Rev Sci Instrum
December 2024
A new high energy proton radiography facility PRIOR-II (Proton Microscope for FAIR) has been designed, constructed, and successfully commissioned at the GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany) pushing the technical boundaries of charged particle radiography with normal conducting magnets to the limits. The setup is foreseen to become a new and powerful user facility for carrying out fundamental science experiments in the fields of plasma and shock wave physics, material science, and medical physics. It will help address several unsolved scientific challenges, which require high-speed and precise non-invasive diagnostic methods capable of probing matter with up to 100 g/cm2 areal density.
View Article and Find Full Text PDFThe NRF2 transcriptional factor is a member of cellular stress response machinery and is activated in response to oxidative stress caused either by cellular homeostasis imbalance or by environmental challenges. NRF2 levels are stringently controlled by rapid and continuous proteasomal degradation. KEAP1 is a specific NRF2 binding protein that acts as a bridge between NRF2 and the E3 ligase Cullin-3.
View Article and Find Full Text PDFHerein, we describe a diastereoselective and straightforward synthetic approach to polysubstituted spirocyclic bis-lactams bearing both β- and γ-lactam cores with diverse substitution patterns. The method developed is based on a microwave-assisted Wolff rearrangement/Staudinger [2 + 2] cycloaddition sequence involving 3-diazopiperidine-2,4-diones and imines. The corresponding reaction tolerates a wide range of functionalities in both substrates, giving the target bis-lactams in generally high yields.
View Article and Find Full Text PDFMonitored tomographic reconstruction (MTR) is a potentially powerful tool for dose and time reduction in computed tomography scanning. We are the first to study the issue of practical implementation of MTR protocols in current-generation real-life instruments. We propose an empirical quantitative model for calculating acquisition and reconstruction times.
View Article and Find Full Text PDFRing artifacts pose a major barrier to obtaining precise reconstruction in computed tomography (CT). The presence of ring artifacts complicates the use of automatic means of processing CT reconstruction results, such as segmentation, correction of geometric shapes, alignment of reconstructed volumes. Although there are numerous efficient methods for suppressing ring artifacts, many of them appear to be manual.
View Article and Find Full Text PDFFluorescence of the vast majority of natural opsin-based photoactive proteins is extremely low, in accordance with their functions that depend on efficient transduction of absorbed light energy. However, several recently proposed classes of engineered rhodopsins with enhanced fluorescence, along with the discovery of a new natural highly fluorescent rhodopsin, NeoR, opened a way to exploit these transmembrane proteins as fluorescent sensors and draw more attention to studies on this untypical rhodopsin property. Here, we review the available data on the fluorescence of the retinal chromophore in microbial and animal rhodopsins and their photocycle intermediates, as well as different isomers of the protonated retinal Schiff base in various solvents and the gas phase.
View Article and Find Full Text PDFWe employed the selective-area-epitaxy technique using metalorganic chemical vapor deposition to fabricate and study samples of semiconductor heterostructures that incorporate highly strained InGaAs quantum wells (980-990 nm emission wavelength). Selective area epitaxy of InGaAs quantum wells was performed on templates that had a patterned periodic structure consisting of a window (where epitaxial growth occurred) and a passive mask (where epitaxial growth was suppressed), each with a width of 100 µm for every element. Additionally, a selectively grown potential barrier layer was included, which was characterized by an almost parabolic curvature profile of the surface.
View Article and Find Full Text PDFComputed tomography is a powerful tool for medical examination, which plays a particularly important role in the investigation of acute diseases, such as COVID-19. A growing concern in relation to CT scans is the radiation to which the patients are exposed, and a lot of research is dedicated to methods and approaches to how to reduce the radiation dose in X-ray CT studies. In this paper, we propose a novel scanning protocol based on real-time monitored reconstruction for a helical chest CT using a pre-trained neural network model for COVID-19 detection as an expert.
View Article and Find Full Text PDFMembrane potential is a fundamental property of biological cells. Changes in membrane potential characterize a vast number of vital biological processes, such as the activity of neurons and cardiomyocytes, tumorogenesis, cell-cycle progression, etc. A common strategy to record membrane potential changes that occur in the process of interest is to utilize organic dyes or genetically-encoded voltage indicators with voltage-dependent fluorescence.
View Article and Find Full Text PDFWe report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.
View Article and Find Full Text PDFThe human olfactory bulb (OB) has a laminar structure. The segregation of cell populations in the OB image poses a significant challenge because of indistinct boundaries of the layers. Standard 3D visualization tools usually have a low resolution and cannot provide the high accuracy required for morphometric analysis.
View Article and Find Full Text PDFVarious government and commercial services, including, but not limited to, e-government, fintech, banking, and sharing economy services, widely use smartphones to simplify service access and user authorization. Many organizations involved in these areas use identity document analysis systems in order to improve user personal-data-input processes. The tasks of such systems are not only ID document data recognition and extraction but also fraud prevention by detecting document forgery or by checking whether the document is genuine.
View Article and Find Full Text PDFWe report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed.
View Article and Find Full Text PDFThe article presents a study of the antioxidant properties of meat from lambs that received organic forms of iodine and selenium during growth. This meat was included in diets of laboratory animals using a model of acute toxic hepatitis. The experiments resulted in developing and testing a technique that was effective in enriching lamb with bioorganic elements of iodine and selenium and contributed to the activation metabolism in the bodies of animals consuming the meat.
View Article and Find Full Text PDFOne of the classical approaches to solving color reproduction problems, such as color adaptation or color space transform, is the use of a low-parameter spectral model. The strength of this approach is the ability to choose a set of properties that the model should have, be it a complete coverage of a color triangle or an accurate description of the addition or multiplication of spectra, knowing only the tristimulus corresponding to them. The disadvantage is that some of the properties of the mentioned spectral models are confirmed only experimentally.
View Article and Find Full Text PDFAzobenzene/tetraethyl ammonium photochromic ligands (ATPLs) are photoactive compounds with a large variety of photopharmacological applications such as nociception control or vision restoration. Absorption band maximum and lifetime of the less stable isomer are important characteristics that determine the applicability of ATPLs. Substituents allow to adjust these characteristics in a range limited by the azobenzene/tetraethyl ammonium scaffold.
View Article and Find Full Text PDFIEEE J Biomed Health Inform
August 2022
Video gaming and eSports is a quickly developing industry already involving billions of players worldwide. Gaming and eSports tournaments require strong mental abilities to avoid severe stress and other negative consequences upon completing the game. In this article, we report on the impact of emotions on a team performance.
View Article and Find Full Text PDFJ Electr Bioimpedance
January 2021
The BIA primary result sheets as a rule contain one-dimensional graphical scales with a selected area of normal values. In 1994, Piccoli . proposed BIVA, an alternative form of BIA data presentation, where two bioimpedance parameters are considered simultaneously as tolerance ellipses: resistance and reactance normalized to height.
View Article and Find Full Text PDFJ Chem Theory Comput
September 2021
We present a novel technique for computing the free energy differences between two chromophore "isomers" hosted in a molecular environment (a generalized solvent). Such an environment may range from a relatively rigid protein cavity to a flexible solvent environment. The technique is characterized by the application of the previously reported "average electrostatic solvent configuration" method, and it is based on the idea of using the free energy perturbation theory along with a chromophore annihilation procedure in thermodynamic cycle calculations.
View Article and Find Full Text PDFAim To study features of diagnosis and treatment of acute myocardial infarction (AMI) in Russian hospitals, results of the treatment, and early and late outcomes (6 and 12 months after AMI diagnosis); to evaluate the consistence of the treatment with clinical guidelines; and to evaluate patients' compliance with the treatment.Material and methods The program was designed for 3 years, including 24 months for recruitment of patients to the study. The study will include 10, 000 patients hospitalized with a confirmed diagnosis (I21 according to ICD-10) of ST segment elevation acute myocardial infarction (MI) (STEMI) or non-ST segment elevation MI (NSTEMI) based on criteria of the European Society of Cardiology Guidelines on Forth Universal Definition of Myocardial Infarction (2018).
View Article and Find Full Text PDFWe report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616 GeV^{2})=0.
View Article and Find Full Text PDFTwo-dimensional nanomaterials such as graphene can provide various functional properties to textiles, which have great potential in sportswear, healthcare etc. In this study, the properties of nylon and cotton-based electronic textiles coated with reduced graphene oxide are investigated. After reduction of graphene oxide coating in hydrazine vapor, e-textiles with a resistance of ~350 Ω/sq for nylon, and ~1 kΩ/sq for cotton were obtained.
View Article and Find Full Text PDFA typical feature of proteins from the rhodopsin family is the sensitivity of their absorption band maximum to protein amino acid composition. For this reason, studies of these proteins often require methodologies that determine spectral shift caused by amino acid substitutions. Generally, quantum mechanics/molecular mechanics models allow for the calculation of a substitution-induced spectral shift with high accuracy, but their application is not always easy and requires special knowledge.
View Article and Find Full Text PDFIn this review, we aim to introduce the reader to the technique of electrical impedance spectroscopy (EIS) with a focus on its biological, biomaterials, and medical applications. We explain the theoretical and experimental aspects of the EIS with the details essential for biological studies, i.e.
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