Synergism of imipenem with fosfomycin associated with the active cell wall recycling and heteroresistance in Acinetobacter calcoaceticus-baumannii complex

The carbapenem-resistant Acinetobacter calcoaceticus-baumannii (ACB) complex has become an urgent threat worldwide. Here, we determined antibiotic combinations and the feasible synergistic mechanisms against three couples of ACB (A. baumannii (AB250 and A10), A. pittii (AP1 and AP23), and A. nosocomialis (AN4 and AN12)). Imipenem with fosfomycin, the most effective in the time-killing assay, exhibited synergism to all strains except AB250. MurA, a fosfomycin target encoding the first enzyme in the de novo cell wall synthesis, was observed with the wild-type form in all isolates. Fosfomycin did not upregulate murA, indicating the MurA-independent pathway (cell wall recycling) presenting in all strains. Fosfomycin more upregulated the recycling route in synergistic strain (A10) than non-synergistic strain (AB250). Imipenem in the combination dramatically downregulated the recycling route in A10 but not in AB250, demonstrating the additional effect of imipenem on the recycling route, possibly resulting in synergism by the agitation of cell wall metabolism. Moreover, heteroresistance to imipenem was observed in only AB250. Our results indicate that unexpected activity of imipenem on the active cell wall recycling concurrently with the presence of heteroresistance subpopulation to imipenem may lead to the synergism of imipenem and fosfomycin against the ACB isolates.

Bactericidal effect of nanostructures via lytic transglycosylases of Escherichia coli

The time profiles of active cell ratios depended on the growth phase and the absence of some lytic transglycosylases of E. coli. Significant cell damage was not found on the autolysis inhibition condition.

Design and Performance Analysis of Active and Passive Cell Balancing for Lithium-Ion Batteries

Electric Vehicles (EV) are growing areas of research since the demand for clean transportation is ever-increasing. Batteries form an integral part of EVs. Battery Management systems (BMS) need to support many features, including charge balancing to improve battery life and longevity. Among passive cell balancing and active cell balancing, the latter provides better battery life and efficiency. Among different active and passive cell balancing techniques, popular techniques like Flyback transformer-based active cell balancing and switched capacitor-based active cell balancing are used. These methods are not only easy to implement but also provide good performance. These balancing circuits are integrated with non-ideal RC models of a lithium-ion battery. The bleed resistor-based passive cell balancing took more than 16000 seconds to reach a 0.01V difference for capacitors with 5F capacitance, whereas the switched capacitor design is estimated to take 500 seconds. The multi-winding flyback active cell balancing system reached a 2% difference in SOC in 1800 seconds. There was a visible increase in time taken for balancing the cells using multi-winding active cell balancing as the cell temperature increased. A 2.32% increase in the time taken for balancing the cells was observed when cell temperature increased from 293K to 313K.

Indices of the body structure and activity of the cardiovascular system in female students in modern professional educational institutions

Introduction. The formation of professional groups occurs under the influence of numerous social, medical, and physiological factors. This phenomenon has been known for a long time, but special attention was drawn to it only in the middle of the last century when the term “healthy worker effect” or self-selection was introduced. Since people with various clinical and physiological indices go to various professions, which affects mortality and morbidity in the future and makes it difficult to assess the impact of professional factors objectively. Later, there were identified several reasons determining the state of health of professional groups, particularly the so-called. “Healthy / unhealthy hiring effect.” Moreover, when comparing different working populations, the health status of workers in some cases depended more on the initial indices of employment than on working conditions. The most common method for evaluating the health status of children and adolescents is the assessment of their physical development, particularly the degree of obesity. An increased level of body fat can negatively affect the health of the cardiovascular system. The choice of a future specialty upon admission of adolescents to professional educational institutions may depend both on hygienic features and the self-assessment of their adaptability to working conditions in future activities. Material and methods. A cross-sectional study was conducted of 141 female students enrolled in the Saratov College of Water Transport, Construction, and Services. During the examination, an anthropometric study, a study of the structure of body mass, and a study of the state of the cardiovascular system were carried out. Results. Body mass analysis found seamstress and hairdresser-trained girls to have lower body fat but higher levels of lean body mass and active cell mass. In contrast, insurance-trained girls and cook-trained girls had increased levels of body fat but lower levels of lean body mass and active cell mass. At the same time, girls who studied insurance and cooks had a higher load on the cardiovascular system. In these two groups, there were higher mean values of blood pressure and heart rate, as well as higher values of the cardiac index, index “rhythm” and index “myocardium”. Conclusion. Signs of latent obesity associated with a deficit in active cell body mass and excess body fat with normal body mass index are found in a significant number of girls entering various specialties of a vocational educational institution. There are found differences in clinical and physiological indices between groups of female adolescents entering various specialties of a vocational educational institution, which can be regarded as signs of the effect of healthy/unhealthy hiring. Trends that arise already at the stage of formation of professional groups can continue in the course of work and affect the state of health in the future.

Current Sensorless Microcontroller-Based Battery Management System with SOC and Active Cell Balancing

Battery management system (BMS) has become an important research topic following the trend and development of the electric vehicle. Although research on Active Cell Balancing, SOC, and current estimation has been carried out, the previous work mostly focused on comparing and developing methods. In this research, we demonstrate the process of designing BMS hardware using a low-cost microcontroller and without using a current sensor. The SOC simulation results produce an RMSE of 0.0832% for the 100% -10% SOC-OCV curve, and the current estimation simulation produces an RMSE of 0.2576 A, while for testing using a 6-ohm pulse load, the RMSE error value is 0.3960 A. The Active Cell Balancing method was successfully performed in simulation with Simulink. Furthermore, our simulation and test results suggest that complex battery models and multiple SOC-OCV curves can be used for better current and OCV estimation results. Our experimental results are also useful to develop a guideline to design a microcontroller-based BMS.