Kazan (Volga Region) Federal University
Recent publications
The aim of this paper is to better understand the dynamics of crystallogenic and starting activity in biological fluids of patients throughout surgery and the late postoperative phase in alveococcosis. Samples of saliva from 22 individuals with alveococcosis were included in the research. Biological fluid samples were taken at the time of admission and before the patient was discharged. Following that, slides were made utilizing the teziocrystalloscopy method, which incorporates the investigation of the crystal forming activity of mixed saliva with its starting characteristics using a 0.9 percent sodium chloride solution as the foundation ingredient. Using our own set of criteria, we evaluated the outcomes of crystalloscopic and tezigraphic experiments. Specrophotometric examination of tezigraphic and crystalloscopic facies was done using a PowerWave XS microplate spectrophotometer at wavelengths of 400, 350, and 300 nm to augment the results from ocular morphometry of dried saliva micro slides. Surgical therapy results in a partial normalization of physical and chemical parameters, as well as the composition of the patient's biological fluids after the patient is discharged from the hospital.
Nanoparticles (NPs) are insoluble particles with a diameter of fewer than 100 nanometers. Two main methods have been utilized in orthodontic therapy to avoid microbial adherence or enamel demineralization. Certain NPs are included in orthodontic adhesives or acrylic resins (fluorohydroxyapatite, fluorapatite, hydroxyapatite, SiO2, TiO2, silver, nanofillers), and NPs (i.e., a thin layer of nitrogen-doped TiO2 on the bracket surfaces) are coated on the surfaces of orthodontic equipment. Although using NPs in orthodontics may open up modern facilities, prior research looked at antibacterial or physical characteristics for a limited period of time, ranging from one day to several weeks, and the limits of in vitro studies must be understood. The long-term effectiveness of nanotechnology‑based orthodontic materials has not yet been conclusively confirmed and needs further study, as well as potential safety concerns (toxic effects) associated with NP size.
We suggest an effective approach for the semi-automated segmentation of biomedical images according to their patchiness based on local edge density estimation. Our approach does not require any preliminary learning or tuning, although a couple of free parameters directly controllable by the end user adjust the analysis resolution and sensitivity, respectively. We show explicitly that the local edge density exhibits excellent correlations with the cell monolayer density obtained by manual domain-expert based assessment, characterized by correlation coefficients ρ>0.97. Our results indicate that the proposed algorithm is capable of an efficient segmentation and quantification of patchy areas in various biomedical microscopic images. In particular, the proposed algorithm achieves 95 to 99% median accuracy in the segmentation of image areas covered by the cell monolayer in an in vitro scratch assay. Moreover, the proposed algorithm effectively distinguishes between the native and regenerated tissue fragments in microscopic images of histological sections, indicated by nearly three-fold discrepancy between the local edge densities in the corresponding image areas. We believe that the local edge density estimate could be further applicable as a surrogate image channel characterizing its patchiness either as a substitute or as a complementary source to the conventional cell- or tissue-specific fluorescent staining, in some cases either avoiding or limiting the use of complex experimental protocols. We implemented a simple open-source software tool with for on-the-fly visualization allowing for a straightforward feedback by a domain expert without any specific expertise in image analysis techniques. Our tool is freely available online at https://gitlab.com/digiratory/biomedimaging/bcanalyzer.
Combining hybrid polymeric platforms with laser-assisted reduced graphene oxide (LArGO) could bridge the gap between a battery and supercapacitor device, overshadow the drawbacks of polymeric configurations, and boost the cyclic stability, specific capacitance (SC), and energy density of the resulting configurations. Herein, drawbacks of polymeric configurations such as polypyrrole (PPy) and polyindole (PIN) are modified via reinforcement with silver nanowires (Ag-PPy and Ag-PIN), and their performances are compared via in-depth fundamental analyses to select the superior one. Accordingly, the SC of PPy and PIN increased from 282 and 324 F.g-1 to 452 and 587 F.g-1 at the current density of 1 A.g-1 upon reinforcement with silver nanowires, respectively. The Ag-PIN configuration as the superior modified polymeric platform is assembled in an asymmetric supercapacitor along with LArGO. The as-developed electrodes show an ideal synergic effect and reveal favorable SC retention (94.2%) after 5000 cycles, high specific capacitance of 368.8 F.g-1, and energy density of 41.5 W.h.Kg-1 at the power density of 450 W.Kg-1. The obtained data illuminate the great capability of the hybrid package that bridges the gap between a high-performance battery and supercapacitor.
Background Migraine is a common brain disorder that predominantly affects women. Migraine pain seems mediated by the activation of mechanosensitive channels in meningeal afferents. Given the role of transient receptor potential melastatin 3 (TRPM3) channels in mechanical activation, as well as hormonal regulation, these channels may play a role in the sex difference in migraine. Therefore, we investigated whether nociceptive firing induced by TRPM3 channel agonists in meningeal afferents was different between male and female mice. In addition, we assessed the relative contribution of mechanosensitive TRPM3 channels and that of mechanosensitive Piezo1 channels and transient receptor potential vanilloid 1 (TRPV1) channels to nociceptive firing relevant to migraine in both sexes. Methods Ten- to 13-week-old male and female wildtype (WT) C57BL/6 J mice were used. Nociceptive spikes were recorded directly from nerve terminals in the meninges in the hemiskull preparations. Results Selective agonists of TRPM3 channels profoundly activated peripheral trigeminal nerve fibres in mouse meninges. A sex difference was observed for nociceptive firing induced by either PregS or CIM0216, both agonists of TRPM3 channels, with the induced firing being particularly prominent for female mice. Application of Yoda1, an agonist of Piezo1 channels, or capsaicin activating TRPV1 channels, although also leading to increased nociceptive firing of meningeal fibres, did not reveal a sex difference. Cluster analyses of spike activities indicated a massive and long-lasting activation of TRPM3 channels with preferential induction of large-amplitude spikes in female mice. Additional spectral analysis revealed a dominant contribution of spiking activity in the α- and β-ranges following TRPM3 agonists in female mice. Conclusions Together, we revealed a specific mechanosensitive profile of nociceptive firing in females and suggest TRPM3 channels as a potential novel candidate for the generation of migraine pain, with particular relevance to females.
Following the publication of the original article [1], we were notified that the first and last name of AMJM van den Maagdenberg had been swapped. Originally published name: van den Maagdenberg AMJM Corrected name: AMJM van den Maagdenberg The original article has been corrected.
Resolved hyperfine structure and narrow inhomogeneously broadened lines in the optical spectra of a rare-earth-doped crystal are favorable for the implementation of various sensors. Here, a well-resolved hyperfine structure in the photoluminescence spectra of LiYF 4 :Ho single crystals and the anticrossings of hyperfine levels in a magnetic field are demonstrated using a self-made setup based on a Bruker 125HR high-resolution Fourier spectrometer. This is the first observation of the resolved hyperfine structure and anticrossing hyperfine levels in the luminescence spectra of a crystal. The narrowest spectral linewidth is only 0.0022 cm ⁻¹ . This fact together with a large value of the magnetic g factor of several crystal-field states creates prerequisites for developing magnetic field sensors, which can be in demand in modern quantum information technology devices operating at low temperatures. Very small random lattice strains characterizing the quality of a crystal can be detected using anticrossing points.
In this paper the effect of supercritical water (SCW) at 374 °C and 22.4–24.6 MPa on the conversion of resins, asphaltenes, and kerogens in rocks of different lithofacies of Domanic deposits of Romashkino, Tavely and Bavly oilfields of Tatarstan was discussed. A feature of the rocks is the different content of organic carbon (7.07, 1.90 and 0.33 %, respectively), the high content of resins and asphaltenes (over 60 % in total) and the presence of type II kerogen with a high oil generation potential. The SCW treatment of the rocks leads to the decomposition of kerogens and the destruction of resins and asphaltenes with the formation of petroleum hydrocarbons. The conversion of resins, asphaltenes, and kerogens is accompanied by the alkyl substituents detachment, which leads to a decrease in the length and degree of aliphatic fragments branching and an increase in the aromatic carbon content. The oxygen-containing groups decrease in kerogens and asphaltenes and increase in resins, indicating the occurrence of degradation and oxidation processes. Destructive processes lead to an increase in the degree of catagenic maturation of kerogens, which is accompanied by partial desulfurization and demetalization of their structure, as well as of asphaltenes and resins. In kerogens, asphaltenes and resins of carbonate-siliceous rocks of the Romashkino and Tavely oilfields the concentration of biogenic microelements (ME) decreases with their subsequent adsorption on the mineral surface of the rocks, in this case, the content of radioactive ME noticeably increases, especially in resins. Under similar conditions of SCW exposure on carbonate rock of the Bavly oilfield as well as high-carbon rocks in kerogen, the concentration of biogenic ME decreases and the concentration of radioactive ME increases, but unlike them, the concentrations of biogenic, radioactive and rare-earth ME increase in asphaltenes and resins, with a decrease in their content in rocks. The identified distinctive features of the conversion of resins, asphaltenes and kerogens of Domanic rocks of different lithofacies, which affect the quality of oil extracted from these rocks, must be taken into account when developing deposits using SCW technologies.
Carbonaceous immunosensors are ideal nanoplatforms for developing rapid, precise, and ultra-specific diagnostic kits capable of early detection of viral infectious illnesses such as COVID-19. However, developing a proper carbonic immunosensor requires stepwise protocols to find optimum operating conditions to minimize drawbacks. Herein, for the first time and through a stepwise protocol, activation, and monoclonal IgG antibody mounting capability of multi-walled carbon nanotubes (MWCNTs) at two diverse outer diameters (ODs), viz., 20–30 nm and 50–80 nm, and graphene deriv atives (graphene oxide (GO) and reduced graphene oxide (rGO)) were examined and compared with each other toward finding the prime carbonaceous nanomaterial(s) for maximized antibody loading efficiency along with an ideal detection limit (DL) and sensitivity. Next, the effect of common amplifying agents, i.e., Au nanostars (Au NSs) and Ag nanowires (Ag NWs), on the total performance of the best carbonaceous structure was carefully assessed, and the responsible detection mechanism is investigated in detail. Next, the developed carbonaceous immunosensors were assessed via voltammetric and impedance assays, and their performances toward specific detection of SARS-CoV-2 antigen through immunoreaction were examined in detail. The study's outcome showed the superior performance of conjugated rGO-based immunosensor with Au NSs toward specific and quick (1 min) detection of SARS-CoV-2 antigen in biological fluids compared with other 1D/2D carbonaceous nanomaterials.
Rapid thermal annealing (RTA) at 800–900 °C in air atmosphere is commonly used to crystallize bismuth-substituted yttrium iron garnet (Bi:YIG) deposited by vacuum evaporation techniques or metal–organic decomposition. However, the conventional RTA leads to undesirable effects in applications where Bi:YIG is the constituent material of a nano- or microstructure. Here we report on an approach to Bi:YIG local crystallization by a focused continuous wave laser beam (LRTA). The structural and optical properties of micron-sized Bi:YIG stripes crystallized in air, oxygen, nitrogen and argon atmospheres are discussed. The demonstrated LRTA can find practical applications for Bi:YIG monolithic integration on non-garnet substrates.
Nutrient acquisition strategies of plants regulate water flow and mass transport within ecosystems, shaping earth surface processes. Understanding plant strategies under current conditions is important to assess and predict responses of natural ecosystems to future climate and environmental changes. Nitrogen (N) and potassium (K) (re-)utilization from topsoil and their acquisition from subsoil and saprolite were evaluated in a continental transect, encompassing three study sites – an arid shrubland, a mediterranean woodland, and a temperate rainforest – on similar granitoid parent material in the Chilean Coastal Cordillera. The short-term (<1 year) plant N and K acquisition was traced with ¹⁵N and the K analogs rubidium and cesium. To do so, the tracers were either injected into topsoil, subsoil, or saprolite, in the immediate vicinity of eight individual plants per study site and injection depth. The long-term (>decades) K uplift by plants was investigated by the vertical distribution of exchangeable K⁺ and Na⁺. Recoveries of ¹⁵N and K analogs by arid shrubland plants were similar from topsoil, subsoil, and saprolite. Mediterranean woodland shrubs recovered the tracers primarily from topsoil (i.e., 89 % of recovered ¹⁵N and 84 % of recovered K analogs). Forest plants recovered the tracers from topsoil (¹⁵N = 49 %, K analogs = 57 %) and partially from greater depth: 38 % of recovered ¹⁵N and 43 % of recovered K analogs were acquired from subsoil and saprolite, respectively. Low nutrient accessibility in the topsoil (e.g., because of frequent droughts) drives shrubland plants to expand their N and K uptake to deeper and moister soil and saprolite. Woodland and forest plants dominantly recycled nutrients from topsoil. In the forest, this strategy was complemented by short-term uplift of N and K from depth. The vertical distribution of exchangeable K indicated long-term uplift of K by roots in all three sites. This highlighted that long-term K uplift from depth complements the nutrient budget across the continental transect.
Understanding the cavity formation and cavity growth mechanisms in solids has fundamental and applied importance for the correct determination of their exploitation capabilities and mechanical characteristics. In this work, we present the molecular dynamics simulation results for the process of homogeneous formation of nanosized cavities in a single-component amorphous metallic alloy. To identify cavities of various shapes and sizes, an original method has been developed, which is based on filling cavities by virtual particles (balls) of the same diameter. By means of the mean first-passage time analysis, it was shown that the cavity formation in an amorphous metallic melt is the activation-type process. This process can be described in terms of the classical nucleation theory, which is usually applied to the case of first order phase transitions. Activation energy, critical size and nucleation rate of cavities are calculated, the values of which are comparable with those for the case of crystal nucleation in amorphous systems.
Porous crystalline nitinol is widely applied in various fields of science and technology due to the unique combination of physical and mechanical properties as well as biocompatibility. Porous amorphous nitinol is characterized by improved mechanical properties compared to its crystalline analogues. Moreover, this material is more promising from the point of view of fundamental study and practical application. The production of porous amorphous nitinol is a difficult task requiring rapid cooling protocol and optimal conditions to form a stable porous structure. In the present work, based on the results of molecular dynamics simulations, we show that porous nitinol with the amorphous matrix can be obtained by injection of argon into a liquid melt followed by rapid cooling of the resulting mixture. We find that the porosity of the system increases exponentially with increasing fraction of injected argon. It has been established that the system should contain about ∼ 18 % –23% argon for obtain an open porous structure, while the system is destroyed by overheated inert gas when the argon fraction is more than ∼ 23 %. It is shown that the method of argon injection makes it possible to obtain a highly porous system with the porosity ∼ 70 % consisting the spongy porous structure similar to aerogels and metallic foams.
Information processing in neuronal networks involves the recruitment of selected neurons into coordinated spatiotemporal activity patterns. This sparse activation results from widespread synaptic inhibition in conjunction with neuron-specific synaptic excitation. We report the selective recruitment of hippocampal pyramidal cells into patterned network activity. During ripple oscillations in awake mice, spiking is much more likely in cells in which the axon originates from a basal dendrite rather than from the soma. High-resolution recordings in vitro and computer modeling indicate that these spikes are elicited by synaptic input to the axon-carrying dendrite and thus escape perisomatic inhibition. Pyramidal cells with somatic axon origin can be activated during ripple oscillations by blocking their somatic inhibition. The recruitment of neurons into active ensembles is thus determined by axonal morphological features.
Development of microfiltration membranes used to separate emulsions of oil and water is highlighted. Oil emulsion microfiltration parameters are studied and the change in particle size of emulsion dispersed phase within membrane filtrates is established. Commercial and composite microfiltration membranes with hydrophilic and hydrophobic surfaces are used. The average pore sizes of the commercial membranes are from 0.22 to 0.45 μm, and particle sizes of the dispersed phase of the oil emulsion are in the range from 525 to 554 nm. During microfiltration of 0.1% oil emulsion, high productivity of polymer membranes is established (800–12,000 dm3/m2 · h) with an operating pressure of 0.2 MPa. After oil emulsion separation using microfiltration membranes a reduction is observed in oil product concentration, the retention capacity of commercial membranes is 88–98%, for the nylon-polystyrene dynamic membrane it is more than 99%, and for NAC-1 composite membrane with a surface layer of cellulose acetate it is 67% (relatively low). After emulsion separation a reduction is observed in dispersed phase particle size in membrane filtrates by up to a factor of ten. A reduction in the absolute value of the ζ-potential of the emulsion in membrane filtrates compared with the initial value is also revealed.
Apart from other severe consequences, the COVID-19 pandemic has inflicted a surge in personal protective equipment usage, some of which, such as medical masks, have a short effective protection time. Their misdisposition and subsequent natural degradation make them huge sources of micro- and nanoplastic particles. To better understand the consequences of the direct influence of microplastic pollution on biota, there is an urgent need to develop a reliable and high-throughput analytical tool for sub-micrometre plastic identification and visualisation in environmental and biological samples. This study evaluated the application of a combined technique based on dark-field enhanced microscopy and hyperspectral imaging augmented with deep learning data analysis for the visualisation, detection and identification of microplastic particles released from commercially available medical masks after 192 hours of UV-C irradiation. The analysis was performed using a separated blue-coloured spunbond outer layer and white-coloured meltblown interlayer that allowed us to assess the influence of the structure and pigmentation of intact and UV-exposed samples on classification performance. Microscopy revealed strong fragmentation of both layers and the formation of microparticles and fibres of various shapes after UV exposure. Based on the spectral signatures of both layers, it was possible to identify intact materials using a convolutional neural network successfully. However, the further classification of UV-exposed samples demonstrated that the spectral characteristics of samples in the visible to near-infrared range are disrupted, causing a decreased performance of the CNN. Despite this, the application of a deep learning algorithm in hyperspectral analysis outperformed the conventional spectral angle mapper technique in classifying both intact and UV-exposed samples, confirming the potential of the proposed approach in secondary microplastic analysis.
The social position of an individual in society depends on the degree of reach of individual social benefits. The presence of low accessibility to significant objects, in particular, to vital values, housing, can provoke deprivation processes. According to official data on housing affordability, on average, Russian agglomerations have a housing market characterized as a market with not very affordable housing. Against the background of the “corona crisis” of 2020, there was a decrease in housing affordability. An analysis of housing affordability based on objective indicators cannot always fully reflect the complex nature of this problem; therefore, it seems relevant to study the level of housing affordability based on subjective indicators (opinions, assessments of the population, specialists). The purpose of the work is to identify the degree of affordability of purchasing housing, the possibilities for its improvement for Kazan citizens, and to characterize the factors that have a negative impact on the possibilities of acquiring housing. Based on the author's mass survey of the population of Kazan (n=1,076), a survey of Kazan realtors (n=348) and an expert interview (n=5), it was revealed that many Kazan families are quite limited in the possibilities of acquiring new housing or improving it: the average value The coefficient of affordability for acquiring new housing ranges from 2 (acquisition of housing is seriously complicated) to 1 (acquisition of housing is practically inaccessible). Negative factors for improving the living conditions of Kazan citizens are: the high market cost of acquiring property, low incomes, income instability, the threat of job loss and unfavorable mortgage lending conditions. Single-parent families and young families with children, pensioners, the disabled, orphans, and students remain among the socially vulnerable groups of the population. In recentyears, this list has been supplemented by public sector employees. For the optimal solution of the housing issue, federal and regional authorities need to pay attention to the growth of real incomes of the population and the regulation of housing prices.
Surrogate measures are becoming increasingly used to measure suspended sediment flux, but only few particular computer techniques of data processing are recently developed. This study demonstrates capabilities of acoustic Doppler current profilers (ADCPs) to infer information regarding suspended-sand concentrations in river systems and calculate suspended sediment flux via big data analytics which includes process of analyzing and data mining of measurements based on ADCP signal backscatter intensity data. We present here specific codes done by R language using RStudio software with open-source tidyverse and plotly packages aimed to generate tables containing data of suspended load for cells, verticals and whole cross-section based on backscattering values from 600 kH Teledyne RDInstruments RioGrande WorkHorse ADCP unit, as well perform estimates of morphometric, suspended sediment concentration (SSC) and velocity characteristics of the flow. The developed tools enabled to process large data array consisting of over 56,526,480 geo-referenced values of river depth, streamflow velocity, and backscatter intensity for each river cross-section measured at six case study sites in Russia.
Lichen secondary metabolites have been suggested to play a great diversity of roles in lichen biology by acting as UV screens, antimicrobials, herbivore deterrents or allelopathic compounds. However, evidence is also beginning to accumulate that in addition to these roles, even faintly pigmented or unpigmented lichen substances can reduce photoinhibition caused by high levels of photosynthetically active radiation (PAR). Here we used an acetone rinsing technique to remove lichen substances from four common epiphytic Afromontane macro lichens, Parmelia perlata, Ramalina celastri, Usnea dasaea, and Heterodermia leucomela. Results showed that lichen substances can increase the tolerance of lichens to the photoinhibition of PSII of their photobionts when hydrated, apparently by increasing reflectance. However, in the field, lichens may suffer more photoinhibition when fully or partially desiccated. Here we show for the first time that, except for the atranorin-containing Heterodermia, lichen substances can also protect desiccated lichens. Interestingly, removal of substances has no effect on reflectance when lichens are dry, suggesting that lichen substances protect photobionts in other ways.
A refined statement of linearized problems on flat internal multiscale buckling modes of a rigid lamina with either fibers or a fiber bundle is presented taking into account their interaction with an epoxy matrix. In the prebuckling (unperturbed) state, these constituent elements are under the influence of not only shear stresses, but also tensile (compressive) ones in the direction of fibers. This prebuckling stress state is formed in fibers and fiber bundles during the tension and compression of flat test specimens from cross-ply reinforced composites with straight fibers. For statement of the problem, equations were constructed by reducing a consistent version of the geometrically nonlinear equations of elasticity theory to one-dimensional equations of the theory of straight rods. The refined Timoshenko shear model was used taking into account the transverse tensile and compressive strains in a rigid lamina. For epoxy layers, models of a transversely soft layer with fixed boundary planes in the perturbed state were used. They differed from the previously constructed equations by taking into account the formation of additional prebuckling tensile (compression) forces in the fiber direction in the rigid lamina of the composite. It is shown theoretically that, in [±45]2s specimens, the most intense and continuous rearrangement of the composite structure, due to the implementation and continuous change of the studied internal buckling modes with a continuous change in the wave formation parameter, has to be observed in compression. In tension, such phenomena are possible only owing to the formation of initial shear stresses.
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3,773 members
Edward Babynin
  • Department of Genetics
Rimma Gamirova
  • Department of Fundamental Basis of Clinical Medicine
Vera Ulyanova
  • Department of Microbiology
Renad Zhdanov
  • Institute of Fundamental Medicine and Biology
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