Light-scattering properties of microorganisms Desulfuromonas acetoxidans by influence of silver

The article deals with the concentration changes and relative content of bacterial cells of Desulfuromonas acetoxidans in the intervals of sizes 0.2–2.0 µm under the influence of nano silver particles. Correlation between these changes of light-scattering properties of bacterial cells and growth abilities of bacteria Desulfuromonas acetoxidans under inflence of silver nanoparticles and ions has been shown. The purpose of the work was to research the intensity of processes the change of indexes of the antioxidant system the cells of Desulfuromonas acetoxidans at influence of silver nanoparticles and silver nitrate. The influence of various concentrations of silver nanoparticles and silver nitrate on enzymatic activity of catalase and reduced glutathione synthesis by Desulfuromonas аcetoxidans cells under their cultivation with fumarate addition and with absence of sulphur has been determined. Specific catalase activity increased with enhancing of concentration and duration of bacterial cultivation under the addition of this salt. The highest specific catalase activity was determined on the second day of bacterial growth under the influence of all concentration range of investigated metal salt. The reduced glutathione content under silver nitrate and silver nanoparticles exposure varied depending on the cultivation time and metal concentration. The maximum reduced glutathione content has been observed. The result of catalase activity changes  and glutathione content changes of sulfur-reducing D. acetoxidans bacteria cell-free extracts and has been investigated under the influence of different concentrations of Ag nanoparticles during four days of cultivation has been investigated

Барботажное активирование растворов и роль этого явления в природных и технологических процессах

Розглянуті можливі молекулярні механізми структурування води та міжфазної поверхні газ/вода у розчинах. Показано, що барботажна активація (БА) відбувається шляхом підвищення структурної температури води і веде до підвищення хімічної активності молекул Н2О та розчиненого кисню. Встановлено, що БА має квазірівноважний характер. Тому при зовнішніх впливах на лініях змін рН і Eh появляються характерні піки або сходинки, які можна використовувати для дослідження взаємодії розчинів з різними твердими матеріалами. Запропонована модель структурних перетворень, яка може пояснити, чому негативно заряджені бульбашки газів утворюють позитивно заряджені краплинки морських аерозолів.The possible molecular mechanisms of water structuring and between the surfaces of gas/water in the solutions are considered. It was shown that barbotage activation (BA) occurs by increasing the structural temperature of water and causes increasing of chemical activity of H2O and dissolved oxygen. It is established that BA has quasi equilibrium character. Therefore external influences on the lines of changes of pH and Eh characteristic peaks or steps appear that can be used to investigate the interaction of solutions with different solid materials. The proposed model of structural transformation may explain why negatively charged bubbles of gas form positively charged droplets of sea spray.Рассмотрены возможные молекулярные механизмы структурирования воды и междуфазной поверхности газ/вода в растворах. Показано, что барботажная активация (БА) происходит путем повышения структурной температуры воды и ведет к повышению химической активности молекул Н2О и растворимого кислорода. Установлено, что БА имеет квазиравновесный характер. Поэтому при внешних воздействиях на линиях изменений рН и Eh появляются характерные пики или ступеньки, которые можно использовать для исследования взаимодействия растворов с различными твердыми материалами. Предложена модель структурных преобразований, которая может объяснить, почему отрицательно заряженные пузырьки газов образуют положительно заряженные капельки морских аэрозолей

The role of students’ individual work in the formation of professional competences of future doctors.

Modern requirements for training of high-skilled specialists require the implementation of international medical and educational standards in the educational and integrative process. Formation of cognitive activity, pursuance of professional development, the necessity to correspond to world standards medical students’ of gained knowledge. Medical students’ individual work is very important for medical students’ education because it helps to systematize and use knowledge that was gained in practical classes. The aim of the work – to analyze the forms of students’ individual work, used at in the Department of Internal Medicine 2 and Phthisiology, in order to improve the educational process and to form the future doctor’s medical judgment, their ability to self-improvement and self-education. The recommended hours attempted for students’ individual work is 90 out of the total of 240 hours assigned to the discipline in teaching the module “internal diseases” for the 5th year students at the Depertment of Internal Medicine 2 and Phthisiology. In studying the discipline of "internal diseases" in the 5th year one of the main tasks of medical student’s occupation training is mastering ability of assimilation on his own, of knowledge and refresh it, and then to use knowledge effectively in the future career. The difference of the individual work lies in the fact that students can study individually choosing the necessary kind of extracurricular activity according to their interests. In addition, the lack of strict grading by the teacher has more advantages compared to practical classes. The curriculum, the teacher’s tasks and methodological materials determine the content of the individual work. The article presents the three main directions of students’ individual work in teaching discipline of "internal diseases" for students of the 5th year as: students’ individual work in classroom learning, students’ individual work individual work under the teacher’s supervision. When discussing the results of individual work, students learn to think critically, communicate with each other, and make their own well-thought-out (educated) decision. Well-structured process of the individual work encourages medical students to its qualitative fulfillment and it is a significant motivation for further professional growth. Significant reserves to increase its efficiency inherent in the use of modern computer technology. Medical students’ individual work should be considered as one of the necessary stages of a modern doctor training. The latest information technologies and individual scientific projects adoption into the educational process leads to efficiency improvement and it forms new future doctor’s professional competences

The influence of xylate on the volumo- and osmoregulatory function of the kidneys in diabetes complicated by the syndrome of endogenous intoxication of purulent-septic origin.

The combination of insulin-independent diabetes mellitus with endogenous purulent-septic genesis syndrome is a fairly common nosology. The search for ways to optimize the results of its treatment, after screening observations, led to the expediency to consider the pharmacodynamic aspects of the action of polyhydric alcohols through the prism of homeostatic support functions. Detailing this direction was focused on the consideration of the action of xylate mediated through the volumetric and osmoregulatory function of the kidneys. The effect of xylate on the volumo-and osmoregulatory function of the kidneys in insulin-independent diabetes mellitus complicated by the syndrome of endogenous intoxication of purulent-septic origin was investigated. The study group consisted of 53 patients with insulin-independent diabetes mellitus complicated by the syndrome of endogenous intoxication of purulent-septic origin (IDCSEI). Under the condition of infusion loading (3 ml/kg/h for three hours) with Ringer's solution or xylate within the fragments of planned intensive care, indicators characterizing the state of the volumo- and osmoregulatory function of the kidneys were investigated. The loading with Ringer's solution in patients with IDCSEI increases sodium clearance by 260±47.8% (Δ, p=0.020), without changing the concentration of sodium ions in the blood plasma and filtration fraction and purifying the blood plasma from osmotically active substances 147±46.9% ( Δ, p=0.011). Extension of the extracellular space by infusion solutions by 3 ml/kg/h for three hours in patients with insulin-dependent diabetes mellitus, complicated by the syndrome of endogenous intoxication by purulent-septic genesis, activates volumetric and osmoregulatory function. Extension of extracellular space with infusion solu­tion by 3 ml/kg/h for three hours in patients with insulin-independent diabetes mellitus activates volumo- and osmo­regulatory function. Activation of volumetric function occurs by reducing the reabsorption of sodium and water in the proximal nephron, without increase of glomerular filtration rate, increasing the distal transport of sodium and water

Вплив ентерококів на чутливість умовно-патогенної мікрофлори до антибіотиків

The article presents the results of determining the ability of enterococci isolated from traditional Carpathian cheese to affect the antibiotic sensitivity of opportunistic gram-positive and gram-negative microorganisms, particularly test strains of S. aureus and E. coli. It was found that enterococci had different effects on the sensitivity of opportunistic pathogens to different groups of antimicrobial drugs. In particular, co-cultivation of S. aureus with enterococci did not affect the change in sensitivity to amoxicillin and glycopeptides (vancomycin). In the study of aminoglycosides, it was found that the sensitivity of staphylococcus to gentamicin increased when co-cultured with strains of E. faecium SB12 and E. durans SB18 by 14.8 (P < 0.05) and 13.1 % (P < 0.01), respectively. The tendency to increase the sensitivity of staphylococcus to streptomycin was also observed in cultivation with E. faecium SB12 and E. durans SB18. Concerning macrolides, in particular erythromycin, only one strain of E. durans SB18 caused a 3.2 % increase in staphylococcal susceptibility, and a probable increase in staphylococcal susceptibility was found in fluoroquinolones. In particular, the sensitivity of staphylococci to enrofloxacin and norfloxacin increased by 7.6 and 5.3 %, respectively (P < 0.05). The antibiotic susceptibility of E. coli with enterococci found a slight increase in sensitivity to penicillins when co-cultured with strains of E. faecium SB12 and E. durans SB18. Thus, the antibiotic sensitivity of E. coli increased by 5.1 and 7.5 %, respectively. In addition, the sensitivity of E. coli to aminoglycosides (streptomycin) increased under co-cultivation with E. durans SB6 and SB18 strains by 7, 5, and 9.7 %, respectively (P < 0.05). In addition, when co-cultured with E. faecium SB12 and E. durans SB18 strain, the sensitivity of E. coli to enrofloxacin increased by 7.6 and 5.3 %, respectively (P < 0.05), and to norfloxacin – by 3, 8, and 4.9 %. Co-cultivation with E. durans SB6 and E. faecium SB12 strains increased the sensitivity of E. coli to ẞ-lactam antibiotics, in particular, cefazolin by 9.1 % (P < 0.05), and in co-cultivation with E. durans SB18 – at 14.1% (P < 0.01).У статті наведено результати визначення здатності ентерококів, виділених з традиційної карпатської бринзи, впливати на антибіотикочутливість умовно-патогенних грампозитивних та грамнегативних мікроорганізмів, зокрема тест-штамів S. аureus та E. сoli. Було встановлено, що ентерококи по-різному впливали на підвищення чутливості умовно-патогенної мікрофлори до різних груп протимікробних препаратів. Зокрема, сумісне культивування S. аureus з ентерококами не впливало на зміну чутливості до амоксициліну та глікопептидів (ванкоміцину). При дослідженні аміноглікозидів встановили, що чутливість стафілококу до гентаміцину зростала за умови спільного культивування із штамами E. faecium SB12 та E. durans SB18 відповідно на 14,8 (Р < 0,05) та 13,1 % (Р < 0,01). Тенденцію до підвищення чутливості стафілококу до стрептоміцину відзначали також при культивуванні із E. faecium SB12 та E. durans SB18. Щодо макролідів, зокрема еритроміцину, тільки один штам E. durans SB18 спричинював підвищення чутливості стафілококу на 3,2 %, а вірогідне підвищення чутливості стафілококу встановили до фторхінолонів. Зокрема, чутливість стафілококу до енрофлоксацину та норфлоксацину підвищувалась відповідно на 7,6 та 5,3 % (Р < 0,05). При вивченні антибіотикочутливості E. coli з ентерококами встановили незначне підвищення чутливості до пеніцилінів за сумісного культивування із штамами E. faecium SB12 та E. durans SB18. Так, антибіотикочутливість E. coli підвищувалась відповідно на 5,1 та 7,5 %. Також чутливість E. coli до аміноглікозидів (стрептоміцину) зростала за умови спільного культивування із штамами E. durans SB6 та SB18 відповідно на 7, 5 та 9,7 % (Р < 0,05). Крім того, за спільного культивування із штамом E. faecium SB12 та E. durans SB18 чутливість E. coli до енрофлоксацину підвищувалась відповідно на 7,6 та 5,3 % (Р < 0,05), а до норфлоксацину ‒  відповідно на 3,8 та 4,9 %. Спільне культивування зі штамами E. durans SB6 та E. faecium SB12 сприяло підвищенню чутливості E. coli до ẞ-лактамних антибіотиків, зокрема цефазоліну на 9,1 % (Р < 0,05), а при спільному культивуванні із E. durans SB18 ‒ на 14,1 % (Р < 0,01)

Enzyme-Directed Mutasynthesis: A Combined Experimental and Theoretical Approach to Substrate Recognition of a Polyketide Synthase

Acyltransferase domains control the extender unit recognition in Polyketide Synthases (PKS) and thereby the side-chain diversity of the resulting natural products. The enzyme engineering strategy presented here allows the alteration of the acyltransferase substrate profile to enable an engineered biosynthesis of natural product derivatives through the incorporation of a synthetic malonic acid thioester. Experimental sequence−function correlations combined with computational modeling revealed the origins of substrate recognition in these PKS domains and enabled a targeted mutagenesis. We show how a single point mutation was able to direct the incorporation of a malonic acid building block with a non-native functional group into erythromycin. This approach, introduced here as enzyme-directed mutasynthesis, opens a new field of possibilities beyond the state of the art for the combination of organic chemistry and biosynthesis toward natural product analogues