Publications by authors named "Antipov S"

The qualitative composition and zeta potential of magnetite nanoparticles (size 4.2±1.2 nm) obtained by co-precipitation method were determined by X-ray and diffraction dynamic light scattering.

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The Editorial Office retracts the article, "The Collagen for Scaffold Preparation and Cell Cultivation: Mechanical and Physicochemical Properties, Morphology, Composition and Cell Viability" [...

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In the present article, the possible mitigation of the toxic effect of imidacloprid low-concentration chronic exposure on by the probiotic strain 47f (1 × 10 CFU/g) was examined. It was found that even sublethal concentration (2500 µg/L) could lead to the death of some fish during the 60-day chronic experiment. However, the use of 47f partially reduced the toxic effects, resulting in an increased survival rate and a significant reduction of morphohistological lesions in the intestines and kidneys of .

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Directed formation of the structure of the culture of living cells is the most important task of tissue engineering. New materials for 3D scaffolds of living tissue are critical for the mass adoption of regenerative medicine protocols. In this manuscript, we demonstrate the results of the molecular structure study of collagen from and reveal the possibility of obtaining a thin membrane material.

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In this study, the effect of three promising feed additives (chelated compounds of trace elements, butyric acid, lycopene) on changes in the culturable microbiota and histological parameters of two sections of the intestines of (zebrafish) was studied. The use of these feed additives can help to eliminate the deficiency of trace elements, modulate the composition of the microbiota due to the postbiotic properties of butyric acid, and reduce oxidative stress when using lycopene. Incorporation of the investigated supplements in the feed resulted in a significant change in the relative abundance of certain groups of microorganisms.

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Laser-plasma accelerators outperform current radio frequency technology in acceleration strength by orders of magnitude. Yet, enabling them to deliver competitive beam quality for demanding applications, particularly in terms of energy spread and stability, remains a major challenge. In this Letter, we propose to combine bunch decompression and active plasma dechirping for drastically improving the energy profile and stability of beams from laser-plasma accelerators.

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Article Synopsis
  • High-quality bi-concave diamond X-ray lenses with a radius of 100 µm were created using laser-ablation and refined through mechanical polishing.
  • The study evaluated individual and stacked lenses, comparing their performance to commercial beryllium lenses of 50 µm with similar focusing capabilities.
  • Results indicated that while polished diamond lenses had comparable figure errors and focal plane beam sizes to beryllium lenses, their small-angle X-ray scattering (SAXS) signal was significantly lower.
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The experimental research was carried out on the juvenile carp (Cyprinus carpio L.). The impact from supplemental feeds consisting of variable concentrations of chelate compounds, biogenic trace elements and probiotic lactobacillus-based product Bacillus subtilis VKPM B-2335 was evaluated.

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In this, work some aspects of the development of the visual system of at the main stages of ontogenesis were described for the first time. It was possible to establish that the formation of the visual system occurs similarly to other representatives of the order , but significantly differs in terms of the individual stages of embryogenesis due to the presence of diapause. In the postembryonic period, there is a further increase in the size of the fish's eyes and head, to the proportions characteristic of adult fish.

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Landau damping is an essential mechanism for ensuring collective beam stability in particle accelerators. Precise knowledge of the strength of Landau damping is key to making accurate predictions on beam stability for state-of-the-art high-energy colliders. In this Letter, we demonstrate an experimental procedure that would allow quantifying the strength of Landau damping and the limits of beam stability using an active transverse feedback as a controllable source of beam coupling impedance.

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Spinel ferrite magnetic nanoparticles have attracted considerable attention because of their high and flexible magnetic properties and biocompatibility. In this work, a set of magnetic nanoparticles of cobalt ferrite doped with zinc was synthesized via the eco-friendly sol-gel auto-combustion method. Obtained particles displayed a room-temperature ferromagnetic behavior with tuned by chemical composition values of saturation magnetization and coercivity.

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We report experimental observations of thermal lens effects in a diamond Raman laser operating up to 1.1 kW output power in a quasi- steady-state regime. Measured changes in the output beam parameters as a function of output power, including beam quality factor and beam divergence after a fixed focusing lens, are compared to modelling enabling us to track the development of a thermal lens up to 16 diopters at maximum output power.

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Enhancement of X-ray excited optical luminescence in a 100 µm-thick diamond plate by introduction of defect states via electron beam irradiation and subsequent high-temperature annealing is demonstrated. The resulting X-ray transmission-mode scintillator features a linear response to incident photon flux in the range 7.6 × 10 to 1.

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Article Synopsis
  • The study focuses on developing biodegradable polymer coatings for stents using poly(lactic-co-glycolic acid) (PLGA), which can release large molecules like prourokinase over time.
  • The coatings exhibit significant elasticity and tensile strength, degrade slowly in isotonic solutions (0.05%-1.0% per day), and maintain around 90% enzymatic activity of prourokinase during release.
  • Testing in animals showed no short-term toxicity or complications post-surgery, with minimal traces of PLGA found after 60 days, indicating the coatings are safe and effective for medical use.
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  • A new method for reducing pulse width and timing jitter in relativistic electron beams using THz-driven beam compression is proposed and demonstrated.
  • The approach manipulates the longitudinal phase space of the electron beam by using a linearly polarized THz pulse, resulting in faster tail movement compared to the head of the beam.
  • The experiment achieved over a fourfold compression of the beam from 130 fs to 28 fs and reduced arrival time jitter from 97 fs to 36 fs, highlighting its potential for advancements in ultrafast dynamics studies and applications in accelerator and ultrafast science facilities.
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We describe the fabrication of metamaterial magnifying hyperlenses with subwavelength wire array structures for operation in the mid-infrared (around 3 μm). The metadevices are composed of approximately 500 tin wires embedded in soda-lime glass, where the metallic wires vary in diameter from 500 nm to 1.2 μm along the tapered structure.

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An external cavity diamond Raman laser with 1.2 kW output power is demonstrated for durations 7 times longer than the thermal lens time constant. An 83% slope efficiency and a 53% optical-to-optical efficiency were obtained for conversion from a 1.

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We propose and demonstrate a terahertz (THz) oscilloscope for recording time information of an ultrashort electron beam. By injecting a laser-driven THz pulse with circular polarization into a dielectric tube, the electron beam is swept helically such that the time information is uniformly encoded into the angular distribution that allows one to characterize both the temporal profile and timing jitter of an electron beam. The dynamic range of the measurement in such a configuration is significantly increased compared to deflection with a linearly polarized THz pulse.

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In recent experiments at Tsinghua University Accelerator Laboratory, the 31 MeV electron beam, which has been compressed to subpicosecond pulse durations, has been used to generate high peak power, narrow band Terahertz (THz) radiation by transit through different slow wave structures, specifically quartz capillaries metallized on the outside. Despite the high peak powers that have been produced, the THz pulse energy is negligible compared to the energy of the electron beam. Therefore, the THz generation process can be complementary to other beamline applications like plasma wakefield acceleration studies and Compton x-ray free electron lasers.

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Article Synopsis
  • Collinear wakefield acceleration can produce very high acceleration gradients, prompting research to improve the transformer ratio (TR), which measures the efficiency of acceleration behind a drive bunch.
  • To maximize TR, researchers have shifted focus to creating asymmetrical drive bunch distributions since conventional symmetrical ones limit TR to below 2.
  • This study showcases the use of an emittance-exchange method to shape the drive bunch, achieving an experimental TR of about 5 in a dielectric wakefield accelerator.
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  • The text discusses various strategies for simulating how molecules behave during ultrafast dynamics caused by electromagnetic fields.
  • It outlines different methods like quantum and semiclassical approaches, mentioning techniques such as Bohmian dynamics and the multiconfiguration time-dependent Hartree method.
  • Lastly, it highlights practical applications of these methods, including studies on molecular collisions and spectroscopy, conducted by the Swiss National Center of Competence in Research "Molecular Ultrafast Science and Technology."
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The Dps protein of , which combines ferroxidase activity and the ability to bind DNA, is effectively used by bacteria to protect their genomes from damage. Both activities depend on the integrity of this multi-subunit protein, which has an inner cavity for iron oxides; however, the diversity of its oligomeric forms has only been studied fragmentarily. Here, we show that iron ions stabilize the dodecameric form of Dps.

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Dps is a multifunctional homododecameric protein that oxidizes Fe2+ ions accumulating them in the form of Fe2O3 within its protein cavity, interacts with DNA tightly condensing bacterial nucleoid upon starvation and performs some other functions. During the last two decades from discovery of this protein, its ferroxidase activity became rather well studied, but the mechanism of Dps interaction with DNA still remains enigmatic. The crucial role of lysine residues in the unstructured N-terminal tails led to the conventional point of view that Dps binds DNA without sequence or structural specificity.

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The Mixed Quantum-Classical Initial Value Representation (MQC-IVR) is a recently introduced approximate semiclassical (SC) method for the calculation of real-time quantum correlation functions. MQC-IVR employs a modified Filinov filtration (MFF) scheme to control the overall phase of the SC integrand, extending the applicability of SC methods to complex systems while retaining their ability to accurately describe quantum coherence effects. Here, we address questions regarding the effectiveness of the MFF scheme in combination with SC dynamics.

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Undesirable electron field emission (also known as dark current) in high gradient rf photocathode guns deteriorates the quality of the photoemission current and limits the operational gradient. To improve the understanding of dark current emission, a high-resolution (∼100  μm) dark current imaging experiment has been performed in an L-band photocathode gun operating at ∼100  MV/m of surface gradient. Scattered strong emission areas with high current have been observed on the cathode.

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