688 results match your criteria: "National Research Nuclear University "Moscow Engineering Physics Institute"[Affiliation]"

An analytical description of the separation probability of a geminate pair in organic semiconductors is given. The initial diffusion of "hot" twins is anomalously strong due to energy disorder. This circumstance significantly increases the photogeneration quantum yield at low temperatures and weakens its temperature dependence relative to predictions of the Onsager model, in agreement with Monte Carlo and experimental results.

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We propose an approximate method to calculate ion partition functions in the context of the chemical-picture representation of plasmas as an interacting mixture of various ions and free electrons under the local-thermodynamic-equilibrium conditions. The method uses the superconfiguration approach and implies that the first-order corrections to the energies of excited electron configurations due to the electron-electron interaction may be replaced by a similar first-order correction to the energy of the basic configuration of an ion with the same number of bound electrons. The method enables one to significantly speed up the calculations and generally provides quite accurate results.

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Proton therapy is one of the promising radiotherapy modalities for the treatment of deep-seated and unresectable tumors, and its efficiency can further be enhanced by using boron-containing substances. Here, we explore the use of elemental boron (B) nanoparticles (NPs) as sensitizers for proton therapy enhancement. Prepared by methods of pulsed laser ablation in water, the used B NPs had a mean size of 50 nm, while a subsequent functionalization of the NPs by polyethylene glycol improved their colloidal stability in buffers.

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Hyperglycemia exacerbates ischemic stroke not through increased generation of hydrogen peroxide.

Free Radic Biol Med

November 2023

M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, 117997, Russia. Electronic address:

Article Synopsis
  • Diabetes increases the risk of ischemic stroke by worsening cerebral damage due to hyperglycemia, though the exact mechanisms are not fully understood.
  • This study presents novel findings on the real-time dynamics of hydrogen peroxide (HO) in neuronal mitochondria during ischemic stroke, using advanced technology on both cultured cells and rat brains.
  • Results indicate that high blood sugar doesn't impact HO generation in the ischemic area but does worsen the overall effects of the stroke, revealing how elevated glucose levels can alter mitochondrial function in neurons.
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Article Synopsis
  • The study compared two wide field-of-view fluorescence imaging systems with different excitation wavelengths (405 nm and 635 nm) for diagnosing tumors.
  • Both systems were tested on tumor phantoms as well as in six patients with basal cell carcinoma and oral mucosa cancer, confirming the ability to define lesion boundaries and fluorescence intensity.
  • The 405 nm system outperformed the 635 nm system in distinguishing between tumor and healthy tissue for oral mucosal cancer, indicating greater effectiveness in eliminating background noise and providing consistent fluorescence quantification.
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Background: the objective of this study was to propose a methodology for the assessment of antimicrobial consumption (AMC) in pediatric inpatients and to estimate variances in consumption levels in multi-field hospitals with pediatric inpatients, calculated by means of the pediatric-adjusted methodology vs. the conventional methodology.

Methods: the pediatric-adjusted methodology based on the conventional ATC/DDD method and children's DDDs (cDDD) for antimicrobials were proposed and validated in a series of probabilistic sensitivity analyses of real clinical data extracted from the receipt notes of three multi-field hospitals.

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techniques have been used to investigate structural changes in semiconducting MgSi and CaSi thin films (from 17 nm down to 0.2 nm corresponding to the 2D structure) along with band-gap variations due to quantum confinement. Cubic MgSi(111) thin films being dynamically stable at thicknesses () larger than 0.

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We have developed a de novo method for the identification of dispersed repeats based on the use of random position-weight matrices (PWMs) and an iterative procedure (IP). The created algorithm (IP method) allows detection of dispersed repeats for which the average number of substitutions between any two repeats per nucleotide () is less than or equal to 1.5.

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We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider.

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Chiral light sources realized in ultracompact device platforms are highly desirable for various applications. Among active media used for thin-film emission devices, lead-halide perovskites have been extensively studied for photoluminescence due to their exceptional properties. However, up to date, there have been no demonstrations of chiral electroluminescence with a substantial degree of circular polarization (DCP) based on perovskite materials, being critical for the development of practical devices.

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Laser printing with cell spheroids can become a promising approach in tissue engineering and regenerative medicine. However, the use of standard laser bioprinters for this purpose is not optimal as they are optimized for transferring smaller objects, such as cells and microorganisms. The use of standard laser systems and protocols for the transfer of cell spheroids leads either to their destruction or to a significant deterioration in the quality of bioprinting.

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The field of cosmic radiation at low-Earth orbit (LEO) has a complex composition. It always contains a component of secondary charged particles, formed by the products of nuclear interactions of the primary high-energy radiation with the nuclei of spacecraft's shielding material, electronic components and biological matter on board. Generation of this secondary radiation can be observed in some track detectors in the form of "stars" formed by tracks-fragments with a common vertex.

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Photocatalytic H evolution is of prime importance in the energy crisis and in lessening environmental pollution. Adopting a single semiconductor as a photocatalyst remains a formidable challenge. However, the construction of an S-scheme heterojunction is a promising method for efficient water splitting.

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We present a general and numerically efficient method for calculation of collision integrals for interacting quantum gases on a discrete momentum lattice. Here we employ the original analytical approach based on Fourier transform covering a wide spectrum of solid-state problems with various particle statistics and arbitrary interaction models, including the case of momentum-dependent interaction. The comprehensive set of the transformation principles is given in detail and realized as a computer Fortran 90 library FLBE (Fast Library for Boltzmann Equation).

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Spectra of low-lying elementary excitations are critical to characterize properties of bosonic quantum fluids. Usually these spectra are difficult to observe, due to low occupation of non-condensate states compared to the ground state. Recently, low-threshold Bose-Einstein condensation was realised in a symmetry-protected bound state in the continuum, at a saddle point, thanks to coupling of this electromagnetic resonance to semiconductor excitons.

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Article Synopsis
  • Fluorescent hydrogels are effective portable biosensors for point-of-care diagnosis, offering better organic molecule binding than traditional test systems.
  • They provide more sensitive detection through fluorescence rather than colorimetric methods, making them superior for identifying analytes.
  • Moreover, these hydrogels are customizable, can be reused, and can be integrated with water-soluble fluorescent nanocrystals to maintain their optical properties for biological imaging.
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Heterogeneous nanostructures composed of metastable tetragonal 1T-MoS and stable hexagonal 2H-MoS phases are highly promising for a wide range of applications, including catalysis and ion batteries, due to the high electrical conductivity and catalytic activity of the 1T phase. However, a controllable synthesis of stabilized 1T-MoS films over the wafer-scale area is challenging. In this work, a metal-organic chemical vapor deposition process allowing us to obtain ultrathin MoS films containing both 1T and 2H phases and control their ratio through rhenium doping was suggested.

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Purpose: Secondary acquired lacrimal duct obstruction (SALDO) is one of the complications of radioiodine therapy. SALDO is formed a few months after therapy if there is a sufficient uptake of radioactive iodine by the nasolacrimal duct. To date, risk factors leading to SALDO are unclear.

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Broadband Optical Properties of BiSe.

Nanomaterials (Basel)

April 2023

Center for Photonics and 2D Materials, Moscow Institute of Physics and Technology, 9 Institutsky Lane, Dolgoprudny 141700, Russia.

Article Synopsis
  • High optical constants in materials are crucial for effective light manipulation in nanophotonics applications.
  • Van der Waals (vdW) materials like BiSe exhibit strong optical responses due to their unique bonding characteristics, showing minimal variation (about 10%) in optical constants across different synthesis methods.
  • This consistency leads to reliable performance in devices such as biosensors and therapeutic nanoparticles, unlike other vdW materials that can have more significant variability.
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Localization constitutes a critical challenge for autonomous mobile robots, with flattened walls serving as a fundamental reference for indoor localization. In numerous scenarios, prior knowledge of a wall's surface plane is available, such as planes in building information modeling (BIM) systems. This article presents a localization technique based on a-priori plane point cloud extraction.

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We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.

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Despite the wide variety of available cationic lipid platforms for the delivery of nucleic acids into cells, the optimization of their composition has not lost its relevance. The purpose of this work was to develop multi-component cationic lipid nanoparticles (LNPs) with or without a hydrophobic core from natural lipids in order to evaluate the efficiency of LNPs with the widely used cationic lipoid DOTAP (1,2-dioleoyloxy-3-[trimethylammonium]-propane) and the previously unstudied oleoylcholine (Ol-Ch), as well as the ability of LNPs containing GM3 gangliosides to transfect cells with mRNA and siRNA. LNPs containing cationic lipids, phospholipids and cholesterol, and surfactants were prepared according to a three-stage procedure.

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The therapeutic potential of short interfering RNA (siRNA) to treat many diseases that are incurable with traditional preparations is limited by the extensive metabolism of serum nucleases, low permeability through biological membrane barriers because of a negative charge, and endosomal trapping. Effective delivery vectors are required to overcome these challenges without causing unwanted side effects. Here, we present a relatively simple synthetic protocol to obtain positively charged gold nanoparticles (AuNPs) with narrow size distribution and the surface modified with Tat-related cell-penetrating peptide.

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MOSFE-Capacitor Silicon Carbide-Based Hydrogen Gas Sensors.

Sensors (Basel)

April 2023

Engineering Center of Microtechnology and Diagnostics, St. Petersburg Electrotechnical University (ETU «LETI»), Professora Popova str. 5, 197022 St. Petersburg, Russia.

The features of the wide band gap SiC semiconductor use in the capacitive MOSFE sensors' structure in terms of the hydrogen gas sensitivity effect, the response speed, and the measuring signals' optimal parameters are studied. Sensors in a high-temperature ceramic housing with the Me/TaO/SiC/4H-SiC structures and two types of gas-sensitive electrodes were made: Palladium and Platinum. The effectiveness of using Platinum as an alternative to Palladium in the MOSFE-Capacitor (MOSFEC) gas sensors' high-temperature design is evaluated.

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