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Low-symmetry van der Waals (vdW) materials have enabled strong confinement of mid-infrared light through hyperbolic phonon polaritons (HPhPs) at the nanoscale. Yet, the bottleneck persists in manipulating the intrinsic polaritonic dispersion to drive further progress in phonon-polaritonics. Here, we present a thermomechanical strategy to manipulate HPhPs in α-MoO 3 using high-pressure and temperature treatment. The hot pressing engineers the stoichiometry of α-MoO 3 by controllably introducing oxygen vacancy defects (OVDs), which cause a semiconductor-to-semimetal transition. Our density functional theory (DFT) and finite-difference time-domain (FDTD) results, combined with experimental studies show that the OVDs induce a metastable metallic state by reducing the bandgap while modifying the intrinsic dielectric permittivity of α-MoO 3 . Photo-induced force microscopy (PiFM) confirms an average dielectric permittivity tunability of |??/?|≈?.?? within a Reststrahlen band of α-MoO 3 , resulting in drastic shifts in the HPhP dispersion. The polariton lifetimes for pristine and hot-pressed flakes were measured as 0.92±0.06 and 0.86±0.11 ps, respectively, exhibiting a loss of only 7%, while the group velocity exhibited an increase of 38.8±0.2%. The OVDs in α-MoO 3 provide a low-loss platform that enables active tuning of mid-infrared HPhPs and have a profound impact on applications in super-resolution imaging, nanoscale thermal manipulation, boosted molecular sensing, and on-chip photonic circuits.

The purpose of the research is to study the species composition of nematodes dwelling in fish in natural reservoirs and on artificial pond fish farms in Armenia.Materials and methods. The studies were performed at the Research Center for Veterinary Medicine and Veterinary and Sanitary Expertise of the Armenian National Agrarian University and at the Laboratory of Molecular Parasitology of the Scientific Center of Zoology and Hydroecology from March 2020 to December 2022. Traditional ichthyo-parasitological methods were used to study 246 fish of 10 species from fish farms in the Ararat and Armavir Regions, from Lake Sevan and the Sevjur, Hrazdan, Marmarik, Akhuryan and Debed Rivers, as well as the Yerevan, Aparan and Akhuryan reservoirs. The study results were statistically processed (descriptive statistics) using the BioStat software.Results and discussion. The fish were found to have four types of nematodes: Contracaecum microcephalum Rudolphi, 1819, Philometroides sanguineus Rudolphi, 1819, Rhabdochona fortunatowi Dinnik, 1933 and Cystidicola farionis Fischer, 1798. Parasites were found in the body, on the serosa, in the air bladder walls, the intestinal lumen and the caudal fin thickness. The total nematode infection rate in fish was 9.76%. The nematode infection rate in fish was characterized by low values of prevalence and intensity other than the infection by the species Rh. fortunatowi (up to 24 specimens per fish). Among the found nematodes, the species C. microcephalum posed a potential threat to human health.

Throughout history, humans have been attempting to develop the ornamental features of domestic animals in addition to their productive qualities. Many chicken breeds have developed tufts of elongated feathers that jut out from the sides and bottom of the beak, leading to the phenotype known as muffs and beard. It is an incomplete autosomal dominant phenotype determined by the Mb locus localised on chromosome GGA27. This project aimed to analyse the genetic diversity of chicken breeds using full genomic genotyping with the Chicken 60K BeadChip. A total of 53,313 Single Nucleotide Polymorphisms were analysed. DNA was obtained from breeds with the muffs and beard as a marker phenotype: Faverolles (n = 20), Ukrainian Muffed (n = 18), Orloff (n = 20), Novopavlov White (n = 20), and Novopavlov Coloured (n = 15). The Russian White (n = 20) was selected as an alternative breed without the muffs and beard phenotype. The chickens are owned by the Centre of Collective Use “Genetic Collection of Rare and Endangered Breeds of Chickens” (St. Petersburg region, Pushkin), and are also included in the Core Shared Research Facility (CSRF) and/or Large­Scale Research Facility (LSRF). Multidimensional scaling revealed that the Novopavlov White and the Novopavlov Coloured populations formed a separate group. The Ukrainian Muffed and the Orloff have also been combined into a separate group. Based on cluster analysis, with the cross­validation error and the most probable number of clusters K = 4 taken into account, the Orloff was singled out as a separate group. The Ukrainian Muffed exhibited a notable similarity with the Orloff under the same conditions. At K = 5, the populations of the Novopavlov White and the Novopavlov Coloured diverged. Only at K = 6, a distinct and separate cluster was formed by the Ukrainian Muffed. The Russian White had the greatest number of short (1–2 Mb) homozygous regions. If the HOXB8 gene is located between 3.402 and 3.404 Mb on chromosome GGA27, homozygous regions are rarely found in the chickens with the muffs and beard phenotype. Scanning the chicken genome with the Chicken 60K BeadChip provided enough information about the genetic diversity of the chicken breeds for the peculiarities of the development of the ornamental muffs and beard phenotypes in them to be understood. For example, Phoenix bantams, whose tail feathers grow throughout their lives, require greater consideration of husbandry conditions.

Background. The subterahertz and terahertz frequency ranges are very promising for development of high speed wireless communications systems because of possibility to get the bandwidth about some tens of GHz, which provides the high channel capacity. However fast signal attenuation at its propagation in atmosphere complicate the operation of communications systems in these ranges. Aim. Use of fixed narrow-beam antennas with high antenna power gain allows to provide the direct surface communications distance to some kilometers. The communications distance limitation can be partially removed decreasing the frequency down to 200 GHz and narrowing the channel bandwidth down to some GHz. Methods.The model of transmitter-receiver system (200-220 GHz) based of modern semiconductor devices is described in the manuscript. Results. The possibility of digital signals transmission with speed up to 1 Gbit/s at the distance of 1 km is experimentally shown. Conclusion. According to calculations the output power of transmitter about some hundreds mW is enough for data transmission at the distance up to 1.5 km with antenna power gain of no less than 50 dB.

The presence of infectious inflammatory process in a pregnant woman can lead to a disorder in the “mother – placenta – fetus” system.Aim of the study was to investigate the level of regulatory and pro-inflammatory molecules in pregnancy occurring against the background of chronic pyelonephritis without exacerbation.Material and methods. The concentration of IL-17A, monocytic chemotactic protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and IgG autoantibodies to double-stranded DNA (AAT to nDNA) was determined in the blood serum of pregnant women with a gestation period of 36–40 weeks using ELISA.Results. It has been shown that in the third trimester of pregnancy occurring against the background of chronic pyelonephritis without exacerbation, compared with a normal pregnancy, the level of MHP-1 and IL-17A increases, the content of VEGF decreases, and the concentration of AAT to nDNA does not change significantly. An increase in the proinflammatory cytokine IL17A and a decrease in VEGF level can lead to intrauterine fetal growth retardation due to inhibition of amino acid transporters in the placenta.Conclusions. In pregnancy occurring against the background of chronic pyelonephritis without exacerbation, a change in the level of IL17A, MСP-1, VEGF can have a significant impact on the course of pregnancy.

Numerical simulation of the process of remagnetization of small pseudo–single-domain magnetite particles (Тc = 580°С) was performed. The particles are cylindrical in shape, with a height h of 60–350 nm and a height-to-diameter ratio of 1.29. This geometry enables preferential anisotropy of the shape, causing the magnetic moment of the particle to align along the cylinder’s axis in a stable state. As the size increases, the domain structure shifts from the single-domain state (60 nm) to the flower mode (h = 70–85 nm), and then to a vortex structure. Particles in the range of h = 75–250 nm are remagnetized through a vortex state, with the axis aligned along their diameter. In the range of h = 300–350 nm, at the top of the potential barrier, the domain structure transforms from a single vortex to a multi-vortex configuration. The blocking temperatures Tb of the particles vary from 520 to 580°C, while the dependence Тb(h) is non-monotonic and manifests a “pit” at h = 90–140 nm. At the same time, at h = 300–350 nm, Tb values differ from by Тс no more than 1°C. At h = 100 nm, the ratio of magnetic energy in the external field B of the order of the earth to thermal energy at T = Tb reaches 1. This suggests a strong nonlinearity of the TRM(B) dependence even in such small fields and particle sizes. The results obtained highlight the need to revise the existing micromagnetic models by taking into account the specific shape and deficiency of the crystal structure of particles in order to bring them in line with the properties of actual ferrimagnets present in rocks.

Abstract: Resonant nanostructures, such as photonic metasurfaces, have created an unprecedented case for enhanced light–matter interactions through local field engineering. However, the presence of resonances fundamentally limits the bandwidth of such interactions. Here, we report on amending the nonlinear optical response of a semiconducting metasurface through Q-boosting, where the Q-factor of a metasurface rapidly increases with time. The coupled-mode theory reveals overcoming the bandwidth limit by coupling a broadband signal to a bandwidth-matched resonance and Q-boosting at a timescale faster than a resonator lifetime. A control–excitation experiment simulation using a tailored Q-boosting silicon-germanium metasurface predicts the third-harmonic enhancement by factors of 8 (peak) and 4.5 (integrated) against the best-case static metasurface. An analysis of free-carrier losses based on experimental data shows robustness to nonradiative losses and offers a viable pathway to increasing the light–matter interactions beyond the bandwidth limit, with implications in nonlinear and quantum optics, sensing, and telecommunication technologies.