Almost 90% of patients with type 2 diabetes mellitus (DM2) are obese. Obesity increases the risk of developing DM2 several times. The calculation of anthropometric indices is used to diagnose the severity of obesity, as well as to assess the risk associated with obesity.
View Article and Find Full Text PDFWe studied the interaction of human buccal mesenchymal stem cells (MSCs) and osteoblasts differentiated from them with the surface of titanium samples. MSCs were isolated by enzymatic method from buccal fat pads. The obtained cell culture was presented by MSCs, which was confirmed by flow cytometry and differentiation into adipocytes and osteoblasts.
View Article and Find Full Text PDFAt the selected frequencies from 0.3 to 10 THz we measured the two-dimensional (2D) distributions of fluence and polarization of terahertz (THz) emission from a single-color femtosecond filament. At the majority of frequencies studied, the THz beam has a donut-like shape with azimuthal modulations and radial polarization.
View Article and Find Full Text PDFType 2 diabetes mellitus is a common chronic metabolic age-associated disease. Elderly patients over 65 years of age predominate among those with type 2 diabetes. 70% of patients with prediabetes develop type 2 diabetes during their lifetime.
View Article and Find Full Text PDFThe terahertz (THz) radiation emitted by an air-based femtosecond filament biased by a static electric field is known to have on-axis shape and relatively low frequency spectrum in contrast to the unbiased single-color and two-color schemes. Here, we measure the THz emission of a 15-kV/cm-biased filament in air produced by a 740-nm, 1.8-mJ, 90-fs pulse and demonstrate that a flat-top on-axis THz angular distribution of the emission at 0.
View Article and Find Full Text PDFType 2 diabetes mellitus is one of the most common non-infectious diseases in the world. Among people with type 2 diabetes, patients of the older age group predominate: 60,5% of all patients are over 65 years old, and the peak prevalence is at the age of 65-69 years. The treatment of this pathology in elderly patients has certain features, which is associated with a high level of polymorbidity in these patients.
View Article and Find Full Text PDFThe new coronavirus infection COVID-19 causes damage to many organs and systems, is a multi-organ disease. Many researchers are studying the relationship of the new coronavirus infection with polymorbid pathology, frailty, sarcopenia. The SARS-CoV-2 virus has the property of neurotropism, therefore, olfactory, taste disorders, as well as cognitive impairments can join the spectrum of clinical manifestations and consequences of the disease.
View Article and Find Full Text PDFHigh-intensity (∼1 TW/cm2 and higher) region formed in the propagation of ∼60 GW, 90 fs Ti:Sapphire laser pulse on a ∼100 m path in air spans for several tens of meters and includes a plasma filament and a postfilament light channel. The intensity in this extended region is high enough to generate an infrared supercontinuum wing and to initiate laser-induced discharge in the gap between the electrodes. In the experiment and simulations, we delay the high-intensity region along the propagation direction by inserting metal-wire meshes with square cells at the laser system output.
View Article and Find Full Text PDFMicromachines (Basel)
August 2022
The paper reports an absorption-transmission multifunctional tunable metamaterial based on graphene. Its pattern graphene layer can achieve broadband absorption, while the frequency selective layer can achieve the transmission of specific band. Furthermore, the absorption and transmission can be controlled by applying voltage to regulate the chemical potential of graphene.
View Article and Find Full Text PDFRecent studies have revealed an interest in the composition of beer biomolecules as a colloidal system and their influence on the formation of beer taste. The purpose of this research was to establish biochemical interactions between the biomolecules of plant-based raw materials of beer in order to understand the overall structure of beer as a complex system of bound biomolecules. Generally accepted methods of analytical research in the field of brewing, biochemistry and proteomics were used to solve the research objectives.
View Article and Find Full Text PDFWe compare transverse structure evolution and energy deposition into the medium within focused multifilament arrays created using two different types of diffraction optical elements (DOEs): TEM phase plate and a Dammann grating. We show that the employment of the Dammann grating provides a robust way to create regular multifilament arrays, which is far less dependent on laser beam quality than one using the phase plate.
View Article and Find Full Text PDFIn the experiment, the laser pulse (744 nm, 0.5 mJ, 90 fs) focused into the air gap between the plane electrodes biased by a 10 kV/cm field (DC-biased filament) produced terahertz (THz) radiation. At the selected frequencies of =0.
View Article and Find Full Text PDFPulses at 744 nm with 90 fs duration, 6 mJ energy, and a weakly divergent wavefront propagate for more than 100 m and generate a filament followed by an unprecedently long high intensity (≥1/) light channel. Over a 20 m long sub-section of this channel, the pulse energy is transferred continuously to the infrared wing, forming spectral humps that extend up to 850 nm. From 3D+time carrier-resolved simulations of 100 m pulse propagation, we show that spectral humps indicate the formation of a train of femtosecond pulses appearing at a predictable position in the propagation path.
View Article and Find Full Text PDFThe sixth-generation wireless communication will exploit the radio band with frequencies higher than 90 GHz, reaching terahertz (THz) band, to achieve huge signal bandwidths. However, the cost-effective fabrication methods of the key components in THz band, which can compromise large scale, high precision, and high efficiency, remain great challenges at present. In this work, we have developed a high throughput fabrication method based on the femtosecond laser filament direct writing.
View Article and Find Full Text PDFAn adaptive method based on the genetic algorithm (GA) is proposed to control the location of femtosecond laser filament. To verify the feasibility of this method, the simulation results obtained through the GA method are compared with those by the chirp method when femtosecond laser pulses with different pulse energies are used. It is found that the intensity profile and the phase of the femtosecond laser pulses obtained by the GA method are nearly identical to those obtained by the chirp method.
View Article and Find Full Text PDFBy rotating the four-section π-shifted phase plate in the transverse plane relatively to the axes of the elliptical beam of 800-nm, 1.1-mJ, 35-fs pulse propagating in air, we switch between the regime of four parallel plasma channels and the regime of spatial symmetry breakup followed by on-axis plasma channel formation identified on the burnt paper images of the beam. Relaxation of the π-phase shift for 45 phase plate rotation is demonstrated explicitly in 3D+time carrier wave resolved numerical simulations yielding the initial step-like phase distribution degradation along the plasma region.
View Article and Find Full Text PDFNonuniform azimuthal distribution of N fluorescence emitted from the femtosecond laser filament in air was discovered. The fluorescence is stronger when the detector is placed perpendicular or parallel to the laser polarization. The experimental results have been confirmed by the theoretical calculation that the azimuthal distribution of fluorescence is reproduced by the convolution of the transition of the dipole and the molecular alignment in the strong laser field.
View Article and Find Full Text PDFWe study angular and frequency-angular distributions of the terahertz (THz) emission of the low-frequency region (0.3-3 THz) from a two-color femtosecond plasma spark experimentally and in three-dimensional numerical simulations. We investigate the dependence of the angular shapes of the THz radiation on focusing conditions and pulse durations by using two laser facilities (pulse durations 35 and 150 fs) for different focusing geometries.
View Article and Find Full Text PDFWe individually control polarizations of 800 and 400 nm beams, which form a two-color femtosecond plasma filament in air irradiating a linear-to-elliptical THz signal. We detected a threshold-like appearance of THz ellipticity at the angle of ∼85° between the fundamental and second-harmonic field polarization directions. The simulations confirm the abrupt change of THz polarization and reveal that the weak ellipticity of the second harmonic is sufficient to generate essentially elliptical THz radiation.
View Article and Find Full Text PDFThe ionization rate of an atom in a strong optical field can be resonantly enhanced by the presence of long-living atomic levels (so-called Freeman resonances). This process is most prominent in the multiphoton ionization regime, meaning that the ionization event takes many optical cycles. Nevertheless, here, we show that these resonances can lead to rapid subcycle-scale plasma buildup at the resonant values of the intensity in the pump pulse.
View Article and Find Full Text PDFA technique is presented to create uninterrupted long ultraviolet filaments in air using appropriately structured transmission mesh. The mesh with different cell sizes was inserted into 10-cm parallel beam of 0.2-J, 248-nm, and 870-fs pulse propagating along ~100-m corridor.
View Article and Find Full Text PDFWe have solved the long-standing problem of the mechanism of terahertz (THz) generation by a two-color filament in air and found that both neutrals and plasma contribute to the radiation. We reveal that the contribution from neutrals by four-wave mixing is much weaker and higher in frequency than the distinctive plasma lower-frequency contribution. The former is in the forward direction while the latter is in a cone and reveals an abrupt down-shift to the plasma frequency.
View Article and Find Full Text PDFThe article presents data on the relationship between thyroid dysfunction and cardiovascular diseases. The role of dyslipidemia, adipokines (adiponectin, leptin, resistin), C-reactive protein, deficiency of vitamin D3 in the development of cardiovascular disease in hypothyroidism is discussed. The article describes characteristics of myocardial remodeling, its dysfunction and their correlation with risk factors of cardiovascular diseases in patients with hypothyroidism.
View Article and Find Full Text PDFPart of the chain in petawatt laser systems may involve extreme focusing conditions for which nonparaxial and vectorial effects have high impact on the propagation of radiation. We investigate the possibility of using propagation equations to simulate numerically the focal spot under these conditions. We derive a unidirectional propagation equation for the Hertz vector, describing linear and nonlinear propagation under situations where nonparaxial diffraction and vectorial effects become significant.
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