RESUMO
Developed areas of the coal industry are subjected to long-term anthropogenic impacts from the input and accumulation of overburdened coal material, containing potentially toxic heavy metals and metalloids (HMM). For the first time, comprehensive studies of soils and plants in the territory of the Donetsk coal basin were carried out using X-ray fluorescence, atomic absorption analysis, and electron microscopy. The observed changes in the soil redox conditions were characterized by a high sulfur content, and formations of new microphases of S-containing compounds: FeS2, PbFe6(SO4)4(OH)12, ZnSO4·nH2O, revealed the presence of technogenic salinization, increased Сorg content, and low pH contents. Exceedances of soil maximum permissible concentrations of Pb, Zn, Cu, and As in areas affected by coal dumps were apparent. As a consequence of long-term transformation of the environment with changes in properties and chemical pollution, a phytotoxic effect was revealed in Phragmites australis (Cav.) Trin. ex Steud, accompanied by changes in ultrastructural and organization features of roots and leaves such as increases in root diameters and thickness of leaf blades. The changes in the ultrastructure of cell organelles: a violation of the grana formation process, an increase in the number of plastoglobules, a decrease in the number of mitochondrial cristae, and a reduction in the electron density of the matrix in peroxisomes were also observed. The accumulation of large electron-dense inclusions and membrane fragments in cell vacuoles was observed. Such ultrastructural changes may indicate the existence of a P. australis ecotype due to its long-term adaptation to the disturbed environment.
Assuntos
Metais Pesados , Poluentes do Solo , Solo/química , Poaceae/metabolismo , Plantas/metabolismo , Poluentes do Solo/análise , Carvão Mineral , Metais Pesados/análiseRESUMO
The relevance of the article lies in the significant reduction of the mammal population in the areas of heavy industry enterprises located in Kazakhstan. The aim of the research is to investigate the technogenic pollution's impact level on the representatives of the species of Rodents and Insectivores order in Northern Kazakhstan. The result of the work on the analysis of the species composition of small mammals in the technogenic territories of Northern Kazakhstan in comparison with the control zone in 2021 is presented. Technogenic sites were located in the vicinity of industrial enterprises. The following methods were used in the study: complex analysis, the method of record lines, and the method of statistical data processing. During the study, 15 species of animals were noted at all sites: 11 species of the Rodentia order and 4 species of representatives of the Eulipotyphla order. The registered animals were classified according to their distance from the emission sources. The dominance index was calculated. The calculation results were marked by low indicators in the impact and buffer territories and an increase in the background and control areas. All plots have dominant species. With the increase in anthropogenic influence and the approximation of the sources of emissions, the number of small mammal species decreases, the structure is simplified, and biodiversity is reduced.
Assuntos
Poluição Ambiental , Mamíferos , Animais , Cazaquistão , Biodiversidade , RoedoresRESUMO
PAHs are one of the most toxic organic compounds classes which is obligatory controlled all over the world. There is a luck of studies devoted to the PAHs levels and sources identification in the south of Russia. The features of the PAHs accumulation and spatial distribution in hydromorphic soils (Fluvisol) were studied on the example of the soils of the Don River delta floodplain landscapes. It has been shown that changes in the PAHs content in soils depended on the type and intensity of the emission source. A factor analysis and multivariate linear regression analysis were carried out to determine the features of the spatial distribution for individual PAH compounds, considering the properties of soils and typical differences in the emission source. The most polluted areas in the studied area located along the transit line of the long-distance tankers, where the content of the most toxic high molecular PAHs compounds reached 8862 ng g-1. As a result of regression analysis, a relationship was established between the PAHs accumulation rate with the content of silt (particles less than 0.001 mm in size) and Ca2+ and Mg2+ exchangeable cations in the soil (at p-level < 0.0001). Differences in individual PAH content for medium and heavy loamy Fluvisol and depend on the influence of different types of pollution sources.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Monitoramento Ambiental , Solo , Rios , Poluentes do Solo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , ChinaRESUMO
Predatory hunting is a complex species-typical behaviour involving different skills, some of which may include learning. This research aims to distinguish between rigid and flexible parts in live-insect hunting behaviour in nine herbivorous and granivorous rodent species, and to find out whether there is room for cognition in this activity. In laboratory experiments, all species studied manifest skilful attacks towards insects in a manner that is typical for specialised predators chasing a fleeing prey. Voles demonstrate a "core" and somewhat primitive scheme of a hunting pattern: approaching a potential victim, biting it, and then seizing and handling. Hamsters display the tendency to start their attacks by actions with paws, but they can achieve success only using teeth as well. Gerbils can successfully use both paws and teeth to start the attack, which brings their hunting behaviour closer to that of specialised rodent predators. We revealed variability in the display of hunting in different species, methods of seizing the prey, and the number of attempts to attack an insect before catching it. We found specific flexible fragments within the "bite-grasp-handle" bouts that can be precursors for adaptive phenotypic variations and include some cognitive attributes. We hypothesise that the divergence and specialisation of predatory behaviour in rodents can be based on the natural fragmentation of the original hunting patterns, that is, on the loss or recombination of particular behavioural elements. We consider a possible link between the fragmentation of hunting behaviour and social learning in different classes of animals and conjecture an intriguing correlation between predatory activity, cognitive skills and personal traits in rodents.
Assuntos
Comportamento Predatório , Roedores , Animais , Cricetinae , Cognição , AprendizagemRESUMO
The on-going developments in laser acceleration of protons and light ions, as well as the production of strong bursts of neutrons and multi-[Formula: see text] photons by secondary processes now provide a basis for novel high-flux nuclear physics experiments. While the maximum energy of protons resulting from Target Normal Sheath Acceleration is presently still limited to around [Formula: see text], the generated proton peak flux within the short laser-accelerated bunches can already today exceed the values achievable at the most advanced conventional accelerators by orders of magnitude. This paper consists of two parts covering the scientific motivation and relevance of such experiments and a first proof-of-principle demonstration. In the presented experiment pulses of [Formula: see text] at [Formula: see text] duration from the PHELIX laser produced more than [Formula: see text] protons with energies above [Formula: see text] in a bunch of sub-nanosecond duration. They were used to induce fission in foil targets made of natural uranium. To make use of the nonpareil flux, these targets have to be very close to the laser acceleration source, since the particle density within the bunch is strongly affected by Coulomb explosion and the velocity differences between ions of different energy. The main challenge for nuclear detection with high-purity germanium detectors is given by the strong electromagnetic pulse caused by the laser-matter interaction close to the laser acceleration source. This was mitigated by utilizing fast transport of the fission products by a gas flow to a carbon filter, where the [Formula: see text]-rays were registered. The identified nuclides include those that have half-lives down to [Formula: see text]. These results demonstrate the capability to produce, extract, and detect short-lived reaction products under the demanding experimental condition imposed by the high-power laser interaction. The approach promotes research towards relevant nuclear astrophysical studies at conditions currently only accessible at nuclear high energy density laser facilities.
RESUMO
The Olkhon mountain vole (Alticola olchonensis) is an endemic species of the Lake Baikal area with an extremely restricted range. We investigated the pattern of differentiation of cranial shape and size in five isolated insular populations of A. olchonensis from the Baikal islands (Olkhon, Hubyn, Borokchin, Ogoy, and Zamogoy). The ventral aspect of the cranium was analysed using landmark-based geometric morphometric methods While the sexes of A. olchonensis did not differ regarding cranium size and shape, multivariate statistical analyses showed that there were inter-island differences in skull morphology. Voles from the four small islands were similar in cranium size; the large skull size of voles inhabiting the Olkhon Island may be due to the more favourable habitat conditions on Olkhon. Shape differences among island populations were not associated with the geographic distances between islands. The voles from Borokchin Island differ the most in skull shape compared to other island populations. The combination of reduced gene flow among island populations (due to isolation and drift during population fluctuations) may be a suitable explanation for the significant differences in skull shape among island populations of A. olchonensis.
Assuntos
Arvicolinae/anatomia & histologia , Crânio/anatomia & histologia , Animais , Feminino , Ilhas , Masculino , Sibéria , Canais de Ânion Dependentes de VoltagemRESUMO
Electrons bound in highly charged heavy ions such as hydrogen-like bismuth 209Bi82+ experience electromagnetic fields that are a million times stronger than in light atoms. Measuring the wavelength of light emitted and absorbed by these ions is therefore a sensitive testing ground for quantum electrodynamical (QED) effects and especially the electron-nucleus interaction under such extreme conditions. However, insufficient knowledge of the nuclear structure has prevented a rigorous test of strong-field QED. Here we present a measurement of the so-called specific difference between the hyperfine splittings in hydrogen-like and lithium-like bismuth 209Bi82+,80+ with a precision that is improved by more than an order of magnitude. Even though this quantity is believed to be largely insensitive to nuclear structure and therefore the most decisive test of QED in the strong magnetic field regime, we find a 7-σ discrepancy compared with the theoretical prediction.
RESUMO
A series of 4H-chromenes containing various modifications in the ring B and polyalkoxy substituents in the ring E has been synthesized by Knoevenagel-Michael-hetero-Thorpe-Ziegler three-component domino reaction with the overall yield of 45-82%. The targeted molecules were evaluated in a phenotypic sea urchin embryo assay for antimitotic and microtubule destabilizing activity. The most active compounds 5{1,5} and 5{5,5} featured sesamol-derived ring B and m-methoxyphenyl or m-methoxymethylenedioxyphenyl ring E. Compounds 5{3,1}, 5{1,2}, 5{5,4}, 5{1,5}, and 5{5,5} exhibited strong cytotoxicity in the NCI60 human tumor cell line anticancer drug screen. Surprisingly, cell growth inhibition caused by these agents was more pronounced in the multidrug resistant NCI/ADR-RES cells than the parent OVCAR-8 cell line. The results suggest that polyalkoxy substited 4H-chromenes may prove to be advantageous for further design as anticancer agents.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Benzopiranos/síntese química , Benzopiranos/farmacologia , Ouriços-do-Mar/efeitos dos fármacos , Animais , Antineoplásicos/química , Benzopiranos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Polímeros/síntese química , Polímeros/química , Polímeros/farmacologia , Ouriços-do-Mar/citologia , Ouriços-do-Mar/embriologiaRESUMO
This report describes a new four-component synthesis of substituted and spiro-conjugated 6-amino-2H,4H-pyrano[2,3-c]pyrazol-5-carbonitriles directly from aromatic aldehydes or heterocyclic ketones, malononitrile, beta-ketoesters, and hydrazine hydrate. The method provides a convenient one-pot route toward divers 2,4-dihydropyrano[2,3-c]pyrazoles, whereas a modified one-step sequential protocol gives access to spiro[indoline-3,4'-pyrano[2,3-c]pyrazol]-2-ones.
Assuntos
Nitrilas/síntese química , Compostos Heterocíclicos/química , Modelos Moleculares , Estrutura Molecular , Nitrilas/químicaRESUMO
A convenient method of synthesis of substituted and annulated 2-amino-spiro[(3' H)-indol-3',4-(4 H)-pyrans] at mild conditions and in good yields is developed. Three component reaction of wide variety of substituted isatins, cyanoacetic acid derivatives, and carbonyl compounds or phenols gives the target compounds. Forty new spiropyrans were obtained, and their structures were proved by elemental analysis and 1H NMR and IR spectral data. It is shown that the use of a not very large set of starting compounds can lead to the synthesis of a thousand-member 2-amino-spiro[(3' H)-indol-3',4-(4 H)-pyran] library.