Determining the location of damage in electrical networks 35-10-6 kV by an analytical method based on matrix equations of the 3rd degree with respect to voltages

The article investigates an analytical method for determining the fault location in 35 kV, 10 kV and 6 kV networks based on thirddegree matrix equations for voltages. The method is remote, with doublesided measurement, according to the emergency mode parameters, the mode parameters are voltages and currents at the beginning and at the end of the line. The case is considered when the errors in determining the location of the damage are calculated theoretical and, as shown by the calculations, are only 1% both for metal closures and for pair closures through the contact resistance. Actual errors will depend on the accuracy classes of current transformers, voltage transformers, voltmeters and ammeters, for example: 0.2 - 0.5 - 2.0 - 5.0. The case is considered with an error of ±5%. The annual economic effect per 1 feeder with a really possible error of 5% is 170 thousand rubles when replacing only the method and 230 thousand rubles when replacing both the method and the device. For 1000 feeders, the annual economic effect will be 170 million rubles and 230 million rubles, respectively. Thus, the considered analytical method for determining the location of damage is effective both from a technical and economic point of view

Molecular remodeling of ion channels, exchangers and pumps in atrial and ventricular myocytes in ischemic cardiomyopathy

Existing molecular knowledge base of cardiovascular diseases is rudimentary because of lack of specific attribution to cell type and function. The aim of this study was to investigate cell-specific molecular remodeling in human atrial and ventricular myocytes associated with ischemic cardiomyopathy. Our strategy combines two technological innovations, laser-capture microdissection of identified cardiac cells in selected anatomical regions of the heart and splice microarray of a narrow catalog of the functionally most important genes regulating ion homeostasis. We focused on expression of a principal family of genes coding for ion channels, exchangers and pumps (CE&P genes) that are involved in electrical, mechanical and signaling functions of the heart and constitute the most utilized drug targets. We found that (1) CE&P genes remodel in a cell-specific manner: ischemic cardiomyopathy affected 63 CE&P genes in ventricular myocytes and 12 essentially different genes in atrial myocytes. (2) Only few of the identified CE&P genes were previously linked to human cardiac disfunctions. (3) The ischemia-affected CE&P genes include nuclear chloride channels, adrenoceptors, cyclic nucleotide-gated channels, auxiliary subunits of Na(+), K(+) and Ca(2+) channels, and cell-surface CE&Ps. (4) In both atrial and ventricular myocytes ischemic cardiomyopathy reduced expression of CACNG7 and induced overexpression of FXYD1, the gene crucial for Na(+) and K(+) homeostasis. Thus, our cell-specific molecular profiling defined new landmarks for correct molecular modeling of ischemic cardiomyopathy and development of underlying targeted therapies

Effect of Cavβ Subunits on Structural Organization of Cav1.2 Calcium Channels

BACKGROUND:Voltage-gated Ca(v)1.2 calcium channels play a crucial role in Ca(2+) signaling. The pore-forming alpha(1C) subunit is regulated by accessory Ca(v)beta subunits, cytoplasmic proteins of various size encoded by four different genes (Ca(v)beta(1)-beta(4)) and expressed in a tissue-specific manner. METHODS AND RESULTS:Here we investigated the effect of three major Ca(v)beta types, beta(1b), beta(2d) and beta(3), on the structure of Ca(v)1.2 in the plasma membrane of live cells. Total internal reflection fluorescence microscopy showed that the tendency of Ca(v)1.2 to form clusters depends on the type of the Ca(v)beta subunit present. The highest density of Ca(v)1.2 clusters in the plasma membrane and the smallest cluster size were observed with neuronal/cardiac beta(1b) present. Ca(v)1.2 channels containing beta(3), the predominant Ca(v)beta subunit of vascular smooth muscle cells, were organized in a significantly smaller number of larger clusters. The inter- and intramolecular distances between alpha(1C) and Ca(v)beta in the plasma membrane of live cells were measured by three-color FRET microscopy. The results confirm that the proximity of Ca(v)1.2 channels in the plasma membrane depends on the Ca(v)beta type. The presence of different Ca(v)beta subunits does not result in significant differences in the intramolecular distance between the termini of alpha(1C), but significantly affects the distance between the termini of neighbor alpha(1C) subunits, which varies from 67 A with beta(1b) to 79 A with beta(3). CONCLUSIONS:Thus, our results show that the structural organization of Ca(v)1.2 channels in the plasma membrane depends on the type of Ca(v)beta subunits present

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements