Chirp-driven control over fast-slow light effects in epsilon-near-zero metamaterials.

Optical applications based on fast and slow light effects force the usage of metamaterials famous for their flexible dispersion properties. In this work, we apply the unique optical nonlocality of metal nanorod-based epsilon-near-zero (ENZ) metamaterials along with the chirp of femtosecond laser pulses for astonishing control of these effects. We demonstrate the switching between the fast and slow light phenomena via the change of the angle of incidence and/or the central wavelength of chirped pulses in the vicinity of metamaterial zero-transmission regime mediated by the ENZ nonlocality. We elucidate that the laser chirp allows one to manipulate and enhance the fast-slow light phenomena.

Temperature dependence of spatial nanoheterogeneities of shear modulus in supercooled glycerol.

The boson peak in the terahertz vibrational spectrum carries information about nano-heterogeneities in the shear modulus in glass formers. Its evolution upon heating or cooling in a supercooled liquid state may shed light on the temperature dependence of heterogeneities. For this purpose, an analysis of the light scattering spectra of supercooled glycerol in the spectral range of the boson peak and fast relaxation was carried out and the parameters of the boson peak in the temperature range 180-330 K were determined. The temperature dependent frequency of the boson peak was then expressed in terms of the mean-square amplitude of the shear modulus fluctuations. This was done using the heterogeneous elasticity theory in combination with the perturbation theory on small fluctuations and Ioffe-Regel criterion for transverse vibrations in glass formers. The contribution of structural relaxation effects to phonon damping becomes significant with increasing temperature. It is shown here that structural relaxation largely determines the temperature dependence of the mean-square fluctuations of the shear modulus at high temperatures. By solving the inverse problem, the temperature dependence of shear modulus fluctuations was obtained. It shows a rapid decrease above ∼250 K with a linear extrapolation going to zero at the so-called Arrhenius temperature TA = 350 K. Comparison with literature data on the Landau-Placzek ratio shows that they have a similar temperature dependence at T < TA, which is explained by the appearance of nanometer scale spatial heterogeneities below TA. This is confirmed by the temperature dependence of the amplitude of the boson peak.

Nonlocality-mediated spatiotemporal optical vortex generation in nanorod-based epsilon-near-zero metamaterials.

Optical vortices have myriad applications in photonics. Very recently, promising concepts of spatiotemporal optical vortex (STOV) pulses based on the phase helicity in the space-time coordinates have attracted much attention owing to their donut shape. We elaborate on the molding of STOV under the transmission of femtosecond pulses through a thin epsilon-near-zero (ENZ) metamaterial slab based on a silver nanorod array in a dielectric host. At the heart of the proposed approach is the interference of the so-called main and additional optical waves enabled by strong optical nonlocality of these ENZ metamaterials, which leads to the appearance of phase singularities in transmission spectra. The cascaded metamaterial structure is proposed for high-order STOV generation.

Cognitive Impairments in Patients with Bronchial Asthma.

The course of bronchial asthma can be accompanied by cognitive impairments. However, the relationship between cognitive dysfunction and asthma has not been fully revealed, nor has it been fully established what causes cognitive impairments in patients with asthma. There is an opinion that transient hypoxia and persistent systemic inflammation with insufficient control of bronchial asthma can be accompanied by neurotoxicity in relation to the hippocampus and indirectly lead to deterioration of cognitive functions. Comorbid conditions, such as obesity, allergic rhinitis, and depressive states can increase cognitive dysfunction in asthmatics. The review considers the pathophysiology of cognitive dysfunction in patients with bronchial asthma, as well as the impact of comorbid conditions on the cognitive status. This information will allow systematizing the available knowledge about the state of cognitive functions in asthma for timely detection and correction of their impairments and, ultimately, optimization of the management of these patients.

Functional Activity of Blood Neutrophils in Patients with Stable Course and Exacerbation of Chronic Obstructive Pulmonary Disease.

We performed a comparative study of the parameters of chemiluminescence of blood neutrophils in patients with different severity of chronic obstructive pulmonary disease in its different periods. The maximum values of induced and spontaneous chemiluminescence were recorded at moderate severity of the disease during exacerbation. Low levels of chemiluminescence indicators were found in severe chronic obstructive pulmonary disease in the stable phase. The values of the induction period of the chemiluminescent response in patients with moderate chronic obstructive pulmonary disease were higher than in the control group. Correlations between the values of induced chemiluminescence of neutrophils and the respiration function parameter FEV1 were established, which may indicate the influence of multidirectional changes in the functional activity of systemic neutrophils on the development and worsening of airway obstruction in chronic obstructive pulmonary disease patients.

[Surgery in patients with severe or inhibitory hemophilia A under prevention injection of emicizumab]. / Khirurgicheskie vmeshatel'stva u bol'nykh tyazheloi ili ingibitornoi formoi gemofilii A na fone profilakticheskogo vvedeniya emitsizumaba.

OBJECTIVE: To determine the features of preoperative hemostatic therapy and laboratory control in patients with severe and inhibitory forms of hemophilia A under preventive treatment by FVIII. MATERIAL AND METHODS: Four patients with severe and inhibitory forms of hemophilia A underwent surgery between 2021 and 2022. All patients received Emicizumab (the first monoclonal drug for «non-factor¼ therapy of hemophilia) for prevention of specific hemorrhagic signs of hemophilia. RESULTS: Surgical intervention under preventive Emicizumab therapy was essential. Additional hemostatic therapy was not carried out or performed in reduced mode. There were no hemorrhagic, thrombotic or other complications. Thus, the so-called «non-factor¼ therapy is one of the variants for uncontrollable hemostasis in patients with severe and inhibitory forms of hemophilia. CONCLUSION: Preventive injection of Emicizumab ensures certain buffer of hemostasis system and stable lower limit of coagulation potential. This is the result of stable concentration of Emicizumab when used in any of the registered forms regardless of age and other individual characteristics. The risk of acute severe hemorrhage is excluded, while the probability of thrombosis is not increased. Indeed, FVIII has higher affinity than Emicizumab and displaces Emicizumab from coagulation cascade that does not result summation of total coagulation potential.

Comparative Study of the Levels of IL-1ß, IL-4, IL-8, TNFα, and IFNγ in Stable Course and Exacerbation of Chronic Obstructive Pulmonary Disease of Varying Severity.

In patients with chronic obstructive pulmonary disease, the levels of cytokines IL-1ß, IL-4, IL-8, TNFα, and IFNγ depended on the degree of bronchial obstruction and severity and period of the disease. The maximum levels of IL-4, IL-8, and TNFα were observed in severe chronic obstructive pulmonary disease during exacerbation. The highest concentration of IL-1ß and IFNγ were recorded during activation of inflammation in patients with moderate bronchial obstruction. The revealed correlations between the tested cytokines and spirometry parameters make it possible to consider the levels of these proteins as quantitative markers of systemic inflammation progression.

Superluminal and slow femtosecond laser pulses in hyperbolic metamaterials in epsilon-near-zero regime.

Flourish of optics of hyperbolic metamaterials (HMMs) is stimulated by their exotic optical properties. Here, we demonstrate resonant changes of the group retardation and superluminal-like propagation of femtosecond laser pulses in nanorod-based HMMs in the vicinity of epsilon-near-zero spectral point responsible for the transition between topologically distinct elliptic and hyperbolic light dispersions. Resonant dynamics of ultrashort pulses appears in a unique case when their spectral components are in both dispersion regimes simultaneously. Our findings suggest HMMs as a powerful platform for future ultrafast photonics and are pivotal for growing nonlinear optics of hyperbolic media.

Combined Preconditioning Reduces the Negative Influence of Cerebral Ischemia on the Morphofunctional Condition of CNS.

We studied the influence of combined preconditioning (compound pQ-4 and moderate hypoxia) on morphometrical parameters of neuronal populations in hippocampal fields CA1 and CA3 in rats after bilateral ligation of the common carotid artery. Preconditioning produced a neuroprotective effect, improved survival of pyramidal neurons in the early and delayed periods of modeled ischemia, prevented the formation of necrotic and apoptotic neurons and hyperactivation of microglia, and protected endotheliocytes. The positive influence of preconditioning factors on the morphometric parameters of the brain under ischemic conditions agrees with the results of behavioral tests (open field and elevated plus maze) that demonstrated increased locomotor activity and exploratory behavior of animals.

[The analysis of failures of intra-familial relationships in families with children suffering of diabetes mellitus].

The article presents the results of study of in-family (child-parents) relationships in families with children suffering with diagnosed diabetes mellitus type I. The purpose of study is to investigate the disorders of family relationships in families of such kind. The established disorders allow to develop psychotherapeutic measures both for children and their parents. Materials and methods. The study covered 30 families with children of primary school age (7-10 years old) with diabetes mellitus. The families with children with severe concomitant diseases and broken families were excluded of the sampling. The control group consisted of 30 relevant families with healthy children. The in-family relationships were explored using a number of psychological tests applied to children and their mothers. The results. In mothers of the studied families prevailed authoritarian type of upbringing, which was expressed in tendency to hyper-protect and to over-control. The phobia of losing child and the tendency to reject it were also established. The children suffered from high level of anxiety. They had more positive attitude to mother than to father. The conclusion. The established disorders of in-family relationships in families with children with diabetes mellitus can serve as targets for psychotherapeutic activities both with children and their parents.

[The mental reactions of psychiatrists and narcologists against the background of COVID-19 pandemic].

The article considers various mental reactions of psychiatrists and narcologists against the background of the SARS-CoV-2 pandemic, based on a brief scientific analysis of publications and experimental psychological research methods. The purpose of study was to identify impact of the COVID-19 pandemic on mental health of psychiatrists and psychiatrists-narcologists. The results of survey of psychiatrists and narcologists are presented. The study was carried out using such test techniques as life quality scale SF-36 (Health Status Survey), Lazarus questionnaire "Coping Behaviors" adjusted to conditions of Russia and Hamilton scales to assess depression and anxiety (HDRS, HARS). The results.The low level of psychological well-being, moderate degree of preference for all coping strategies were established. The anxiety was determine in 34.8% of respondents and depression in 8.7%. It was established that actually, the impact of the COVID-19 pandemic on medical workers is conditioned by complex of mental reactions (from anosognosia to expressed anxiety and depressive disorders) and is accompanied by increasing general anxiety.

[The medical social problems and methods of diagnostic of cognitive disorders in patients taking "Spice"].

The article presents the results of pilot study implemented to determine cognitive disorders in patients taking "Spice". The purpose of research is to identify targets of psychological correction interventions to prevent cognitive deficiency in patients addicted to synthetic cannabinoids. The pilot sampling consisted of 30 patients taking "Spice". The control group consisted of 30 healthy individuals. Along with social consequences, one of the important focuses of the study was investigation of cognitive sphere of patients. A number of pathopsychologic tests was applied. The study established that patients demonstrated disorders of various functions of memory, attention, mental pace and thinking. In particular, disorders of short-term, long-term and mediate memory and mental tempo were revealed. Also, reduced activity of attention took place. The distortion and decreasing of generalization and poor prehension occurred reliably more often as compared with control group. The established cognitive disorders in patients taking "Spice" can be considered as targets for psychological correction interventions to prevent cognitive deficiency in patients addicted to synthetic cannabinoids.

Second-harmonic generation spectroscopy in gold nanorod-based epsilon-near-zero metamaterials.

The interest in hyperbolic metamaterials is fueled by fascinating optical properties exhibited by this class of artificial media. Their optical features originate from hyperbolic dispersion emerging due to the shape anisotropy of the metal-dielectric composite. In this work, we study experimentally and numerically the second-harmonic generation (SHG) in ordered arrays of Au nanorods embedded in porous aluminum oxide. Strong increase of the SHG intensity in the vicinity of the epsilon-near-zero (ENZ) spectral point accompanied by dramatic phase modulation of the SHG wave is revealed. These effects are attributed to resonant enhancement of the electric field of the light wave and transition from the elliptical to hyperbolic dispersion law in hyperbolic metamaterials near the ENZ point.

The specific features of phononic and magnetic subsystems of type-VII clathrate EuNi2P4.

A type-VII clathrate with a Eu2+ guest embedded into a Ni-P covalent framework, EuNi2P4, was synthesized by a standard two-stage ampoule synthesis and confirmed to crystallize in the orthorhombic space group Fddd with unit cell parameters a = 5.1829(1) Å, b = 9.4765(1) Å, and c = 18.9900(1) Å. A general technique for studying the lattice and magnetic properties of REE containing compounds is proposed. The temperature and field dependences of electrical resistivity ρ(T,H), magnetization M(T,H), magnetic susceptibility χ(T,H), heat capacity Cp(T), and unit cell parameters a(T), b(T), c(T), and volume V(T) were experimentally studied and analyzed at different pressures in the temperature range of 2-300 K. A cascade of anomalies in the studied dependences was identified and attributed to the magnetic phase transformation and peculiar lattice contributions at temperatures below 20 K. As a result of comparison with an isostructural clathrate SrNi2P4, the parameters of the magnetic and lattice contributions were determined. It is characteristic that the phase transition from the paramagnetic to the magnetically ordered state is not reflected in the temperature changes of the lattice parameters due to weak bonds between guest europium atoms and the Ni-P host matrix. We have constructed a tentative H-T phase diagram based on the M(T) and M(H) data, which includes 6 different phases. It is established that the anomalous lattice contribution to the clathrate heat capacity CTLS(T) appears due to the effect of two-level systems (TLS) in the Eu2+ subsystem on the thermodynamic properties of EuNi2P4. The values of TLS parameters as well as the parameters of the magnetic subsystem of the clathrate were determined.

Serum Protein Corona Abolishes Changes in the Expression of Proinflammatory Genes Induced by Quantum Dots in Human Blood Mononuclear Cell.

We studied changes in the transcription of genes encoding cytokines (TNF, IL-6, IL-10, and IL-32), cell activation markers (ICAM1, CD38, Fas, and FCGRIII), ROS production catalyst (NOX2), autophagy (Beclin 1, LC3B, and p62) and apoptosis (BAX, BCL2) regulators in peripheral blood mononuclear cells upon contact with quantum dots CdSe/ZnS-MPA and CdSe/CdSeZnS/ZnS-PTVP. Up-regulation of TNF, ICAM1, Fas, p62 mRNA and down-regulation of the FCGRIII and NOX2 mRNA in response to the presence of quantum dots were revealed. The formation of serum protein corona on the surface of quantum dots abolished this effect.

Anomalous birefringence and enhanced magneto-optical effects in epsilon-near-zero metamaterials based on nanorods' arrays.

Hyperbolic metamaterials based on the ordered arrays of metal nanorods in a dielectric media are of great interest owing to new optical effects appearing in such artificial media. Here we study the effects in the polarization state of light passing through a nanocomposite material consisting of Au nanorods in porous alumina and a similar structure supplemented by a nanolayer of ferromagnetic nickel. We demonstrate that close to the epsilon-near-zero dispersion point, under the transition to the hyperbolic dispersion region, the nanocomposites reveal anomalously high modulation of the polarization state of light, which appears as polarization plane rotation and ellipticity changes of probing radiation with a zero ellipticity. This effect is applied for the giant enhancement of the Faraday effect in a continuous ferromagnetic film staying in contact with hyperbolic material. These findings open a path for the design of polarization state control by using hyperbolic metamaterials.

Thermodynamic properties and lattice dynamics investigation of LuB2C: experiment and ab initio calculations.

A sample of lutetium carboboride LuB2C was synthesized from a mixture of lutetium hydride, boron and carbon by annealing in argon. The temperature dependence of the heat capacity Cp(T) (2-300 K) and lattice parameters a(T), b(T), and c(T) (5-300 K) of the carboboride was experimentally determined. The experimental values of the heat capacity were fitted with the approximation Cp(T) = aT + ΣCD + CE + CTLS(T). Here the first term is the electronic contribution, the second is the sum of the Debye components, the third is the Einstein contribution, and the fourth is the contribution to the heat capacity due to the vibrations of the two-level systems which are formed in the Lu-subsystem due to the asymmetry of the B-C atomic arrangement around the Lu3+-ions and, as a consequence, the possible transition of the lutetium atoms between spatially close, but energetically non-equivalent positions. A strong anisotropy of the thermal expansion of the carboboride was revealed. Along the c axis the coefficient of thermal expansion monotonically increases; in the basal plane, the expansion is practically not observed. The temperature dependence of the unit cell volume Vu(T) has been analyzed in the Debye-Einstein approximation taking into account the electronic contribution and effect of two-level systems. The values of the Gruneisen parameters corresponding to different modes of the phonon spectrum of the carboboride have been determined. The frequencies of the lattice vibrations, determined in a Raman scattering experiment, are in satisfactory agreement with the parameters obtained from Cp(T) using the Debye-Einstein approximation. Using ab initio band theory methods and an exchange-correlation functional in the PBE form in the VASP package, it was established that the total energies of these two crystal structures differ by no more than 0.01 eV f.u.-1. Calculations of the thermodynamic properties of LuB2C yielded similar results for orthorhombic and tetragonal phases of the carboboride.

Signal Mechanism of the Protective Effect of Combined Preconditioning by Amtizole and Moderate Hypoxia.

The content of regulatory proteins involved in adaptation to hypoxia and ischemia was studied in brain rat homogenate under conditions of normoxia and after bilateral ligation of the common carotid arteries. Preconditioning with amtizole in combination with moderate hypoxia increased the levels of HIF-1α, erythropoietin, vascular endothelial growth factor under conditions of normoxia. During experimental ischemia, combined preconditioning led to stabilization of the content of these regulatory proteins at the level of intact control and to a decrease in glycogen synthase-3ß kinase activity. This pattern of changes in regulatory proteins was noted during the early and late periods of preconditioning.

Influence of Magnetite Nanoparticles and Quantum Dots on the Expression of Reference Genes in Peripheral Blood Cells.

We studied the influence of magnetite nanoparticles (FeO•Fe2O3) and quantum dots (CdSe/ZnS coated with mercaptopropionic acid) on the expression of 5 common reference genes (BA, B2M, PPIA, UBC, and YWHAZ) in peripheral blood cells from 20 volunteers by reverse transcription PCR method. The stability of the expression of reference genes varied depending of the cells type and chemical structure of nanoparticles. The level of YWHAZ mRNA after exposure by nanoparticles demonstrated highest stability in lymphocytes, neutrophils, and monocytes. Stability of YWHAZ expression was confirmed by Western blotting. Our findings suggest that YWHAZ is the most suitable as the reference gene.

Expression of Genes Encoding Cell Motility Proteins during Progression of Head and Neck Squamous Cell Carcinoma.

The model of head and neck squamous cell carcinoma (HNSCC) was used to study the expression of genes encoding actin-binding proteins depending on the type of cell motility. The expression of SNAIL1 and CAPN2 mRNA in HNSCC tissue was higher than in specimens of dysplastic epithelium of the larynx and hypopharynx, which can be explained by activation of mesenchymal and amoeboid types of cell motility. In biopsy material of HNSCC patients with T1-2N0M0, expression of genes responsible for actin-binding proteins differed from that of patients with pretumor pathology of the larynx and hypopharynx: expression of FSCN was lower, while expressions of EZR and CAP1 were higher. The data attest that progression of HNSCC is associated with activation of both types of cell motility and with the changes in the expression of mRNA encoding cell motility proteins.