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This paper reveals and describes the features of NicoreAushell nanoparticles’ magnetic properties. Their activation energy of monodomain thermal relaxation (5.1 × 10–20 J) and constant of magnetic ...

An association between high serum calcium/phosphate and cardiovascular events or death is well-established. However, a mechanistic explanation of this correlation is lacking. Here, we examined the role of calciprotein particles (CPPs), nanoscale bodies forming in the human blood upon its supersaturation with calcium and phosphate, in cardiovascular disease. The serum of patients with coronary artery disease or cerebrovascular disease displayed an increased propensity to form CPPs in combination with elevated ionised calcium as well as reduced albumin levels, altogether indicative of reduced Ca2+-binding capacity. Intravenous administration of CPPs to normolipidemic and normotensive Wistar rats provoked intimal hyperplasia and adventitial/perivascular inflammation in both balloon-injured and intact aortas in the absence of other cardiovascular risk factors. Upon the addition to primary human arterial endothelial cells, CPPs induced lysosome-dependent cell death, promoted the release of pro-inflammatory cytokines, stimulated leukocyte adhesion, and triggered endothelial-to-mesenchymal transition. We concluded that CPPs, which are formed in the blood as a result of altered mineral homeostasis, cause endothelial dysfunction and vascular inflammation, thereby contributing to the development of cardiovascular disease.

Properties of single-walled carbon nanotubes (SWCNTs) obtained by the floating catalyst CVD method using ethyl alcohol and coal (anthracite and semi-anthracite) particles are investigated. Structural and vibrationalcharacteristics of synthesis products are determined. It is revealed that enrichment of the reaction mixture by anthracite particles increases the concentrations of CO and CH4 in the reaction zone, which contributes to the growth of the SWCNTs. A comparison of the Raman spectra of the samples shows an increase in the content of small-diameter semiconductor SWCNTs, whereas a set of chirality indices of the resulting nanotubes remains unchanged.

The Ni-nanoparticles, being similar to the nanocores of the Ni/Au core–shell nanoparticles, are made up of the structural domains with the dimensions about 1 nm. It is experimentally shown in this work for the first time by the combination of the small-angle X-ray scattering (SAXS) and the powder X-ray diffraction (XRD). The atomic structure of these domains is not a face-centered cubic lattice (FCC) inherent in the bulk state of Ni. This fact has been established by using the transmission electron microscopy (TEM) and XRD, calculated and confirmed by the observed features of an anodic oxidation and the differential scanning calorimetry (DSC) results for the investigated Ni-nanoparticles. Thus, the Ni-nanocores are composed of the domains with a structure formed by the icosahedra in the synthesis often used to obtain the core–shell nanoparticles.

The possibility of producing hexane-insoluble asphaltenes from a toluene solution of mid-temperature coal pitch is demonstrated. The topography, morphology, and structure of films consisting of asphaltene associates are studied by scanning and transmission electron microscopy. The thermal decomposition of hexane-insoluble asphaltenes is investigated in the range 20–800°C. Structuring of the film is observed at 495°C, regardless of the method employed: X-ray phase analysis or differential calorimetry. According to IR spectroscopic data, films heat-treated at 500°C contain graphene-like structures. X-ray diffraction shows the formation of graphene-like structures on heating the films to 800°C.

Three gold nanoparticle suspensions are obtained, and mean radii in distributions – (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm – are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450–800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie–Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

In this study, the gaseous and condensate products of ethanol decomposition during the synthesis of single-walled carbon nanotubes (SWCNTs) by aerosol chemical vapor deposition (floating catalyst CVD) method were investigated. To determine the conditions for perfect and clean SWCNT formation the products synthesized at different temperatures and collected inside and outside the reactor were studied by transmission electron microscopy, Raman, Fourier transform infrared (FT-IR) and optical absorption spectroscopy. The individual and bundled SWCNTs of a predominantly small diameter (∼1 nm) were revealed. The obtained tubes exhibit a stable distribution of chiral indices in a wide range of the set temperature (750–1000 °C), which is promising for the development of controlled synthesis methods. The FT-IR analysis results show that the main gaseous products of thermal ethanol decomposition in our CVD system are methane and carbon monoxide. Acting as carbon source, the mixture of CO and CH4 makes possible to produce pure SWCNTs, as those obtained in the catalytic CO disproportionation method, with higher yield, taking into account twice the amount of carbon release during CH4 catalytic pyrolysis. The carbon deposit on the reactor wall is found to play important role in maintaining an optimal regime of CNT synthesis.

We examined a fiber formation from pristine and modified single-walled carbon nanotube (SWCNT) films using a recently developed wet pulling technique. Crucial phenomena in the wet pulling process are a folding of a solvent soaked SWCNT film due to the liquid surface tension and fiber densification during the solvent evaporation. It is shown that electrical characteristics of the as-produced fibers are determined by the type of the liquid employed in their formation, which defines the SWCNT packing degree. The obtained specific strength (0.6–0.8 N/tex), toughness (up to 127 J/g) and specific conductivity (0.5–1.2 kS·m2/kg) are in many cases comparable with published data for fibers produced by more resource-consuming methods. These, in combination with the simplicity of our method and high piezoresistive gauge factor of 14 (for untwisted fibers at a 1% elongation), make SWCNT fibers promising components in future applications of stretchable electronics and robotics.

The surface plasmon resonance of gold nanoparticles in a polycrystalline energy-related material – pentaerythritol tetranitrate (PETN) – has been observed for the first time. The extinction spectra of this material are recorded, and its absorption characteristics are determined by the photoacoustic method using pulsed laser irradiation. Using the data obtained, it is concluded that gold nanoparticles are promising inclusions in explosive materials when designing an optical detonator.

In this work, on the example of bimetallic systems FePt and FePd, an approach is developed to assessing the structural parameters of nanoscale mono-and polymetallic systems by transmission electron microscopy (TEM), in comparison with the X-ray diffraction method of analysis. The interplanar distances, average sizes and phase compositions of FePt and FePd nanosystems are calculated.

Joint reduction with hydrazine from aqueous solutions of precursors produced nanostructured powders of the Fe – Pt system in three characteristic phase regions. The samples were subjected to heat treatment in the range up to 800 ° C and characterized at all stages by X-ray diffraction and high-resolution electron microscopy; the elemental composition of the samples was refined by the method of optical emission spectroscopy with inductively coupled plasma. In the initially obtained samples, only a part of the substance is detected by diffraction-the largest, platinum-rich crystals with dimensions of about 10 nm (established from TEM images and broadening of diffraction lines). The fcc-type cubic lattice parameters and the composition of the observed crystals were estimated from the distances between the regular bands in TEM images, identified with atomic rows, based on the composition dependence of the bulk characteristics of mixed iron-platinum phases (according to ICDD databases). In the course of heating, the processes of phase transformation are traced in detail, the parameters of the resulting crystal structures of intermetallic compounds are fixed, and the mechanisms of these transformations are discussed. Based on the measured lattice parameters, the thermal expansion coefficients of some mixed phases are calculated and the phase compositions are estimated at different stages of heat treatment.

ZnO, TiO2 and SiO2 nanomaterials were prepared by chemical syntheses and tested for the antimicrobial activity. The phase composition and micromorphology of powder samples were evaluated with the use of XRD and TEM methods. The nanomaterial aqua suspensions with concentrations in the range from 0.01 to 0.25% were prepared and their bactericidal properties were evaluated by interaction with eight types of microorganisms most commonly affecting building materials: Bacillus subtilis, Aspergillus niger, Aspergillus terreus, Aureobasidium pullulans, Cladosporium cladosporioides, Penicillium ochrochloron, Trichoderma viride, Paecilomyces variotii. It is established that ZnO nanoparticles (particle size 2–7 nm) at a suspension concentration varying from 0.01 to 0.25% are the most efficient. In the interaction of microorgamisms with ZnO nanoparticle suspensions, the concentration of microorganisms decreases by 2–3 orders of magnitude depending on their type. The TiO2 and SiO2 nanoparticles demonstrated their low bactericidal activity in the day sun light. The results are promising for the application of ZnO nanomaterials in the creation of building materials and protective coatings that are resistant to biodeterioration.

Core-shell Ni/Au nanoparticles are synthesized in a two-stage process in aqueous solutions. The core-shell structure of the synthesized particles is proven by using results of HRTEM, TEM, SAXS and CVA methods. The thickness of the core is estimated at 1 nm and it is formed from 1–2 layers of mutually oriented gold crystallites. The CVA results show that the Au-shells are nanoporous, and that a layer of nickel oxidation products is formed. These results were obtained by using Vis spectrophotometer, TEM, HRTEM, SAXS, CVA and elemental analysis.

Calcium phosphate bions (CPB) are biomimetic mineralo-organic nanoparticles which represent a physiological mechanism regulating the function, transport and disposal of calcium and phosphorus in the human body. We hypothesised that CPB may be pathogenic entities and even a cause of cardiovascular calcification. Here we revealed that CPB isolated from calcified atherosclerotic plaques and artificially synthesised CPB are morphologically and chemically indistinguishable entities. Their formation is accelerated along with the increase in calcium salts-phosphates/serum concentration ratio. Experiments in vitro and in vivo showed that pathogenic effects of CPB are defined by apoptosis-mediated endothelial toxicity but not by direct tissue calcification or functional changes in anti-calcification proteins. Since the factors underlying the formation of CPB and their pathogenic mechanism closely resemble those responsible for atherosclerosis development, further research in this direction may help us to uncover triggers of this disease.