432 research outputs found

    Water-soluble hybrid materials based on {Mo₆X₈}⁴⁺ (X = Cl, Br, I) cluster complexes and sodium polystyrene sulfonate

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    Development of water-soluble forms of octahedral molybdenum clusters {Mo₆X₈}⁴⁺ (X = Cl, Br, I) is strongly motivated by the tremendous potential that these complexes have for biological applications, namely as agents for bioimaging and photodynamic therapy. In these work we report the first water-soluble hybrid materials, which represent sodium polystyrene sulfonate doped by molybdenum clusters, and evaluation of their photophysical and biological properties (dark and photoinduced cytotoxicity and cellular uptake) with the use of cervical cancer (HeLa) and human epidermoid larynx carcinoma (Hep-2) cell-lines as models

    A comparative study of hydrophilic phosphine hexanuclear rhenium cluster complexes’ toxicity

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    Octahedral rhenium cluster compound Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] has recently emerged as a very promising X-ray contrast agent for biomedical applications. However, the synthesis of this compound is rather challenging due to difficulty to control the hydrolysis of initial P(C2H4CN)3 ligand during the reaction process. Therefore, in this report we compare the in vitro and in vivo toxicity of Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] with those of related compounds featuring fully hydrolysed form of the phosphine ligand, namely Na2H14[{Re6Q8}(P(C2H4COO)3)6] (Q = S or Se). Our results demonstrate that cytotoxicity and acute in vivo toxicity of the complex Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] solutions were considerably lower than those of compounds with fully hydrolysed ligand P(C2H4COOH)3. Such behavior can be explained by the higher osmolality of Na2H14[{Re6Q8}(P(C2H4COO)3)6] versus Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6]

    Optical properties of photonic crystal slabs with asymmetrical unit cell

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    Using the unitarity and reciprocity properties of the scattering matrix, we analyse the symmetry and resonant optical properties of the photonic crystal slabs (PCS) with complicated unit cell. We show that the reflectivity is not changed upon the 180deg-rotation of the sample around the normal axis, even in PCS with asymmetrical unit cell. Whereas the transmissivity becomes asymmetrical if the diffraction or absorption are present. The PCS reflectivity peaks to unity near the quasiguided mode resonance for normal light incidence in the absence of diffraction, depolarisation, and absorptive losses. For the oblique incidence the full reflectivity is reached only in symmetrical PCS.Comment: 5 pages, 2 Postscript figure

    Experimental infection of H5N1 HPAI in BALB/c mice

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    ECOLOGY OF INFLUENZA VIRUS IN WILD BIRD POPULATIONS IN CENTRAL ASIA

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    The study provides the results of AIV surveillance in Central Asia region during 2003-2009. We have analyzed. 2604 samples from wild birds. These samples were collected in Kazakhstan. (279), Mongolia (650), and Russia (1675). Isolated viruses from samples collected in Mongolia (13 isolates) and. in Russia (4 isolates) were described. Virological analysis has shown that 6 isolates belong to H3N6 subtype and. 5 isolates belong to H4N6 subtype. Two H1N1 influenza viruses, one H10N7 virus, two H3N8 viruses, and. H13N8 virus, which is new for Central Asia, have been also isolated. Samples were taken from birds of 6 orders, including several species, preferring water and semi-aquatic biotopes, one species, preferring dry plain regions, and one more species which can inhabit both dry and. water biotopes

    Lens connexins α3Cx46 and α8Cx50 interact with zonula occludens protein-1 (ZO-1)

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    Connexin α1Cx43 has previously been shown to bind to the PDZ domain–containing protein ZO-1. The similarity of the carboxyl termini of this connexin and the lens fiber connexins α3Cx46 and α8Cx50 suggested that these connexins may also interact with ZO-1. ZO-1 was shown to be highly expressed in mouse lenses. Colocalization of ZO-1 with α3Cx46 and α8Cx50 connexins in fiber cells was demonstrated by immunofluorescence and by fracture-labeling electron microscopy but showed regional variations throughout the lens. ZO-1 was found to coimmunoprecipitate with α3Cx46 and α8Cx50, and pull-down experiments showed that the second PDZ domain of ZO-1 was involved in this interaction. Transiently expressed α3Cx46 and α8Cx50 connexins lacking the COOH-terminal residues did not bind to the second PDZ domain but still formed structures resembling gap junctions by immunofluorescence. These results indicate that ZO-1 interacts with lens fiber connexins α3Cx46 and α8Cx50 in a manner similar to that previously described for α1Cx43. The spatial variation in the interaction of ZO-1 with lens gap junctions is intriguing and is suggestive of multiple dynamic roles for this association

    ECOLOGY AND EVOLUTION OF HIGHLY PATHOGENIC AVIAN INFLUENZA H5N1 IN RUSSIA (2005-2012)

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    Russia covering a large part of Eurasia is of special interest for influenza virus ecology and evolution. The importance of this region has been confirmed by the previous outbreaks of HPAI H5N1 among wild birds from 2005 to 2010. Avian influenza virus surveillance is an important task prior the fundamental study and introduction. these data in practice. The article contains detailed comparative virological, molecular, pathogenic characteristics of H5N1 viruses isolated in Russia. Some molecular-epidemiological aspects are discussed. This study demonstrates the need for ongoing surveillance to detect new variants of influenza viruses and. facilitate prevention of outbreaks

    RARE INFLUENZA VIRUS SUBTYPES ISOLATED FROM BIRDS OF THE SOUTH OF WESTERN SIBERIA

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    During avian influenza virus (AIV) surveillance in Russia, 2008, H15N4 subtype of the virus was isolated. All the H15 viruses had been previously isolated in Australia in 1979 and 1983. This is the first report about isolation. of AIV H15 subtype elsewhere. Genetic and. antigenic analyses were made. The significant antigenic differences between A/teal/Chany/7119/2008 strain and. reference strain A/shearwater/ Australia/2376/1979 were revealed. The results of this study show the necessity of monitoring for avian influenza viruses, study of pathogen genetic variability, evolution and ecology

    Lassa virus: characterization of infectious agent, biological models for pathogenesis studies and variants of vaccine

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    Lassa virus (LASV) is classified into genus Mammarenavirus of Arenaviridae family. This virus is etiological agent of Lassa fever (LF) which is widespread in Africa. On average, in four out of five infected people, LF occurs without symptoms. The annual incidence ranges from 100,000 to 500,000 registered clinical cases, at a mortality rate of 1-2%. Among hospitalized patients with severe symptoms of hemorrhagic fever, this figure may be from 14 to 89.5%. Signs of an adverse outcome in LF are open bleeding and disorders of CNS (convulsions, tremor, disorientation and coma). Death occurs from multiple organ failure. Severely ill people recover slowly and may have relapses and complications such as pneumonia, myocarditis, psychosis, and hearing loss.Transmission of the virus in endemic territories occurs by alimentary way, air-dust and airborne droplets from a zoonotic source – rodents of the species African multimammate rat (Mastomys natalensis), by accidental contacts of people with their secretions (urine, feces, saliva) as well as when butchering carcasses and eating rodents. These animals are characterized by asymptomatic carrier and life-long persistence of the virus. Cases of transmission of the virus from person to person through the blood or other body fluids of patients are described. A sick person is contagious for two months, because the virus circulates in the blood despite high levels of antibodies. Infection of medical staff occurs during emergency surgical operations, or when the rules of contact precautions are not observed. Currently, with the ongoing LF outbreak in Nigeria, since 2016, hospitals have registered mortality rates of 22 and 8% for patients and health workers, respectively. During 1969-2016, 33 imported cases of this disease were described from West Africa to non-endemic territories (in the USA, Canada, Great Britain, the Netherlands, Germany, Israel and Japan). The mortality rate among these patients was 39%.The lack of prophylactic vaccines and specific therapeutic drugs is the major challenge for the prevention of LF. Thus, this review considers biological models (cell cultures and animals) that are suitable for studying the pathogenesis of this disease, preclinical studies of the specific activity and harmlessness of candidate vaccines, as well as options for these developments based on the platforms such as inactivated LASV and its DNA, the reassortant of Mopeia arenavirus, and measles virus attenuated strains, recombinant and replication-defective viruses (smallpox vaccine, Venezuelan equine encephalitis, bovine vesicular stomatitis, adenovirus of chimpanzee) and virus-like particles

    ECOLOGY OF INFLUENZA A VIRUSES, ISOLATED FROM GULLS OF THE RUSSIAN FAR EAST

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    During this research huge surveillance study, the role of Gulls as the nature host of influenza A viruses was established. Oral and cloacal samples from Gulls were collected on the territory of the Russian Far East. Fourteen influenza A viruses were isolated
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