Gram-Negative Bacteria Salmonella typhimurium Boost Leukotriene Synthesis Induced by Chemoattractant fMLP to Stimulate Neutrophil Swarming

Leukotriene synthesis in neutrophils is critical for host survival during infection. In particular, leukotriene B4 (LTB4) is a powerful neutrophil chemoattractant that plays a crucial role in neutrophil swarming. In this work, we demonstrated that preincubation of human neutrophils with Salmonella typhimurium strongly stimulated LTB4 production induced by the bacterial chemoattractant, peptide N-formyl-L-methionyl-L-leucyl-l-phenylalanine (fMLP), while the reverse sequence of additions was ineffective. Preincubation with bacterial lipopolysaccharide or yeast polysaccharide zymosan particles gives weaker effect on fMLP-induced LTB4 production. Activation of 5-lipoxygenase (5-LOX), a key enzyme in leukotrienes biosynthesis, depends on rise of cytosolic concentration of Ca2+ and on translocation of the enzyme to the nuclear membrane. Both processes were stimulated by S. typhimurium. With an increase in the bacteria:neutrophil ratio, the transformation of LTB4 to ω-OH-LTB4 was suppressed, which further supported increased concentration of LTB4. These data indicate that in neutrophils gathered around bacterial clusters, LTB4 production is stimulated and at the same time its transformation is suppressed, which promotes neutrophil swarming and elimination of pathogens simultaneously.

Ensuring an effective voltage regime in the electrical network when powering ships of the technical fleet and floating objects from the shore

The article deals with topical issues of reducing the asymmetry of linear voltages in the electrical networks of water transport enterprises. Asymmetric modes in the electrical network are researched, which defined the need for automated determination of conductive electromagnetic disturbance. A mathematical description of the occurrence process and strategy for determining the conductive low-frequency electromagnetic disturbance by the voltage asymmetry coefficient in the reverse sequence are presented. The parameters of this coefficient are described: mathematical expectation, standard deviation, probability of occurrence during the calculation period. A mathematical model is obtained that represents a conductive electromagnetic disturbance and explains the probability of its occurrence. A method of automated determination of conductive electromagnetic disturbance has been developed. A software product is presented (certificate of registration No. 2016661752), which allows processing the voltage coefficients obtained as a result of measurements in the reverse sequence. The conductive disturbance is determined for the purpose of suppression and ensuring electromagnetic compatibility. To ensure an effective mode by powering ships from the shore and to increase the efficiency of power transmission, a strategy for voltage symmetry in the electrical network is presented.

Concordance of acquired mutations between metastatic lesions and liquid biopsy in metastatic colorectal cancer

Aim: To evaluate whether PCR-reverse sequence-specific oligonucleotide can examine the concordance between liquid biopsy and metastatic lesions with acquired resistance. Materials & methods: We examined acquired mutations in chemoresistant lesions and blood obtained from four patients with RAS wild-type metastatic colorectal cancer who underwent treatment with anti-epidermal growth factor receptor antibodies. Results: In one patient, metastatic lesions harbored diverse acquired mutations in KRAS in all seven metastases; the two acquired mutations were detectable in blood collected after the patient acquired resistance. None of the other patients exhibited liquid biopsy mutations, except one, with a BRAF mutation confirmed in primary tumor and peritoneal dissemination. Conclusion: Liquid biopsy based on PCR-reverse sequence-specific oligonucleotide is a successful procedure for capturing acquired mutations with precise information on the RAS mutational spectrum.

A method for Improving the Accuracy of Reactive Power Regulation by a Capacitor Plant

The problem of low accuracy of reactive power regulation by the most common three-component condenser installations in the industry and its impact on the quality of electricity and the efficiency of its consumption and use in industrial power supply systems is considered. To increase the accuracy of reactive power regulation by at least 2.3 times without changing the circuit of the capacitor plant and the number of switching equipment, a new control algorithm is proposed and described in detail. The results of testing a method for regulating reactive power in the Matlab environment based on the proposed algorithm for controlling capacitor blocks with changed parameters are presented. Numerical experiments have shown the possibility of seven-stage regulation, versus three-stage control in known industrial installations. The capacitor unit is switched on by a mains switch and then by thyristor switches without a surge of currents in the capacitors and without an asymmetry of currents in the network. The installation is switched off in the reverse sequence, first by thyristor switches with natural switching, and then by a mains switch without arcing on its contacts.

Analysis of influencing factors affecting the operational reliability of low-voltage asynchronous electric motors

THE PURPOSE. The main purpose of the work is a comprehensive study of external influences that affect the operational reliability of low-voltage asynchronous motors. Attention is focused on the evaluation of the operational reliability of electric motors, the systematization of their operating conditions, with the simultaneous impact of a group of operational factors. Among these factors that are subject to detailed analysis, we will highlight the following: the asymmetry of the stress and its duration, loading of the motor, the temperature of the environment. In this regard, it becomes obvious that the task of improving the operational reliability of low-voltage asynchronous electric motors depends on a qualitative study of the quantitative values of external influencing factors in various operating modes of electric motors. METHODS. The tool for implementing this task is a visual and effective simulation tool Simulink interactive programming environment Matlab. RESULTS. The research was performed on an asynchronous electric motor with a short-circuited rotor AIR160S8 with PH = 7,5 kW, rated speed n = 1500 rpm. The physical processes of the electric motor under study were modeled by changing the following parameters: the coefficient of stress asymmetry in the reverse sequence (K2U), the load on the motor shaft (Kz), the ambient temperature (tocr), and the duration of stress asymmetry in the reverse sequence (T). Based on the obtained simulation results, groups of planes of the studied quantities are constructed. CONCLUSION. A set of studies performed using the Matlab software package allowed us to estimate the limits of acceptable values of external factors and identify the area of acceptable operation of asynchronous motors. The analysis and discussion of the research results were carried out, and measures were proposed to improve the operational reliability of asynchronous electric motors.

Analysis of influencing factors affecting the operational reliability of low-voltage asynchronous electric motors

THE PURPOSE. The main purpose of the work is a comprehensive study of external influences that affect the operational reliability of low-voltage asynchronous motors. Attention is focused on the evaluation of the operational reliability of electric motors, the systematization of their operating conditions, with the simultaneous impact of a group of operational factors. Among these factors that are subject to detailed analysis, we will highlight the following: the asymmetry of the stress and its duration, loading of the motor, the temperature of the environment. In this regard, it becomes obvious that the task of improving the operational reliability of low-voltage asynchronous electric motors depends on a qualitative study of the quantitative values of external influencing factors in various operating modes of electric motors. METHODS. The tool for implementing this task is a visual and effective simulation tool Simulink interactive programming environment Matlab. RESULTS. The research was performed on an asynchronous electric motor with a short-circuited rotor AIR160S8 with PH = 7,5 kW, rated speed n = 1500 rpm. The physical processes of the electric motor under study were modeled by changing the following parameters: the coefficient of stress asymmetry in the reverse sequence (K2U), the load on the motor shaft (Kz), the ambient temperature (tocr), and the duration of stress asymmetry in the reverse sequence (T). Based on the obtained simulation results, groups of planes of the studied quantities are constructed. CONCLUSION. A set of studies performed using the Matlab software package allowed us to estimate the limits of acceptable values of external factors and identify the area of acceptable operation of asynchronous motors. The analysis and discussion of the research results were carried out, and measures were proposed to improve the operational reliability of asynchronous electric motors.

IDENTIFICATION ERROR OF UNBALANCE VOLTAGE SOURCES IN POWER SUPPLY SYSTEMS BY THE DISTORTING NODAL CURRENT CRITERION

One of the properties of electrical energy, that causes significant economic losses for both suppliers and consumers of electricity, is voltage unbalance. The most universal criterion for identifying voltage unbalance sources is the nodal distorting current. The accuracy of its determination depends on the method of measurement organization and is characterized by the greatest error for the local approach. The reason for this lies in an approximate method for determining the equivalent circuits of consumers of electrical energy and their parameters when measuring the parameters of the network operation mode only at one point of common connection to the power supply system. Analysis of the influence of approximate equivalent circuits and their parameters on the determination of the nodal distorting current showed that adequate identification of the sources of voltage unbalance distortion is possible only in the reverse sequence. At the same time, it is difficult to accurately determine the error in calculating this criterion in real time measurements due to the presence of additional unknowns that are required for its calculation. Based on this, it is proposed to carry out an upper estimate of this error. This required the introduction of additional functions with the search for their maximum under the given constraints. In addition, the uncertainty associated with the non-zero value of the identification criterion for a non-asymmetric consumer of electricity was taken into account that led to the need to introduce a dead zone for it. As a result of the studies carried out, expressions were obtained for an upper estimate of the error in determining the criterion for identifying sources of voltage symmetry distortion in the reverse sequence and determining its dead zone in real time measurements in relation to three-phase three- and four-wire power supply systems.

Diversity as Immigration Governmentality: Insights from France

This article aims to examine the ambiguous connections between immigration, diversity politics, and white supremacy in twenty-first century France by considering them both theoretically and empirically. It offers to elucidate the ways in which the recent growth and expansion of the diversity framework in Europe and France have gone hand in hand with the unfolding of particularly repressive migration policies, hostility towards migrants, and outright institutional racism. Drawing on qualitative longitudinal data on corporate diversity policies, based on semi-structured interviews (n = 86), the article also relies on secondary data analysis from other policy domains (migration, education, urban development), favoring a globally comparative lens. First, I engage with some major trends of the recent reinvention of diversity at the EU level, underscoring the ambiguous effects of Europeanizing antiracism and nondiscrimination in a reverse sequence; second, I critically revisit the ways in which this European reinvention, combined with the legal universalization of equal opportunity, has given rise to the articulation of “white diversity” conceptions; then I explore their even more problematic nexus with governing migration. Finally, I call for a critical scrutiny of how universalized and thoroughly individualized notions of diversity diversification may emerge as instrumental in upholding hegemonic whiteness, in the fields of race relations as well as international migration.