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Existing models for accounting for the “skin effect” in conductors have been examined and analyzed. A mathematical model has been developed that features increased accuracy and allows for the determination of the coefficient of increase in active resistance in relation to direct current resistance k ν ( f ) for conductors of various cross sections, including steel–aluminum wires of the AC brand. A model based on piecewise linear approximation of dependence k ν ( f ) has been developed, taking into account the cross section of the conductors. This model allows for the consideration of additional active power losses due to higher harmonics when the frequency is increased up to 1000 Hz.

To improve the efficiency of existing networks, special mathematical models for assessing the losses and temperature of conductors in real time can be used, with the climatic factors being taken into account. The approximate analytical solution of the nonlinear differential equation of heating and cooling of the insulated conductor with numerical method simulation of heat transfer is proposed comparison in this work. The solution is based on lowering the degree of temperature of the conductor using the least squares method in the integral form. A positive feature of the proposed solution is its universality. It allows the analysis of overhead conductors both with and without insulation. The developed method is almost as accurate as the calculation of the conductor temperature by numerical methods. The reliability of the heat balance equation of overhead power lines at non-stationary thermal mode developed by this method is confirmed by comparison with the results obtained by the finite elements method.

The CRISPR–Cas9 system has significantly advanced genome editing but remains constrained by its requirement for specific protospacer adjacent motifs (PAMs). To overcome this limitation, PAM-relaxed nucleases, including the novel near-PAMless chimeric SpRYc, have been developed. Here, we evaluated SpRYc editing activity across multiple experimental systems, including human HEK293 and CEM-R5 cells, as well as Drosophila melanogaster S2 cells and embryos. In HEK293 cells, SpRYc exhibited broad PAM compatibility, enabling editing at non-canonical PAMs, albeit with reduced and variable efficiency at canonical NGG sites compared to SpCas9. This context dependency was more pronounced in CEM-R5 T cells, where SpRYc activity at endogenous CXCR4 and B2M loci was largely restricted to NGG PAMs. In contrast, unlike SpCas9, SpRYc displayed negligible genome-editing activity in Drosophila embryos in vivo. Notably, the transcriptional activator dSpRYc-VPR showed robust activity in Drosophila S2 cells at both canonical and non-canonical PAMs. Reduced chromatin occupancy of dSpRYc-VPR suggests a balance between expanded PAM recognition and DNA-binding stability, providing a mechanistic explanation for context-dependent performance of SpRYc. Overall, our results highlight that expanded targeting flexibility comes at the cost of variable efficiency, underscoring the need for extensive locus- and context-specific validation of PAM-relaxed genome-editing tools.

Let be a set of primes. A finite group  is a  -group if all prime divisors of the order of  belong to  . Following Wielandt, the -Sylow theorem holds for if all maximal -subgroups of are conjugate; if the -Sylow theorem holds for every subgroup of  then the strong -Sylow theorem holds for  . The strong -Sylow theorem is known to hold for  if and only if it holds for every nonabelian composition factor of  . In 1979, Wielandt asked which finite simple nonabelian groups obey the strong -Sylow theorem. By now the answer is known for sporadic and alternating groups. We give some arithmetic criterion for the validity of the strong -Sylow theorem for the groups  .

High-throughput ribosome profiling demonstrates the translation of thousands of small open reading frames located in the 5′ untranslated regions of messenger RNAs (upstream ORFs). Upstream ORF can both perform a regulatory function by influencing the translation of the downstream main ORF and encode a small functional protein or microprotein. In this work, we showed that the 5′ untranslated region of the PRPF19 mRNA encodes an upstream ORF that is translated in human cells. Inactivation of this upstream ORF reduces the viability of human cells.

Abstract BACKGROUND Expandable cages are often used to reconstruct cervical corpectomies but there are few long-term follow-up studies with large numbers. OBJECTIVE To analyze the clinical and radiographic results of cervical corpectomy reconstructed with expandable cages for degenerative stenosis. METHODS We performed a retrospective analysis of 78 patients with degenerative cervical stenosis treated with a corpectomy reconstructed with an expandable cage. We evaluated the clinical and radiographic outcomes, as well as complications of the procedure at a minimum 2-yr follow-up. RESULTS There was a decrease in the visual analog scale pain average from 75 mm to 8.5 mm (P = .02); a decrease in the Neck Disability Index average from 55% to 12% (P = .009); and improvement in the Japanese Orthopaedic Association average from 12 to 14 points (P = .01). There was a change in cervical lordosis (Cobb method) average from −9.3° to −15.1° (P = .002), without significant loss of lordosis (P = .63). The fusion rate, by criteria of the Cervical Spine Research Society (CSRS), was low: using dynamic X-rays – 50% (n = 39/78) and using computed tomography (CT) – 47.4% (n = 37/78). A total of 11 patients (14.1%) suffered complications. CONCLUSION To our knowledge, this is the largest series (78) with a minimum 2-yr follow-up in the literature and the first using the dynamic radiographic and CT criteria endorsed by the CSRS. Using these criteria, our fusion rates were much lower than all previous reports in the literature. Despite this, patient-reported outcomes were reasonable. There was a relatively low incidence of perioperative complications, most of which were likely not implant-specific and there was only 1 case of implant failure.

The new quasi-likelihood algorithm is considered for detecting a radio signal with the unknown amplitude, duration, initial phase and inexactly known envelope shape against Gaussian white noise. The structure and the statistical characteristics of the introduced detection algorithm are found. The influence is studied of the difference in the envelope shapes of the received and reference signals upon detection efficiency.

The toxicity standards of modern cars are constantly tightening. Such standards can be reached only when using special systems and assemblies. The existing diagnostic methods are too time-consuming and do not exclude possible multiple errors. The article proposes a method for diagnosing the ICE (internal combustion engine) exhaust system of cars by the run-down time in test modes. An active study of possible diagnostic parameters allowed us to identify a sensitive diagnostic parameter – the run-down time. As the resistance of the catalytic converter increases, the run-down time decreases significantly. The experimental test showed the following: 1) when the run-down starts from 5,000 rpm, the run-down time in case of reaching the limiting resistance of the catalyst is halved - from 4.8 to 2.4 s; 2) in case of a limiting change in the resistance of the catalytic converter from 34 to 10 mm in the exhaust gases, the O2 content increases from 2.53 to 4.92 %, the CO2 content decreases from 13.17 to 12.57 %, and there is a sharp decrease in CH from 100 to 8 ppm. The run-down parameters control range is from 15 to 0.1 s. The production test of the new method for diagnosing the ICE exhaust system showed its significant performance.

The relevancy of the problem of modified starches production is determined by its diversity by raw materials using in manufacture process (banana, chestnut, tapioca, rice, barley, wheat, corn, potato modified starches), by main consumers (food, construction, oil and gas industries), goals of use (production of biodegradable containers, bio-absorbents, micro composites, bio-lubricants, enzyme technology of nanotechnology). The regional relevance of the study problem is based on the need to produce iodized starches for the food industry consumption. Food products produced from these starches will reduce the thyroid gland incidence, at the same time the magnetized wheat starches production will reduce the cardiovascular disease incidence. The analysis of the Russian and world market of modified starches was conducted. The current state and capacity of the world market of modified starches, trends and technology of various modified starches (phosphate, acetate, cationic, cationic cold swelling starches, etc.) production were studied. Results of the study show that Russia's export of modified starches has a weak potential for growth. Russian market of modified starches demonstrates a tendency of increase the competition between modified starches manufacturers due to the new participants' entry in the market. Generally it stimulates the import substitution process. The volume of modified starches imports in Russia is associated with the correlation of manufacturers' prices and expectations of Russia state support for the deepening of domestic agricultural products processing.