Estimation of the friction coefficient of a nanostructured composite coating

The frictional-mechanical properties of a thin polymer-ceramic coating obtained by gas-phase impregnation of nanoporous anodic alumina with a fluoropolymer (octafluorocyclobutane) have been investigated. The coefficient of sliding friction of the coating is predicted based on an analysis of contact deformation within the framework of the Winkler elastic foundation hypothesis and a three-phase micromechanical model. It is shown that an acceptable prediction accuracy can be obtained considering the uniaxial strain state of the coating. It was found that, on impregnation by the method of plasmachemical treatment, the relative depth of penetration of the polymer increased almost in proportion to the processing time. The rate and maximum possible depth of penetration of the polymer into nanoscale pores grew with increasing porosity of the alumina substrate

Morphofunctional characteristics of leaves and fruits in Maloideae (Rosaceae): a. Microstructure of surface tissues

Background. The formation of cover tissues (epidermis, cork), providing a connection with the environment, in the evolution of flowering plants was one of the main consequences of the transition to life on earth. The epidermis, which emerged as a device for protecting deeper underlying tissues from drying, subsequently acquired additional functions (participation in gas exchange and transpiration, absorption and isolation of certain substances as well as protection from the penetration of pathogens) and became a multifunctional tissue consisting of several types of cells (basic, stomatal, and trichomes). Features of the fine structure of the epidermis are of interest in representatives of the subfamily Maloideae Werber (Rosaceae Juss.), which grow, inter alia in mountain agrobiocenoses with their rather harsh conditions. They extended their area of distribution to various habitats due to the development of structural adaptations that play an important role in the formation of resistance to stressors of different etiologies.Objective. Representatives of 4 genera were chosen as model objects from subfam. Maloideae for the study: Malus domestica Borkh., Pyrus communis L., Cydonia oblonga Mill., and Mespilus germanica L.Materials and methods. Mature leaves and fruits were selected from the middle part of the crown of three model trees of each species. The samples were studied by scanning electron microscopy (SEM), with a freezing attachment.Results. Leaves of Maloideae were found to be hypostomatic, while the abaxial (lower) epidermis is multifunctional: it performs a barrier function together with the cuticle. Formation of the cuticular nature can be attributed to the surface structures: peristomatic rings and ridges as well as radially extending folds, all forming a specific microrelief. The adaxial (upper) and abaxial surfaces clearly differ not only in the features of the structure, but also in the specificity of the microrelief’s arrangement. Species-specific traits were also found in the structure of the surface tissue of the pericarp. M. germanica, unlike the other species, does not have a continuous cuticular cover and wax deposits: most of a mature fruit’s surface is covered with a peeling cork layer. In the study of the surface of C. oblonga fruits, numerous rather large stomata with peristomatic rings and cuticular cushions were found similar to those in leaves.Conclusion. Surface structures of leaves and fruits in subfam. Maloideae include formations of cuticular nature, with different specificities of microrelief shaping due to the functional load of the epidermal tissue and environmental conditions. They can also be involved in building resistance to biotic stressors. The obtained data on the features of the fine structure of surface tissues are of interest for applied and theoretical studies, especially environmental and botanical, relating to taxonomic issues

Effects of lateral processes on the seasonal water stratification of the Gulf of Finland: 3-D NEMO-based model study

This paper aims to fill the gaps in knowledge of processes affecting the seasonal water stratification in the Gulf of Finland (GOF). We used a state-of-the-art modelling framework NEMO (Nucleus for European Modelling of the Ocean) designed for oceanographic research, operational oceanography, seasonal forecasting, and climate studies to build an eddy-resolving model of the GOF. To evaluate the model skill and performance, two different solutions were obtained on 0.5 km eddy-resolving and commonly used 2 km grids for a 1-year simulation. We also explore the efficacy of non-hydrostatic effect (convection) parameterizations available in NEMO for coastal application. It is found that the solutions resolving submesoscales have a more complex mixed layer structure in the regions of the GOF directly affected by the upwelling/downwelling and intrusions from the open Baltic Sea. Presented model estimations of the upper mixed layer depth are in good agreement with in situ CTD (BED) data. A number of model sensitivity tests to the vertical mixing parameterization confirm the model's robustness. Further progress in the submesoscale process simulation and understanding is apparently not connected mainly with the finer resolution of the grids, but with the use of non-hydrostatic models because of the failure of the hydrostatic approach at submesoscale

INFLUENCE OF APOE GENOTYPES ON BIOCHEMICAL INDICES OF IRON AND LIPID METABOLISM IN PATIENTS WITH THE ENDOMETRIUM NEOPLASTIC DISEASES AND HEAL THY WOMEN

Objective. APOE genotype association with the level of iron in plasma and the risk of endometrial neoplastic diseases has not been studied. The aim of the work was to analyze the genotypic associations of the apolipoprotein E (APOE) with iron and lipid levels in endometrial hyperplasia (EH)/endometrial cancer (EC) patients and healthy women.Materials and methods. The biochemical blood levels of iron and cholesterol metabolism detected in women d with diagnosed endometrial hyperplasia (53), endometrial cancer (87) and healthy women (70) are determined on an automated analyzer «OLYMPUS AU – 400”. The genotyping was performed with a PCR-RFLP (polymerase chain reaction with restriction fragment length polymorphism) technique.Results. A statistically significant decrease in the levels of serum iron, transferrin saturation, high-density lipoprotein on the one hand, and a statistically significant increase in body mass index, triglycerides, very low density lipoproteins, atherogenic index in patients with endometrial adenocarcinoma was observed. Statistically significant differences in the distribution of E3, E4, E2 allele frequencies between patients and healthy women (P = 0.048) was revealed. E3 allele frequency was reduced, and the E2 allelewas increased in patients with EC. It was shown that the serum iron level was significantly increased in EC patients and healthy carriers of the genotype E3/E2 (P= 0,0014 and 0,0363 respectively). There was significantly elevated triglyceride level in carriers of the minor genotypes E2/E4, E4/E4 among patients with EH (0,0389).Conclusions. Genotype E3/E2 compared with other APOE genotypes under study is associated with elevated levels of iron and the risk of endometrial cancer. The association APOE 2/2, 2/4, 4/4 as well as 3/2 with endometrial neoplastic diseases requires further investigation. The data obtained can be the basis for the creation of a marker system for determining a high level susceptibility to malignant disease of the female reproductive system