[Evaluation of the antibacterial effect of passive nanoimpregnation of tooth root dentin by real-time PCR]. / Otsenka antibakterial'nogo effekta passivnoi nanoimpregnatsii dentina kornya zuba metodom polimeraznoi tsepnoi reaktsii v real'nom vremeni.

OBJECTIVE: Assessment of antibacterial properties of a new intracanal paste based on calcium hydroxocuprate (CHC) and silver nanoparticles hydrosol for passive root impregnation. MATERIAL AND METHODS: The study included 55 teeth with 69 root canals belonging patients with chronic apical periodontitis. The main group, including 44 root canals, was filled with a new paste based on CHC and silver nanoparticles for 7 days after preparation and irrigation. In the control group, 25 root canals were sealed with an aqueous paste of calcium hydroxide for 14 days. The presence of the endodontic microorganisms was evaluated by real-time PCR. RESULTS AND DISCUSSION: Further analysis showed that the amount of the DNA, common for P. gingivalis, T. forsythia and T. denticola, after treatment was less in the main group, where the new paste was applied. These results were significant at the p=0.05 level (p=0.005, p=0.006, p=0.003 according to each mentioned bacterial sample). No significant differences were found between the groups in the number of genome equivalents specific for P. intermedia and F. nucleatum (p=0.543, p=0.554). CONCLUSION: These findings suggest that the new method of passive root impregnation with the CHC and silver nanoparticles paste may be an effective method for the treatment of chronical apical periodontitis.

Topological superfluid defects with discrete point group symmetries.

Discrete symmetries are spatially ubiquitous but are often hidden in internal states of systems where they can have especially profound consequences. In this work we create and verify exotic magnetic phases of atomic spinor Bose-Einstein condensates that, despite their continuous character and intrinsic spatial isotropy, exhibit complex discrete polytope symmetries in their topological defects. Using carefully tailored spinor rotations and microwave transitions, we engineer singular line defects whose quantization conditions, exchange statistics, and dynamics are fundamentally determined by these underlying symmetries. We show how filling the vortex line singularities with atoms in a variety of different phases leads to core structures that possess magnetic interfaces with rich combinations of discrete and continuous symmetries. Such defects, with their non-commutative properties, could provide unconventional realizations of quantum information and interferometry.

Synthesis of CuO nanoparticles stabilized with gelatin for potential use in food packaging applications.

In the present study, a method for the synthesis of gelatin-stabilized copper oxide nanoparticles was developed. Synthesis was carried out by direct chemical precipitation. Copper sulfate, chloride, and acetate were used as precursors for the copper oxide synthesis. Gelatin was used as a stabilizer. It was found that the formation of monophase copper oxide II only occurred when copper acetate was used as a precursor. Our results showed that particles of the smallest diameter are formed in an aqueous medium (18 ± 6 nm), and those of th largest diameter-in an isobutanol medium (370 ± 131 nm). According to the photon correlation spectroscopy data, copper oxide nanoparticles synthesized in an aqueous medium were highly stable and had a monomodal size distribution with an average hydrodynamic radius of 61 nm. The study of the pH effect on the colloidal stability of copper oxide nanoparticles showed that the sample was stable in the pH range of 6.8 to 11.98. A possible mechanism for the pH influence on the stability of copper oxide nanoparticles is described. The effect of the ionic strength of the solution on the stability of the CuO nanoparticles sol was also studied, and the results showed that Ca2+ ions had the greatest effect on the sample stability. IR spectroscopy showed that the interaction of CuO nanoparticles with gelatin occurred through the hydroxyl group. It was found that CuO nanoparticles stabilized with gelatin have a fungicidal activity at concentration equivalent 2.5 · 10-3 mol/L and as a material for food nanopackaging can provide an increase in the shelf life of products on the example of strawberries and tomatoes. We investigated the possibility of using methylcellulose films modified with CuO nanoparticles for packaging and storage of hard cheese "Holland". The distribution of CuO nanoparticles in the methylcellulose film was uniform. We found that methylcellulose films modified with CuO nanoparticles inhibited the growth and development of QMAFAM, coliforms, yeast and mold in experimental cheese sa mples. Our research has shown that during the cheese storage in thermostat at 35 ± 1 °C for 7 days, CuO nanoparticles migrated to the product from the film. Nevertheless, it is worth noting that the maximum change in the concentration of copper in the experimental samples was only 0.12 µg/mg, which is not a toxic concentration. In general, the small value of migration of CuO nanoparticles confirms the high stability of the developed preparation. Our results indicated that the CuO nanoparticles stabilized with gelatin have a high potential for use in food packaging - both as an independent nanofilm and as part of other packaging materials.

Optimization of the Technique for Obtaining Selenium Nanoparticles Stabilized with Cocamidopropyl Betaine.

With the aim of optimizing the technique for the synthesis of selenium nanoparticles stabilized with cocamidopropyl betaine, a multifactorial experiment with three input parameters and three levels of variation was carried out. The selenous acid, cocamidopropyl betaine, and ascorbic acid concentrations were considered as input parameters. The output parameters were the average hydrodynamic radius of the particles (r av) and ζ-potential. Photon correlation spectroscopy analysis revealed monomodal size distribution in all the samples. It was shown that the average hydrodynamic radius is most strongly influenced by the concentrations of selenous and ascorbic acids. The minimal size of the selenium nanoparticles (r av ≤ 20 nm) is achieved at selenous acid concentration of 0.05 to 0.15 M and at ascorbic acid concentrations of 0.0332 to 0.5 M. Acoustic and electroacoustic spectroscopy examination showed that the technique proposed allows formation of both positively (ζ-potential = +29.71 mV) and negatively (ζ-potential = -2.86 mV) charged nanoparticles. It was found that the ζ-potential of the selenium nanoparticles depends very heavily on the concentrations of the stabilizer and of selenous acid. For obtaining positively charged selenium nanoparticles the selenous acid concentration should not exceed 0.15 M and the cocamidopropyl betaine concentrations should be greater than 0.12 M. Negatively charged selenium nanoparticles are formed at selenous acid concentrations above 0.15 M and at cocamidopropyl betaine concentration under 0.12 M. The micelle structure for the positively charged and negatively charged selenium nanoparticles was proposed.

[Nanomaterials in the modern dentistry (review)]. / Nanomaterialy v praktike sovremennoi stomatologii (obzor literatury).

THE AIM: Was to study the promising areas for using nanotechnologies in dentistry, existing methods of diagnostics, treatment and prevention of the dental diseases based on the properties of nanoparticles, to review the scientific literature devoted to this problem. In this literature review we use 86 sources: 1 Russian and 85 foreign articles. Analyzed articles were published within the last 5 years. The literature review summarizes and presents up-to-date methods of diagnosing, treating, and preventing dental disease that use nanotechnologies. Development and implementation of nanotechnological treatment are a promising direction for modern dentistry.

Decay of a Quantum Knot.

We experimentally study the dynamics of quantum knots in a uniform magnetic field in spin-1 Bose-Einstein condensates. The knot is created in the polar magnetic phase, which rapidly undergoes a transition toward the ferromagnetic phase in the presence of the knot. The magnetic order becomes scrambled as the system evolves, and the knot disappears. Strikingly, over long evolution times, the knot decays into a polar-core spin vortex, which is a member of a class of singular SO(3) vortices. The polar-core spin vortex is stable with an observed lifetime comparable to that of the condensate itself. The structure is similar to that predicted to appear in the evolution of an isolated monopole defect, suggesting a possible universality in the observed topological transition.

Controlled creation of a singular spinor vortex by circumventing the Dirac belt trick.

Persistent topological defects and textures are particularly dramatic consequences of superfluidity. Among the most fascinating examples are the singular vortices arising from the rotational symmetry group SO(3), with surprising topological properties illustrated by Dirac's famous belt trick. Despite considerable interest, controlled preparation and detailed study of vortex lines with complex internal structure in fully three-dimensional spinor systems remains an outstanding experimental challenge. Here, we propose and implement a reproducible and controllable method for creating and detecting a singular SO(3) line vortex from the decay of a non-singular spin texture in a ferromagnetic spin-1 Bose-Einstein condensate. Our experiment explicitly demonstrates the SO(3) character and the unique spinor properties of the defect. Although the vortex is singular, its core fills with atoms in the topologically distinct polar magnetic phase. The resulting stable, coherent topological interface has analogues in systems ranging from condensed matter to cosmology and string theory.

Experimental realization of Josephson junctions for an atom SQUID.

We report the creation of a pair of Josephson junctions on a toroidal dilute gas Bose-Einstein condensate (BEC), a configuration that is the cold atom analog of the well-known dc superconducting quantum interference device (SQUID). We observe Josephson effects, measure the critical current of the junctions, and find dynamic behavior that is in good agreement with the simple Josephson equations for a tunnel junction with the ideal sinusoidal current-phase relation expected for the parameters of the experiment. The junctions and toroidal trap are created with the painted potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single atom-SQUID case reported here. Since rotation plays the same role in the atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor.

Dynamics of morpho-physiological changes in endocrine glands in pigs in postnatal period after treatment with biogenic substances.

Structural and functional features of the thyroid and adrenal glands of boars and hogs in postnatal period were determined by administration of bioactive substances Trepel and Suvar.

[Normal values of temporal parameters of ECG in children according to results of clinico-epidemiological study ECG-screening of children and adolescents in Russian federation].

In order to obtain reliable information about time-domain ECG parameters in Russian children and to analyse their links with physiological changes the Project "ECG screening of children and adolescents of the Russian Federation" was carried out in 2003-2008. Time domain ECG parameters were studied in the representative sample of 5387 healthy individuals aged 0 to 18 years. In each age group, lower and upper limits of the norm for heart rate (HR), P wave, PQ and QRS intervals were defined as 2nd and 98th percentiles of their distribution. The equivalent limits of QT interval duration were defined as its 5th and 95th percentiles. Relationship between time domain parameters of pediatric ECG and HR was analyzed as well as relationship of these parameters with sex and age. The most important differences from prior pediatric studies completed 30 years ago were obtained for the heart rate limits. Among children aged 0 to 3, there was a tendency toward lowering of age-specific lower limits and elevation of age-specific upper limits. At ages older than 3 years, there was a tendency toward lowering of both the upper and the lower limits of HR. The newly obtained 2nd percentiles of the heart rate were lower than the known lower limits in nearly all ages. This indicates the necessity for revision of criteria of bradicardia in children. The present study showed that 5th and 95th percentiles of QTc interval (Bazett's formula) varied between 340 ms and 465 ms and were not significantly dependent on children's age and only for ages under 13 also on sex. Results of the study allowed to build age-specific ranges of norm for the time domain ECG parameters presented in a tabular form.