PLLA scaffold modification using magnetron sputtering of the copper target to provide antibacterial properties

Using the electrospinning method, we produced biodegradable scaffolds from poly-l-lactide acid polymer (PLLA - poly-l-lactide acid). Using DC magnetron sputtering of the copper target we modified the surface of the scaffolds. For investigate scaffolds morphology, structure and elemental composition were used scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis. The results of scanning electron microscopy reveal that scaffolds consist of chaotically located fibres. The diameters of fibres range from 0.8 to 2 μm. Initially amorphous scaffold after modification has crystalline structure. The count of oxygen and copper with modification is increased, but count of carbon decreased. For the investigation of the scaffolds wetting ability were used glycerol and water. The wetting angles for the both liquids were similarly comparable. The values for the wetting angles range from 114 ± 5° to 125 ± 5°, what indicated that scaffolds had hydrophobic properties. Testing for antibacterial features indicated that the modified scaffolds are capable to have a bacteriostatic effect. Compared to the number of bacteria cultured without scaffold (11.8 ± 1.26 CFU×104/ml), two modified samples have bacteriostatic properties (reducing the number of bacteria on 30 and 50%). Economically effective method PLLA scaffolds modification could be used for creating low-cost wound dressings with antibacterial properties

Buryat Language in Multi-Ethnic Buryatia: Functional Distribution, Language Competence, Motivations

The analysis of some of the results of a sociolinguistic survey conducted in 2020 in the Republic of Buryatia is presented in the article. A feature of this survey is a large sample (1289 respondents of Buryat and Russian nationality) and a wide coverage of the problems of the functioning of the Buryat language. A comparative analysis with the results of previous surveys showed that the level of proficiency in the native language of the Buryats and the degree of its use in various areas of communication continues to decline. A positive and tolerant attitude to the study of the Buryat language on the part of the Russian population was revealed, while at the same time a low assessment of its “necessity” by both Russians and Buryats. A causal relationship has been established between the compulsory teaching of the Buryat language in schools and an increase in the number of people who read and write in Buryat. It was revealed that when choosing a language of study, territorial motivation is the main one for Russians, for Buryats it is the motivation of ethnic identity. At the same time, the ethnoidentification factor has recently lost its significance, which is manifested in a high level of dual (ethno) linguistic identification and a decrease in the number of Buryats who consider the Buryat language to be their native language