Snake venom phospholipase A2s exhibit strong virucidal activity against SARS-CoV-2 and inhibit the viral spike glycoprotein interaction with ACE2.

The COVID-19 pandemic caused by SARS-CoV-2 requires new treatments both to alleviate the symptoms and to prevent the spread of this disease. Previous studies demonstrated good antiviral and virucidal activity of phospholipase A2s (PLA2s) from snake venoms against viruses from different families but there was no data for coronaviruses. Here we show that PLA2s from snake venoms protect Vero E6 cells against SARS-CoV-2 cytopathic effects. PLA2s showed low cytotoxicity to Vero E6 cells with some activity at micromolar concentrations, but strong antiviral activity at nanomolar concentrations. Dimeric PLA2 from the viper Vipera nikolskii and its subunits manifested especially potent virucidal effects, which were related to their phospholipolytic activity, and inhibited cell-cell fusion mediated by the SARS-CoV-2 spike glycoprotein. Moreover, PLA2s interfered with binding both of an antibody against ACE2 and of the receptor-binding domain of the glycoprotein S to 293T/ACE2 cells. This is the first demonstration of a detrimental effect of PLA2s on β-coronaviruses. Thus, snake PLA2s are promising for the development of antiviral drugs that target the viral envelope, and could also prove to be useful tools to study the interaction of viruses with host cells

α-Conotoxins and α-Cobratoxin Promote, while Lipoxygenase and Cyclooxygenase Inhibitors Suppress the Proliferation of Glioma C6 Cells

Among the brain tumors, glioma is the most common. In general, different biochemical mechanisms, involving nicotinic acetylcholine receptors (nAChRs) and the arachidonic acid cascade are involved in oncogenesis. Although the engagement of the latter in survival and proliferation of rat C6 glioma has been shown, there are practically no data about the presence and the role of nAChRs in C6 cells. In this work we studied the effects of nAChR antagonists, marine snail α-conotoxins and snake α-cobratoxin, on the survival and proliferation of C6 glioma cells. The effects of the lipoxygenase and cyclooxygenase inhibitors either alone or together with α-conotoxins and α-cobratoxin were studied in parallel. It was found that α-conotoxins and α-cobratoxin promoted the proliferation of C6 glioma cells, while nicotine had practically no effect at concentrations below 1 µL/mL. Nordihydroguaiaretic acid, a nonspecific lipoxygenase inhibitor, and baicalein, a 12-lipoxygenase inhibitor, exerted antiproliferative and cytotoxic effects on C6 cells. nAChR inhibitors weaken this effect after 24 h cultivation but produced no effects at longer times. Quantitative real-time polymerase chain reaction showed that mRNA for α4, α7, β2 and β4 subunits of nAChR were expressed in C6 glioma cells. This is the first indication for involvement of nAChRs in mechanisms of glioma cell proliferation

Evaluation of distribution coefficients and concentration ratios of 90Sr and 137Cs in the Techa River and the Miass River

Empirical data on the behavior of radionuclides in aquatic ecosystems are needed for radioecological modeling, which is commonly used for predicting transfer of radionuclides, estimating doses, and assessing possible adverse effects on species and communities. Preliminary studies of radioecological parameters including distribution coefficients and concentration ratios, for 90Sr and 137Cs were not in full agreement with the default values used in the ERICA Tool and the RESRAD BIOTA codes. The unique radiation situation in the Techa River, which was contaminated by long-lived radionuclides (90Sr and 137Cs) in the middle of the last century allows improved knowledge about these parameters for river systems. Therefore, the study was focused on the evaluation of radioecological parameters (distribution coefficients and concentration ratios for 90Sr and 137Cs) for the Techa River and the Miass River, which is assumed as a comparison waterbody. To achieve the aim the current contamination of biotic and abiotic components of the river ecosystems was studied; distribution coefficients for 90Sr and 137Cs were calculated; concentration ratios of 90Sr and 137Cs for three fish species (roach, perch and pike), gastropods and filamentous algae were evaluated. Study results were then compared with default values available for use in the well-known computer codes ERICA Tool and RESRAD BIOTA (when site-specific data are not available). We show that the concentration ratios of 137Cs in whole fish bodies depend on the predominant type of nutrition (carnivores and phytophagous). The results presented here are useful in the context of improving of tools for assessing concentrations of radionuclides in biota, which could rely on a wider range of ecosystem information compared with the process limited the current versions of ERICA and RESRAD codes. Further, the concentration ratios of 90Sr are species-specific and strongly dependent on Ca2+ concentration in water. The universal characteristic allows us to combine the data of fish caught in the water with different mineralization by multiplying the concentration of Ca2+. The concentration ratios for fishes were well-fitted by Generalized Logistic Distribution function (GLD). In conclusion, the GLD can be used for probabilistic modeling of the concentration ratios in freshwater fishes to improve the confidence in the modeling results. This is important in the context of risk assessment and regulatory

The Institutional Foundations of the Digital Economy in the 21st Century/ Elena G. Popkova, Artem Krivtsov, Aleksei V. Bogoviz.

In English.The development of the Digital Economy has been a landmark breakthrough for economic systems in the 21st century, as it opens up opportunities for the full-scale implementation of new digital technologies and the optimization of economic activities. While the conceptual essence and specific features of the digital economy are described in detail in the existing literature, the practical foundations of its formation are poorly studied. In this book, the digital economy is studied from the perspective of neo-institutional economic theory. This allows for the tracking of the process of formation (institutionalization) of the digital economy, determining the basic institutions that are necessary for its formation and that exist in modern economic practice, and analyzing scenarios for the future development of the digital economy in the 21st century.Frontmatter -- Contents -- Digital Economy in the 21 Century: An Introduction to the Institutional Approach -- Part I: The Scientific Concept of the Digital Economy in the 21st Century -- 1 Digital Economy as a Modern Type of Economic System -- 2 “Digitalization”- Overcoming Institutional Barriers -- 3 Development of the Information Technologies Sector in Latvia under Globalization -- 4 The Principles of Functioning and Priorities of Development of the Digital Economy -- 5 Classification of Breakthrough Digital Technologies and the Perspectives of Their Application in Economy -- Part II: The Process of Digital Economy Institutionalization in the 21st Century -- 6 The Essence and Logic of the Process of Sectorial Markets' Digital Transformation -- 7 The Current Tendencies of Economy Digitalization in Developed and Developing Countries -- 8 The Main Stages of the Digital Modernization of Economy -- 9 Implementation of Cluster Initiatives in the Digital Sphere as a Tool of Digital Entrepreneurship's Institutionalization -- 10 Institutions of Support for Digital Entrepreneurship: Special Economic Zones, Innovative Networks and Technological Parks -- Part III: Meso-Level Institutions of the Digital Economy in the 21st Century -- 11 Digitalization of Regional Economy: Problems and Perspectives -- 12 The Institutional Model of the Digital Economy Creation in a Modern Region -- 13 Managing a Modern Region Based on Digital Technologies -- Part IV: Macro-Level Institutions of the Digital Economy in the 21st Century -- 14 State Institutional Regulation of Economy Digital Modernization -- 15 The Role of Financial Institutions in Supporting the Digital Economy -- 16 Digital Economy of the 21st Century: A View from the Positions of Developed and Developing Countries -- Part V: The Global Institutions of the Digital Economy in the 21st Century -- 17 International Trade in the Digital Sphere: Barriers and Prospects for Development -- 18 The Existing and Perspective International Institutions for Supporting Digital Transformation of Economy -- 19 The Scientific and Methodological Approach to Provision and Evaluation of the Digital Economy's Global Competitiveness -- 20 The Strategy of Optimal Development of the Digital Economy: A View from the Positions of Game Theory -- 21 The Institutional Model of Well-Balanced and Sustainable Digital Economy -- 22 The Institutional Mechanism of Managing the Digital Economy's Development -- Part VI: Case Studies of Institutions of the Digital Economy in the 21st Century -- 23 Problems and Prospects of Economic Cooperation Between Russia and Mexico -- 24 Innovative Critical Success Factors for Public - Private Partnerships (PPP) in Infrastructure Projects of Developing Countries. A Case of Zambia -- 25 Prediction Mechanism of the Territorial Socio-Economic Processes in Formation of the Information Systems -- 26 Specific Economic Security Regulations in the Context of Pathological Crises of Digital Transformation of Agricultural Organizations -- Conclusion: Institutional Perspectives of the Digital Economy's Development in the 21st Century -- List of Figures -- List of Tables -- Index.1 online resource (XI, 258 p.)