The purpose of this study is to highlight the modern possibilities of magnetic resonance as a unique method for assessing and visualizing living systems from the standpoint of chemistry and physics, ...in particular, from the standpoint of biochemistry and biophysics of metabolism: circulation and mass transfer of protons as a part of water and macromolecules due to flow, diffusion, and perfusion effects in tissues. The main sections of the review are devoted to the use of the mapping method of the macromolecular proton fraction for the determination of the biochemical composition of tissues, evaluation of free diffusion of molecules based on diffusion-tensor and diffusion-kurtosis magnetic resonance tomography (MRI), analysis of the mass transfer of protons in human body fluids due to the flow (circulation) and perfusion effects in the permeable tubular structures (vessels), as well as in complex multicomponent life support systems of the human central nervous system. The effects of oxy- and deoxyhemoglobin conversions during cognitive disorders are specially considered. The results obtained by the listed MRI techniques are used in the construction of models of proton, macromolecular, cellular, and system interactions in living systems.
Abstract
The mechanisms of origin of ultrahigh-energy gamma radiation are poorly studied. One way to find out is to search for temporal and directional coincidences of high-energy galactic neutrinos ...with photons of similar energies. The results of such a search could provide indications of the hadronic origin of this radiation. In this paper, we report on the search for photons with energies above 300 TeV in coincidence with high–energy neutrinos. The searches of ultrahigh–energy gammas were carried out at the Carpet–2 EAS array, using three years of data taking.
The Carpet-3 air shower array is being built at the Baksan Neutrino Observatory, which is located near Mount Elbrus (North Caucasus) at an altitude of 1700 m above sea level. The main aim of the ...experiment is gamma-ray astronomy in the energy range above 100 TeV to search for diffuse gamma radiation and sources and to study the generation mechanisms of this radiation. The paper provides an overview of the current state of the experiment, as well as its prospects.
The Carpet-3 array at the Baksan Neutrino Observatory is designed to detect extensive air showers generated by primary cosmic rays of more than 100 TeV in energy. The main aim is to search for cosmic ...extrahigh-energy gamma rays. In this work, we describe the current state of the facility and the results from searching for extrahigh-energy photons from regions of the localization of candidates for gravitational-wave events detected by LIGO/Virgo during the third observational period.
The purpose of the work is to select and substantiate the design of a conformal antenna array for a medical microwave radiothermograph to be used for gynecology. The results of calculations ...confirming the possibility of manufacturing a conformal antenna array for a microwave radiothermograph are presented. The optimal dimensions of the conformal antenna array and its components were determined in the course of the work. The antenna has an antenna diameter of 18 mm, and the total length of the antenna is 180 mm. The antenna is designed in such a way as to detect the pathology of the pelvic organs of small sizes, located at a depth of 4-18 mm or deeper), as well as for temperature monitoring of small ones with an error of ±0.3 \circ C. The use of a conformal antenna array as part of a microwave radiothermograph has a high potential in gynecology, for pregnancy planning, primary diagnosis of cancer, monitoring of biological indicators.
Chemical investigation of a coculture of the marine-derived fungi Beauveria felina KMM 4639 and Aspergillus carneus KMM 4638 led to the identification of three new drimane-type sesquiterpenes, ...asperflavinoids B, D and E (2, 4, 5), and nine previously reported related compounds. The structures of these compounds were established using spectroscopic methods and by comparison with known analogues. We also investigated the cytotoxic activity of the isolated compounds against several cancer and normal cell lines. Asperflavinoid C (3) and ustusolate E (9) exerted a significant effect on human breast cancer MCF-7 cell viability, with IC50 values of 10 µM, and induced in caspase-dependent apoptosis and arrest of the MCF-7 cell cycle in the G2/M phase in these cells.
New anthraquinone derivatives acruciquinones A–C (1–3), together with ten known metabolites, were isolated from the obligate marine fungus Asteromyces cruciatus KMM 4696. Acruciquinone C is the first ...member of anthraquinone derivatives with a 6/6/5 backbone. The structures of isolated compounds were established based on NMR and MS data. The absolute stereoconfigurations of new acruciquinones A–C were determined using ECD and quantum chemical calculations (TDDFT approach). A plausible biosynthetic pathway of the novel acruciquinone C was proposed. Compounds 1–4 and 6–13 showed a significant antimicrobial effects against Staphylococcus aureus growth, and acruciquinone A (1), dendryol B (4), coniothyrinone B (7), and ω-hydroxypachybasin (9) reduced the activity of a key staphylococcal enzyme, sortase A. Moreover, the compounds, excluding 4, inhibited urease activity. We studied the effects of anthraquinones 1, 4, 7, and 9 and coniothyrinone D (6) in an in vitro model of skin infection when HaCaT keratinocytes were cocultivated with S. aureus. Anthraquinones significantly reduce the negative impact of S. aureus on the viability, migration, and proliferation of infected HaCaT keratinocytes, and acruciquinone A (1) revealed the most pronounced effect.
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