Explore the vast range of titles available.

Background Spastic paraplegia type 30 (SPG30) caused by KIF1A mutations was first reported in 2011 and was initially considered a very rare autosomal recessive (AR) form. In the last years, thanks to the development of massive parallel sequencing, SPG30 proved to be a rather common autosomal dominant (AD) form of familial or sporadic spastic paraplegia (SPG),, with a wide range of phenotypes: pure and complicated. The aim of our study is to detect AD SPG30 cases and to examine their molecular and clinical characteristics for the first time in the Russian population. Methods Clinical, genealogical and molecular methods were used. Molecular methods included massive parallel sequencing (MPS) of custom panel ‘spastic paraplegias’ with 62 target genes complemented by familial Sanger sequencing. One case was detected by the whole -exome sequencing. Results AD SPG30 was detected in 10 unrelated families, making it the 3rd (8.4%) most common SPG form in the cohort of 118 families. No AR SPG30 cases were detected. In total, 9 heterozygous KIF1A mutations were detected, with 4 novel and 5 known mutations. All the mutations were located within KIF1A motor domain. Six cases had pure phenotypes, of which 5 were familial, where 2 familial cases demonstrated incomplete penetrance, early onset and slow relatively benign SPG course. All 4 complicated cases were caused by novel mutations without familial history. The phenotypes varied from severe in two patients (e.g. lack of walking, pronounced mental retardation) to relatively mild non-disabling symptoms in two others. Conclusion AD SPG30 is one of the most common forms of SPG in Russia, the disorder has pronounced clinical variability while pure familial cases represent a significant part.

We study the possibilities of developing electrodeless plasma jet engines on the basis of an electron cyclotron resonance (ECR) discharge. The efficiency of using the working substance in the engine is achieved by increasing the speed of its outflow, which is determined by the maximum electron energy achievable in the ECR discharge. The work involved the measurement of the energy distribution function of the electrons emitted from a discharge maintained in a simple magnetic trap by high-power microwave radiation in the continuous-wave regime. A discharge combustion mode is discovered, which realizes a nonequilibrium electron energy distribution function characterized by the presence of a clearly expressed hot fraction with a characteristic energy of more than 100 keV .

AbstractOzone anomalies that occur in the winter–spring period in the Northern Hemisphere have been increasingly observed in recent decades not only in the polar, but also in midlatitudes, including those near populous cities. A decrease in the stratospheric ozone content can lead to dangerous for humans levels of UV radiation; therefore, the study of processes associated with the variability of the content of stratospheric ozone is an urgent task for developing methods to predict the appearance of ozone miniholes and the growth of UV surface illumination. Using the example of measurements of solar IR radiation with a Bruker 125HR Fourier spectrometer in the vicinity of St. Petersburg, we demonstrate the capabilities of the ground-based spectroscopic method for studying and explaining the temporal variability of stratospheric trace gases involved in the cycles of the destruction and formation of the ozone layer. We have shown the importance of the temperature and dynamic state of the stratosphere for the formation of conditions for the chemical destruction of ozone, as well as the efficiency of using measurements of the total HF content as a dynamic tracer that makes it possible to identify periods of potential activation of the chemical mechanism of ozone loss.

The procedure for determining the total content of chlorine nitrate (ClONO2) from ground-based measurements of the solar radiation spectra on a Bruker 125HR Fourier spectrometer at the St. Petersburg station (59.88oN, 29.82oE, 20 m above sea level) of the international observational network NDACC is examined. The method was applied to spectra measured in the period from 2009 to 2019, and the results were compared with calculations by the EMAC chemistry-climate model. Good qualitative and quantitative agreement was obtained between the experimental data and the results of numerical modeling. For the period 2009–2017 the average mismatch between model and experiment was 3%, the standard deviation was 43%, and the correlation coefficient was 0.79 ± 0.02, which indicates an adequate description of the variability of the total ClONO2 content by the model. Assessment of the linear trend of the total ClONO2 content showed a significant decrease in the total chlorine nitrate content in the atmosphere over St. Petersburg according both to the ground-based measurements (–2.3 ± 1.9% per year) and to the model (–1.2 ± 0.4% per year).

In case of COVID-19 epidemic spread the requirements for protection of medical personnel were increased. This category of specialists has exposure of high risk of COVID-19, due to inevitable numerous contacts with infected persons.Because of this, existing practicable models of medical care are needed to be upgraded (Tavakoli, 2020). The emergency response path was implemented through the opening of new infectious hospitals, re-profiling clinics, as well as increasing workload on medical personnel. This approach is associated with the possible rapid drop-up of qualified medical specialists due to the illness, which is a strong limiting factor to respond to new threats of COVID-19 due to the risks of exhaustion of the human resource. In the worst scenario, a threat of collapse of the emergency and specialized medical care system due to peak load of severe patients under the shortage of doctors and support personnel. To prevent such an emergency, a complex of anti-epidemic events is provided, most of the purpose of interrupting infection contacts, isolation of the most vulnerable contingents, extended population testing for virus or contact with infected persons, this allows you to follow unwanted contacts with the subsequent mobility limitation.Digital monitoring technologies with digitization of incoming data of significant events played the increasing role in all these options. Today they are complemented by robotic supporting. Due to the high risk of the infection in the COVID-19 spread, including the intra-clinic infections, the requirements for reliable disinfection of closed premises intended for patients and medical personnel should be fulfilled. At the same time, the following circumstance should be taken into account. When these work-time activities are imposed on the employee who is forced to stay long in an infected air environment, he is subjected to additional impact of pathogenes. To reduce these threats, robotic support for the work for disinfection of premises with automated air environment control and tracing contacts.

AbstractThe noise covariance matrix, whose diagonal square root is commonly referred to as radiometric noise (NESR), is one of the most important characteristics of hyperspectral infrared sounders measurements. It is used in spectral data inversion and in estimating the atmospheric state vector. This paper presents new results of noise covariance matrix characterization in measurements of the IKFS-2 infrared Fourier transform spectrometer, which has been successfully operating on board the Meteor-M No. 2 spacecraft for more than 6 years. The main factors leading to the interchannel noise correlation are considered. They are associated both with the properties of noise in the interferograms measured by the instrument and the specifics of the initial processing procedure. The noise covariance matrix in the IKFS-2 output spectra has been experimentally estimated in three different ways: (1) from measurements of reference radiation sources, (2) from measured atmospheric spectra, and (3) from the imaginary part of the calibrated atmospheric spectra. The results of the experimental assessment are consistent with the calculations and can be used in the problems of thematic processing and assimilation of IKFS-2 data in numerical weather prediction models of Roshydromet.

AbstractThe current-carrying capacity of second-generation commercial high-temperature superconducting REBCO tapes with a width of 12 mm without a stabilizing copper coating (high-temperature superconductor (HTSC) tapes) in liquid helium has been experimentally investigated at current injection rates up to 350 kA/s. In the experiments, tape samples in the form of rings with junctions are placed in the working volume of a superconducting magnet at 4.2 K. The current in the samples is induced by the transformer method. With an increase in the rate of current injection in the ring-shaped samples, single mechanical defects of the superconducting layer appear in the region of junctions, which causes premature transitions of the samples to the normal state. As a result, the maximum attained currents in the ring samples turned out to be up to 50% lower than the critical currents of short HTSC tape samples at 4.2 K. In conclusion, the analysis of the experimental results is given. Possible explanations for the observed effect are given. In addition, the thermomagnetic stability of two single pancake coils comprised of five isolated turns wound from REBCO tapes supplied from different manufacturers is investigated. The jumps in the magnetic flux are not detected up to an external magnetic field variation rate of 1.7 T/s.

The importance of controlling total ozone (TO) and surface ultraviolet irradiance is a reason for continuous monitoring of the ozonosphere using various ground-based and satellite methods and instruments. The global monitoring of TO has been carried out with the Russian instrument IKFS-2 on the Meteor-M No. 2 satellite since 2015. These measurements are conducted during the whole day and in polar night conditions. The developed algorithm based on using artificial neural networks and OMI satellite instrument measurements is periodically updated and allows determining TO with an average total error of 3–5%. The IKFS-2 measurements can be used for analyzing spatial and temporal (seasonal, interannual) variations in ozone, its long-term trends, verifying modern numerical stratospheric models, studying ozone anomalies, etc. The examples of analyzing TO in autumn-spring periods and TO anomalies in winter and spring of 2020 are given. They clearly demonstrate advantages of satellite TO measurements with the thermal radiation method.

The recommendations are given for conical pick patterns to prevent growing forces on neighbor picks of a failed pick. It is proposed to detect promptly pick failures by analyzing the burden variation in the transmission system of the cutting head. According to the theoretical calculations, when a pick fails, the relative growth of the feed force is not higher than the relative growth of the cutting force as against the increase in the burden as a consequence of change in the cut rock strength. This hypothesis was tested and proved during shafting at Talitsky site of the Upper Kama Potash–Magnesium Ore Deposit using shaft cutting machine 1SPKV-8.0.

Optimum parameters were selected for determining the total content (TC) of Freon R-12 (CCl2F2) from ground spectrometric measurements of solar radiation at the St. Petersburg NDACC station on a Bruker FS125HR Fourier interferometer. On the basis of the obtained optimum set of parameters the total content of R-12 over the station was established over the period of 2009–2018 with a systematic error of 2.7% and a random error of 2.5% over the whole period of the investigations. The preliminary trend estimate was –0.46 ± 0.06% per year.