Publications by authors named "Sergeev A"

Solution-processed metal halide perovskites are widely studied for their potential in high-efficiency light-emitting diodes, yet they are facing several challenges like insufficient brightness, short operational lifetimes, and reduced power conversion efficiency under practical operation conditions. Here, we develop an interfacial amidation reaction on sacrificial ZnO substrates to produce perovskite films with low trap density (1.2 × 10cm), and implement a device structure featuring a mono-molecular hole-injection layer and an all-inorganic bi-layered electron-injection layer.

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Background: The methylation of cytosine residues at CpG sites within the O6-methylguanine-DNA methyltransferase () promoter is a key biomarker in glioblastoma therapy. The promoter (MGMTp) contains multiple guanine-rich sequences capable of folding into G-quadruplexes (G4s), but their relevance for MGMTp methylation is poorly understood.

Objectives: Our study explores the impact of potential G-quadruplex-forming sequences (PQS) in the promoter CpG island on the activity of de novo DNA methyltransferase Dnmt3a.

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Introduction: This work provides preclinical in vitro studies of an innovative antimicrobial agent named pyridosept, belonging to the quaternary bis-ammonium salts and synthesized on the base of pyridoxine. Since the wide spread of pathogens with tolerance to both antibiotics and antiseptics challenges the development of new antimicrobials providing high efficiency against fungi and microorganisms with multiple resistance.

Method: This work presents in vitro studies of pyridosept, such as antibacterial and anti-fungal activities (determination of minimal inhibitory concentration and quantitative suspension test method), as well as antibacterial activity of metal surface test, sporicidal and spermicidal activities, formation of resistance (to bacteria and fungi), Skin-PAMPA (study of membrane transdermal permeability), mutagenicity assays (in Ames test and OS-chromotest), cytotoxicity (MTT-assay) and comet assay in human skin fibroblasts.

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Two-dimensional tin halide perovskites are of significant interest for light emitting applications. Here, we investigate the effect of organic cation A on the stability of different Dion-Jacobson tin-based halide perovskites. The ASnBr materials using diammonium cation A with shorter alkyl chains are found to exhibit improved stability, exhibiting dramatic stability difference between the most stable HDASnBr, where HDA denotes 1,6-hexanediammonium, and two materials with 8- and 10-carbon alkyl chain ammonium cations.

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Objective: The aim of the study was to clarify the clinical and psychological characteristics of girls with ADHD at different age periods.

Material And Methods: During the screening study, outpatient records of 1430 children with ADHD were analyzed, among which two age groups were identified (872 children with ADHD aged 7-8 years, 558 adolescents with ADHD aged 13-14 years). The control group consisted of 60 girls without psychoneurological pathology (30 aged 7-8 years and 30 aged 13-14 years).

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Although mRNA vaccines encapsulated in lipid nanoparticles (LNPs) have demonstrated a safety profile with minimal serious adverse events in clinical trials, there is opportunity to further reduce mRNA reactogenicity. The development of naked mRNA vaccines could improve vaccine tolerability. Naked nucleic acid delivery using the jet injection method may be a solution.

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Giant dimeric acceptors (GDAs), a sub-type of acceptor materials for organic solar cells (OSCs), have garnered much attention due to the synergistic advantages of their monomeric and polymeric acceptors, forming a well-defined molecular structure with a giant molecular weight for high efficiency and stability. In this study, for the first time, two new GDAs, DYF-V and DY2F-V are designed and synthesized for OSC operation, by connecting one vinylene linker with the mono-/di-fluorinated end group on two Y-series monomers, respectively. After fluorination, both DYF-V and DY2F-V exhibit bathochromic absorption and denser packing modes due to the stronger intramolecular charge transfer effect and torsion-free backbones.

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Redox-active polymer gels are promising materials for various applications, such as energy conversion and storage systems, organic electronics, soft-robotics, sensors and others. This is in part due to the remarkable structural tunability of these materials. The gel may adopt different conformations depending on the crosslinking density, solvent temperature and other conditions.

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The chemical modifications of DNA are of pivotal importance in the epigenetic regulation of cellular processes. Although the function of 5-methylcytosine (5mC) has been extensively investigated, the significance of 5-hydroxymethylcytosine (5hmC) has only recently been acknowledged. Conventional methods for the detection of DNA methylation frequently lack the capacity to distinguish between 5mC and 5hmC, resulting in the combined reporting of both.

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Article Synopsis
  • This study focuses on improving light emission from perovskite nanocrystal films, which are important for light-emitting devices, by using a TiO grating to enhance light extraction.
  • The research found that this method resulted in a 10-fold increase in emission intensity and a reduction in photoluminescence lifetime, indicating a more efficient light output.
  • Results from various imaging techniques revealed how the grating interacts with the nanocrystals, paving the way for developing higher-performing perovskite optoelectronic devices.
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The annual number of reported human cases of flavivirus infections continues to increase. Measures taken by local healthcare systems and international organizations are not fully successful. In this regard, new approaches to treatment and prevention of flavivirus infections are relevant.

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Article Synopsis
  • - Chiral semiconducting nanomaterials, like AgBiS nanocrystals (NCs), have great potential in various fields, but achieving a strong circular dichroism (CD) signal has been challenging due to complex surface engineering and unclear mechanisms.
  • - A new strategy involving chiral ligand exchange with cysteine was developed, leading to significant enhancements in the CD signal in the near-UV region, with peaks at 260 and 320 nm, which help explain the ligand binding effects on the signal.
  • - The research utilized density-functional theory to show how ligand interactions cause crystal distortion and efficient electron transfer, resulting in an impressive CD signal, which was further validated by creating a spin-filter device with over 86
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Dinuclear complexes bearing Ru(II) photoactive centers are of interest for the development of efficient dual catalysts for many photocatalyzed reactions. Ditopic polypyridine ligands, bis(pyridin-2-yl)amino-1,10-phenanthrolines, containing an additional coordination site (bis(pyridin-2-yl)amine, dpa) at positions 3, 4 or 5 of the 1,10-phenanthroline core (Phen-3NPy2, Phen-4NPy2 and Phen-5NPy2) were synthesized. They were used as bridging ligands to obtain dinuclear complexes [(bpy)Ru(Phen-NPy2)PdCl](PF) (Ru(Phen-NPy2)Pd) in good yields stepwise complexation.

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Zero-dimensional CsCuX (X=Cl, Br, or I), the intensively studied light-emitting materials, generally exhibit single-band emissions from intrinsic self-trapped excitons (STEs), while defect-induced (extrinsic) STEs were considered nonemissive. Herein, we observed a dual-band emission from intrinsic and extrinsic STEs for CsCuBr at low temperature, and their emission mechanisms are elucidated. The intrinsic and extrinsic STEs are trapped from different initial states, with remarkably large trapping depths (>900 meV) evaluated at 50 K, indicating their negligible detrapping rates.

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Single-component organic solar cells based on double cable polymers have achieved remarkable performance, with DCPY2 reaching a high efficiency of over 13%. In this study, DCPY2 is further optimized with an efficiency of 13.85%, maintaining a high fill factor (FF) without compromising the short circuit current.

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Article Synopsis
  • - The vaccinia virus has been historically used as a smallpox vaccine, but due to its reactogenicity, WHO recommended discontinuation after smallpox was eradicated, leading to a rise in orthopoxvirus infections, notably the 2022 monkeypox epidemic.
  • - Researchers developed modified VACV strains, LAD and LADA, with specific genetic alterations to reduce reactogenicity while enhancing the immune response compared to the original L strain.
  • - Both LAD and LADA strains demonstrated superior cellular immune responses and higher levels of VACV-specific IgG in vaccinated mice, indicating their potential as safer and more effective vaccines against orthopoxvirus infections.
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The application of solar-thermal surfaces for antifrosting and defrosting has emerged as a passive and environmentally friendly approach to mitigate the negative consequences of frost formation, such as structural damage and reduced heat transfer efficiency. However, achieving robust all-day frostphobicity solely through interfacial modification and solar-thermal effects is challenging in practical applications: The thick frost that accumulates at night strongly scatters solar radiation, rendering the solar-thermal coatings ineffective during the daytime. Additionally, these nanostructured coatings are susceptible to wear and tear when exposed to the outdoors for extended periods of time.

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We develop computational mechanical modeling and methods for the analysis and simulation of the motions of a human body. This type of work is crucial in many aspects of human life, ranging from comfort in riding, the motion of aged persons, sports performance and injuries, and many ergonomic issues. A prevailing approach for human motion studies is through lumped parameter models containing discrete masses for the parts of the human body with empirically determined spring, mass, damping coefficients.

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Rapid hot-carrier/exciton cooling constitutes a major loss channel for photovoltaic efficiency. How to decelerate the hot-carrier/exciton relaxation remains a crux for achieving high-performance photovoltaic devices. Here, we demonstrate slow hot-exciton cooling that can be extended to hundreds of picoseconds in colloidal HgTe quantum dots (QDs).

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Aquaculture supplies the world food market with a significant amount of valuable protein. Highly productive aquaculture fishes can be derived by utilizing genome-editing methods, and the main problem is to choose a target gene to obtain the desirable phenotype. This paper presents a review of the studies of genome editing for genes controlling body development, growth, pigmentation and sex determination in five key aquaculture Salmonidae and Cyprinidae species, such as rainbow trout (), Atlantic salmon (), common carp (), goldfish (), Gibel carp () and the model fish zebrafish ().

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Producing heterostructures of cesium lead halide perovskites and metal-chalcogenides in the form of colloidal nanocrystals can improve their optical features and stability, and also govern the recombination of charge carriers. Herein, the synthesis of red-emitting CsPbI/ZnSe nanoheterostructures is reported via an in situ hot injection method, which provides the crystallization conditions for both components, subsequently leading to heteroepitaxial growth. Steady-state absorption and photoluminescence studies alongside X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy analysis evidence on a type-I band alignment for CsPbI/ZnSe nanoheterostructures, which exhibit photoluminescence quantum yield of 96% due to the effective passivation of surface defects, and an enhancement in carrier lifetime.

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Article Synopsis
  • The H5N8 avian influenza virus poses a risk to bird populations and potential human health concerns, necessitating the development of a safe and effective vaccine.
  • Researchers created an experimental pVAX-H5 DNA vaccine that encodes a modified version of the virus's hemagglutinin and tested it on mice, resulting in a strong antibody and T-cell response.
  • Both liquid and lyophilized versions of the pVAX-H5 vaccine provided complete protection for mice against lethal influenza A virus challenges, showing promise as a candidate for combating H5N8.
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Study of swirling flows in channels corresponding to the static approximation of flow channels of the heart and major vessels with a longitudinal-radial profile zR = const and a concave streamlined surface at the beginning of the longitudinal coordinate has been carried out. A comparative analysis of the flow structure in channel configurations zR = const, where N = -1, 1, 2, 3, in the absence and presence of a concave surface was carried out. The numerical modeling was compared with the results of hydrodynamic experiments on the flow characteristics and the shape of the flow lines.

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The methylation of cytosines at CpG sites in DNA, carried out de novo by DNA methyltransferase Dnmt3a, is a basic epigenetic modification involved in gene regulation and genome stability. Aberrant CpG methylation in gene promoters leads to oncogenesis. In oncogene promoters, CpG sites often colocalize with guanine-rich sequences capable of folding into G-quadruplexes (G4s).

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Polymer microgel particles decorated with redox-active functional groups are a new and promising object for electrochemical applications. However, the process of charge exchange between an electrode and a microgel particle carrying numerous redox-active centers differs fundamentally from charge exchange involving only molecular species. A single act of contact between the microgel and the electrode surface may not be enough to fully discharge the microgel, and partial charge states are to be expected.

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