23 research outputs found

    Geosituational modelling of coastal marine systems

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    The article summarizes years of experience of geosituational modelling of coastal marine systems in the Baltic Sea region and adjacent territories. Kaliningrad universities and academic institutions have done extensive research on the diversity of approaches and models of the regional geosituations as well as on identifying the most promising coastal marine areas. Some of the models presented in the present paper are qualitative, while others are empirical and statistical ones. However, the majority of the models can be referred to as forms of graphic and image mapping. The significance of the regional models lies in their specificity, a more detailed character (compared to the generalist ones) and the possibility of using them to back up managerial decisions in critical and emergency situations in order to minimize the negative effects of natural (storms, floods, earthquakes, etc.) and anthropogenic emergency situations. The authors developed a matrix classification attributable to a particular class of models for the situations leading to uncertain outcomes. The authors suggest using numerical methods combined with the empirical and statistical models for the assessment of the impact of industrial fishing on marine environment, minimizing the consequences of storms, floods and others factors. Special attention is paid to the modelling of climate change and geo-ecological consequences, as well as to atlas mapping and landscape planning. As a result of the geosituational analysis the authors got new insights into the solar-terrestrial links, marine-terrestrial ecosystems, global and regional processes related to climate change, oceanization, the vulnerability of natural systems under the increasing pressure of anthropogenic activities, and continuously increasing risks presented by industrial agriculture and other types of land use

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Geosituational Modelling of Coastal Marine Systems

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    The article summarizes years of experience of geosituational modelling of coastal marine systems in the Baltic Sea region and adjacent territories. Kaliningrad universities and academic institutions have done extensive research on the diversity of approaches and models of the regional geosituations as well as on identifying the most promising coastal marine areas. Some of the models presented in the present paper are qualitative, while others are empirical and statistical ones. However, the majority of the models can be referred to as forms of graphic and image mapping. The significance of the regional models lies in their specificity, a more detailed character (compared to the generalist ones) and the possibility of using them to back up managerial decisions in critical and emergency situations in order to minimize the negative effects of natural (storms, floods, earthquakes, etc.) and anthropogenic emergency situations. The authors developed a matrix classification attributable to a particular class of models for the situations leading to uncertain outcomes. The authors suggest using numerical methods combined with the empirical and statistical models for the assessment of the impact of industrial fishing on marine environment, minimizing the consequences of storms, floods and others factors. Special attention is paid to the modelling of climate change and geo-ecological consequences, as well as to atlas mapping and landscape planning. As a result of the geosituational analysis the authors got new insights into the solar-terrestrial links, marine-terrestrial ecosystems, global and regional processes related to climate change, oceanization, the vulnerability of natural systems under the increasing pressure of anthropogenic activities, and continuously increasing risks presented by industrial agriculture and other types of land use

    Опыт геоситуационного моделирования прибрежно-морских систем

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    The article summarizes years of experience of geosituational modelling of coastal marine systems in the Baltic Sea region and adjacent territories. Kaliningrad universities and academic institutions have done extensive research on the diversity of approaches and models of the regional geosituations as well as on identifying the most promising coastal marine areas. Some of the models presented in the present paper are qualitative, while others are empirical and statistical ones. However, the majority of the models can be referred to as forms of graphic and image mapping. The significance of the regional models lies in their specificity, a more detailed character (compared to the generalist ones) and the possibility of using them to back up managerial decisions in critical and emergency situations in order to minimize the negative effects of natural (storms, floods, earthquakes, etc.) and anthropogenic emergency situations. The authors developed a matrix classification attributable to a particular class of models for the situations leading to uncertain outcomes. The authors suggest using numerical methods combined with the empirical and statistical models for the assessment of the impact of industrial fishing on marine environment, minimizing the consequences of storms, floods and others factors. Special attention is paid to the modelling of climate change and geo-ecological consequences, as well as to atlas mapping and landscape planning. As a result of the geosituational analysis the authors got new insights into the solar-terrestrial links, marine-terrestrial ecosystems, global and regional processes related to climate change, oceanization, the vulnerability of natural systems under the increasing pressure of anthropogenic activities, and continuously increasing risks presented by industrial agriculture and other types of land use

    Synthesis of Novel Carborane-Containing Derivatives of RGD Peptide

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    Short peptides containing the Arg-Gly-Asp (RGD) fragment can selectively bind to integrins on the surface of tumor cells and are attractive transport molecules for the targeted delivery of therapeutic and diagnostic agents to tumors (for example, glioblastoma). We have demonstrated the possibility of obtaining the N- and C-protected RGD peptide containing 3-amino-closo-carborane and a glutaric acid residue as a linker fragment. The resulting carboranyl derivatives of the protected RGD peptide are of interest as starting compounds in the synthesis of unprotected or selectively protected peptides, as well as building blocks for preparation of boron-containing derivatives of the RGD peptide of a more complex structure

    Carborane-Containing Folic Acid bis-Amides: Synthesis and In Vitro Evaluation of Novel Promising Agents for Boron Delivery to Tumour Cells

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    The design of highly selective low-toxic, low-molecular weight agents for boron delivery to tumour cells is of decisive importance for the development of boron neutron capture therapy (BNCT), a modern efficient combined method for cancer treatment. In this work, we developed a simple method for the preparation of new closo- and nido-carborane-containing folic acid bis-amides containing 18–20 boron atoms per molecule. Folic acid derivatives containing nido-carborane residues were characterised by high water solubility, low cytotoxicity, and demonstrated a good ability to deliver boron to tumour cells in in vitro experiments (up to 7.0 µg B/106 cells in the case of U87 MG human glioblastoma cells). The results obtained demonstrate the high potential of folic acid–nido-carborane conjugates as boron delivery agents to tumour cells for application in BNCT

    Synthesis of Charge-Compensated <i>nido</i>-Carboranyl Derivatives of Sulfur-Containing Amino Acids and Biotin

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    A new group of charge-compensated nido-carboranyl derivatives of sulfur-containing amino acids and biotin has been synthesized in which the boron atom in position 9 or 10 of carborane is attached to a positively charged sulfur atom. The possibilities of obtaining symmetrical B(10)-substituted and asymmetric B(9)-substituted nido-carboranes were studied. Using the example of (S)-methionine and D-biotin derivatives, water-soluble S-substituted charge-compensated nido-carboranes with free functional groups were prepared. The results obtained open up prospects for the development of potential boron delivery agents for BNCT as well as new bioactive compounds containing a negatively charged nido-carboranyl fragment bearing a positive charge on the sulfur atom associated with the boron cluster

    Synthesis and Cytotoxic Activity of the Derivatives of <i>N</i>-(Purin-6-yl)aminopolymethylene Carboxylic Acids and Related Compounds

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    Testing a number of N-[omega-(purin-6-yl)aminoalkanoyl] derivatives of 7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4]benzoxazine in a panel of nine tumor cell lines has shown that the studied compounds exhibit high cytotoxic activity, especially against 4T1 murine mammary carcinoma, COLO201 human colorectal adenocarcinoma, SNU-1 human gastric carcinoma, and HepG2 human hepatocellular carcinoma cells. Synthesis and study of structural analogs of these compounds made it possible to find that the presence of both a difluorobenzoxazine fragment and a purine residue bound via a linker of a certain length is crucial for the manifestation of the cytotoxic activity of this group of compounds. The study of the effect of the most promising compound on the cell cycle of the human tumor cell lines, the most sensitive and least sensitive to cytotoxic action (MDA-MB-231 breast adenocarcinoma and COLO201 colorectal adenocarcinoma, respectively), allows us to conclude that this compound is an inhibitor of DNA biosynthesis. The found group of purine conjugates may be of interest in the design of new antitumor agents

    Hydrogen bond effects in multimode nuclear dynamics of acetic acid observed via resonant x-ray scattering

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    A theoretical and experimental study of the gas phase and liquid acetic acid based on resonant inelastic x-ray scattering (RIXS) spectroscopy is presented. We combine and compare different levels of theory for an isolated molecule for a comprehensive analysis, including electronic and vibrational degrees of freedom. The excitation energy scan over the oxygen K-edge absorption reveals nuclear dynamic effects in the core-excited and final electronic states. The theoretical simulations for the monomer and two different forms of the dimer are compared against high-resolution experimental data for pure liquid acetic acid. We show that the theoretical model based on a dimer describes the hydrogen bond formation in the liquid phase well and that this bond formation sufficiently alters the RIXS spectra, allowing us to trace these effects directly from the experiment. Multimode vibrational dynamics is accounted for in our simulations by using a hybrid time-dependent stationary approach for the quantum nuclear wave packet simulations, showing the important role it plays in RIXS
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