3%--osteoarthrosis (OA), 14%--reactive arthritis. 18.9% were not diagnosed, other diagnoses were considered in 12.6% patients. At primary examination RA was diagnosed in 212 (57.9%) patients, UA was in 133 (36.3%) patients, 21 (5.7%) patients had other diagnoses. Twelve months later RA, UA and other diseases were diagnosed in 256 (69.9%), 70 (19.1%) and 40 (10.9%) patients, respectively., Conclusion: A 3-stage algorithm of early RA diagnosis is proposed. At the stage of the first contact with the patient in an outpatient clinic a valid RA suspition with consideration of modified EULAR criteria must be formulated. At the second stage a district rheumatologist must examine the patient outpatiently with determination of ACR classification criteria. In diagnosis verification the treatment must be started according to APP and EULAR clinical recommendations. If RA diagnosis can not be verified or rejected, the patient must be refered to hospital (stage 3). If verification of RA diagnosis is impossible, the diagnosis should be formulated as UA.

Significant differences in the luminescence properties of dibenzoylmethanate and ditoluylmethanate of boron difluoride bulk crystals and microcrystals were detected. The size-dependent blue-to-green colour change of the luminescence is connected with the band intensity redistribution of monomer and excimer luminescence and fluorescence due to interdimer interaction., (Copyright (c) 2007 John Wiley & Sons, Ltd.)

Essential differences in the luminescence properties of dibenzoylmethanatoboron difluoride (1) bulk and microcrystals were detected. Analysis of the spectral data showed that in every case the fluorescence spectrum of 1 consisted of three components: monomer fluorescence, excimer fluorescence, and fluorescence related with interdimer interaction. Evolution of luminescence spectra observed with decrease of the crystal size are bound with decrease of monomer fluorescence intensity and considerable growth of intensity of fluorescence related to interdimer interaction. The presence of reversible luminescence thermochromism was discovered for 1: lowering the temperature from 300 to 77 K resulted in essential hypsochromic shift of the luminescence band maximum ( approximately 60 nm) connected with considerable decrease of the distances between the planes of the neighboring molecules ( approximately 0.1 Angstrom) that lead to the weakening of interdimer interaction and intensification of monomer luminescence.