We propose a novel combination of high-throughput luminescent bacterial tests for the evaluation of the reactive oxygen species (ROS)-generating potential of engineered nanoparticles (eNPs) and the ...role of solubilised metal ions in this process. The set of tests consists of differently engineered recombinant Escherichia coli strains: (1) a new sensor strain, which bioluminescence is induced by superoxide anions; (2) six recombinant E. coli strains (superoxide dismutase (sod) single, double and triple mutants and a respective wild-type strain), transformed with luxCDABE genes responding to toxic compounds by decreasing their luminescence; and (3) three strains in which bioluminescence is specifically induced by bioavailable metals (Cu, Zn and Ag). The applicability of this battery of tests in profiling oxidative potential of eNPs was evaluated on nTiO₂, nCuO, nZnO and nAg (25, 30, 70 and <100 nm, respectively) NPs and fullerenes. As controls for the size or solubility, the bulk formulations (bTiO₂, bCuO and bZnO) and soluble salts (ZnSO₄, CuSO₄ and AgNO₃) were also analysed. Bacterial toxicity tests showed that nCuO was four-fold more toxic, and nAg was 15-fold more toxic to triple sod mutant than to wild type (2-h EC₅₀ values were 8.1 and 2.0 mg Cu l⁻¹, respectively, and 46 and 3.1 mg Ag l⁻¹, respectively). Formation of ROS by nCuO and nAg was proved by superoxide anion-inducible strain. The metal sensor bacteria showed that the ROS formation by CuO NPs was caused by solubilised Cu ions, but in case of nAg, particles also had an effect. nZnO was remarkably more toxic to sod triple mutant than to wild type strain (2-h EC₅₀ were 4.5 and 54 mg Zn l⁻¹, respectively). Fullerenes inhibited the bioluminescence of sod triple mutant at 3,882 mg l⁻¹ but had no effect on the wild-type strain even at 20,800 mg l⁻¹. Nano and bTiO₂ showed some effect on viability of bacteria only at high concentrations (>4,000 mg l⁻¹) although nTiO₂ (but not bTiO₂) induced the bioluminescence of the superoxide anion sensing bacteria starting from 100 mg l⁻¹. Thus, our innovative combined approach is expected to provide more consistent and informative data concerning the general toxicity, ROS-production potential and also solubilisation of metals in the case of metallic NPs. graphic removed
Abstract
The article is devoted to the problem of incorporation geographic information systems (GIS) in world school practice. The authors single out the stages of GIS application in school ...geographical education based on the retrospective analysis of the scientific literature. The first stage (late 70 s – early 90s of the 20
th
century) is the beginning of the first educational GIS programs and partnership agreements between schools and universities. The second stage (mid-90s of the 20
th
century – the beginning of the 21
st
century) comprises the distribution of GIS-educational programs in European and Australian schools with the involvement of leading developers of GIS-packages (ESRI, Intergraph, MapInfo Corp., etc.). The third stage (2005–2012) marks the spread of the GIS school education in Eastern Europe, Asia, Africa and Latin America; on the fourth stage (from 2012 to the present) geographic information systems emerge in school curricula in most countries. The characteristics of the GIS-technologies development stages are given considering the GIS didactic possibilities for the study of school geography, as well as highlighting their advantages and disadvantages.
A technique for assessing the levels of injury to passengers and train crew members in emergency collisions is proposed. It is based on the use of physical methods for simulating fast-flowing ...non-linear processes of material deformation in emergency situations and anthropometric dummies. Based on the analysis of world and domestic experience in the study of injuring people in emergency situations in transport, an anthropometric 50 percentile male Dummy Hybrid III was adopted as a research tool. Its mathematical model is developed. It was verified by data from field experiments. The developed dummies are integrated into mathematical models for the development of emergency scenarios. As objects of study, the most promising types of rail car layout and two locomotive options were considered for the domestic rolling stock. Based on the simulation results, the values of the criteria for injuring passengers and members of locomotive crews in emergency situations are obtained. The most dangerous positions of passengers in the car during longitudinal collision of trains for the considered layout options are determined. It has been established that the most serious injuries are suffered by passengers and members of locomotive crews as a result of their interaction with car interior items and controls of the driver's cab.
Original design solutions for passenger car bodies equipped with emergency exits have been proposed. The operability and safety of the proposed structures is evaluated based on the modeling of the ...load bearing structures in emergency situations. Two options for the development of an emergency are considered: a collision with a car on a level crossing and rollover. The analysis of loading was performed by the finite element method in a dynamic nonlinear formulation. The finite element models of the supporting structures of the bodies of passenger cars with evacuation exits and without them have been developed. Model verification was performed by field bench tests. The dynamic loading was estimated in a dynamic setting by the explicit integration method based on the central difference method with keeping the accelerations constant within the step and quadratic approximation of the displacement vector for three consecutive moments of time. The data obtained as a result of the study on the stress-strain state of the supporting structure indicate the operability and safety of the proposed solutions. A variant of the body structure of a double-decker car is protected by a patent for a utility model.
A technology was developed for obtaining glass silica based on fractionated cullet of colored container glass and the waste from enrichment of ferruginous quartzites of the Kursk of Magnetic Anomaly ...(KMA) at the Lebedinskii Mining and Processing Combine Lebedinskii GOK. By using the waste from enrichment of ferruginous quartzites of the KMA the sintering temperature could be lowered and the quality of the glass raised. The obtained glass silica exhibits high performance and aesthetic properties.
Abstract
The article addresses the relevant issue of today – digitalization of geographic higher education. The future of geographic education in the digital world depends on the use of digital ...technologies, which are dramatically changing approaches to teaching geography. The generalization of scientific literature and the analysis of pedagogical experience allow the authors to define the concept digitalization of geographic. The article explores some challenges in the implementation of digital technologies in geographic disciplines in higher education: narrowing geographic education digitalization to the use of various gadgets; the application of general purpose digital technologies; underestimation of GIS technologies during the study of geography; occasional use of VR, AR technologies and mobile applications of geographic and cartographic content; the lack of educational and methodological support and proper technological availability. The authors pay special attention to the prospects for the development of geographic education digitalization, which are envisioned in the introduction of “Digitalization of geographic education” into the curriculum of future geography teachers training; the use of high-quality free educational resources (ArcGIS Online, QGIS); the creation of own geo-information platforms (“Digital Geography”); and updating of the material and technical base of the scientific research laboratory on the methodology of teaching geo-information technologies.
The article is devoted to an important and topical issue of legal description of the role and activities of the public in the implementation of anti-corruption reforms.
Countering corruption has ...always been an important task for Ukraine. It has been proven that the public is the most interested stakeholder in the fight against corruption. It is the members of civil society who want to live in a state governed by the rule of law, where the principles of equality, publicity and transparency are truly in place. And the success of anti-corruption changes depends on the willingness and participation of every member of civil society.
It is noted that civil society involves active participation of citizens in political processes, civil dialogue and various public initiatives. Its main goal is to protect the rights and interests of citizens, as well as to oversee the activities of government agencies and prevent possible abuses.
The legal and numerous doctrinal definitions of the concept of “public” and its components in the context of anti-corruption reforms are analysed.
It is substantiated that the experience of involving the public in the implementation of anti-corruption reforms can be successful only if representatives of public authorities and business are open and transparent.
It is emphasised that citizens and civil society organisations play an important role in combating corruption, as they serve as advocates for the public interest, provide independent oversight, mobilise communities, protect whistleblowers, advocate for policy reforms and promote transparency, accountability and good governance. In particular, citizens are empowered to demand responsibility, act as whistleblowers, influence policy and elections, raise public awareness and promote ethical values. Their participation is essential for the development of transparent, accountable and corruption-free societies. Civil society organisations are also important actors in the anti-corruption fight in Ukraine. Their independent oversight, advocacy, support for whistleblowers, policy analysis and engagement with citizens contribute significantly to the promotion of transparency, accountability and good governance in the country.
Abstract
The model of before- and intrahepatic blockage of the portal system was proposed. Modeling of before-hepatic blockage of the portal system after development of toxic liver dystrophy lead to ...formation of the liver cirrhosis with stable portal hypertension. Gastritis with signs of hyperplastic and atrophy processes of the mucosa, formation of erosia, inflammatory infiltration of intermediate tissue and rebuilding of the glandulae were the basis of morphological changes of gastric mucosa in rats with experimental before- and intrahepatic portal blockage. Transformation of the cardiac mucosa with expressed polymorphism occured in the patients with the portal liver cirrhosis. Dystrophic and necrobiotic changes typical of hepatic gastropathy with signs of acute or chronic gastritis, formation of inflammatory infiltrates and rebuilding of the cardial mucosa into intestinal type were established microscopically. It is possible to believe that a widening of the veins leads to venous hyperemia and stasis in the portal hypertension. Therefore the morphology of the gastric mucosa was disturbed. It was accompanied bythe indurate changes and cellular destruction with erosia formation. These erosia may be a cause of rupture of the gastric mucosa in strong vomiting in Mallory-Weiss syndrome. This hypothesis needs clinic and experimental study in the future.
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