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The article discusses ‟the power of stone” in the tales by P. P. Bazhov on the example of iconic stones of the Ural lytic culture: malachite, emerald, chrysolite. Using the method of cultural-historical, ideological-figurative and symbolic-contextual analysis, the author examines the history of the discovery of the stone riches of the Urals, the place of lytic discourse in the world of Bazhov’s tales, as well as the specific symbolism of gemstones (malachite, copper emerald, chrysolite) in the writer’s fantastic work. This is the relevance of the study. The author of the work proves the ambivalent nature of malachite as the main stone of the Ural mountains, symbolizing the beauty of the Mistress-Malachite, copper emerald, embodying the absolute power of the “stone force”, embodying the secret wealth of the mountains, inaccessible to ordinary mortals, like the secret of the stone flower. The third stone that embodies the lytic power of the Ural Mountains is the Bazhov chrysolite. The article consistently examines the evolution of Bazhov’s “iconic” stones in the writer’s artistic world during the transition from fairy tales depicting the pre-revolutionary life of the Urals to fairy tales depicting the realities of the revolutionary and Soviet Urals. It can be said that by depicting the evolution of the “stone power” of the main Ural gems, Bazhov prepared the ground for depicting the lytic discourse of the tales of the new Urals. In these tales, along with real stones, such as the eagle stone from the tale Eagle feather or “sun stone” ‒ plagioclase from the same tale, mystical and semi ‒ mystical stones will be used: “at all simple, on five faces” stone key of the earth (the fairy tale Key of the Earth, “patient stone” (the fairy tale Distant little body). The article will be of interest to all humanitarians working with the symbolism of stones in Russian literature of the XIX–XX centuries.

In this study, glycerin was used instead of traditional solvents such as methanol in combination with ultrasonic treatment for the high-efficiency extraction of multiple chemical components from tea. Furthermore, a quantitative analytical method for 130 chemical components belonging to seven classes in tea and its by-products was developed using ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS). The results showed that the extraction efficiency of glycerol was comparable to that of methanol and ethanol, and significantly better than that of water. The developed method had high sensitivity (limit of detection of 0.000 1-4.332 1 mg/kg) and accuracy (recoveries of 80.10%–121.12%). Appling this method to real samples, the content of each component varied greatly among different types of tea and by-products. Compared with tea samples, tea residue, a tea by-product, contained higher contents of caffeine, catechin and theanine, indicating the potential value of this by-product.

AbstractThe small size, surface effect, and tunneling effect of nanomaterials enable their applications in various fields, including catalysis, sensing. Fe3O4 has been widely used in nanotechnology owing to its excellent photoelectromagnetic properties. In this study, polygonal Fe3O4 nanoparticles were prepared through a high-temperature synthesis method. Subsequently, silica coating was applied via the Stöber method to obtain a nanomaterial with uniform particles. The prepared Fe3O4 exhibited a distinct crystal structure and an ultra-high saturation magnetization, reaching up to 134.2 emu/g. Moreover, the dodecyl trimethyl ammonium bromide (DTAB) templating agent facilitated the coating of Fe3O4 with silica. The coated Fe3O4@SiO2 particles featured a well-defined core–shell structure and corrosion resistance, making them highly promising candidates for magnetic targeting medical tools, magnetic resonance imaging agents and other biological applications. [ABSTRACT FROM AUTHOR]

The restoration of fine motor function in the hand is crucial for stroke survivors with hemiplegia to reintegrate into daily life and presents a significant challenge in post-stroke rehabilitation. Current mirror rehabilitation systems based on wearable devices require medical professionals or caregivers to assist patients in donning sensor gloves on the healthy side, thus hindering autonomous training, increasing labor costs, and imposing psychological burdens on patients. This study developed a low-load wearable hand function mirror rehabilitation robotic system based on visual gesture recognition. The system incorporates an active visual apparatus capable of adjusting its position and viewpoint autonomously, enabling the subtle monitoring of the healthy side's gesture throughout the rehabilitation process. Consequently, patients only need to wear the device on their impaired hand to complete the mirror training, facilitating independent rehabilitation exercises. An algorithm based on hand key point gesture recognition was developed, which is capable of automatically identifying eight distinct gestures. Additionally, the system supports remote audio–video interaction during training sessions, addressing the lack of professional guidance in independent rehabilitation. A prototype of the system was constructed, a dataset for hand gesture recognition was collected, and the system's performance as well as functionality were rigorously tested. The results indicate that the gesture recognition accuracy exceeds 90% under ten-fold cross-validation. The system enables operators to independently complete hand rehabilitation training, while the active visual system accommodates a patient's rehabilitation needs across different postures. This study explores methods for autonomous hand function rehabilitation training, thereby offering valuable insights for future research on hand function recovery. [ABSTRACT FROM AUTHOR]

Herein, orderly arranged bamboo-like mesoporous silica materials were prepared using cetyltrimethylammonium bromide (CTAB) as the template and n-hexanol as the long-chain alcohol cosurfactant. The ordered meso-structure was characterized by XRD analysis, field emission scanning electron microscopy (FE-SEM, Hitachi S4800), transmission electron microscopy, BET and IR spectroscopy analysis. The effects of the CTAB/n-hexanol molar ratio(R), length of the hydrophobic chain with a terminating hydroxyl group on the long-chain alcohol cosurfactant, parity of the hydrophobic carbon atoms on the surface topography, specific surface area, and pore size of the powder were investigated. The results showed that when the molar ratio = 1, the mesoporous silica presented neatly arranged bamboo segment lengths of 19.6–23.9 μm, platycodon grandiflorum widths of 2.13–3.32 μm, pore size of 3.04 nm, and surface area of 820.034 m2/g. Increasing or decreasing the amount of n-hexanol directing led to denser or looser lateral molecular interactions between CTAB and the co-structure-directing agents that respectively reduced or increased the pore size, with the latter resulting in the formation of spherical particles. When n-hexanol was replaced by n-heptanol or n-octanol, the pore size and surface area of the mesoporous silica decreased significantly with the increase in the hydrophobic chain length. [ABSTRACT FROM AUTHOR]

In this study, nanosilica particles were prepared from self-made silica gel under the protection of citric acid in situ complexation and ethyl acetate as the latent acid reagent. The effects of ethyl acetate, citric acid, reaction temperature, and reaction time on the particle size of nanosilica were studied. The optimum process parameters were determined as follows: Vethyl acetate: Vsilica sol = 9:50, citric acid addition amount 3.64%, reaction time 8 h, and reaction temperature 70 °C. The products were characterized by IR, XRD, SEM and TEM analyses. The results show that the nano-silica particles prepared by complexation precipitation method employing silica sol as silicon source has good dispersion with average particle size controlled about 19.44 nm. The method has numerous advantages over the conventional inverse extraction method under colloid protection, and is expected to achieve industrial production. [ABSTRACT FROM AUTHOR]