Search

To design an algorithm of decreasing dentin hypersensitivity in children after professional oral hygiene.Intact teeth extracted for orthodontic reasons in children and adults were involved in the pilot study. The enamel surface was cleaned by manual instruments and then polished with polishing pastes containing sodium bicarbonate, fluoride, calcium and phosphates. The results were studied with the help of a scanning electronic microscope. 60 14-15 years schoolchildren, the residents of Krasnogorsk, a town in the Moscow region, took part in the study. All of them were diagnosed dental plaque (K03.6) and underwent professional oral hygiene by manual instruments. Then the teeth were polished with polishing toothpastes. To reduce dentin hypersensitivity after these procedures the SENSODYNE Rapid Relief toothpaste was applied.The pilot study showed a destructive effect of a manual instrument on the tooth enamel especially in children. The data of the scanning electronic microscope demonstrated that the manual method with the use of polishing pastes containing sodium bicarbonate, fluoride, calcium and phosphates led to a significantly lower negative effect of this manual method on the tooth enamel both in children and adults. The application of SENSODYNE Rapid Relief by children at home after professional oral hygiene led to a decrease of dentin hypersensitivity by 65, 37%.The designed algorithm of the children's follow-up procedures after professional oral hygiene includes the application of polishing pastes containing sodium bicarbonate, fluoride, calcium, phosphates and the Sensodyne Rapid Relief toothpaste at home. This helps to minimize negative consequences of manual tooth plaque removal in case of professional oral hygiene.Разработка алгоритма снижения повышенной чувствительности зубов у детей после проведения профессиональной гигиены.Было проведено экспериментальное исследование с использованием сканирующего электронного микроскопа на интактных, удаленных по ортодонтическим показаниям зубах детей (20 зубов) и взрослых (20 зубов), которым проводилась обработка поверхности эмали ручными инструментами, с дальнейшим полированием поверхности эмали зубов полировочной пастой с содержанием бикарбоната натрия, фторида, кальция и фосфатов. Было обследовано 60 школьников Красногорска Московской области в возрасте 14—15 лет с диагнозом зубные отложения (К03.6). Им проводилась профессиональная гигиена с использованием ручных инструментов, с дальнейшим полированием зубов полировочной пастой и использованием зубной пасты SENSODYNE Мгновенный Эффект для снижения повышенной чувствительности зубов.В ходе экспериментального исследования выявлены данные о повреждающем действии ручных инструментов на поверхность эмали зубов, особенно выраженные у детей. Согласно данным сканирующего электронного микроскопа применение полировочной пасты с бикарбонатом натрия, фторида, кальция и фосфатов привело к значительной минимизации негативного воздействия профессиональной гигиены с использованием ручных инструментов на поверхность эмали зубов как у детей, так и у взрослых. Применение зубной пасты SENSODYNE Мгновенный Эффект детьми в домашних условиях привело к снижению повышенной чувствительности зубов после профессиональной гигиены на 65,37%.Разработанный алгоритм тактики ведения детей после профессиональной гигиены, включающий применение полировочной пасты с бикарбонатом натрия, фторида, кальция и фосфатов и использование детьми зубной пасты SENSODYNE Мгновенный Эффект в домашних условиях позволяет минимизировать негативные последствия удаления зубных отложений ручным методом при проведении профессиональной гигиены.

Purpose To determine resistance to dehydratation of bacteria resistant to UV irradiation. Methods Objects of research - extremophilic bacteria (from Antarctic islands and hypersaline reservoirs of Israel and Crimea). Dehydratation of bacteria was carried out in sealed desiccator; the exposure without access of moisture was 5 weeks, temperature - 22 - 25 °C, humidity - 1 - 4 %. UV irradiation of bacteria was carried out by lamp BUF 15 (A = 254 nm) in the range of 40 - 2400 J/m(2). After cultivation irradiated and not irradiated strains (before and after UV irradiation and before and after drying) we determined the number of cells. Results The extremely resistant to dehydratation (Firmicutes) and extremely sensitive to dehydratation (Proteobacteria, Bacteroidetes) strains was found among the studied bacteria. Most strains of bacteria that were resistant to dehydratation were also resistant to UV irradiation. Survival after dehydratation in these bacteria was 6.32 - 55.26 % and UV LD99.99 240-600 J/m(2). Instead, representatives of Proteobacteria were extremely sensitive to these extreme factors: the cell survival was 0 - 1.6 % after dehydratation and UV LD99.99 80 - 180 J/m(2). Conclusions The results support the hypothesis that between bacteria resistance to electromagnetic radiation (UV) and their resistance to dehydratation there is a correlation.

Search of methylotrophic bacteria has been carried out during time VIIth Ukranian Antarctic expedition (2003) at station «Academic Vernadsky». The psychrotolerant bacteria obligately using a methane have been found out in samples of mosses in an island part of Antarctic Region and in soil-plant samples. The quantity of methane oxidizing bacteria in samples from Antarctica (101–103 /g of the sample) was lower, than in samples from regions with a temperate climate (102–106 /g of the sample). The psychrotolerant bacteria of genus Methylobacterium facultatively using a methanol have been revealed in the silt of fresh and «Red» lakes, and also in soil-plant samples. Single psychrophilic strain which, probably is a new species of genus Methylobacterium was isolated at 10oС from soil-plant sample of Antarctic Region. The majority of the collection mesophilic strains Methylobacterium isolated earlier from soils and plant phyllosphere from various regions of Ukraine is shown, that, also were capable to grow at 10oС. It was shown, that strains Methylobacterium are not catalysts of process of formation of ice. Moreover, some from them are capable to reduce temperature of freezing of water (process of crystallization of ice at their presence began at temperature lower-13°С), that is, naturally they have «antifreezing»effect on process of crystallization of ice. These properties of strains Methylobacterium may be very important in conditions of Antarctica for a survival both microbic, and plant forms. As a whole, psychrotolerant facultative methylotrophs and the obligate methane oxidizing bacteria revealed by us in various ecosystems of Antarctic Region, expand representation about a physiological diversity of these groups of bacteria, about their distribution to biosphere and the contribution to a global cycle of carbon.

Bacteria that produce exopolysaccharides (EPS) and use methane as the only source of carbon were selected by studying a collection of methanotroph strains: Methylococcus capsulatusE 494, 874, and 3009; M. thermophilus111p, 112p, and 119p; Methylobacter ucrainicus159 and 161; M. luteus57v and 12b; Methylobactersp. 100; Methylomonas rubra15 sh and SK-32; Methylosinus trichosporiumOV3b, OV5b, and 4e; M. sporium5,12, A20d, and 90v; and Methylocystis parvusOVVP. Mesophilic methanotroph strains with the ribulose monophosphate way of C1-compound assimilation synthesized EPS more actively than bacteria operating the serine cycle. The dynamics of EPS synthesis by methanotrophs during chemostat cultivation was studied.

Methanotrophic bacteria utilize only methane (some species methanol) as a source of carbon and energy. They can co-metabolize a number of non-growth substrates due to the low specificity of methane monooxygenase (MMO). The reducer for monooxygenation is obtained during dehydrogenation of intermediates of methane oxidation. During growth on methane, co-metabolism of non-growth substrates leads to exhaustion of the methanotroph energy sources, accumulation of toxic products and growth cessation. To evaluate a role of the monooxygenation process in the metabolism of methanotrophs, co-metabolism of methanol and a substrate of MMO (ethane or carbon monoxide) was studied during the growth of Methylomonas rubra 15sh and Methylococcus thermophilus 111p. These organisms, being grown at low copper content, did not oxidize naphthalene. Thus, they possess particulate MMO, which can use reducing equivalents at the level of methanol dehydrogenase. Methanol did not support growth of Mc. thermophilus 111p. Growth of Mm. rubra 15sh on methanol was inefficient and was accompanied by accumulation of formaldehyde. When a second substrate (ethane or carbon monoxide) was added into the gas phase (5–20 vol.%), the growth of Mc. thermophilus 111p occurred, and the yield from methanol of Mm. rubra 15sh was enhanced. At low methanol concentration (to 12.5 mM), the yield of the Mm. rubra 15sh biomass from methanol was proportional to the amount of the second substrate co-oxidized, and the whole methanol utilized was converted into biomass. Theoretical calculations showed that such high efficiency of growth could be achieved when MMO received reducing equivalents from methanol dehydrogenase and, moreover, electron transport chain from NADH to MMO contained a proton translocating segment. Thus, monooxygenation of the MMO substrate was profitable for the methanotroph metabolism. During the growth of methanotrophs studied on methanol plus ethane or carbon monoxide, the major part of electrons of methanol utilized was used for the monooxygenation of the MMO substrate. For methanotrophs, this allows to consider the monooxygenation process as the energy yielding mechanism of the electron transport to oxygen.

The properties of In2O3-based ceramic sensors, doped with Pt4+ and Au3+ ions, at detection of NH3 and other reducing gases have been compared. It was stated that Pt increases while Au decreases In2O3 sensitivity to NH3. The ceramics resistance decreases, when In2O3 is doped with Pt. Au addition to In2O3 leads to the opposite effect. The high sensitivity of In2O3–Pt sensors to NH3 and decrease of In2O3–Pt ceramics resistance, when compared with undoped In2O3, may be caused by the formation of InxPty in In2O3–Pt systems. In2O3–Pt sensors allow analysing the content of NH3 in air in the concentration range of 15–2000 ppm.

The interaction and the electronic state of the components in the RuO2–TiO2 film system, obtained by the sol–gel method from poly(butyl titanate) and ruthenium chloride, are considered. After the films had been heat-treated in air at 770 K a composite oxide film was formed, which is mostly a phase of solid solution of TiO2 in RuO2. Further annealing of the film in H2 led to deterioration of the solid solution and partial reduction of both components, Ti4+ and Ru4+ions. Within the reduced system ruthenium in oxidation states 0–VIII was identified by XPS. Titanium appeared in the form of non-stoichiometric TinO2n– 1, oxides, mostly Ti4O7, but TiO and Ti2O are also possible.

Transparent fine-granular SnO2 and SnO2-Pd films (SnO2 verage particle size 25–30 nm) have been obtained by annealing of tin hydroxide sols, stabilised with oleic acid. The structure of the films was investigated by TEM, ED and Mossbauer spectroscopy. In SnO2-Pd films, annealed at 800 °C, palladium is present as homogeneously distributed thermally stable particles (d = 5–8 nm). Observed isomeric shifts of 119Sn Mossbauer spectra suggests the presence of partially reduced tin ions, Sn2+ and Sn3+, in the films. Deeper reduction of SnO2 and formation of SnO are observed in SnO2-Pd films, annealed at 500 °C. Thin-film sensors based on sol-gel obtained SnO2 and SnO2-Pd are high-sensitive to different gases (H2, CH4, NO, CO). They enable detection of CO and CH4, CO and NO selectively in mixtures by controlling of sensor's operating temperature.

Natural latent human antibodies cross-reacting with DNA and cardiolipin, interact with human endothelial cells, decrease antiaggregation activity of rat aortic wall, and increase fibrinolytic activity of the wall of the inferior vena cava. It is assumed that natural antiphospholipid antibodies present in immunoglobulin preparations in a latent state modify antithrombogenic activity of the vascular wall and are a potential cause of antiphospholipid syndrome.

The interaction and the electronic state of the components in the RuO2–TiO2 film system, obtained by the sol–gel method from poly(butyl titanate) and ruthenium chloride, are considered. After the films had been heat-treated in air at 770 K a composite oxide film was formed, which is mostly a phase of solid solution of TiO2 in RuO2. Further annealing of the film in H2 led to deterioration of the solid solution and partial reduction of both components, Ti4+ and Ru4+ions. Within the reduced system ruthenium in oxidation states 0–VIII was identified by XPS. Titanium appeared in the form of non-stoichiometric TinO2n– 1, oxides, mostly Ti4O7, but TiO and Ti2O are also possible.

High molecular weight compounds find wide application at the present time in modern medicine as raw materials for the preparation of instruments, sanitation articles, materials for stomatology, medicaments, blood substitutes, and for producing artificial organs [4, 9]. Prostheses of the latter present the science with several problems, the most important being the investigation of the reaction of polymers with tissues and blood of the organism. One of the principal requirements of polymers for medical purposes is their antithrombogenic character, and therefore production of polymers, which do not cause the production of thrombi is a current problem. We studied the influence of a "Diflon" polycarbonate, poly(butylene terephthalate), poly(4-methylpentene), polyfluoroethylene resin, a TPU-3BT polyurethane, and polyethylene on the hemocoagulation process, the electrophoretic mobility of erythrocytes and thromboeytes and the resistance of erythrocytes in hydrochloric acid. The results of biochemical investigations are given for connective tissue capsules developing around polymeric materials made of a PPE-201 polyurethane and polyethylene, in order to study the biocompatibility of tissues and blood of animals with the above polymers.

This paper concerns prospects in the use of immobilized cells of methane-oxidizing bacteria as bioorganic catalysts. Test unit for studies of catalytic properties of immobilized cells of bacteria utilizing gases as source of nutrition has been designed. Cometabolism of nongrowth substrates by immobilized cells of methane-oxidizers has been investigated. The catalytic properties of immobilized cells have been established to be markedly influenced by both the chemical composition of a carrier and type of binding of cells to the surface of a carrier. Silochromes modified by the toluylenediisocyanate and carboxyl groups as well as agar gel appear to hold much promise for immobilization of methane-oxidizing cells, and nonmodified silochrome and asbestos have considerable promise for immobilization of methane-producing cells. Results obtained indicate that the immobilized cells of methane-oxidizing and methanogenic bacteria can be used as a convenient model in studying processes of methane synthesis and conversion. KEYWORDS Immobilization; cometabolism; methane oxidation; methane production; carbon cycle.