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The article focuses on such a concept as “network topology”, which plays an important role in increasing the efficiency of managing the transportation process on the railway. The authors carry out detailed analysis of such network topologies as star, ring, bus, tree and others, and also explore their potential for improvement of the efficiency of railway transportation management. The work examines the advantages and disadvantages of each topology, and also evaluates their capabilities for optimizing the transportation process. Evaluation and comparative analysis of varieties of different network topologies is a relevant and interesting area of research. The results of the study confirm that the choice of a specific network topology can significantly affect the efficiency of transportation process management. Some network topologies can significantly reduce shipping costs and improve the overall delivery record, while other topologies can have the opposite effect.

High-resolution spectroscopy in soft X-rays will open a new window to map multiphase gas in galaxy clusters and probe physics of the intracluster medium (ICM), including chemical enrichment histories, circulation of matter and energy during large-scale structure evolution, stellar and black hole feedback, halo virialization, and gas mixing processes. An eV-level spectral resolution, large field of view, and effective area are essential to separate cluster emissions from the Galactic foreground and efficiently map the cluster outskirts. Several mission concepts that meet these criteria have been proposed recently, e.g. LEM, HUBS, and Super DIOS. This theoretical study explores what information on ICM physics could be recovered with such missions and the associated challenges. We emphasize the need for a comprehensive comparison between simulations and observations to interpret the high-resolution spectroscopic observations correctly. Using Line Emission Mapper (LEM) characteristics as an example, we demonstrate that it enables the use of soft X-ray emission lines (e.g. O  vii / viii and Fe-L complex) from the cluster outskirts to measure the thermodynamic, chemical, and kinematic properties of the gas up to r 200 and beyond. By generating mock observations with full backgrounds, analysing their images/spectra with observational approaches, and comparing the recovered characteristics with true ones from simulations, we develop six key science drivers for future missions, including the exploration of multiphase gas in galaxy clusters (e.g. temperature fluctuations, phase-space distributions), metallicity, ICM gas bulk motions and turbulence power spectra, ICM-cosmic filament interactions, and advances for cluster cosmology. [ABSTRACT FROM AUTHOR]

Pigs as laboratory animals are used in preclinical studies aimed at developing medical devices for cardiac surgery. The anatomy of the cardiovascular system of these animals has been well studied and acknowledged as suitable for use and the testing of new cardiovascular devices developed for humans. However, there are no morphometric characteristics of the aortic root and thoraco-abdominal part of porcine aorta. This can lead to difficulties in experimental surgery and even result in the death of experimental animals due to the mismatch in the size of the implantable devices. Thus, such information is essential to enhance the efficiency of surgical technologies used for eliminating aortic pathologies in their various sections. The purpose of our research is to study the anatomy of the aorta in mini pigs and to assess whether the size, age, and sex of the animals affect the size of the main structures in their aortas. In addition, we attempted to compare the results obtained by transesophageal echocardiography (TEE) and angiography. We studied 28 laboratory mini pigs, dividing them into three groups by body weight (40–70 kg, 71–90 kg, and 90 kg). We did not find any relationship between the external somatometric characteristics of the animals and the size of their aortas. Animals have individual anatomical variability in their cardiovascular systems, which means that they need to be examined in terms of preoperative planning by any available method—echocardiography, angiography, or multispiral computed tomography (CT). [ABSTRACT FROM AUTHOR]

The role of railway transport in the modern economy is highlighted in the article. Directions for improving automation and telemechanics devices have been determined: the creation and implementation of modern devices for monitoring track occupancy of a new type, as well as increasing the reliability of track devices to a large extent, and putting into operation systems for interval regulation of train traffic. The importance of such an element of the railway infrastructure as a rail circuit is also determined. The authors of the work revealed the function of track circuits. In addition to this, the article presents an information diagram of the search for failures in an extensive rail circuit of electrical centralization. The concept of a decision device is disclosed. Possible expressions of the Bayes criterion are also considered. A priori probabilities of finding rail lines are singled out. As a result, a decision rule is revealed that leads to the minimization of the average damage.

Background: Driven by the ongoing need to provide high‐quality learning and teaching, universities recently have shown an increased interest in using learning analytics (LA) for improving learning design (LD). However, the evidence of such improvements is scarce, and the maturity of such research is unclear. Objectives: This study is aimed to evaluate the maturity of research discussing LA‐driven LD improvements in higher education. Methods: The systematic review analyses 49 empirical papers, assesses their quality and suggests further research directions. The review elaborates on methodological (research questions, strategy and methods, LA‐LD integration theoretical backgrounds) and substantial (LA‐driven LD improvements, types of data used, LA software development) features of the papers. Results and Conclusions: The findings demonstrated the lack of theoretical alignment between LA and LD, with research tending towards user experience studies. The most frequently used research strategy was a case study; experiments were very rare. Researchers predominantly used parsing for collecting data and AI methods for analysing it; mostly used data types related to registering learners' engagement with learning activities as well as resources and tools provided in digital learning environments. Takeaways: The research area discussing LA‐driven LD improvements still has a way to go before attaining the level of full maturity. Only a third of the papers reported actual LA‐driven LD improvements; moreover, only three papers measured their effectiveness. The presented LA software was mostly at the beta or implementation stages and did not assess the impact of using this software. Lay Description: What is already known about this topic: Universities show an increased interest in using LA for improving LD.The evidence of such improvements being efficient is scarce.Learning analytics is weakly grounded in learning and teaching. What this paper adds: LA‐LD research presented in the reviewed papers cannot yet be considered fully mature.Almost half of the research was carried out using a case study approach, intrinsically challenging in terms of replication and validity. As few as three out of the reviewed studies applied an experimental approach, capable of stating the cause–effect relationship between LA and LD.All the studied papers mentioned improvements in LD, but only around a third of them reported actual improvements, another one‐third suggested potential improvements, and the rest did not come down to describing any.The LA software presented in the papers was mostly at the testing or implementation stages, and the impact of implemented software on LD has yet to be evaluated. Implications for practice and/or policy: Future LA‐LD research to become more mature may well elaborate on theoretical footing, contribute to the cause–effect relationship between LA and LD utilising experimental research design, ensure sufficient sample size.Practitioners' efforts should be directed to operationalising LD for efficient measurements, addressing pedagogical challenges when applying LA, and assessing LA‐driven improvements introduced into LD. [ABSTRACT FROM AUTHOR]

The hot intracluster medium (ICM) provides a unique laboratory to test multiscale physics in numerical simulations and probe plasma physics. Utilizing archival Chandra observations, we measure density fluctuations in the ICM in a sample of 80 nearby (z ≲ 1) galaxy clusters and infer scale-dependent velocities within regions affected by mergers (r < R 2500c), excluding cool-cores. Systematic uncertainties (e.g. substructures, cluster asymmetries) are carefully explored to ensure robust measurements within the bulk ICM. We find typical velocities ∼220 (300) km s−1 in relaxed (unrelaxed) clusters, which translate to non-thermal pressure fractions ∼4 (8) per cent, and clumping factors ∼1.03 (1.06). We show that density fluctuation amplitudes could distinguish relaxed from unrelaxed clusters in these regions. Comparison with density fluctuations in cosmological simulations shows good agreement in merging clusters. Simulations underpredict the amplitude of fluctuations in relaxed clusters on length scales <0.75  R 2500c, suggesting these systems are most sensitive to 'missing' physics in the simulations. In clusters hosting radio haloes, we examine correlations between gas velocities, turbulent dissipation rate, and radio emission strength/efficiency to test turbulent re-acceleration of cosmic ray electrons. We measure a weak correlation, driven by a few outlier clusters, in contrast to some previous studies. Finally, we present upper limits on effective viscosity in the bulk ICM of 16 clusters, showing it is systematically suppressed by at least a factor of 8, and the suppression is a general property of the ICM. Confirmation of our results with direct velocity measurements will be possible soon with XRISM. [ABSTRACT FROM AUTHOR]

Among the vascular prostheses used for aortic replacement, 95% are woven or knitted grafts from polyester fibers. Such grafts require sealing, for which gelatin (Gel) is most often used. Sometimes antibiotics are added to the sealant. We used gelatin type A (GelA) or type B (GelB), containing one of the three antibiotics (Rifampicin, Ceftriaxone, or Vancomycin) in the sealant films. Our goal was to study the effect of these combinations on the mechanical and antibacterial properties and the cytocompatibility of the grafts. The mechanical characteristics were evaluated using water permeability and kinking radius. Antibacterial properties were studied using the disk diffusion method. Cytocompatibility with EA.hy926 endothelial cells was assessed via indirect cytotoxicity, cell adhesion, and viability upon direct contact with the samples (3, 7, and 14 days). Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to visualize the cells in the deep layers of the graft wall. "GelA + Vancomycin" and "GelB + vancomycin" grafts showed similar good mechanical characteristics (permeability~10 mL/min/cm2, kinking radius 21 mm) and antibacterial properties (inhibition zones for Staphilococcus aureus~15 mm, for Enterococcus faecalis~12 mm). The other samples did not exhibit any antibacterial properties. The cytocompatibility was good in all the tested groups, but endothelial cells exhibited the ability to self-organize capillary-like structures only when interacting with the "GelB + antibiotics" coatings. Based on the results obtained, we consider "GelB + vancomycin" sealant to be the most promising. [ABSTRACT FROM AUTHOR]

The paper proposes a methodology for the formation of monitoring of sustainable development of a territory. The existing addition to the concept of sustainable development is presented. This methodology is a recommendation for authorities. The main goal of the proposed methodology is connected with conducting research on socio-economic and environmental development and planning of territories in order to achieve sustainable development and increase inter-regional and intraregional spatial connectivity. The authors give recommendations on the formation of the state monitoring of sustainable development a territory system for the Ministry of Economic Development and Industry of the Irkutsk Region. It is proposed to form a permanent analytical department and give name “Coordination Council for Spatial Development”. The Coordination Council for Spatial Development carries out activities to study the issues of sustainable development of a territory and spatial connectivity. The monitoring results can be used by regional authorities to formulate provisions for achieving the sustainable development of a territory within the framework of formation the Strategy for the socioeconomic development of a region. The algorithm is presented in the form of diagram. The diagram describes the sequence of actions for the formation of provisions for the sustainable development of a territory by assessing the socio-economic, ecological state and the level of territorial connectivity.

Poly-ε-caprolactone ((1,7)-polyoxepan-2-one; PCL) is a biodegradable polymer widely used in various fields of bioengineering, but its behavior in long-term studies appears to depend on many conditions, such as application specificity, chemical structure, in vivo test systems, and even environmental conditions in which the construction is exploited in. In this study, we offer an observation of the remote outcomes of PCL tubular grafts for abdominal aorta replacement in an in vivo experiment on a rat model. Adult Wistar rats were implanted with PCL vascular matrices and observed for 180 days. The results of ultrasound diagnostics and X-ray tomography (CBCT) show that the grafts maintained patency for the entire follow-up period without thrombosis, leakage, or interruptions, but different types of tissue reactions were found at this time point. By the day of examination, all the implants revealed a confluent endothelial monolayer covering layers of hyperplastic neointima formed on the luminal surface of the grafts. Foreign body reactions were found in several explants including those without signs of stenosis. Most of the scaffolds showed a pronounced infiltration with fibroblastic cells. All the samples revealed subintimal calcium phosphate deposits. A correlation between chondroid metaplasia in profound cells of neointima and the process of mineralization was supported by immunohistochemical (IHC) staining for S100 proteins and EDS mapping. Microscopy showed that the scaffolds with an intensive inflammatory response or formed fibrotic capsules retain their fibrillar structure even on day 180 after implantation, but matrices infiltrated with viable cells partially save the original fibrillary network. This research highlights the advantages of PCL vascular scaffolds, such as graft permeability, revitalization, and good surgical outcomes. The disadvantages are low biodegradation rates and exceptionally high risks of mineralization and intimal hyperplasia. [ABSTRACT FROM AUTHOR]

Valved conduits are often required to replace pulmonary arteries (PA). A widely used Contegra device is made of bovine jugular vein (BJV), preserved with glutaraldehyde (GA) and iso-propanol. However, it has several drawbacks that may be attributed to its chemical treatment. We hypothesized that the use of an alternative preservation compound may significantly improve BJV conduit performance. This study aimed to compare the macroscopic and microscopic properties of the BJV treated with diepoxide (DE) and GA in a porcine model. Twelve DE-BJVs and four Contegra conduits were used for PA replacement in minipigs. To assess the isolated influence of GA, we included an additional control group—BJV treated with 0.625% GA (n = 4). The animals were withdrawn after 6 months of follow-up and the conduits were examined. Explanted DE-BJV had a soft elastic wall with no signs of thrombosis or calcification and good conduit integration, including myofibroblast germination, an ingrowth of soft connective tissue formations and remarkable neoangiogenesis. The inner surface of DE-BJVs was covered by a thin neointimal layer with a solid endothelium. Contegra grafts had a stiffer wall with thrombosis on the leaflets. Calcified foci, chondroid metaplasia, and hyalinosis were observed within the wall. The distal anastomotic sites had hyperplastic neointima, partially covered with the endothelium. The wall of GA-BJV was stiff and rigid with degenerative changes, a substantial amount of calcium deposits and dense fibrotic formations in adventitia. An irregular neointimal layer was presented in the anastomotic sites without endothelial cover in the GA BJV wall. These results demonstrate that DE treatment improves conduit integration and the endothelialization of the inner surface while preventing the mineralization of the BJV, which may reduce the risk of early conduit dysfunction. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are used in applications ranging from electrical engineering to medical device manufacturing. It is well known that the addition of nanotubes can influence the mechanical properties of various industrial materials, including plastics. Electrospinning is a popular method for fabricating nanomaterials, widely suggested for polymer scaffold manufacturing. In this study, we aimed to describe the influence of single-walled carbon nanotube (SWCNT) suspensions on polymeric poured films and electrospun scaffolds and to investigate their structural and mechanical properties obtained from various compositions. To obtain films and electrospun scaffolds of 8 mm diameter, we used poly-ε-caprolactone (PCL) and poly(cyclohexene carbonate) (PCHC) solutions containing several mass fractions of SWCNT. The samples were characterized using tensile tests, atomic force and scanning electronic microscopy (AFM and SEM). All the studied SWCNT concentrations were shown to decrease the extensibility and strength of electrospun scaffolds, so SWCNT use was considered unsuitable for this technique. The 0.01% mass fraction of SWCNT in PCL films increased the polymer strength, while fractions of 0.03% and more significantly decreased the polymer strength and extensibility compared to the undoped polymer. The PHCH polymeric films showed a similar behavior with an extremum at 0.02% concentration for strength at break. [ABSTRACT FROM AUTHOR]

We study the impact of resonantly scattered X-ray line emission on the observability of the hot circumgalactic medium (CGM) of galaxies. We apply a Monte Carlo radiative transfer post-processing analysis to the high-resolution TNG50 cosmological magnetohydrodynamical galaxy formation simulation. This allows us to model the resonant scattering of  O  vii (r) X-ray photons within the complex, multiphase, multiscale CGM. The resonant transition of the O  vii He-like triplet is one of the brightest, and most promising, X-ray emission lines for detecting the hot CGM and measuring its physical properties. We focus on galaxies with stellar masses |$10.0\lt \log {(M_\star /\rm {M_\odot })}\lt 11.0$| at z ≃ 0. After constructing a model for  O  vii (r) emission from the central galaxy, as well as from CGM gas, we forward model these intrinsic photons to derive observable surface brightness maps. We find that scattering significantly boosts the observable  O  vii (r) surface brightness of the extended and diffuse CGM. This enhancement can be large – an order of magnitude on average at a distance of 200 projected kpc for high-mass M ⋆ = 1010.7 M⊙ galaxies. The enhancement is larger for lower mass galaxies and can even reach a factor of 100, across the extended CGM. Galaxies with higher star formation rates, AGN luminosities, and central  O  vii (r) luminosities all have larger scattering enhancements, at fixed stellar mass. Our results suggest that next-generation X-ray spectroscopic missions, including XRISM, LEM, ATHENA, and HUBS – which aim to detect the hot CGM in emission – could specifically target haloes with significant enhancements due to resonant scattering. [ABSTRACT FROM AUTHOR]

While awaiting direct velocity measurements of gas motions in the hot intracluster medium, we rely on indirect probes, including gas perturbations in galaxy clusters. Using a sample of ∼80 clusters in different dynamic states from Omega500 cosmological simulations, we examine scaling relations between the fluctuation amplitudes of gas density, δρ/ρ, pressure, δ P / P , X-ray surface brightness, Sunyaev–Zel'dovich (SZ) y-parameter, and the characteristic Mach number of gas motions, M 1d. In relaxed clusters, accounting for halo ellipticities reduces δρ/ρ or δ P / P by a factor of up to 2 within r 500 c . We confirm a strong linear correlation between δρ/ρ (or δ P / P) and M 1d in relaxed clusters, with the proportionality coefficient η ≈ 1. For unrelaxed clusters, the correlation is less strong and has a larger η ≈ 1.3 ± 0.5 (1.5 ± 0.5) for δρ/ρ (δ P / P). Examination of the M 1d − δρ/ρ relation shows that it is almost linear for relaxed clusters, while for the unrelaxed ones, it is closer to |$\delta \rho /\rho \propto M_{\rm 1d}^2$|⁠. In agreement with previous studies, we observe a strong correlation of M 1d with radius. Correcting for these correlations leaves a residual scatter in M 1d of ∼4(7) per cent for relaxed (perturbed) clusters. Hydrostatic mass bias correlates with M 1d as strongly as with δρ/ρ in relaxed clusters. The residual scatters after correcting for derived trends is ∼6−7 per cent. These predictions can be verified with existing X-ray and SZ observations of galaxy clusters combined with forthcoming velocity measurements with X-ray microcalorimeters. [ABSTRACT FROM AUTHOR]

The causes of heart valve bioprosthetic calcification are still not clear. In this paper, we compared the calcification in the porcine aorta (Ao) and the bovine jugular vein (Ve) walls, as well as the bovine pericardium (Pe). Biomaterials were crosslinked with glutaraldehyde (GA) and diepoxide (DE), after which they were implanted subcutaneously in young rats for 10, 20, and 30 days. Collagen, elastin, and fibrillin were visualized in non-implanted samples. Atomic absorption spectroscopy, histological methods, scanning electron microscopy, and Fourier-transform infrared spectroscopy were used to study the dynamics of calcification. By the 30th day, calcium accumulated most intensively in the collagen fibers of the GA-Pe. In elastin-rich materials, calcium deposits were associated with elastin fibers and localized differences in the walls of Ao and Ve. The DE-Pe did not calcify at all for 30 days. Alkaline phosphatase does not affect calcification since it was not found in the implant tissue. Fibrillin surrounds elastin fibers in the Ao and Ve, but its involvement in calcification is questionable. In the subcutaneous space of young rats, which are used to model the implants' calcification, the content of phosphorus was five times higher than in aging animals. We hypothesize that the centers of calcium phosphate nucleation are the positively charged nitrogen of the pyridinium rings, which is the main one in fresh elastin and appears in collagen as a result of GA preservation. Nucleation can be significantly accelerated at high concentrations of phosphorus in biological fluids. The hypothesis needs further experimental confirmation. [ABSTRACT FROM AUTHOR]

The cytocompatibility of titanium oxides (TiO2) and oxynitrides (N-TiO2, TiOxNy) thin films depends heavily on the surface topography. Considering that the initial relief of the substrate and the coating are summed up in the final topography of the surface, it can be expected that the same sputtering modes result in different surface topography if the substrate differs. Here, we investigated the problem by examining 16 groups of samples differing in surface topography; 8 of them were hand-abraded and 8 were machine-polished. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. Abraded and polished uncoated samples served as controls. The surfaces were studied using atomic force microscopy (AFM). The cytocompatibility of coatings was evaluated in terms of cytotoxicity, adhesion, viability, and NO production. It has been shown that the cytocompatibility of thin films largely depends on the surface nanostructure. Both excessively low and excessively high density of peaks, high and low kurtosis of height distribution (Sku), and low rates of mean summit curvature (Ssc) have a negative effect. Optimal cytocompatibility was demonstrated by abraded surface with a TiOxNy thin film sputtered at N2:O2 = 1:1 and Ub = 0 V. The nanopeaks of this surface had a maximum height, a density of about 0.5 per 1 µm2, Sku from 4 to 5, and an Ssc greater than 0.6. We believe that the excessive sharpness of surface nanostructures formed during magnetron sputtering of TiO2 and N-TiO2 films, especially at a high density of these structures, prevents both adhesion of endothelial cells, and their further proliferation and functioning. This effect is apparently due to damage to the cell membrane. At low height, kurtosis, and peak density, the main factor affecting the cell/surface interface is inefficient cell adhesion. [ABSTRACT FROM AUTHOR]

The current state of the financial security of Ukraine's regions based on the taxonomic index is defined. Neural networks of financial security of Ukraine's regions with the help of Statistica Neural Networks are built. Potential threats to the financial security of Ukraine's regions based on sensitivity analysis are identified.Определено текущее состояние финансовой безопасности регионов Украины на базе таксономического показателя. Построены нейронные сети финансовой безопасности регионов Украины с помощью Statistica Neural Networks. Выявлены потенциальные угрозы финансовой безопасности регионов Украины на основе анализа чувствительности.

We present a Chandra study of surface brightness fluctuations in the diffuse intracluster medium of the Perseus Cluster. Our study utilizes deep, archival imaging of the cluster core as well as a new mosaic of 29 short |$\, 5\,$| -ks observations extending in eight different directions out to radii of |$r_{500} \sim 2.2\, r_{2500}$|⁠. Under the assumption that the distribution of densities at a given radius is log-normally distributed, two important quantities can be derived from the width of the log-normal density distribution on a given spatial scale: the density bias, that is equal to the square root of the clumping factor C ; and the one-component turbulent velocity, v k ,1D. We forward-model all contributions to the measured surface brightness, including astrophysical and particle background components, and account for the Poisson nature of the measured signal. Measuring the distribution of surface brightness fluctuations in 1 arcmin2 regions, spanning the radial range |$0.3\rm {-}2.2\, r_{2500}$| (⁠|$7.8\rm {-}57.3\,$|  arcmin), we find a small to moderate average density bias of around |$3{{\ \rm per\ cent}}$| at radii below |$1.6\, r_{2500}$|⁠. We also infer an average turbulent velocity at these radii of V 1D < 400 km s−1. Direct confirmation of our results on turbulent velocities inferred from surface brightness fluctuations should be possible using the X-ray calorimeter spectrometers to be flown aboard the XRISM and Athena observatories. [ABSTRACT FROM AUTHOR]

Titanium oxide (TiO2) and oxynitride (N-TiO2) coatings can increase nitinol stents' cytocompatibility with endothelial cells. Methods of TiO2 and N-TiO2 sputtering and cytocompatibility assessments vary significantly among different research groups, making it difficult to compare results. The aim of this work was to develop an integral cytocompatibility index (ICI) and a decision tree algorithm (DTA) using the "EA.hy926 cell/TiO2 or N-TiO2 coating" model and to determine the optimal cytocompatible coating. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. The samples' morphology was studied by scanning electron microscopy (SEM) and Raman spectroscopy. The cytocompatibility of the coatings was evaluated in terms of their cytotoxicity, adhesion, viability, and NO production. The ICI and DTA were developed to assess the cytocompatibility of the samples. Both algorithms demonstrated the best cytocompatibility for the sample sputtered at Ubias = 0 V and a gas ratio of N2:O2 = 2:1, in which the rutile phase dominated. The DTA provided more detailed information about the cytocompatibility, which depended on the sputtering mode, surface morphology, and crystalline phase. The proposed mathematical models relate the cytocompatibility and the studied physical characteristics. [ABSTRACT FROM AUTHOR]

Buoyant bubbles of relativistic plasma are essential for active galactic nucleus feedback in galaxy clusters, stirring and heating the intracluster medium (ICM). Observations suggest that these rising bubbles maintain their integrity and sharp edges much longer than predicted by hydrodynamic simulations. In this study, we assume that bubbles can be modelled as rigid bodies and demonstrate that intact bubbles and their long-term interactions with the ambient ICM play an important role in shaping gas kinematics, forming thin gaseous structures (e.g. H α filaments), and generating internal waves in cluster cores. We find that well-developed eddies are formed in the wake of a buoyantly rising bubble, and it is these eddies, rather than the Darwin drift, that are responsible for most of the gas mass uplift. The eddies gradually elongate along the bubble's direction of motion due to the strong density stratification of the atmosphere and eventually detach from the bubble, quickly evolving into a high-speed jet-like stream propagating towards the cluster center in our model. This picture naturally explains the presence of long straight and horseshoe-shaped H α filaments in the Perseus cluster, inward and outward motions of the gas, and the X-ray-weighted gas velocity distributions near the northwestern bubble observed by Hitomi. Our model reproduces the observed H α velocity structure function of filaments, providing a simple interpretation for its steep scaling and normalization: laminar gas flows and large eddies within filaments driven by the intact bubbles, rather than spatially homogeneous small-scale turbulence, are sufficient to produce a structure function consistent with observations. [ABSTRACT FROM AUTHOR]

Electrospun tissue-engineered grafts made of biodegradable materials have become a perspective search field in terms of vascular replacement, and more research is required to describe their in vivo transformation. This study aimed to give a detailed observation of hemodynamic and structural properties of electrospun, monolayered poly-ε-caprolactone (PCL) grafts in an in vivo experiment using a rat aorta replacement model at 10, 30, 60 and 90 implantation days. It was shown using ultrasound diagnostic and X-ray tomography that PCL grafts maintain patency throughout the entire follow-up period, without stenosis or thrombosis. Vascular compliance, assessed by the resistance index (RI), remains at the stable level from the 10th to the 90th day. A histological study using hematoxylin-eosin (H&E), von Kossa and Russell–Movat pentachrome staining demonstrated the dynamics of tissue response to the implant. By the 10th day, an endothelial monolayer was forming on the graft luminal surface, followed by the gradual growth and compaction of the neointima up to the 90th day. The intense inflammatory cellular reaction observed on the 10th day in the thickness of the scaffold was changed by the fibroblast and myofibroblast penetration by the 30th day. The cellularity maximum was reached on the 60th day, but by the 90th day the cellularity significantly (p = 0.02) decreased. From the 60th day, in some samples, the calcium phosphate depositions were revealed at the scaffold-neointima interface. Scanning electron microscopy showed that the scaffolds retained their fibrillar structure up to the 90th day. Thus, we have shown that the advantages of PCL scaffolds are excellent endothelialization and good surgical outcome. The disadvantages include their slow biodegradation, ineffective cellularization, and risks for mineralization and intimal hyperplasia. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the mechanical properties and thermal stability of the venous wall depending on the treatment method used, and, accordingly, on those structural changes in the tissue that this treatment causes. Bovine jugular vein walls (BJVWs) cross‐linked with glutaraldehyde (GA), ethylene glycol diglycidyl ether (DE), and Contegra commercial conduit were evaluated using uniaxial stretching [with and without pre‐conditioning (PreC)], differential scanning calorimetry, amino acid analysis, and attenuated total reflection infrared spectroscopy. Fresh BJVW was used as a control. It was shown that failure stress in non‐PreC GA‐treated and DE‐treated materials was lower than that in fresh and Contegra counterparts. Contegra samples were the stiffest among the tested materials. Cyclic preloading leads to distortion of the mechanical behavior of this material, which is heterogeneous in composition and structure. The denaturation temperatures (Td) of all cross‐linked BJVWs were higher than the Td of the fresh vein. The microstructures of the tested BJVWs did not exhibit any differences, but the cross‐linking density and hydration of the DE‐vein were the highest. GA‐cross‐linking or DE‐cross‐linking and isopropanol exposure (Contegra) changed the protein secondary structures of the tested materials in different ways. We hypothesized that the protein secondary structure and hydration degree are the main causes of differences in the mechanical properties and thermal stability of BJVW. [ABSTRACT FROM AUTHOR]