The influence of characteristics of electrochemically activated aqueous processing mediums in the treatment of fur skins with different contents of fatty substances was investigated. The use of electroactive water, namely anolytes and catholytes, forgoing antiseptics or surface-active materials, helped to restore the hydration of fur skins and to remove from them soluble proteins, carbohydrates and fatty substances. The activating effect of anolyte and catholyte in solutions of water on the processes of treating raw furs is explained by their special physical and chemical properties, namely the presence of free radicals, ions and molecules of water which easily penetrate cells’ membranes and into the structure of non-collagen components and microfiber structure of dermic collagen. The stage of lengthy acid and salt treatment is excluded from the technical treatment as a result of using electroactivated water with high oxidizing power. A low-cost technology of processing different kinds of fur with the use of electroactivated water provides for substantial economy of water and chemical reagents, a two to threefold acceleration of the soaking and tanning processes and creation of highly elastic fur materials with a specified set of physical and chemical properties. At the same time the technology of preparatory processes of fur treatment excludes the use of such toxic antiseptics as formalin and sodium silicofluoride, which gives grounds to regard it as ecologically safe.
Improving the collagen structure, which was impacted by the curing process, increases the efficiency of all subsequent structural transformations during leather production and results in the formation of a high-quality leather material. Herein, we studied the process of soaking green-salted horsehides in electrochemically activated aqueous solutions and the properties of resulting chrome-tanned leather. It was found that the process of soaking horsehides can be effectively carried out using an electrochemically activated solution (ECAS) – a mixture of catholyte and anolyte at a volume ratio of 5 : 1. Using this soaking solution, sodium sulfide (an environmentally harmful reagent), sodium carbonate, and detergent can be completely excluded from the technological solution. The use of ECAS at the soaking stage effectively regenerates the water balance of horsehides while maintaining a stable pH during the soaking process and increases the efficacy of liming and all subsequent processes. Considering the prominent structural differences (density and thickness) between the front and shell of horsehide, the developed method, which utilize ECAS for soaking, allows the entire process to be carried out on uncut horse hides instead of processing two parts separately, which is normally required. The chrome-tanned leather produced by the developed method in semi-industrial conditions has elastic-plastic properties which are superior compared to the leather produced by current technology. The developed method also results in increasing the area yield by 2.5%. The resulting elastic leather can be used for manufacturing a variety of articles, including clothing, accessories, and footwear.
Introduction. The frequency of infective endocarditis (IE) in children with congenital heart disease (CHD) is 15– 140 times higher than that in the overall population and varies from 2 to 18% according to different authors. The aim. To define the main groups of causative agents of infective endocarditis in children and adults in order to build up an antibiotic treatment algorithm. Materials and methods. The analysis of examination findings and treatment outcomes in 124 patients was conducted from 2014 to 2019. These patients received medical treatment at the Ukrainian Children`s Cardiac Center (UCCC), Kyiv. The patients were divided into two groups by age: group 1 included children aged from 6 days to 18 years (62 [50.0%]), group 2 comprised adults aged from 18 to 79 years (62 [50.0%]). Results and discussion. Forty-nine isolates were recovered from 124 patients during the analysis of microbiological study results. The frequency of bacterial IE causative agents was 26 (41.9%) in group 1, and 17 (27.4%) in group 2. Comparative analysis of the spectrum of IE pathogens revealed differences in the two study groups. Coagulase-negative staphylococcus was the most common causative agent in group 1 (46.7% of all isolated strains; n = 12) and in group 2 (44.4%; n = 8). Staphylococcus aureus in children was detected in 5 (8.1%) cases, whereas in adults only in 2 (11.1%) cases. Pathogens of the Enterococcus spp. family (E. faecalis) were recovered in both study groups: in 6.5% (n = 2) and 16.6% (n = 3) of the patients, respectively. Gram-negative flora was detected in 3 (9.7%) patients of group 1 and, in 2 (11.1%) patients of group 2. Fungal flora was more commonly found in children (7 [22.6%] cases represented by the Candida family), whereas in adults only 1 (5.6%) case represented by the Mucor family was revealed. Conclusions. Etiological structure of the infective endocarditis pathogens in both groups was represented mainly by gram-positive bacteria, with S. epidermidis (24.5%) being the most essential. The changes were revealed in the species composition of the pathogens in group 1 with fungal microflora dominance: Candida parapsilosis in 9.7%, C. albicans and C. famata in 6.5% of the total number of plated cultures in this group. The difference in surgical operations due to possible IE in both groups was established based on the specific features of operations determined by the age factor.
УДК 675.023.6 ФЕРМЕНТНА ОБРОБКА ШКІРЯНОГО НАПІВФАБРИКАТУ В ПРОЦЕСІ М'ЯКШЕННЯ А. Г. Д а н и л к о в и ч Доктор технічних наук, професор Кафедра технології шкіри та хутра*
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