95 results match your criteria: "St. Petersburg Electrotechnical University[Affiliation]"

Dislocation Filter Based on LT-GaAs Layers for Monolithic GaAs/Si Integration.

Nanomaterials (Basel)

December 2022

Laboratory of Physical Bases of Semiconductor Heterostructures Epitaxy, Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.

Article Synopsis
  • - The study explores using low-temperature (LT) GaAs layers as a method to reduce dislocation defects in GaAs/Si heterostructures by investigating the effects of these layers and post-growth annealing.
  • - Results showed that introducing LT-GaAs layers and performing cyclic annealing significantly reduced dislocation density, surface roughness, and non-radiative recombination centers in the GaAs/Si regions.
  • - The improvements in the quality of near-surface GaAs layers are attributed to elastic deformations causing dislocation line bending and gallium vacancies diffusing into the GaAs layers, making these heterostructures suitable for high-quality light-emitting applications with quantum dots.
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Background and Objectives: Candida albicans causes various diseases ranging from superficial mycoses to life-threatening systemic infections often associated with biofilm formation, including mixed fungal−bacterial consortia. The biofilm matrix protects cells, making Candida extremely resistant to treatment. Here, we show that the bovhyaluronidase azoximer (Longidaza®) in vitro destroys the biofilm formed by either C.

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Article Synopsis
  • Small heat shock proteins (sHSPs) like IbpA help maintain protein stability in cells, preventing damage from environmental stressors.
  • In Acholeplasma laidlawii, IbpA interacts with the division protein FtsZ, a first for prokaryotes, and this interaction aids in protein stability during temperature fluctuations.
  • The study shows that IbpA enhances FtsZ's stability and polymerization at both low (4°C) and high (42°C) temperatures, contributing to cell division under stressful conditions.
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Sensors based on chaotic oscillators have a simple design, combined with high sensitivity and energy efficiency. Among many developed schemes of such sensors, the promising one is based on the Duffing oscillator, which possesses a remarkable property of demonstrating chaotic oscillations only in the presence of a weak sine wave at the input. The main goal of this research was to evaluate the maximal sensitivity of a practically implemented metal detector based on the Duffing oscillator and compare its sensitivity with conventional sensors.

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Due to difficulties in obtaining monomaterials, intensive research into the properties of ceramic compositions has been undertaken, along with developments to the properties of the compositions. These are not inferior to monomeric structures for a number of basic parameters. Among the different types of ceramics, magnesium fluoride and zinc sulfide occupy a special place due to their unique properties and specific applications.

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Holographic interferometry is a well-established field of science and optical engineering. It has a half-century history of successful implementation as the solution to numerous technical tasks and problems. However, fast progress in digital and computer holography has promoted it to a new level of possibilities and has opened brand new fields of its application.

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A rare case of oncocytic Schneiderian papilloma originating from the sphenoid sinus characterised, for 3 years, by non-specific symptoms of severe headache, a block of nasal breathing, and deprecating sense of smell was presented by an elderly female patient. Sphenoid sinus functional endoscopic sinus surgery (FESS), with a one-block tumour excision, through an endonasal approach, with a histological study of removed tumour masses, were performed on the patient. Long observation in the post-operative period was necessary, considering the risk of recurrence and malignancy of oncocytic Schneiderian papilloma (OSP).

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Advances in Material Nanosensitization: Refractive Property Changes as the Main Parameter to Indicate Organic Material Physical-Chemical Feature Improvements.

Materials (Basel)

March 2022

Lab for Photophysics of Media with Nanoobjects, Vavilov State Optical Institute, Kadetskaya Liniya V.O., Dom 5, Korp.2/Babushkina Str., Dom 36, Korp.1, 199053 St. Petersburg, Russia.

In the current paper, the results of the sensitization process' influence on the refractive organic materials' features are shown. The correlation between the refractive properties and the intermolecular charge transfer effect of doped organic thin films are shown via estimation of the laser-induced change in the refractive index. The refractive parameter is shown for a model organics matrix based on a polyimide doped with fullerenes, carbon nanotubes, reduced graphene oxides, etc.

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Currently, personal data collection and processing are widely used while providing digital services within mobile sensing networks for their operation, personalization, and improvement. Personal data are any data that identifiably describe a person. Legislative and regulatory documents adopted in recent years define the key requirements for the processing of personal data.

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Article Synopsis
  • This study enhances the calculation of nuclear moments by integrating an iterative solution for core triple cluster amplitudes into the relativistic coupled-cluster method, improving precision.
  • It focuses on the low-lying states of ^{229}Th^{3+} to compute hyperfine structure constants and various corrections to the properties.
  • The researchers determine the nuclear magnetic dipole and electric quadrupole moments, achieving a significant reduction in the uncertainty of the quadrupole moment and exploring the effect of nuclear magnetization distribution.
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This paper proposes a novel identification method for memristive devices using Knowm memristors as an example. The suggested identification method is presented as a generalized process for a wide range of memristive elements. An experimental setup was created to obtain a set of intrinsic I-V curves for Knowm memristors.

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Objective: To analyze the health resort care (HRC) system for people with disabilities and provide the rationale of the HRC system improvements.

Material And Methods: A content analysis of the regulatory framework and analysis of data from the Forms of Federal Statistical Monitoring of Rosstat, the Russian Ministry of Health, and the Russian Ministry of Labor were performed.

Results: The 19 main legal and regulatory documents are presented, and the 16 main areas of legal regulation on the HRC organization are highlighted.

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Scanning tunneling spectroscopy in ultrahigh vacuum conditions and conductive atomic-force microscopy in ambient conditions were used to study local electroresistive properties of ferroelectric tunnel junctions SrTiO/LaSrMnO/BaTiO. Interestingly, experimental current-voltage characteristics appear to strongly depend on the measurement technique applied. It was found that screening conditions of the polarization charges at the interface with a top electrode differ for two scanning probe techniques.

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Physical mechanisms underlying the multilevel resistive tuning over seven orders of magnitude in structures based on TiO/AlO bilayers, sandwiched between platinum electrodes, are responsible for the nonlinear dependence of the conductivity of intermediate resistance states on the writing voltage. To improve the linearity of the electric-field resistance tuning, we apply a contact engineering approach. For this purpose, platinum top electrodes were replaced with aluminum and copper ones to induce the oxygen-related electrochemical reactions at the interface with the AlO switching layer of the structures.

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While in a biofilm, bacteria are extremely resistant to both antimicrobials and the immune system, leading to the development of chronic infection. Here, we show that bovine hyaluronidase fused with a copolymer of 1,4-ethylenepiperazine N-oxide and (N-carboxymethyl) -1,4-ethylenepiperazinium bromide (Longidaza) destroys both mono- and dual-species biofilms formed by various bacteria. After 4 h of treatment with 750 units of the enzyme, the residual biofilms of , , , and preserved about 50-70% of their initial mass.

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Identification of small molecules is a critical task in various areas of life science. Recent advances in mass spectrometry have enabled the collection of tandem mass spectra of small molecules from hundreds of thousands of environments. To identify which molecules are present in a sample, one can search mass spectra collected from the sample against millions of molecular structures in small molecule databases.

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Chitosan, the product of chitin deacetylation, is an excellent candidate for enzyme immobilization purposes. Here we demonstrate that papain, an endolytic cysteine protease (EC: 3.4.

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A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range.

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Potential advantages of chiral molecules for a sensitive search for parity violating cosmic fields are highlighted. Such fields are invoked in different models for cold dark matter or in the Lorentz-invariance violating standard model extensions and thus are signatures of physics beyond the standard model. The sensitivity of a 20-year-old experiment with the molecule CHBrClF to pseudovector cosmic fields as characterized by the parameter |b_{0}^{e}| is estimated to be O(10^{-12}  GeV) employing ab initio calculations.

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Many pathogenic bacteria and microscopic fungi form rigid polymicrobial biofilms this way enhancing their resistant to treatment. A series of novel pyridoxine-based quaternary ammonium derivatives of terbinafine characterized by both antifungal and antibacterial activities was designed. The leading compound named KFU-127 exhibits promising antifungal and antibacterial activities against various bacteria and micromycetes in both planktonic and biofilm-embedded forms demonstrating MIC values comparable with those of conventional antifungals and antimicrobials.

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A combined study of local structural, electric and ferroelectric properties of SrTiO[Formula: see text]/La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]/BaTiO[Formula: see text] heterostructures was performed by Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy in the temperature range 30-295 K. The direct correlation of film structure (epitaxial, nanocrystalline or polycrystalline) with local electric and ferroelectric properties was observed. For polycrystalline ferroelectric films the predominant polarization state is defined by the peculiarity of screening the built-in field by positively charged point defects.

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Biofouling is among the key factors slowing down healing of acute and chronic wounds. Here we report both anti-biofilm and wound-healing properties of the chitosan-immobilized Ficin. The proposed chitosan-adsorption approach allowed preserving ~90% of the initial total activity of the enzyme (when using azocasein as a substrate) with stabilization factor of 4.

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In mixed infections, the bacterial susceptibility differs significantly compared to monocultures of bacteria, and generally the concentrations of antibiotics required for the treatment increases drastically. For S. aureus and P.

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Development of molecular beam epitaxy (MBE) of two-dimensional (2D) layered materials is an inevitable step in realizing novel devices based on 2D materials and heterostructures. However, due to existence of numerous polytypes and occurrence of additional phases, the synthesis of 2D films remains a difficult task. This paper reports on MBE growth of GaSe, InSe, and GaTe layers and related heterostructures on GaAs(001) substrates by using a Se valve cracking cell and group III metal effusion cells.

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For more than 40 years, most astrophysical observations and laboratory studies of two key soft x-ray diagnostic 2p-3d transitions, 3C and 3D, in Fe XVII ions found oscillator strength ratios f(3C)/f(3D) disagreeing with theory, but uncertainties had precluded definitive statements on this much studied conundrum. Here, we resonantly excite these lines using synchrotron radiation at PETRA III, and reach, at a millionfold lower photon intensities, a 10 times higher spectral resolution, and 3 times smaller uncertainty than earlier work. Our final result of f(3C)/f(3D)=3.

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