Multifunctional oil-produced reduced graphene oxide - Silver oxide composites with photocatalytic, antioxidant, and antibacterial activities.

Graphene-based nanomaterials that combine significant photocatalytic, antioxidant and antibacterial activity are very attractive candidates for biomedical and environmental applications. Conventional chemical synthesis routes may contaminate the resultant materials with toxic molecules, compromising their properties and limiting their use in biomedical applications. Ideally, to avoid any contamination, the nanomaterials should be synthesized from non-toxic precursors and reagents, e.g. foodstuff via a simple technology that does not rely on the use of hazardous chemicals yet produces materials of high quality. Here, we report an environmentally friendly, low cost reduced graphene oxide-silver-silver oxide nanocomposite with strong photocatalytic, antioxidant and antibacterial activity for environmental remediation. The reduced graphene oxide (FRGO) is synthesized from edible sunflower oil via a simple flame synthesis method. Next, silver nanoparticles (Ag/AgO/Ag2O) are produced by phytochemical reduction of AgNO3 using a reducing agent based on flavonoids from Coleus aromaticus (Mexican mint), also used in food industry. Thus-obtained FRGO-Ag/AgO/Ag2O composite is characterized using X-ray diffraction spectroscopy, scanning electron microscopy, fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The degradation of anionic textile dye Methylene blue (MB) is used as a measure of photocatalytic activity of FRGO and FRGO/Ag/AgO/Ag2O, with solution pH, initial dye concentration, and quantity of the catalyst considered as influencing factors. FRGO-Ag/AgO/Ag2O composites show strong antioxidant activity, with improved radical inhibition as well as dye degradation properties when compared to pristine FRGO.

[Features and significance of adhesion of bacteria and fungi of the oral cavity as the initial stage of the formation of a microbial biofilm on dental polymer materials]. / Osobennosti i znachenie adgezii bakterii i gribov polosti rta kak etapa formirovaniya mikrobnoi bioplenki na stomatologicheskikh polimernykh materialakh.

OBJECTIVE: Characteristics of the adhesion of yeast fungi and oral bacteria of various types in vitro to samples of polymeric materials for fixed structures of dental prostheses, obtained using various technologies: adjective digital 3D printing and traditional methods. MATERIAL AND METHODS: Conducted model experiments on the adhesion of bacterial (including the main periodontopic-pathogenic species - P. gingivalis, P. intermedia, etc.) and fungal pathogens (C. albicans) to standard samples of polymer materials NextDent C & B Micro Filled Hybrid («NextDent¼, Netherlands), Detax Freeprint temp UV («Detax¼, Germany), obtained by digital additive 3D printing technology, and Luxatemp Automix Plus («DMG¼, Germany) and Acrytemp («Zhermack¼, Italy) - by the traditional method as a control. Removal of adhering microbes from the material was carried out using an ultrasound machine (exposure time 10 minutes, power 60 kHz). RESULTS: The dependence of the degree of microbial adhesion on the nature of the material and processing technology (3D printing, milling) was established. The materials of NextDent C & B Micro Filled Hybrid and Detax Freeprint temp UV showed high resistance to adhesion of clinical isolates of periodontal pathogenic bacteria and C. albicans fungi. CONCLUSION: The lowest adhesion values for periodontopathogenic species and C. albicans fungi were detected when using samples of materials obtained by 3D printing: NextDent C & B Micro Filled Hybrid and Detax Freeprint temp UV compared to Luxatemp Automix Plus and Acrytemp polymers.

Wearable, Flexible, Disposable Plasma-Reduced Graphene Oxide Stress Sensors for Monitoring Activities in Austere Environments.

In austere environments, for example, in outer space, on surfaces of extra-terrestrial bodies (Moon, Mars, etc.), or under water, technologies that can enable continuous, reliable, and authentic monitoring of movement of human operators and devices can be critical. We report here the production and human body test of wearable, flexible graphene oxide stress sensors suitable for real-time monitoring of body parameters, state and position of humans, and automatic equipment. These sensors have excellent sensitivity and signal strength across a wide strain range, alleviating the need for additional instrumentation for signal processing and amplification. Their low cost makes them virtually disposable, which may benefit such applications as smart clothing. The sensors were fabricated by a concomitant reduction and N-doping of graphene oxide on polydimethylsiloxane in N2-H2 plasma. The direct bias and other plasma parameters have a significant effect on the reduction and properties of graphene oxide sensors, as shown by optical emission, Raman and X-ray photoelectron spectroscopies, and X-ray diffraction. Optical emission showed different excitation and ionization processes involving atomic and molecular species in the N2-H2 discharge. The photoelectron spectroscopy has confirmed the graphene reduction and introduction of nitrogen doping into the reduced graphene oxide. The bias efficiently controls plasma-induced electric fields, and plasma-related effects determine the N-doping levels. The reduced graphene oxides demonstrate excellent tensile properties, which make them suitable for efficient but cheap stress sensors. This eco-friendly, fast, room-temperature method shows a great potential for fabrication of efficient, flexible sensors.

[The preconceptional preparation of the patients presenting with chronic endometritis: the evaluation of the effectiveness of phyto- and physiotherapy]. / Pregravidarnaia podgotovka patsientok s khronicheskim éndometritom: otsenka éffektivnosti fito- i fizioterapii.

BACKGROUND: The necessity of the comparative studies with special reference to the preconceptional preparation of the patients presenting with chronic endometritis is self-evident bearing in mind the lack of common approaches to the preconceptional preparation of the patients with this condition. AIMS: The objective of the present study was the evaluation of the effectiveness of preconceptional with the use phyto- and/or physiotherapies for the treatment of the patients suffering from chronic endometritis. MATERIAL AND METHODS: This prospective study included 309 patients from the couples in the infertile marriage attributable to chronic endometritis. All the patients were divided into three group depending on the choice of the preconceptional preparation modality. Those comprising the first group (n=148) received 2.5 mg in days the aqueous extract of one-sided-wintergreen (Orthilia secunda) at a daily dose of 2.5 mg during three months. The patients of the second group (n=101) were given the combined physiotherapeutic treatment. The patients of the third group (n=60) refused any preconceptional preparation; therefore an expectant strategy was chosen to manage them. Part of patients of the first and second groups (n=30) underwent the immunohistochemical investigation aimed at evaluation of the methods employed in this study to the solution of the infertility problem. The data obtained were treated with the use of the Statistica 11.0 software package. RESULT: The preconceptional preparation of the patients suffering infertility associated with chronic endometritis with the use of the aqueous extract of one-sided-wintergreen in the combination with physiotherapeutic treatment resulted in the development of pregnancy in 72.9% and 81.2% of the participants in the study respectively and its completion with labors in 95.3% and 90.1% of the women respectively. The results of the immunohistochemical study involving the patients treated with the aqueous extract of one-sided-wintergreen alone gave evidence of the reduced frequency of frequency of leukocytic infiltration and leukocytic activity in dynamics of an experiment (CD 20+, CD138+, CD 56+, CD 16+, HLA-DRII+); simultaneously, an augmentation of the reception of endometrium to sex steroids. CONCLUSION: The preconceptional preparation of infertile women with the application of the aqueous extracts of one-sided-wintergreen can be recommended for the patients with chronic endometritis, especially in the presence of contraindications for physiotherapy. Phytotherapy made use of in the present study restored reception of endometrium to estrogens and alleviated the autoimmune manifestations of local immunity.

Oxygen plasmas: a sharp chisel and handy trowel for nanofabrication.

Although extremely chemically reactive, oxygen plasmas feature certain properties that make them attractive not only for material removal via etching and sputtering, but also for driving and sustaining nucleation and growth of various nanostructures in plasma bulk and on plasma-exposed surfaces. In this minireview, a number of representative examples is used to demonstrate key mechanisms and unique capabilities of oxygen plasmas and how these can be used in present-day nano-fabrication. In addition to modification and functionalisation processes typical for oxygen plasmas, their ability to catalyse the growth of complex nanoarchitectures is emphasized. Two types of technologies based on oxygen plasmas, namely surface treatment without a change in the size and shape of surface features, as well as direct growth of oxide structures, are used to better illustrate the capabilities of oxygen plasmas as a powerful process environment. Future applications and possible challenges for the use of oxygen plasmas in nanofabrication are discussed.

Publisher Correction: Recent progress and perspectives of space electric propulsion systems based on smart nanomaterials.

The original PDF version of this Article had an incorrect volume number of '8'; it should have been '9'. This has been corrected in the PDF version of the Article. The HTML version was correct from the time of publication.

Recent progress and perspectives of space electric propulsion systems based on smart nanomaterials.

Drastic miniaturization of electronics and ingression of next-generation nanomaterials into space technology have provoked a renaissance in interplanetary flights and near-Earth space exploration using small unmanned satellites and systems. As the next stage, the NASA's 2015 Nanotechnology Roadmap initiative called for new design paradigms that integrate nanotechnology and conceptually new materials to build advanced, deep-space-capable, adaptive spacecraft. This review examines the cutting edge and discusses the opportunities for integration of nanomaterials into the most advanced types of electric propulsion devices that take advantage of their unique features and boost their efficiency and service life. Finally, we propose a concept of an adaptive thruster.

MONITORING OF CHANGES IN PHYSICOCHEMICAL AND CLINICAL CHARACTERISTICS OF THE DENTAL POLYMER MATERIALS USED IN ADDITIVE MANUFACTURING OF DENTAL PROSTHESES.

The use of additive technologies in dentistry is a promising trend; however, the physical and mechanical properties of the materials intended for the fabrication of long-term fixed restorations remain understudied. The aim of this research is to determine the feasibility of the use of long-term fixed provisional restorations made of polymer materials, fabricated using 3D printing. The conformance of the physical and mechanical properties of NextDent C&B Micro Filled Hybrid (ND) and Detax Freeprint temp UV (DX) materials to ISO 1567:1999 standard, stability of their physical and mechanical properties under the conditions of accelerated aging, as well as their resistance to the oral cavity environment were studied. As a result of the performed studies, the DX material turned out to be superior to ND with respect to most characteristics. Clinical observations were conducted on the treatment of chronic generalized periodontitis using the following fixed provisional splints made of various materials: DX, fabricated according to the Slide-And-Separate technology, splints fabricated using the CAD/CAM technology, and adhesive splints reinforced with a GlasSpan fiberglass thread. As a result of the analysis of the OHI-S and PI indices values, the absence of any statistically significant difference between the above-describe treatment methods was determined. The studied materials conform to the requirements of ISO 1567:1999; the materials exhibited different stability under the conditions of accelerated aging, nevertheless, they can be utilized for the fabrication of long-term fixed provisional restorations.

EAN consensus review on prevention, diagnosis and management of tick-borne encephalitis.

BACKGROUND AND PURPOSE: Tick-borne encephalitis (TBE) is an infection of the central nervous system (CNS) caused by tick-borne encephalitis virus (TBEV) and transmitted by ticks, with a variety of clinical manifestations. The incidence of TBE in Europe is increasing due to an extended season of the infection and the enlargement of endemic areas. Our objectives are to provide recommendations on the prevention, diagnosis and management of TBE, based on evidence or consensus decisions. METHODS: For systematic evaluation, the literature was searched from 1970 to 2015 (including early online publications of 2016), and recommendations were based on evidence or consensus decisions of the Task Force when evidence-based data were not available. RECOMMENDATIONS: Vaccination against TBE is recommended for all age groups above 1 year in highly endemic areas (≥5 cases/100 000/year), but also for individuals at risk in areas with a lower incidence. Travellers to endemic areas should be vaccinated if their visits will include extensive outdoor activities. Post-exposure prophylaxis after a tick bite is not recommended. A case of TBE is defined by the presence of clinical signs of meningitis, meningoencephalitis or meningoencephalomyelitis with cerebrospinal fluid (CSF) pleocytosis (>5 × 106 cells/l) and the presence of specific TBEV serum immunoglobulin M (IgM) and IgG antibodies, CSF IgM antibodies or TBEV IgG seroconversion. TBEV-specific polymerase chain reaction in blood is diagnostic in the first viremic phase but it is not sensitive in the second phase of TBE with clinical manifestations of CNS inflammation. Lumbar puncture should be performed in all patients with suspected CNS infection unless there are contraindications. Imaging of the brain and spinal cord has a low sensitivity and a low specificity, but it is useful for differential diagnosis. No effective antiviral or immunomodulating therapy is available for TBE; therefore the treatment is symptomatic. Patients with a potentially life threatening meningoencephalitis or meningoencephalomyelitis should be admitted to an intensive care unit. In the case of brain oedema, analgosedation should be deepened; osmotherapy and corticosteroids are not routinely recommended. If intracranial pressure is increased, therapeutic hypothermia or decompressive craniectomy might be considered. Seizures should be treated as any other symptomatic epileptic seizures. CONCLUSIONS: Tick-borne encephalitis is a viral CNS infection that may result in long-term neurological sequelae. Since its incidence in Europe is increasing due to broadening of endemic areas and prolongation of the tick activity season, the health burden of TBE is enlarging. There is no effective antiviral treatment for TBE, but the disease may be effectively prevented by vaccination.

Hybrid Carbon-Based Nanostructured Platforms for the Advanced Bioreactors.

Mankind faces several global challenges such as chronic and acute hunger, global poverty, energy deficiency and environment conservation. Common biotechnologies based on batch, fluidbed and other similar processes are now extensively used for the production of a wide range of products such as antibiotics, biofuels, cultured and fermented food products. Unfortunately, these processes suffer from low efficiency, high energy demand, low controllability and rapid biocatalyst degradation by microbiological attack, and thus still are not capable of seriously addressing the global hunger and energy deficiency challenges. Moreover, sustainable future technologies require minimizing the environmental impact of toxic by-products by implementing the "life produces organic matter, organic matter sustains life" principle. Nanostructure-based biotechnology is one of the most promising approaches that can help to solve these challenges. In this work we briefly review the unique features of the carbon-based nanostructured platforms, with some attention paid to other nanomaterials. We discuss the main building blocks and processes to design and fabricate novel platforms, with a focus on dense arrays of the vertically-aligned nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these systems are considered.

Nanoherding: Plasma-Chemical Synthesis and Electric-Charge-Driven Self Organization of SiO2 Nanodots.

We report on the chemical synthesis of the arrays of silicon oxide nanodots and their self-organization on the surface via physical processes triggered by surface charges. The method based on chemically active oxygen plasma leads to the rearrangement of nanostructures and eventually to the formation of groups of nanodots. This behavior is explained in terms of the effect of electric field on the kinetics of surface processes. The direct measurements of the electric charges on the surface demonstrate that the charge correlates with the density and arrangement of nanodots within the array. Extensive numerical simulations support the proposed mechanism and prove a critical role of the electric charges in the self-organization. This simple and environment-friendly self-guided process could be used in the chemical synthesis of large arrays of nanodots on semiconducting surfaces for a variety of applications in catalysis, energy conversion and storage, photochemistry, environmental and biosensing, and several others.

[One of the approaches to psychological-pedagogical help to children with severe movement disorders].

The objective of the study was to work out an effective model of complex help to children with severe movement disorders. We examined 440 preschoolers with children cerebral palsy with severe movement disorders and 70 children with mild movement disorders. Functions of motor, emotional-personal and cognitive spheres and independence status with determination of 5 levels were studied in 47 patients. Three groups (from the group without concomitant (sensor, intellectual etc) disorders to the group with most severe disorders) were singled out. The authors characterize the model as an open integral system of methods, tools and ways providing the adaptation of children in response to external circumstances and changes in the state of patients. The creation of a correction-developing environment, consisting of 3 components: spatial-objective, technological (methodological) and social, is discussed. We present results of the development of children, evaluated by the following indices: general technique, sensory perceptive development, social adaptation, anxiety, cognitive activity, from 1997 to 2008. The 15 year follow-up demonstrated the stability of achieved positive results.

Demonstration of nonlinear absorption in Au semi-continuous film by electrical measurement.

We have demonstrated the nonlinear absorption at 532 nm wavelength in an Au semi-continuous film (SF) resulting from smearing of the Fermi distribution and diffusion of conduction electrons into the substrate. The Au SF was irradiated by a pulsed laser with 8 ns pulse width at 532 nm in near resonance with the interband transition of the Au. We determined the temperature increase in the SF for different intensities by electrical measurement. We calculated the temperature increase by using a 1D heat transport equation; comparing the results of the calculation with measured values for the temperature increase, revealed the nonlinear absorption in the Au SF. We employed this deviation from linear behaviour to determine the nonlinear absorption coefficient.

Controlled synthesis of a large fraction of metallic single-walled carbon nanotube and semiconducting carbon nanowire networks.

Controlled synthesis of both single-walled carbon nanotube and carbon nanowire networks using the same CVD reactor and Fe/Al(2)O(3) catalyst by slightly altering the hydrogenation and temperature conditions is demonstrated. Structural, bonding and electrical characterization using SEM, TEM, Raman spectroscopy, and temperature-dependent resistivity measurements suggest that the nanotubes are of a high quality and a large fraction (well above the common 33% and possibly up to 75%) of them are metallic. On the other hand, the carbon nanowires are amorphous and semiconducting and feature a controlled sp(2)/sp(3) ratio. The growth mechanism which is based on the catalyst nanoisland analysis by AFM and takes into account the hydrogenation and temperature control effects explains the observed switch-over of the nanostructure growth modes. These results are important to achieve the ultimate control of chirality, structure, and conductivity of one-dimensional all-carbon networks.

Single-step synthesis and magnetic separation of graphene and carbon nanotubes in arc discharge plasmas.

The unique properties of graphene and carbon nanotubes made them the most promising nanomaterials attracting enormous attention, due to the prospects for applications in various nanodevices, from nanoelectronics to sensors and energy conversion devices. Here we report on a novel deterministic, single-step approach to simultaneous production and magnetic separation of graphene flakes and carbon nanotubes in an arc discharge by splitting the high-temperature growth and low-temperature separation zones using a non-uniform magnetic field and tailor-designed catalyst alloy, and depositing nanotubes and graphene in different areas. Our results are very relevant to the development of commercially-viable, single-step production of bulk amounts of high-quality graphene.

Silicon on silicon: self-organized nanotip arrays formed in reactive Ar+H2 plasmas.

The formation of arrays of vertically aligned nanotips on a moderately heated (up to 500 degrees C) Si surface exposed to reactive low-temperature radio frequency (RF) Ar+H(2) plasmas is studied. It is demonstrated that the nanotip surface density, aspect ratio and height dispersion strongly depend on the substrate temperature, discharge power, and gas composition. It is shown that nanotips with aspect ratios from 2.0 to 4.0 can only be produced at a higher RF power density (41.7 mW cm(-3)) and a hydrogen content of about 60%, and that larger aspect ratios can be achieved at substrate temperatures of about 300 degrees C. The use of higher (up to 500 degrees C) temperatures leads to a decrease of the aspect ratio but promotes the formation of more uniform arrays with the height dispersion decreasing to 1.5. At lower (approximately 20 mW cm(-3)) RF power density, only semispherical nanodots can be produced. Based on these experimental results, a nanotip formation scenario is proposed suggesting that sputtering, etching, hydrogen termination, and atom/radical re-deposition are the main concurrent mechanisms for the nanostructure formation. Numerical calculations of the ion flux distribution and hydrogen termination profiles can be used to predict the nanotip shapes and are in a good agreement with the experimental results. This approach can be applied to describe the kinetics of low-temperature formation of other nanoscale materials by plasma treatment.

Plasma-assembled carbon nanotubes: electric field-related effects.

The paper presents results of comparative investigation of carbon nanotubes growth processes in dense low-temperature plasma and on substrate surface. Hybrid/Monte-Carlo numerical simulations were used to demonstrate the differences in the ion fluxes, growth rates and kinetics of adsorbed atoms re-distribution on substrate and nanotubes surfaces. We show that the plasma parameters significantly affect the nanotubes growth kinetics. We demonstrate that the growth rates of the nanotubes in plasma and on surface can differ by three orders, and the specific fluxes to the nanotube in the plasma can exceed the flux to surface-grown nanotube by six orders. We also show that the metal catalyst used for the nanotubes production on surface and in arc is a subject to very different conditions and this may be a key factor for the nanotube growth mode. The obtained dependencies for the ion fluxes to the nanotubes and nanotubes growth rates on the plasma parameters may be useful for selection of the production methods.

Carbon saturation of arrays of Ni catalyst nanoparticles of different size and pattern uniformity on a silicon substrate.

The kinetics of saturation of Ni catalyst nanoparticle patterns of the three different degrees of order, used as a model for the growth of carbon nanotips on Si, is investigated numerically using a complex model that involves surface diffusion and ion motion equations. It is revealed that Ni catalyst patterns of different degrees of order, with Ni nanoparticle sizes up to 12.5 nm, exhibit different kinetics of saturation with carbon on the Si surface. It is shown that in the cases examined (surface coverage in the range of 1-50%, highly disordered Ni patterns) the relative pattern saturation factor calculated as the ratio of average incubation times for the processes conducted in the neutral and ionized gas environments reaches 14 and 3.4 for Ni nanoparticles of 2.5 and 12.5 nm, respectively. In the highly ordered Ni patterns, the relative pattern saturation factor reaches 3 for nanoparticles of 2.5 nm and 2.1 for nanoparticles of 12.5 nm. Thus, more simultaneous saturation of Ni catalyst nanoparticles of sizes in the range up to 12.5 nm, deposited on the Si substrate, can be achieved in the low-temperature plasma environment than with the neutral gas-based process.

Tailoring the composition of self-assembled Si(1-x)C(x) quantum dots: simulation of plasma/ion-related controls.

Precise control of composition and internal structure is essential for a variety of novel technological applications which require highly tailored binary quantum dots (QDs) with predictable optoelectronic and mechanical properties. The delicate balancing act between incoming flux and substrate temperature required for the growth of compositionally graded (Si(1-x)C(x); x varies throughout the internal structure), core-multishell (discrete shells of Si and C or combinations thereof) and selected composition (x set) QDs on low-temperature plasma/ion-flux-exposed Si(100) surfaces is investigated via a hybrid numerical simulation. Incident Si and C ions lead to localized substrate heating and a reduction in surface diffusion activation energy. It is shown that by incorporating ions in the influx, a steady-state composition is reached more quickly (for selected composition QDs) and the composition gradient of a Si(1-x)C(x) QD may be fine tuned; additionally (with other deposition conditions remaining the same), larger QDs are obtained on average. It is suggested that ionizing a portion of the influx is another way to control the average size of the QDs, and ultimately, their internal structure. Advantages that can be gained by utilizing plasma/ion-related controls to facilitate the growth of highly tailored, compositionally controlled quantum dots are discussed as well.

[The addiction of ephedrine like psychostimulators and use of nimotop for its correction]. / Zloupotreblenie éfedrinopodobnymi psikhostimuliatorami i primenenie preparata nimotop dlia ego korrektsii.

Twenty six patients, used home-made ephedrine like psychostimulators were examined. Nervous system pathology in these cases was characterized by short (several months) period of the pathological process formation, young patient's age, absence of family psychiatric history, pronounced systemic and multilevel affection of the organism, severity of psychic defects and patients disability. Electrophysiological study revealed essential changes of neurodynamics manifesting with insufficiency of non-specific activating brain system, diencephalic stem structure dysfunction, deep structure irritation that might correspond to clinical picture of multisystem CNS lesions. An involvement of limbic reticular structures in pathological process on the background of neurophysiological immaturity was detected as well. In patients disorders of brain homeostatic mechanisms and cognitive functions were also found. Deprivation of reactivity of upper-segmental autonomic system regulation can determine rigidity and pathological adaptation of such patients. Insufficiency of activating systems of reticular formation, arrhythmia, disturbances of cognitive functions and cerebral homeostasis dictate a need for nootropics prescription for these patients. Clinical experience justifies including drug nimotop in complex treatment and rehabilitation schemes.