Publications by authors named "Olga Smirnova"

Objective: Aim: To study the psychological peculiarities of the manifestation of leadership qualities by modern managers of police organizations..

Patients And Methods: Materials and Methods: The research conducted in 2022-2024 involved 64 mid-level managers of police organizations and 462 officers from police units directly subordinated to these managers.

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The topological response of matter to electromagnetic fields is a highly demanded property in materials design and metrology due to its robustness against noise and decoherence, stimulating recent advances in ultrafast photonics. Embedding topological properties into the enantiosensitive optical response of chiral molecules could therefore enhance the efficiency and robustness of chiral optical discrimination. Here we achieve such a topological embedding by introducing the concept of chiral topological light-a light beam which displays chirality locally, with an azimuthal distribution of its handedness described globally by a topological charge.

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Background: Wound healing represents a complex biological process, critically important in clinical practice due to its direct implication in a patient's recovery and quality of life. Conservative wound management frequently falls short in providing an ideal environment for the optimal tissue regeneration, often resulting in extended healing periods and elevated risk of infection and other complications. The emerging biomaterials, particularly hydrogels, have shown substantial promise in addressing these challenges by offering properties such as biocompatibility, biodegradability, and the ability to cure wound environment.

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Introduction: The purpose was to study the indicators of physical development of primary-school-aged children with intellectual disability by observing the type of autonomic nervous regulation and their levels of catecholamines and serotonin.

Methods: A total of 168 primary school age children were examined, of which 54 had intellectual disability. The autonomic nervous system was assessed using cardiointervalography; anthropometric parameters were applied in accordance with recommendations.

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Cavity-free lasing in atmospheric air has stimulated intense research toward a fundamental understanding of underlying physical mechanisms. In this Letter, we identify a new mechanism-a third-harmonic photon mediated resonant energy transfer pathway leading to population inversion in argon via an initial three-photon excitation of nitrogen molecules irradiated by intense 261 nm pulses-that enables bidirectional two-color cascaded lasing in atmospheric air. By making pump-probe measurements, we conclusively show that such cascaded lasing results from superfluorescence rather than amplified spontaneous emission.

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Article Synopsis
  • Enzymatic transglycosylation of a specific fleximer base using recombinant purine nucleoside phosphorylase (PNP) resulted in the production of both expected and unexpected reaction products, including N1-pyrazole nucleosides and novel derivatives.
  • The study revealed that certain minor products, like a 4-imino-pyridinium riboside and bis-ribose derivatives, were formed, while a particular expected product (4-imino-pyridinium deoxyriboside) was absent.
  • Molecular modeling helped identify how the structure of the heterocyclic substrates interacts with the PNP active site, suggesting that the spatial arrangement may facilitate secondary glycosylation, leading to
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1,2,4-Triazole derivatives have a wide range of biological activities. The most well-known drug that contains 1,2,4-triazole as part of its structure is the nucleoside analogue ribavirin, an antiviral drug. Finding new nucleosides based on 1,2,4-triazole is a topical task.

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Extracellular vesicles (EV) are a heterogeneous group of lipid particles excreted by cells. They play an important role in regeneration, development, inflammation, and cancer progression, together with the extracellular matrix (ECM), which they constantly interact with. In this review, we discuss direct and indirect interactions of EVs and the ECM and their impact on different physiological processes.

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Hepatitis C virus (HCV) is an oncogenic virus that causes chronic liver disease in more than 80% of patients. During the last decade, efficient direct-acting antivirals were introduced into clinical practice. However, clearance of the virus does not reduce the risk of end-stage liver diseases to the level observed in patients who have never been infected.

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Chiral molecules, used in applications such as enantioselective photocatalysis, circularly polarized light detection and emission and molecular switches, exist in two geometrical configurations that are non-superimposable mirror images of each other. These so-called (R) and (S) enantiomers exhibit different physical and chemical properties when interacting with other chiral entities. Attosecond technology might enable influence over such interactions, given that it can probe and even direct electron motion within molecules on the intrinsic electronic timescale and thereby control reactivity.

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Neuroglobin (Ngb) is a cytosolic heme protein that plays an important role in protecting cells from apoptosis through interaction with oxidized cytochrome (Cyt ) released from mitochondria. The interaction of reduced Ngb and oxidized Cyt is accompanied by electron transfer between them and the reduction in Cyt . Despite the growing number of studies on Ngb, the mechanism of interaction between Ngb and Cyt is still unclear.

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The valley degree of freedom of electrons in materials promises routes towards energy-efficient information storage with enticing prospects for quantum information processing. Current challenges in utilizing valley polarization are symmetry conditions that require monolayer structures or specific material engineering, non-resonant optical control to avoid energy dissipation and the ability to switch valley polarization at optical speed. We demonstrate all-optical and non-resonant control over valley polarization using bulk MoS a centrosymmetric material without Berry curvature at the valleys.

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Mathematical models, which describe effects of partial-body, two- and multiple-pulse irradiation at high total doses D and at average dose rates N from FLASH to conventional rates on the level of surviving blood lymphocytes in humans and mice, have been developed originating in the previously proposed approach. These models predict that levels of surviving blood lymphocytes in humans and mice increase with increasing the dose rate from N=D/TR (TR is the time of the blood flowing into or out of the irradiated segment of the blood circulatory system) to FLASH rates and approach an upper limiting level equal to (1-vR), where vR is the fraction of blood volume in the irradiated segment of the blood circulatory system. Levels of surviving blood lymphocytes computed at total doses D of 10-40 Gy and at average of dose rates N, which are equal to or exceed 40 Gy/s for humans and 400 Gy/s for mice, are nearly indistinguishable from the upper limiting level.

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A mathematical model developed by Cucinotta and Smirnova is extended to describe effects of continuous, partial-body irradiation at high doses D and at dose rates N from FLASH to conventional rates on the level of surviving blood lymphocytes in humans and small laboratory animals (mice). Specifically, whereas the applicability of the model is limited to the exposure times shorter than a single cardiac cycle T0, the extended model is capable of describing such effects for the aforementioned and longer exposure times. The extended model is implemented as the algebraic equations.

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Article Synopsis
  • Abnormal epigenetic modifications, particularly DNA hypomethylation, can lead to cancerous changes in gastrointestinal (GI) cells, which represent 20% of all cancers globally.
  • CpG methylation and promoter hypermethylation serve as important biomarkers for various malignancies and can disrupt key processes like cell cycle control and DNA repair in GI cancers.
  • By studying DNA methylation patterns in GI cancers, researchers aim to enhance targeted treatments and discover new diagnostic tools.
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The number of patients with functional loss of bone and cartilage tissue has shown an increasing trend. Insufficient or inappropriate conventional treatments applied for trauma, orthopedic diseases, or other bone and cartilage-related disorders can lead to bone and cartilage damage. This represents a worldwide public health issue and a significant economic burden.

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Ever since its discovery, the notion of the Berry phase has permeated all branches of physics and plays an important part in a variety of quantum phenomena. However, so far all its realizations have been based on a continuous evolution of the quantum state, following a cyclic path. Here we introduce and demonstrate a conceptually new manifestation of the Berry phase in light-driven crystals, in which the electronic wavefunction accumulates a geometric phase during a discrete evolution between different bands, while preserving the coherence of the process.

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Multipotent mesenchymal stromal cells (MSCs)-derived extracellular vesicles (EVs) play important roles in cellular communication and are extensively studied as promising therapeutic agents. While there is a substantial pool of studies on liquid-phase EVs, data on EVs bound to the extracellular matrix (ECM) is lacking. There is also an emerging trend of accumulating and comparing data on characteristics of EVs obtained in different culturing conditions.

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The quality of soft tissue defect regeneration after dental surgeries largely determines their final success. Collagen membranes have been proposed for the healing of such defects, but in some cases, they do not guarantee a sufficient volume of the regenerated tissue and vascularization. For this purpose, lactoferrin, a protein with natural pro-regenerative, anti-inflammatory, and pro-angiogenic activity, can be added to collagen.

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Progesterone exerts multiple effects in different tissues through nuclear receptors (nPRs) and through membrane receptors (mPRs) of adiponectin and progestin receptor families. The effect of progesterone on the cells through different types of receptors can vary significantly. At the same time, it affects the processes of proliferation and apoptosis in normal and tumor tissues in a dual way, stimulating proliferation and carcinogenesis in some tissues, suppressing them and stimulating cell death in others.

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Optical alignment and optical orientation of excitons are studied experimentally on an ensemble of core/shell CdSe/CdS colloidal nanoplatelets. Linear and circular polarization of photoluminescence during resonant excitation of excitons is measured at cryogenic temperatures and with magnetic fields applied in the Faraday geometry. The developed theory addresses the optical alignment and optical orientation of excitons in colloidal nanocrystals, taking into account both bright and dark exciton states in the presence of strong electron-hole exchange interaction and the random in-plane orientation of nanoplatelets within the ensemble.

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We introduce an ultrafast all-optical approach for efficient chiral recognition that relies on the interference between two low-order nonlinear processes that are ubiquitous in nonlinear optics: sum-frequency generation and third-harmonic generation. In contrast to traditional sum-frequency generation, our approach encodes the medium's handedness in the intensity of the emitted harmonic signal, rather than in its phase, and it enables full control over the enantiosensitive response. We show how, by sculpting the sub-optical-cycle oscillations of the driving laser field, we can force one molecular enantiomer to emit bright light while its mirror twin remains dark, thus reaching the ultimate efficiency limit of chiral sensitivity via low-order nonlinear light-matter interactions.

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Aim: To study the processes of lipid peroxidation and the activity of antioxidant defense enzymes depending on the chemiluminescent activity of neutrophilic granulocytes in patients with gastric cancer associated with infection, depending on the stage.

Materials And Methods: A total of 39 patients with stage I-II gastric cancer and 30 patients with stage III-IV gastric cancer were examined. A study of the chemiluminescent activity of neutrophilic granulocytes was carried out and the parameters of the lipid peroxidation system and antioxidant protection in plasma were determined using the spectrophotometric method.

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The biogenic polyamines, spermidine (Spd) and spermine (Spm), are present at millimolar concentrations in all eukaryotic cells, where they participate in the regulation of vitally important cellular functions. Polyamine analogs and derivatives are a traditional and important instrument for the investigation of the cellular functions of polyamines, enzymes of their metabolism, and the regulation of the biosynthesis of antizyme-a key downregulator of polyamine homeostasis. Here, we describe convenient gram-scale syntheses of a set of -methylated analogs of Spd.

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