Nanotechnologies in Russia最新文献

It is shown that when the content of cellulose nanoparticles in polycrystalline freshwater ice increases from 0 to 1 wt % its compressive strength almost doubles. The concentration dependence of the compressive strength of ice composites reaches saturation at about 1 wt %. It is found that an increase in the concentration of cellulose nanoparticles leads to a transition from brittle to ductile fracture of the ice composites, as well as an increase in both the relative strain corresponding to the peak stress and the specific work required to achieve the peak stress. An increase in the concentration of nanoparticles introduced into ice to 1 wt %, which are additional crystallization centers, leads to an almost fourfold decrease in the average size of its grains. The predominant factor determining the strength of pure ice and ice composites is the size of the intergranular cracks formed, which is proportional to the average size of the ice grains.

The work presents the results of studying metal thimbles found in 14th century slab graves on the Eski-Kermen plateau. It is established that they are made of pure brass. The thimbles are divided into two groups according to their technological features. The first group includes thimbles from graves 10 and 11/2021, similar both in shape and in the nature of their decoration. To create the decoration on the thimble from grave 11/2021, one simple impact tool with a blunt-needle point (a kanfarnik) was used. To decorate the thimble from grave 10/2021, a kanfarnik was used only to create punched rows on the body. The decoration on the top of the thimble is made more carefully, using a complex tool with an oval working end. A thimble from grave 16/2022 is allocated to a separate group, it belongs to a completely different production tradition. It is made by folding and soldering a pre-decorated flat pattern of the product, which is followed by pressure in a mold matrix. Soldering of the seam of the product was carried out with tin solder.

The effect of nickel (30–1000 mg/L) in nanoscale (64 nm) and ionic forms on the length of 48‑hour roots and nine-day shoots and roots on electrical conductivity and NO(_{3}^{ - }) content in the tissue extracts of wheat seedlings (Triticum aestivum L.) is studied. The concentration-dependent inhibition of the root system of seedlings by nickel ions is characterized by a linear dependence, while for nanoparticles, it is characterized by a threshold dependence, which is not affected by the size of particle aggregates in the germination medium. The inhibitory action of Ni nanoparticles on germination is statistically significant at 1000 mg/L, while the post-exposition effects influencing the ionic status of shoots are insignificant in the entire concentration range. The obtained results may be relevant for the development of biotesting the toxic effects of nanoparticles on plants.

The bidirectional interaction between the gut, its microbiota, and the brain has been actively studied in the last decade. It is shown that microbiota plays an important role in the development and functioning of the human nervous system. Approximately one in eight people worldwide suffers from mental disorders. In 2013, the separate term psychobiotics was introduced to describe probiotics that provide health benefits for patients with mental illnesses. This review considers current clinical trials devoted to the use of probiotics in the treatment of various mental and neurodegenerative disorders. The existing data in the scientific literature are analyzed, highlighting the potential of psychobiotics as a new approach for correcting psychiatric symptoms; the existing challenges and future prospects are outlined.

Samples of the internal and external coatings of the hull of a warship that sank in the seaport of Phanagoria (modern Taman Bay) in the 1st century BC are studied. As a result of the application of a complex of complementary natural-science methods (optical microscopy, X-ray diffractometry, scanning electron microscopy with energy dispersive X-ray microanalysis, gas chromatography with mass-selective detection), it is found that the internal wooden part of the ship was treated with a “mastic,” based on clay mixed with wool and down. The outer surface of the ship’s sheathing board was coated by realgar mixed with wax and pine resin. Thus the recipes used for the waterproofing, fireproofing, and bioprotection of warships used by sailors of the Pontic Kingdom more than 2000 years ago are presented.

The technological features of fragments of a polychrome painted six-petal rosette are studied on a metal plate from a slab grave on the Eski-Kermen plateau. The pigments are analyzed by means of large-scale mapping with the application of X-ray fluorescence analysis and scanning electron microscopy with energy-dispersive X-ray microanalysis. The composition of the binders is identified using gas chromatography with mass spectrometry. It is found that red paint of a mixed composition of cinnabar and minium, carbon black pigment, and lead yellow were used. The paints were mixed using glue made from the bones or skins of ruminants. The increased tin content in the primer samples from the surface of the plate, the presence of resin and the complete absence of vegetable-oil traces allowed us to assume that signs of two technological operations are detected: tinning of the plate using tin and resin and painting with pigments mixed with bone glue. The traces of these operations are mixed due to the peculiarities of degradation of the adhesive paint layer and the metal base.

This study is focused on the reconstruction of the formation mechanisms of the eponymous Alakul cemetery (Kurgan oblast, Russia), characterized by a large number of burial mounds. Modeling the chronological framework of its usage suggests a period spanning from the 1800s to 1550s BCE according to radiocarbon dating. To assess population homogeneity, isotopic analysis of δ¹⁵N, δ¹³C (n = 37), and ⁸⁷Sr/⁸⁶Sr (n = 26) was conducted on the human and animal bone remains. This analysis identified a core of local values, as well as several individuals and animals originating from different regions and relying on different dietary systems. These instances are rare and do not constitute a distinct population group, a pattern consistent with other Bronze Age sites in the Southern Trans-Urals. The characteristics of the burial rites and the style of funerary ceramics indicate the integration of these individuals into Alakul society, suggesting diverse pathways in the formation of social groups in the Bronze Age.

We presents the results of studying the rocks used in the construction of a port berth of the city of Phanagoria. It is shown that in the 5th–3rd centuries BC, Phanagoria received large quantities of building stone of various types from the Black Sea coast of Turkey (the cities of Sinop, Trabzon, and Hopa) and the coasts of the Aegean Sea (Aegina and Rhodes). The expediency of such deliveries was due to an acute shortage of building stone on the Taman Peninsula and the need for Phanagoria’s residents to create the necessary port infrastructure.

A study of the design and removable wooden elements of a two-part cabinet (four doors) from the collection of the Pushkin Museum of Fine Arts is presented. The cabinet is made in the style of the second French Renaissance of the Burgundian-Lyon school of the late 16th–early 17th centuries with renovation in the 19th century. X-ray tomography studies reveal areas of natural damage to the wood material caused by woodworm, the methods for joining the door parts, and areas of later modifications of the design. According to infrared (IR) spectroscopy data, it is established that all door parts are made of hardwood, presumably walnut.

The chemical composition of the metal of the staters of the Bosporan King Rhescuporis V with the date ΔΞФ (564 Bosporan era = AD 267/8) is studied. For the first time, the presence of chlorine is detected not only on the surface of coins, which is associated with the technique of using special silvering pastes based on silver chlorides, but precisely in the core of the coin, which is rich in copper. The discovery of copper chloride in the core of the coin suggests that the raw material for the coinage alloy could be metal from oxidation zones of copper deposits in the steppe zone or deserts, or deposits located near the Black Sea coast. Similar deposits with chlorine-containing copper ores, which were mined in ancient times, are known in the Eastern Black Sea region, the Caucasus, Anatolia, the Urals, and Kazakhstan.