The object of research is cured thermosetting epoxy polymer and FRP on the base of the same polymer matrix. The purpose of this research is to develop the finite element (FE) method in the modeling of cured thermosetting polymers and FRPs to predict their mechanical and thermal properties. The structural mathematical modeling with subsequent computer FE modeling was performed.
View Article and Find Full Text PDFChronic disturbances of consciousness (CDC) are a consequence of severe brain damage and are conditions that arise after emerging from a coma with the preservation of the sleep-wake cycle in the absence of signs of conscious behavior. When conducting inpatient medical rehabilitation of this group of patients, the state of nutritional status is not always taken into account and, as a rule, there is no nutritional support with an assessment of metabolic needs, including the introduction of various modes of physical activity during physical therapy and an increase in physical load on the patient's body. of the study was to assess the nutritional status and optimize the nutritional support system in patients with CDC at the inpatient stage of medical rehabilitation (MR).
View Article and Find Full Text PDFMalaria-causing protozoa of the genus Plasmodium have exerted one of the strongest selective pressures on the human genome, and resistance alleles provide biomolecular footprints that outline the historical reach of these species. Nevertheless, debate persists over when and how malaria parasites emerged as human pathogens and spread around the globe. To address these questions, we generated high-coverage ancient mitochondrial and nuclear genome-wide data from P.
View Article and Find Full Text PDFPolymerization of 5-n-alkyl-substituted 2-norbornenes synthesized a series of polymers having the same structure of the main polymer chain, but differing in the length of the alkyl substituent (up to 14 methylene units). The obtained polymers were studied by the capillary IGC method as a stationary phase during separation of a mixture of normal hydrocarbons C6-C10. Retention data in the form of a logarithm of the retention factor lnk were correlated with the size of the sorbate (via the carbon number of the alkane Z) and with the size of the n-alkyl substituent in the polymer chain (via the carbon number of the polymer Z).
View Article and Find Full Text PDFThe Yamnaya archaeological complex appeared around 3300BCE across the steppes north of the Black and Caspian Seas, and by 3000BCE reached its maximal extent from Hungary in the west to Kazakhstan in the east. To localize the ancestral and geographical origins of the Yamnaya among the diverse Eneolithic people that preceded them, we studied ancient DNA data from 428 individuals of which 299 are reported for the first time, demonstrating three previously unknown Eneolithic genetic clines. First, a "Caucasus-Lower Volga" (CLV) Cline suffused with Caucasus hunter-gatherer (CHG) ancestry extended between a Caucasus Neolithic southern end in Neolithic Armenia, and a steppe northern end in Berezhnovka in the Lower Volga.
View Article and Find Full Text PDFDeveloping a viscoelastic model for the cyclic thermomechanical loading of thermosetting polymers is the main goal of this study. The model includes memory for residual thermal stresses and can consider stress accumulation across many loading cycles. By considering stress accumulation, we can improve predictions and understand how thermosetting polymers' stress-strain state changes under cyclic thermomechanical loading.
View Article and Find Full Text PDFA rat biological model of septoplasty was used to study the effect of surgery on passive avoidance conditioning (PAC). Septoplasty was shown to increase anxiety and to reduce exploratory activity in rodents during PAC. A neurochemical analysis of the hypothalamus was carried out immediately after the end of the experiment and showed an increase in norepinephrine (NE) metabolism after septoplasty.
View Article and Find Full Text PDFDevelopment of load-bearing fiber reinforced plastic (hereinafter referred to as FRP) composite structures in civil engineering, exploited under high temperatures, such as industrial chimneys and gas ducts, requires the knowledge of their long-term behavior under constant and cyclic mechanical and temperature loads. Such conditions mean that the viscoelasticity of FRP should be considered along with the thermal aging effect. This research is devoted to the effects of thermal aging on the viscoelastic behavior of polymers.
View Article and Find Full Text PDFVopr Kurortol Fizioter Lech Fiz Kult
January 2024
Introduction: Subacromial impingement syndrome is a common pathology that leads to a persistent decrease in the functioning of the affected limb and, as a consequence, a decrease in the quality of life and work ability of patients. According to various authors, the study of the effectiveness of treatment and rehabilitation of this pathology is quite widely presented in the literature: surgical, including arthroscopic operations, rehabilitation using various factors of physical therapy, manual and other practices. However, the issue of assessing the effectiveness of movement therapy, both alone and in combination with other therapeutic methods, remains relevant.
View Article and Find Full Text PDFBackground: The manifestations, severity, and mortality of COVID-19 are considered to be associated with the changes in various hematological parameters and in immunity. Associations of immunoglobulin G antibodies against severe acute respiratory syndrome-linked coronavirus (IgG-SARS)-positive status with cardiac function and hematological and biochemical parameters in apparently health subjects are poorly understood.
Methods: The present cross-sectional study included 307 healthy volunteers (24-69 years of age; 44.
We propose an approximate method to calculate ion partition functions in the context of the chemical-picture representation of plasmas as an interacting mixture of various ions and free electrons under the local-thermodynamic-equilibrium conditions. The method uses the superconfiguration approach and implies that the first-order corrections to the energies of excited electron configurations due to the electron-electron interaction may be replaced by a similar first-order correction to the energy of the basic configuration of an ion with the same number of bound electrons. The method enables one to significantly speed up the calculations and generally provides quite accurate results.
View Article and Find Full Text PDFModeling septoplasty and modeling sensory deprivation of the olfactory analyzer in rats were compared for the effect on the frequency domain of heart rate variability (HRV). Bulbectomy provoked more pronounced changes in HRV as compared with septoplasty simulation.
View Article and Find Full Text PDFBackground: Rifaximin effectively treats symptomatic uncomplicated diverticular disease (SUDD) and has shown eubiotic potential (i.e., an increase in resident microbial elements with potential beneficial effects) in other diseases.
View Article and Find Full Text PDFSince emerging in Brazil in 1985, wheat blast has spread throughout South America and recently appeared in Bangladesh and Zambia. Here we show that two wheat resistance genes, Rwt3 and Rwt4, acting as host-specificity barriers against non-Triticum blast pathotypes encode a nucleotide-binding leucine-rich repeat immune receptor and a tandem kinase, respectively. Molecular isolation of these genes will enable study of the molecular interaction between pathogen effector and host resistance genes.
View Article and Find Full Text PDFThis research was completed in the development of studies devoted to relations between the elastic modulus (MoE) and thermal expansivity (CTe) of different materials. This study, based on experimental data, confirmed the models of the relations between MoE and CTe under normal and heating temperatures for thermosetting epoxy polymers and glass-fiber FRPs in two variants (unfilled and filled by mineral additives), after the usual glassing and prolonged thermal conditioning (thermo-relaxation). The experiment was based on dilatometric and elastic deformation testing.
View Article and Find Full Text PDFSolid particle erosion at room and elevated temperatures of filled and unfilled hot-cured epoxy resin using an anhydride hardener were experimentally tested using an accelerated method on a special bench. Micro-sized dispersed industrial wastes were used as fillers: fly ash from a power plant and spent filling material from a copper mining and processing plant. The results showed that the wear of unfilled epoxy resin significantly decreases with increasing temperature, while the dependence on the temperature of the wear intensity at an impingement angle of 45° is linear and inversely proportional, and at an angle of 90°, non-linear.
View Article and Find Full Text PDFThe main purpose of this paper is to compare the chromatographic properties of capillary columns prepared with polymers with different backbone structures and to demonstrate the possibility of polymer differentiation via inverse gas chromatography. With the use of addition and metathesis types of polymerization of tricyclononenes, two new stationary phases were prepared. The metathesis polymer contained double bonds in the polymeric backbone while the backbone of the addition polymer was fully saturated and relatively mobile.
View Article and Find Full Text PDFExo-inulinases are applied in inulin hydrolysis and production of feed additives and need to be stable at temperatures of 60-95 °C. Aspergillus awamori exo-inulinase Inu1 is considerably thermostable, with a T of 73.2 °C.
View Article and Find Full Text PDFFunctional characterization of effector proteins of fungal obligate biotrophic pathogens, especially confirmation of avirulence (Avr) properties, has been notoriously difficult, due to the experimental intractability of many of these organisms. Previous studies in wheat have shown promising data suggesting the type III secretion system (T3SS) of bacteria may be a suitable surrogate for delivery and detection of Avr properties of fungal effectors. However, these delivery systems were tested in the absence of confirmed Avr effectors.
View Article and Find Full Text PDFObjectives: To evaluate on animal models the health effects of the combined or separate exposure to main chemical and physical hazards of plasma-based material processing technology environment.
Materials And Methods: Male Wistar rats were exposed to actual levels of hazardous factors in plasma technology occupational environment: i.e.
Thermal expanding is the important property that defines the stress-strain condition of GRP structures exploited under heating and having limited thermal resistance. So, the GRPs' thermal expanding prediction is the actual requirement of such structures design. The experimental accurate dilatometric study resulted in the non-linearity of thermosetting polymers and plastics thermal expanding under heating.
View Article and Find Full Text PDFMixed-phase clouds are recognized as significant contributors to the modulation of precipitation and radiation transfer on both regional and global scales. This study is focused on the analysis of spatial inhomogeneity of mixed-phase clouds based on an extended data set obtained from airborne in situ observations. The lengths of continuous segments of ice, liquid, and mixed-phase clouds present a cascade of scales varying from 10 km down to a minimum scale of 100 m determined by the spatial resolution of measurements.
View Article and Find Full Text PDFThe discovery of new magnetic materials is a big challenge in the field of modern materials science. We report the development of a new extension of the evolutionary algorithm USPEX, enabling the search for half-metals (materials that are metallic only in one spin channel) and hard magnetic materials. First, we enabled the simultaneous optimization of stoichiometries, crystal structures, and magnetic structures of stable phases.
View Article and Find Full Text PDFStudy Purpose: To conduct a cross-sectional study on the structural and functional characteristics of various parts of skin microcirculation in working-age men with newly diagnosed hypertension (HTN).
Materials And Methods: The study included 118 male participants (ages 30 to 60) who were not regularly taking any medicine, had no medical complaints, and subjectively considered themselves healthy at the time of study. All participants underwent a cross-sectional comprehensive medical examination.