Despite the fact that electron transport in condensed helium has been studied for over half a century 1, observations of new intriguing effects still appear 2. Alas, the traditional methods of ...injecting electrons into condensed helium (radioactive-sources, electrical discharge or field emission) lead to generation of helium ions, recombination of which is accompanied by emergence of a large number of excitations. As a result, interpretation of such experiments is not simple and sometimes may be questionable. In this respect, photoelectron emitters, which operate with energies substantially smaller than the ionization energy of helium, are preferable. However, immersion of the photocathode into condensed helium suppresses electron emission. Nevertheless, we managed to achieve electron currents (>20 fA) with the In photocathode immersed directly in liquid superfluid helium. The UV light (λ=254 nm) was guided to the photocathode through a two-meter long Al-covered quartz optical fiber.
The study covers bull-calves of the Kalmyk breed (n=182) aged 12-14 months. It considers the impact of polymorphism of the growth differentiation factor 5 (T586C in exon 1) ensuring development, ...maintenance and restoration of bones and cartilage on body parameters, body weight and musculoskeletal diseases. The frequency of occurrence of TT alleles in selection made 48.9%, TC - 46.7 and CC - 4.4%, χ2 test - 4.94. Bull-calves with CC genotype surpassed their analogues with TT and TC genotypes in terms of growth intensity and body measurements. The analysis of non-contagious musculoskeletal diseases (arthritides, bursitides, arthrobursitides) since birth until the 12th month of age revealed diseases among 17 heads (19.1%) with TT genotype, 9 heads (10.6%) with TC genotype and absence of diseases with CC genotype. There is a need for further study with increasing the group of animals with C homozygous genotype.
Transcranial direct current stimulation has proven to be the method that can modulate neural activity in various cases. As this method has been shown to be effective in improving muscular strength, ...reaction time and accuracy, motor learning, it seems to be promising in elite sports.
This paper provides an overview of studies on tDCS and its impact on central nervous system functioning, with an emphasis on potential sports utility. This review demonstrates that the basic mechanism of the effect of tDCS on nervous system functioning is its ability to modulate the excitability of neurons.
tDCS is able to influence various components of electrocortical potentials, the amplitude of the motor evoked potential, as well as the mechanisms of long-term potentiation and, as a consequence, the cellular mechanisms of motor learning and neuroplasticity in general. The beneficial effect of tDCS on attention selectivity and signal detection has been noted. It is also shown that tDCS can accelerate learning and enhance performance in a range of complex cognitive tasks.
In addition, a number of studies showing that tDCS can increase the efficiency of performing arithmetic and problem solving tasks are considered.
In the context of sports, the influence of tDCS over motor areas on motor learning and on the accuracy of voluntary movements seems to be important. Its ability to influence speed and strength indicators, namely, the maximum isometric force of various muscle groups and explosive strength, as well as endurance indicators seems promising, too. The review also shows that tDCS is reasonably safe and that serious adverse effects are extremely rare; the most common adverse effect is local skin irritation due to poor electrode placement.
ABSTRACT
Baikal-GVD has recently published its first measurement of the diffuse astrophysical neutrino flux, performed using high-energy cascade-like events. We further explore the Baikal-GVD cascade ...data set collected in 2018–2022, with the aim to identify possible associations between the Baikal-GVD neutrinos and known astrophysical sources. We leverage the relatively high angular resolution of the Baikal-GVD neutrino telescope (2–3 deg.), made possible by the use of liquid water as the detection medium, enabling the study of astrophysical point sources even with cascade events. We estimate the telescope’s sensitivity in the cascade channel for high-energy astrophysical sources and refine our analysis prescriptions using Monte-Carlo simulations. We primarily focus on cascades with energies exceeding 100 TeV, which we employ to search for correlation with radio-bright blazars. Although the currently limited neutrino sample size provides no statistically significant effects, our analysis suggests a number of possible associations with both extragalactic and Galactic sources. Specifically, we present an analysis of an observed triplet of neutrino candidate events in the Galactic plane, focusing on its potential connection with certain Galactic sources, and discuss the coincidence of cascades with several bright and flaring blazars.
Introduction. When a pathological process emerges in a part of the cardiac conduction system, it results in various cardiac arrhythmias causing cardiac activity disorders affecting the entire body ...and posing a threat to the patient’s life.Today, the endovascular treatment of arrhythmias has replaced many open heart surgeries becoming a widely accepted alternative to drug therapy. The key techniques of x-ray-guided endovascular treatment of arrhythmias includes the implantation of various devices, transcatheter radiofrequency ablation of arrhythmogenic zones and cryoablation. An excellent comparison of ablation techniques has been presented in the most extensive international randomized clinical trial FIRE AND ICE.The implantation of single-and two-chamber pacemakers, electrophysiological research, radio frequency ablation are all performed at the Bashkir State Medical University Clinic.Material and methods. The electrophysiological research and transcatheter radiofrequency endocardial ablation using the Carto 3 system for complex rhythm disorders have been carried out at the Bashkir State Medical University Clinic since 2013.Results and discussion. 159 EPIs and RFAs have been performed at the Bashkir State Medical University Clinic.Conclusions. X-ray guided endovascular surgery is the method of choice in the treatment of various forms of arrhythmias.
Development study of a wavelength shifter (WLS) to convert a noble gas emission light from the VUV region to the visible range is presented. The shifter is developed for the use with an array of ...blue-sensitive multipixel avalanche Geiger photodiodes (MRS APD) to detect Xe 175nm emission. It was found that a polycrystalline p-terphenyl having an absorption peak at 180nm with a molar extinction coefficient ε of 37500±5000mol−1·lcm−1 is well suited for this. To satisfy a requirement of compatibility with an extra pure noble gas detection medium the p-terphenyl layer was coated with an ∼1μm thick poly-para-xylylene protection film.
A new WLS with maximum of emission spectrum at 390nm and at 420nm is developed on the basis of a nanostructured organosilicon luminophore.
Nematic superconductors are characterized by an apparent crystal symmetry breaking that results in the anisotropy of the in-plane upper critical magnetic field \(H_{c2}\). The symmetry breaking is ...usually attributed to the strain of the crystal lattice. The nature and the value of the strain are debatable. We perform systematic measurements of the \(H_{c2}\) anisotropy in the high-quality Sr\(_x\)Bi\(_2\)Se\(_3\) single crystals in the temperature range 1.8~K\(<T<T_c\approx 2.7\)~K using temperature stabilization with an accuracy of 0.0001 K. We observe that in all tested samples the anisotropy is weakly temperature dependent when \(T<0.8\,T_c\) and smoothly decreases at higher temperatures without any sign of singularity when \(T\rightarrow T_c\). Such a behavior {is in a drastic contradiction with the prediction of} the Ginzburg-Landau theory for the nematic superconductors. We discuss possible reasons for this discrepancy.
PDF
