Silicas with Polyoxyethylene Branches for Modification of Membranes Based on Microporous Block Copolymers

We have synthesized cubic and linear polysiloxanes containing polyoxyethylene branches (ASiP-Cu) using tetraethoxysilane, polyoxyethylene glycol, and copper chloride as precursors; the products are stable to self-condensation. The effect of copper chloride content on the chemical structure of ASiP-Cu has been established. A special study was aimed at defining the modifying effect of ASiP-Cu on the sorption characteristics of membranes based on microporous, optically transparent block copolymers (OBCs). These OBCs were produced using 2,4-toluene diisocyanate and block copolymers of ethylene and propylene oxides. The study demonstrated significantly increased sorption capacity of the modified polymers. On the basis of the modified microporous block copolymers and 1-(2-pyridylazo)-2-naphthol (PAN) analytical reagent, an analytical test system has been developed. Additionally, the modified OBCs have the benefit of high diffusion permeability for molecules of organic dyes and metal ions. It has been shown that the volume of voids and structural features of their internal cavities contribute to the complex formation reaction involving PAN and copper chloride.

Femtosecond Laser-Printed Gold Nanoantennas for Electrically Driven and Bias-Tuned Nanoscale Light Sources Operating in Visible and Infrared Spectral Ranges

Nanoscale electrically driven light-emitting sources with tunable wavelength represent a milestone for implementation of integrated optoelectronic chips. Plasmonic nanoantennas exhibiting an enhanced local density of optical states (LDOS) and strong Purcell effect hold promise for fabrication of bright nanoscale light emitters. Here, we justify gold parabola-shaped nanobumps and their ordered arrays produced by direct ablation-free femtosecond laser printing as broadband plasmonic light sources electrically excited by a probe of scanning tunneling microscope (STM). I-V curves of the probe-nanoantenna tunnel junction reveal characteristic bias voltages correlating with visible-range localized (0.55 and 0.85 μm) and near-IR (1.65 and 1.87 μm) collective plasmonic modes of these nanoantennas. These multiband resonances confirmed by optical spectroscopy and full-wave simulations provide enhanced LDOS for efficient electrically driven and bias-tuned light emission. Additionally, our studies confirm remarkable applicability of STM for accurate study of optical modes supported by the plasmonic nanoantennas at nanoscale spatial resolution.

Nanoscale Electrically Driven Light Source Based on Hybrid Semiconductor/Metal Nanoantenna

A micro- or nanosized electrically controlled source of optical radiation is one of the key elements in optoelectronic systems. The phenomenon of light emission via inelastic tunneling (LEIT) of electrons through potential barriers or junctions opens up new possibilities for development of such sources. In this work, we present a simple approach for fabrication of nanoscale electrically driven light sources based on LEIT. We employ STM lithography to locally modify the surface of a Si/Au film stack via heating, which is enabled by a high-density tunnel current. Using the proposed technique, hybrid Si/Au nanoantennas with a minimum diameter of 60 nm were formed. Studying both electronic and optical properties of the obtained nanoantennas, we confirm that the resulting structures can efficiently emit photons in the visible range because of inelastic scattering of electrons. The proposed approach allows for fabrication of nanosized hybrid nanoantennas and studying their properties using STM.

Organosilica-Modified Multiblock Copolymers for Membrane Gas Separation

Organosubstituted silica derivatives were synthesized and investigated as modifiers of block copolymers based on macroinitiator and 2,4-toluene diisocyanate. A peculiarity of the modified block copolymers is the existence in their structure of coplanar rigid polyisocyanate blocks of acetal nature (O-polyisocyanates). Organosubstituted silica derivatives have a non-additive effect on high-temperature relaxation and α-transitions of modified polymers and exhibit the ability to influence the supramolecular structure of block copolymers. The use of the developed modifiers leads to a change in the gas transport properties of block copolymers. The increase of the permeability coefficients is due to the increase of the diffusion coefficients. At the same time, the gas solubility coefficients do not change. An increase in the ideal selectivity for a number of gas pairs is observed. An increase in the selectivity for the CO2/N2 gas pair (from 25 to 39) by 1.5 times demonstrates the promising use of this material for flue gases separation.

[Persistent Shallot virus X infection correlates with transcriptional repression of plant cell RNA-dependent RNA polymerase and DCL proteins in plant roots]

Shallot virus X is a typical representative of Allexiviruses. The transcription levels of principal genes involved in the RNA silencing in healthy and shallot virus X-infected plants have been quantified by real-time polymerase chain reaction. There is a negative correlation between the reproduction rates of RNA virus and the levels of RNA-dependent RNA polymerase and DCL proteins in roots and leaves of infected plants. These observations indicate that Shallot X virus employs noncanonical ways of overcoming the antiviral defense of the plant by systemic RNA silencing.

[The flagship of the national naval medical science (on the 80th anniversary of establishment of the 1st Central Research Institute of the Defense Ministry of Russian Federation)]

The article is devoted to the 80th anniversary of the formation of the naval medical science subunit, which is the part of the 1st Central Research Institute of the Defense Ministry of Russian Federation. In the 30th years of XX century, a group of naval doctors formulated the main directions of preventive naval medicine. For eight decades, several generations of medical scientists have developed and ensured implementation of regulatory requirements for habitability and ergonomics of Navy ships. At the present stage, this work focuses on promising directions of the development of the domestic military shipbuilding and the use of advanced and innovative biomedical technologies.

[Implant-retained restoration in esthetically important zone]

The article analyzes the features and clinical aspects of implant-retained restorations in the anterior maxilla important for achieving optimal functional and esthetic results.

[Experimental assessment of biodegradable polyglycolic and polylactic acid polymers for medical use]

Interrelations of biodegradable poliglicolic and polilactic acid polymers in various proportions implanted in standardized bone defects were evaluated in animal model with 40 Wister line rats. During 10 month follow-up period bone capsule surrounded all implants, but timing of bone formation and bone quality varied significantly being optimal in LactoSorb group. Destructive features of polymers were also seen in implant-bone contact area defined as inflammation, fibrous tissue formation and cell dystrophy.

[New type titan alloy with shape memory for use in dental implantology]

The paper summarizes the results of in vitro and in vivo studies that have proved biocompatibility and medical safety of Ta and Ti-Nb-Ta-bases alloys. According to some in vitro data Ti-Nb-Ta-based alloy possesses certain advantages when comparing to Ta-based. In particular, it contributes to elevation of viability of cellular elements and to definite increase of their adhesive potential.

A study of the efficacy, safety and tolerance of cosmetic products for basic care and hygiene in a combined therapy of patients suffering from atopic dermatitis in the mild to moderate forms

The article is considering contemporary views on the role and significance of microorganisms in pathogenesis of atopic dermatitis. One can also find here efficiency analysis of cosmetics Emolium P «Triaktivnyj cream» and «Triaktivnaja bath emulsion» as treatments for low and middle severity atopic dermatitis, as well as research results of skin microbiota (before study initiation and on 14 day).

[Perspectives of use of polytetrafluoroethylene with nanostructured surface in dentistry]

The perspectives of use of porous polytetrafluorethilen (PTPE) with modified surface combined with mesenchymal stem cells for tissue-engineering constructions were studied. The paper also describes the mode of PTPE surface modification consisting in nanostructured metallic or ceramic layer application resulting in biocompatibility and surface adhesion rates increase. The magnetic atomizing of Ti and Ti-Ca-P-C-O-N nanolayers enhances the material integration potential as well as adhesion rates thus making it perspective when combined with mesenchymal stem cells for bone defects plasty.

[Measures for prevention of maxillary sinus mucosa perforation by sinus-lifting procedure]

The paper describes the sinus-lifting technique useful in patients with alveolar bone deficiency. The technique allows significantly lowering the risk of maxillary sinus mucosa perforation and improves bone tissue regeneration.

[Dental implantation by low-density bone]

The paper analyzes modern approaches to bone density evaluation by planning of dental implantation procedure. Implantation technique in patients with low-density bone creating favorable conditions for osseous integration is described.

[Implants integration into bone tissue: theoretical aspects of the problem]

It was analyzed the status of dental implants integration into bone tissue problem. The concept of stages and mechanisms of development of integration process in the implant-bone interface based on literature data and own study was presented.

[Reactive transformation of human urinary smooth muscular tissue in some diseases (structural-metabolic aspects of organization)]

Smooth muscular tissue (SMT) of human urinary system was studied at different levels (renal pelvis, proximal and distal parts of the ureter) in health and some urological diseases (vesicoureteral reflux, ureteral obstruction). The method of target cell dissociation was used. The volume of myocytes, nuclei, nuclear-cytoplasmic correlation were calculated. Content of DNA and cytoplasmic protein was studied cytospectrophotometrically. Electron-microscopic study was also made. Three types of myocytes with different structural-metabolic parameters were detected. There were significant differences in mean volumes of myocytes, cytophotometric indices of SMT in different parts of the urinary tracts related to the pattern of these zones functioning. A comparative analysis of intact and affected SMT of the distal ureter demonstrated changes in the structure of leiomyocytes population, optic density of cytoplasmic protein and proliferative activity of myocytes which correlated depending on the kind and change of functional load.

Influence of dietary cereal and energy content on the accumulation of lipids in the liver in fatty liver-haemorrhagic syndrome in the fowl

Isocaloric diets supplying about 2900 kcal/kg and based on maize, wheat and barley respectively, were fed to pullets for 13 weeks from point of lay. The number of cases of subclinical fatty liver-haemorrhagic syndrome and the mean total lipid, triglyceride and monoglyceride content of the liver decreased in the above order of diets. The final body weight, weight gain and abdominal fat score followed the order wheat greater than maize greater than barley. Reduction of the energy content of the wheat and barley diets to 2670 and 2490 kcal/kg respectively by the omission of animal fat was associated with a reduction in the lipid content of the liver only in the case of the wheat diets. Egg production and quality were uniformly high and no difference was detected in plasma triglyceride and free fatty acid levels.