Nanotechnologies in Russia最新文献

The pigments and binders of ruined pre-Mongolian wall paintings (12th century) of four architectural monuments in Veliky Novgorod are studied. The examined fragments are from the Church of the Annunciation on Gorodishche, St. George’s Cathedral of the Yuriev Monastery, St. Nicholas Cathedral at Yaroslav’s Court, and lifting material from the bottom of the Volkhov River, presumably related to St. Sophia Cathedral. The mineral composition of the painted layers of the samples is determined using scanning electron microscopy with energy-dispersive X-ray microanalysis and X-ray diffraction analysis using synchrotron radiation. Using infrared (IR) spectroscopy and gas chromatography with mass spectrometry, an organic binder is identified in several samples, and the binder for all four monuments was the same: protein products from chicken egg. Thus, it is shown that two painting techniques were used on the studied fragments: fresco and a secco.

A buckle and a belt plate decorated with glass inlays using the cloisonné technique were found in a male burial of the first half of the sixth century at a Gothic–Alanian burial ground near Luchistoe village (southwestern Crimea). The items are rare for this region. Analysis of the alloy composition of the belt set parts is performed, and the manufacturing process is reconstructed. It is established that the parts of the belt set are made of materials of different composition based on copper. The plaque is made of copper lightly alloyed with tin, the buckle tongue is cast from brass lightly alloyed with zinc, the frame is made of bronze lightly alloyed with lead, and the body of the shield plate around the perimeter is made of a material containing both bronze and brass components. According to the research results, the set is attributed to the products of Byzantine workshops that operated in the Early Middle Ages in the Eastern Mediterranean.

The work presents the results of studying the alloy composition of metal items of the final period of the Middle Bronze Age (the Kostroma stage of metal production in the northwestern Caucasus) found near the Natukhaevskaya stanitsa in the Krasnodar krai using X-ray fluorescence. It is found that the items from the Second Natukhaevskaya hoard under study were made of low-alloy arsenic bronze, in which the arsenic content ranges from 0.37% to 1%. They can be attributed to the Kuban center of metallurgy and metalworking, which is characterized by an almost complete absence of tin in the alloy. Taking into account the items from the hoard under study, the total number of bronze sickles from the Taman and Anapa-Novorossiysk hoards already exceeds three dozen (32). This indicates that already in the final Middle Bronze Age, high-quality and carefully processed harvesting tools were being used by the population of Taman and the low-mountain coastal Black Sea region, probably when harvesting cereal crops, as well as preparing hay for the winter stall keeping of livestock.

This article describes the diet of the Alakul miners from the Bronze Age in the Vorovskaya Yama mine in the Southern Trans-Urals (17th–16th centuries BCE) based on an archaeozoological analysis of animal bones, a GC-MS study of burnt-on remains on ceramics, the reconstruction of vessel volumes, and the planigraphic distribution of kitchen waste. It also presents a comparative description of the dietary practices of miners and inhabitants of non-specialized settlements of the same period. Similarities between the diets include the predominance of cattle and ovicaprid meat, the use of similar cutting up carcasses and cooking methods, and the use of similar types of cooking utensils. However, there are also some differences, such as the dependence of the mining settlement on outside food supplies, the lack of traces of hunting in the settlement, the absence of miniature and very large vessels, and a significant number of burnt-on remains on vessels. Additionally, there is an area designated for the disposal of animal bones. The data suggest the emergence of a separate group of miners, while maintaining close connections with the original community.

This work continues a series of publications devoted to the results of studying materials from a shipwreck of the 1st century BC that were found in the ancient seaport of Phanagoria (Taman Bay, Sea of Azov). Animal hair samples and bird feathers included in the composite protective coatings of the hull of a ship of the Pontic king Mithridates VI Eupator are studied. Using light and scanning electron microscopy, the species of ancient animals and birds whose hair and feathers were used to make the composite clay-fiber coating are determined.

The Raman spectra of ink from two 15th-century manuscripts and replicated inks simulating formulations common in medieval Russian written culture are analyzed. Two main sources of tannin, gall nuts and alder bark, are used in the preparation of the replicated inks. The sets of bands in the Raman spectra of ink from manuscript KB 295/552 on three pages are found to be similar to those of model inks made from gall-nut tannins. Based on the presence of a band at 980 cm^–1 in the spectra of ink from manuscript KB 295/552 on three pages, an assumption is made about the use of alum or iron sulfate in the formulation of the ink. Based on the observed bands in the Raman spectra of the ink in manuscript FI-792, it is concluded that the ink on page 12 was made using gall-nut tannins, while the ink on pages 41 and 157 was made using a bark decoction. In addition, due to deterioration of the original iron-gall ink, many letters on various pages were retraced with carbon-black-based ink.

The physical and chemical properties (size, ξ potential) of aqueous solutions of chitosans with different molecular weights (6, 26, and 50–80 kDa) and different degrees of deacetylation are studied using the dynamic light scattering method. Liposomes from a mixture of phosphatidylcholine and phosphoethanolamine (S75) with different types of chitosans adsorbed on the surface are also characterized and their stability is studied. Conditions for the preparation of S75 liposomes coated with chitosan and having a positive ζ potential, in the absence of free (not bound to the liposome surface) chitosan in the aqueous medium are selected. S75 liposomes with a lipid concentration of 2 mg/mL coated with 6 kDa chitosan (0.05%) and containing carotenoid astaxanthin esters (0.01 and 0.05 mg/mL) are obtained and characterized. The stability of astaxanthin esters in the liposomes is studied. The most stable are S75 liposomes containing 0.01-mg/mL astaxanthin esters and coated with 0.05% 6 kDa chitosan.

It is shown that the treatment of electronic textiles in a solution of carbon dots leads to quenching of its luminescence. The luminescence intensity of electronic textiles with mildly oxidized graphene decreases by 55%, electronic textiles with graphene oxide by 80%, and the initial textile by 100%. Of particular interest is the possibility of modifying the initial textile with a composite based on polyvinyl alcohol and carbon dots, which results in the appearance of luminescence in the red region of the spectrum with a maximum intensity at 588 nm. The obtained results showed that carbon dots strongly interact with electronic textiles, which can be used to tune the luminescent properties of electronic textiles containing graphene oxide.

The design of spherical ferrogels (FG) for biomedical applications to improve their biocompatibility and visualization is described. Hydrogels and FG with a diameter of ~2.2 mm are synthesized based on calcium alginate and maghemite magnetic nanoparticles (MNPs). The elastic properties of the samples are determined by solving the Hertzian contact problem for the deformation of spheres, and the echogenicity is determined using a medical ultrasound device based on the intensity of the echo signal reflected from the spheres (brightness). The addition of 10-wt-% MNPs to the gel is accompanied by a significant increase in Young’s modulus, brightness at the gel–water boundary, and the emergence of clear visualization of the FG contents. It is likely that the increase in echogenicity at the gel–water boundary reflects the effect of MNPs on the elasticity of FGs, and the echogenicity of the FG contents is associated with the aggregation of MNPs in the polymer.