Nanotechnologies in Russia最新文献

At present, there is every reason to assume that ETosis by various blood cells leads to the formation of different types of extracellular traps (ETs), the biological functions and clearance of which are apparently not the same. The results of in vitro model experiments to create DNA–histone networks at different DNA : histone ratios allow us to propose a method using polymer microspheres with surface amino (PMS⁺) and carboxyl (PMS^–) groups as sorbents for the isolation from whole blood and quantification of oppositely charged ETs. Quantitative analysis of the interaction of blood ETs with PMS⁺ and PMS^– shows that the total number of ETs adsorbed on PMS⁺ and PMS^– is significantly increased in patients with type-2 diabetes mellitus and polyneuropathy compared to healthy volunteers. Moreover, a significant predominance of ETs adsorbed on PMS⁺ is associated with microalbuminuria. The obtained data suggest that the proposed approach could be promising for application in both fundamental research and clinical practice.

A new version of the theory of the nanofocusing of synchrotron radiation (SR) into nanometer transverse size using a long compound refractive lens (CRL) is developed, which adequately takes into account the aperture over the entire length of the CRL within the framework of geometrical optics, fully compatible with the theory based on the CRL propagator. For hard SR, absorption no longer completely limits the CRL aperture and taking into account the real aperture is important to obtain reliable information about the size of the SR beam at the focus. The new theory is almost analytical and allows one to determine the rocking curve of a long CRL with good accuracy, and also gives an answer in those exotic cases where standard numerical methods are not applicable.

Magnetoelectric efficiency of polymer-based multiferroic composites was improved. The changes in the piezoelectric and magnetoelectric properties of PVDF-based composites as a result of coating of CoFe₂O₄ nanoparticles with oleic and citric acid, which leads to an increase in the voltage coefficient α_ME of the magnetoelectric effect, are shown. Coating with oleic and citric acid increases the α_ME value from 0.7 mV/(cm Oe) for a composite with bare nanoparticles to 4.5 and 8.7 mV/(cm Oe), respectively.

The mechanisms of parasitic effects in combined memristor-diode arrays of logic and memory matrices within a neuroprocessor are described. To assess the impact of parasitic effects on the output signal waveform and cell states, circuit models of the matrices are developed by incorporating parasitic elements, known memristor models, and Zener diode models into LTspice. Numerical simulations demonstrate that in both matrices, the primary contribution to signal propagation delays comes from RC circuits formed by the load resistance, parasitic cell capacitance, and substrate capacitance. The nonlinear increase in signal propagation delay is shown to depend on the crossbar array dimensionality and memristor size. Compensation methods for parasitic effects are proposed, including modifications to the encoding scheme and reduction of the memristor dimensions to 100 nm.

The degradation resistance of modified SiO₂ carbon supports for electrocatalysts was evaluated using accelerated stress testing under model conditions. No direct correlations were found between the degradation resistance of the supports and that of the electrocatalysts based on them. The intensification of electrochemical corrosion processes is attributed to the presence of oxygen-containing groups in the silicon dioxide modifier on the carbon support surface. Conversely, electrocatalysts based on modified carbon supports exhibit an increase in electrochemically active surface area and degradation resistance by an average of 10‒25%.

In the last decade, there has been progress in the efficiency of halide-perovskite-based photovoltaics. The combination of unique physical and chemical properties of these materials, such as the strong absorption of X-ray quanta due to the presence of heavy elements (Cs, Pb, Bi, and I) in their composition, significant bulk resistivity, a tunable band gap, and compatibility with integrated circuits, arouse interest in their use in fields involving X-ray radiation. This review discusses the basic operating principles and architecture of direct X-ray detectors. Their key characteristics are discussed, and the advantages of perovskite X-ray detectors compared to existing commercial analogues are described. Ways to optimize the characteristics of perovskite X-ray detectors are considered.

Two samples of silver nanoparticles (AgNPs) stabilized with the salt of a natural polysaccharide (sodium alginate) are obtained. The samples differed in their synthesis conditions, in particular, they had different nanoparticle growth rates. At a lower growth rate, the formation of smaller AgNPs with a narrower size distribution, as indicated by the assessment of the width of the surface plasmon resonance for this sample, is observed. Testing the antimicrobial activity of the studied composites against acetic acid bacteria of the strain Gluconobacter oxydans sbsp. industrius VKM B-1280 (All-Russian Collection of Microorganisms) show that the inhibition of colony growth occurred with both AgNP samples. The test is carried out using the method of diffusion of the active component in agar gel. The obtained results indicate that the formed coating based on sodium alginate-stabilized AgNPs inhibits the occurrence of the bacterial rot of apples and such a coating can be used as an antimicrobial agent.

Several types of devices are proposed for closing annulus fibrosus defects after sequestrectomy to restore the biomechanics of the intervertebral disc. Polylactide, poly-ε-caprolactone, and copolymers of lactide and ε-caprolactone are selected as the materials. The compressive modulus values of the materials range from 0.54 to 210 MPa, depending on the composition and structure of the devices being developed. Sponge-type devices made from copolymers of polylactide and polycaprolactone show the most promise for further in vivo research studies.

Single-walled carbon nanotubes (SWCNTs) filled with silver chloride (AgCl) are studied by scanning transmission electron microscopy (STEM) and Raman spectroscopy. Based on the STEM data, a model of an embedded silver chloride nanocrystal with parameters different from its three-dimensional analogue is constructed. The doping of SWCNTs with embedded silver chloride was investigated using Raman spectroscopy. It is found that 1D silver chloride leads to the acceptor doping of SWCNTs.

The possibilities of synthesizing composite organic-inorganic materials from agricultural waste (biochars based on rice husks, sunflower husks, and ferrites of the composition MFe₂O₄ (M = Ni, Co) are studied. The synthesis of materials is carried out using the sol-gel method. It is established that the nature of the biochar influences the product yield: for a composite with biochar from rice husk, the yield of the composite material is approximately 25% higher than for sunflower husk. This fact is explained by the loose structure of biochar obtained from sunflower husks, which ensures more complete contact of the surface with oxygen during heat treatment and leads to the partial burnout of the biochar during the synthesis of the composite material. The synthesized materials are characterized by X-ray diffraction analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cobalt(II) and nickel(II) ferrites crystallize on the surface of the organic carrier in the form of a film. The composite material has significant catalytic properties in the reaction of destruction of the organic dye (methyl orange) under the influence of hydrogen peroxide and daylight: complete removal of the azo dye from the solution in the presence of the cobalt(II) ferrite/sunflower catalyst is achieved after just 60 min.