Modeling Impact of Regiodefects on the Electrocaloric Effect in Poly(VDF--TrFE) Copolymers.

Impact of regiodefects in the ferroelectric poly(vinylidene difluoride--trifluoroethylene) copolymer [poly(VDF--TrFE)] on the electrocaloric effect was studied with use of a developed analytical model and molecular dynamics (MD) simulations. It was shown earlier that the electrocaloric effect in these polymers is caused by the first-order phase transition from the ferroelectric β phase to the paraelectric conformationally disordered (condis) phase. MD simulations performed in the current work show that the presence of regiodefects in polymer chains makes this phase transition more gradual, the second order.

Tunable entangled photon-pair generation in a liquid crystal.

Liquid crystals, with their ability to self-assemble, strong response to an electric field and integrability into complex systems, are key materials in light-beam manipulation. The recently discovered ferroelectric nematic liquid crystals also have considerable second-order optical nonlinearity, making them a potential material for nonlinear optics. Their use as sources of quantum light could considerably extend the boundaries of photonic quantum technologies.

Photon pairs bi-directionally emitted from a resonant metasurface.

Metasurfaces are artificially structured surfaces able to control the properties of light at subwavelength scales. While, initially, they have been proposed as means to control classical optical fields, they are now emerging as nanoscale sources of quantum light, in particular of entangled photons with versatile properties. Geometric resonances in metasurfaces have been recently used to engineer the frequency spectrum of entangled photons, but the emission directivity was so far less studied.

Photon Pairs from Resonant Metasurfaces.

All-dielectric optical metasurfaces are a workhorse in nano-optics, because of both their ability to manipulate light in different degrees of freedom and their excellent performance at light frequency conversion. Here, we demonstrate first-time generation of photon pairs via spontaneous parametric-down conversion in lithium niobate quantum optical metasurfaces with electric and magnetic Mie-like resonances at various wavelengths. By engineering the quantum optical metasurface, we tailor the photon-pair spectrum in a controlled way.

Entangled photons from subwavelength nonlinear films.

Miniaturized entangled photon sources, in particular based on subwavelength metasurfaces, are highly demanded for the development of integrated quantum photonics. Here, as a first step towards the development of quantum optical metasurfaces (QOMs), we demonstrate generation of entangled photons via spontaneous parametric down-conversion (SPDC) from subwavelength films. We achieve photon pair generation with a high coincidence-to-accidental ratio in lithium niobate and gallium phosphide nanofilms.

Hypolipidemic and Hepatoprotective Effects of a Polyprenol-Containing Drug in Patients with Acute Coronary Syndrome.

In a double-blind placebo-controlled trial POLYNCOR (registration No. NCT03122340 at clinicaltrials.gov ), lipid-lowering and hepatoprotective effects of polyprenol-containing drug Ropren were evaluated in patients with acute coronary syndrome.

Surface tension model for surfactant solutions at the critical micelle concentration.

A model for the limiting surface tension of surfactant solutions (surface tension at and above the critical micelle concentration, cmc) was developed. This model takes advantage of the equilibrium between the surfactant molecules on the liquid/vacuum surface and in micelles in the bulk at the cmc. An approximate analytical equation for the surface tension at the cmc was obtained.

[On the possibility of bipolaronic states in DNA].

The possibility of the occurrence of bipolaronic states in homogeneous polynucleotide chains has been considered on the basis of the Holstein-Hubbard model. A phase diagram of the stability of bipolaronic states has been calculated for these chains. It was shown that, with the parameters characteristic for DNA, DNA can exhibit superconductivity with a transition temperature Tc approximately 6 K.

[Effect of new polyprenol drug ropren on anxiety-depressive-like behavior in rats with experimental Alzheimer disease].

Influence of the chronic administration of ropren (Trademark)--a plant preparation based on the neutral fraction of extract of spruce and pine needles--on affective status in male rats with amyloid peptide (Abeta(25-35)) induced amnesia has been studied. Ropren was administered per os in a dose of 8.6 mg/kg for 28 days.

On the Possibility of Electronic DNA Nanobiochips.

We have considered as a theoretical possibility for the development of a nanobiochip the operation principle of which is based on measuring conductance in single-stranded and double-stranded DNA. Calculations have demonstrated that in the majority of cases the conductance of double-stranded nucleotides considerably exceeds that of single-stranded ones. The results obtained are in agreement with recent experiments on measuring the oligonucleotide conductance.

[Combined hopping-superexchange mechanism of charge transfer in DNA; a model with nearest interactions].

In the framework of the earlier developed combined hopping-superexchange mechanism of charge transfer in DNA, a model with all nearest interactions between nucleobases is proposed. It is shown that the transfer rates for various types of nucleotide sequences calculated within this model are in a good agreement with experimental data.

[Hopping and superexchange mechanisms of charge transport to DNA].

A theory for charge transport in nucleobase sequences was constructed in which the hole migration proceeds via hopping between guanines. Each hop over the adenine-thymine (A-T) bridge connecting neighboring guanines occurs by means of the superexchange mechanism. The experimental data and theoretical results for various types of nucleobase sequences are compared.

[The pathogenic role of Helicobacter pylori].

The urease test and bacterioscopy of impression smears were used to detect Helicobacter pylori (HP) in biopsies from pyloric gastric mucosa of 77 (89.5%) of 86 chronic gastritis patients, of 27 (4%) from 32 duodenal ulcer patients, of 84 (84.0%) from 100 healthy male subjects aged 18-20.

[Reactive arthritis in young men in organized collectives].

The authors followed up 398 young males with reactive arthritis who had been admitted from organized collectives to hospital settings. Only one third of them could connect the development of reactive arthritis (ReA) with a survived infection: acute nasopharyngeal (26%), acute enterocolitis (7%), urethritis venerea (1%). Analysis of the clinical picture demonstrated that in case of indefinite ReA etiology together with the signs of myocardiac involvement one should not only exclude the presence of rheumatic attack but also to establish a possible relation of the disease with a prior survived poorly manifest intestinal infection.

[The typical features and clinical characteristics of Reiter's syndrome with a nonvenereal origin].

Analysis of the clinical picture in 37 patients with Reiter's syndrome unrelated to venereal urethritis showed that in the majority of cases, it was preceded by acute intestinal infection which occasionally ran an unmarked course. The difficulties in diagnosing Reiter's syndrome were caused in some patients by the fact that in the disease debut, conjunctivitis and urethritis were little manifest and of short duration or occurred at the later stages, especially where the triad was preceded by the provoking factors, such as supercooling and nasopharyngeal infection. Also, in the acute phase of the disease, the patients demonstrated catarrh of the upper respiratory tract, the signs of myocardial injury and some symptoms characteristic of other rheumatological diseases.

[Comparative clinical characteristics of rheumatic and reactive arthritis].

The difficulties encountered in differential diagnosis of rheumatic and reactive arthritides are caused by the similarity of the articular syndrome not infrequently seen in both diseases, especially in their acute phases, a high frequency of little manifest forms of rheumocarditis and the rarity of other main manifestations of rheumatic fever as well as by a possibility of myocardial derangement in reactive arthritides. At the same time of paramount diagnostic importance are a detailed study of the disease history, estimation of the epidemic situation, careful clinical assessment of the character and evolution of the articular syndrome, the signs of lesions of the heart, other organs and symptoms, recognition of the symptoms characteristic for diseases of the group of seronegative spondylarthropathies, particularly Reiter's syndrome.

[Effect of lignins and their model compounds on amine nitrosation in a human gastric juice medium and in the body of mice].

The study was concerned with the influence of lignins of leaf-bearing and coniferous timber and 22 model compounds (lignin components) on nitrosation of dimethylamine, amidopyrine and morpholine in human gastric juice. Some results of the study were confirmed in murine experiments. Compounds of the guaiacyl series showed the highest inhibitory activity.

[A comparative evaluation of the efficacy of sucralfate and H2-histamine blockaders in treating peptic ulcer].

Sucralfate (55 patients), cimetidine (25 patients), ranitidine (30 patients), antacids and cholinolytics (32 patients) were studied and compared in open clinical trials for the efficacy in the treatment of ulcer disease of the stomach and duodenum. During 5 weeks, ulcers completely healed in 100% of the patients given sucralfate (in 94.5% for 4 weeks), in 90% of the patients treated with ranitidine, in 84% on cimetidine, and in 78% of the patients undergoing treatment with antacids and cholinolytics.