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Poly(diphenylene phthalide) (PDP) belongs to the class of carbocyclic organic electroactive polymers, which exhibits electric conductive properties when an external electric field and/or mechanical stress is applied. In this work, the transport properties of thin-film layered lead–PDP–lead structures were experimentally studied in a wide temperature range. At sufficiently high temperatures, the current voltage characteristics are satisfactorily described in terms of the injection model of currents limited by the space charge. At temperatures below ≈8 K, a number of samples exhibit features that can be explained by the effect of induced superconductivity in a thin film of conducting polymer enclosed between two massive superconductors (lead).

Owing to exceptionally high selectivity, membranes based on palladium alloys are widely used for obtaining high-purity hydrogen. An important issue for providing high hydrogen permeability of the membranes is to form the required phase composition. The structural organization of the solid solutions consisting of Cu–36.4 at .% Pd and Cu–50 at .% Pd were studied by X-ray diffraction (XRD), electron diffraction (ED), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDXS). It was found that the former composition can be ordered in the temperature range of 300–400 °C and in the heating (up to 800 °C)–cooling cycle. In the presence of excess Cu atoms (27.2%), this structure can be represented by CsCl type structural units (β-phase) and distributed body center cubic (BCC) copper structural units in the corresponding concentration dose. The formation of a single crystal ordered phase within the mosaic blocks of the disordered phase was established. Experimental evidence was obtained for the separation of the α-phase solid solution in the elemental composition; the very low rate of ordering inherent in this system was attributed to this effect. The hydrogen permeability of a foil of the equiatomic composition was described.

Polyribosomes, the groups of ribosomes simultaneously translating a single mRNA molecule, are very common in both, prokaryotic and eukaryotic cells. Even in early EM studies, polyribosomes have been shown to possess various spatial conformations, including a ring-shaped configuration which was considered to be functionally important. However, a recent in situ cryo-ET analysis of predominant regular inter-ribosome contacts did not confirm the abundance of ring-shaped polyribosomes in a cell cytoplasm. To address this discrepancy, here we analyzed the cryo-ET structure of polyribosomes in diluted lysates of HeLa cells. It was shown that the vast majority of the ribosomes were combined into polysomes and were proven to be translationally active. Tomogram analysis revealed that circular polyribosomes are indeed very common in the cytoplasm, but they mostly possess pseudo-regular structures without specific inter-ribosomal contacts. Although the size of polyribosomes varied widely, most circular polysomes were relatively small in size (4–8 ribosomes). Our results confirm the recent data that it is cellular mRNAs with short ORF that most commonly form circular structures providing an enhancement of translation.

The strong fascination exerted by the binary compound of FeSe demands reliable engineering protocols and more effective approaches towards inducing superconductivity in FeSe thin films. Our study addresses the peculiarities in pulsed laser deposition which determine FeSe thin film growth and focuses on the film/substrate interface, the tendency for domain matching epitaxial growth but also the disadvantage of chemical heterogeneity. We propose that homogenization of the substrate surface improves the control of stoichiometry, texture, and nanostrain in a way that favors superconductivity even in ultrathin FeSe films. The controlled interface in FeSe/Fe/MgO demonstrates the proof-of-principle., Submitted

Vacuum heat treatment of mechanically alloyed powders of boron and aluminium leads to the formation of a metastable Al-rich phase, which can be quenched. Its structure, composition and thermal stability are established. With the chemical formula Al1.28B the rhombohedral phase is unusually rich in Al. The parameters of the unit cell determined from X-ray powder diffraction are a = 18.3464 (19), c = 8.9241 (9) Å, V = 2601.3 (6) Å3, space group R 3. It is stable on heating to 630°C. It is suggested that this phase is an important intermediate step in the formation of AlB2 and, eventually, of other borides; its nucleation and thermal stability are explained by high elastic energy hindering the formation of equilibrium phases at low temperatures.

Using deagglomerated nanodiamond particles of 4–5 nm suspended in polydimethylsiloxane (PDMS) we have fabricated fluids demonstrated pronounced electrorheological effect. It has been revealed that the type of functional groups on nanodiamond particle surface plays a crucial role in the behavior of the suspensions under electric field. Suspension of hydrogenated nanodiamonds has demonstrated the most powerful electrorheogical effect. The high values of yield stress of the order of 80–90 Pa have been detected at extremely low concentrations of nanodiamond particles (3–4 wt%). The suspensions has outstanding sedimentation stability: the sedimentation ratio is more than 90% after 30 days. A power law dependence of the yield stress on the electric field, τ ∼ E1.0-1.5 indicates mainly the conduction mechanism of the effect. Suspensions of carboxylated nanodiamonds in PDMS reveal qualitatively different behavior and the electrophoresis occurs. The paper discusses the reasons of different rheological behavior depending on nanodiamond surface functionalization. The prospects of nanodiamonds application as filler for electrorheological fluids have been shown.

Thin films of in-bulk unstable multiferroic hexagonal LuFeO3 were synthesized on coherent (111) and for the first time on incoherent (100) YSZ and Pt/YSZ surfaces by the metal–organic chemical vapo...

We report on the formation of epitaxial perovskite oxide superlattice structures by atomic layer deposition (ALD), which are integrated monolithically on Si wafers using a template layer of SrTiO3 deposited by hybrid molecular beam epitaxy. ALD film growth was carried out at 360 °C, which is significantly lower than the typical deposition temperatures for epitaxial perovskite thin films. The high control over the stacking sequence of different constituents is demonstrated in a series of (BaTiO3)m/(SrTiO3)n superlattices with various m/n cycle ratios. All superlattice structures were coherently strained to the virtual substrate layer of SrTiO3 on Si. Irrespective of the m/n superlattice sequence, SrTiO3 sublayers retain slight compressive strain which is transmitted to the BaTiO3 layers.

Oxide dispersion strengthened steels ODS Eurofer and ODS 13.5Cr-0.3Ti were irradiated with 945 MeV Au ions and 167 MeV Xe ions at room temperature. Beam-induced microstructural changes were analyzed by high-resolution transmission electron microscopy in the region of maximum electronic energy loss of 55 and 30 keV/nm, respectively. In both ODS steels, an increase in the fraction of small oxide inclusions (

Improved mechanical properties of oxide dispersion strengthened (ODS) steels, the advanced materials for the reactor core, are due to the high density of uniformly distributed nanosized oxide inclusions. Transformation of the nanostructure of ODS steels under irradiation determines their stability during operation in the reactor conditions. In this work, three ODS steels are studied: Eurofer ODS, 10Cr ODS, and KP-3 ODS with different alloying systems. In these steels, the chromium content varies from 9 to 14 at %; such alloying elements as V, Ti, Al, W, and Mn are present in different proportions. The effect of irradiation with iron ions up to 3, 6, and 30 dpa at a temperature of 350°C was studied. The radiation-induced changes were analyzed by transmission electron microscopy and atom probe tomography. Although the sizes of oxide inclusions remained almost without change under irradiation, a decrease in their number density was observed in 10Cr ODS and KP-3 ODS steels, while the number density of oxides in Eurofer ODS steel did not change under the irradiation to 30 dpa. On the whole, the strengthening of the ODS steels due to inclusions during the irradiation to 30 dpa at 350°C changed insignificantly, which indicates their radiation resistance and their low propensity for low-temperature radiation strengthening and embrittlement.

The possibility of the comprehensive study of great arrays of historical manuscripts by a complex of methods incorporating multispectral imaging, X-ray fluorescence analysis, and transmission- and scanning-electron microscopy with energy dispersive X-ray microanalysis is discussed. The presented examples of the application of such a complex approach show its high efficiency for the acquisition of significant technical and technological information about the inks without any essential impact on the studied objects of cultural heritage.

Undoped and Mg-doped Pr2MoO6oxymolybdate polycrystals and single crystals have been prepared by solid-state reactions and flux growth. The compounds have been characterized by powder X-ray diffraction, energy-dispersive spectroscopy, inductively coupled plasma mass spectrometry, scanning transmission electron microscopy, single crystal X-ray structure analysis, differential scanning calorimetry and thermogravimetry. The (MgO)x(Pr2O3)y(MoO3)z(x+y+z= 1) solid solution series has been shown to extend tox= 0.03. The structure of the Mg-doped Pr2MoO6single crystals can be represented as superimposed lattices of the main matrix (Pr2MoO6) and lattices in which Mo atoms are partially replaced by Mg. The incorporation of Mg atoms into the structure of Pr2MoO6results in the disordering of the praseodymium and oxygen lattices. Both the polycrystalline and single-crystal Mg-doped samples are hygroscopic.

The paper describes the data on unusual rheological properties of detonation nanodiamonds (DND) hydrosols and presents the fractal model explaining such behavior. The hydrosols of DND with particles size of 4–5 nm and concentration range of 1.1–7.3 wt% with negative (ζ 0) electrokinetic potentials have been studied by rotational viscometry, small-angle X-ray scattering, nuclear magnetic resonance and Cryo Electron Tomography. Remarkable hysteresis of viscosity and thixotropic effect demonstrate the sol-gel transition at very low concentrations of the DND: 4–5 wt% for ζ > 0 and 5–6 wt% for ζ

The comprehensive study of radiation hardening of the ferritic-martensitic steels RUSFER-EK-181 (Fe–12 Cr–2 W–V–Ta–B–0.16 С) and ChS-139 (Fe–12 Cr–Ni–Mo–W–Nb–V–N–B–0.20 C) using Fe ion irradiation at temperatures of 250–400°С to damage doses of ~6 dpa is conducted. The quantitative analysis of radiation-induced changes in the RUSFER-EK-181 and ChS-139 steel microstructure is performed by transmission electron microscopy and atom probe tomography. The study of hardening of steel samples irradiated with ions by nanoindentation and the evaluation within the framework of the dispersed barrier model show that the detected radiation-induced clusters and dislocation loops play an important role in the low-temperature radiation hardening of the RUSFER-EK-181 and ChS-139 steels.

Anti-PbO-type FeSe shows an advantageous dependence of its superconducting properties with mechanical strain, which could be utilized as future sensor functionality. Although superconducting FeSe thin films can be grown by various methods, ultrathin films needed in potential sensor applications were only achieved on a few occasions. In pulsed laser deposition, the main challenges can be attributed to such factors as controlling film stoichiometry (i.e., volatile elements during the growth), nucleation, and bonding to the substrate (i.e., film/substrate interface control) and preventing the deterioration of superconducting properties (i.e., by surface oxidization). In the present study, we address various technical issues in thin film growth of FeSe by pulsed laser deposition, which pose constraints in engineering and reduce the application potential for FeSe thin films in sensor devices. The results indicate the need for sophisticated engineering protocols that include interface control and surface protection from chemical deterioration. This work provides important actual limitations for pulsed laser deposition (PLD) of FeSe thin films with the thicknesses below 30 nm.

The core@shell nanostructures were obtained in the process of transformation of ferrocene Fe(C5H5)2 at high pressure (HP) of 8 GPa and high temperature (HT) of 900 °C with an isothermal exposure time t varying from 10 to 10000 s. At t > 300 s, the iron carbide o-Fe7C3 nanoparticles with an orthorhombic crystal structure (sp.gr. Pnma) can be created, which are dispersed in highly defective carbon matrix. After opening the high-pressure cell, a series of redox reactions occurs, leading to a formation of iron oxides on the surface of the iron carbide core. When the size of Fe7C3 nanoparticle is less than critical one the nanoparticle is fully oxidized, while in the larger particle an amorphous iron oxide shell is formed. A sequential increase in t initiates crystallization processes both in the iron carbide subsystem and in the carbon subsystem, resulting in the formation of core@shell Fe7C3/FexOy/C structures. Iron oxides with a cubic spinel-type structure (Fe3O4/γ-Fe2O3) appear in the shell. However, under oxygen reduction, part of magnetite can be transformed into wustite FeO. The magnetic properties of magnetite and wustite are radically different, and by varying the thickness of these layers, structures with the desired functional properties can be obtained.

International journal of molecular sciences 22(11), 6056 (1-12) (2021). doi:10.3390/ijms22116056, Two independent, complementary methods of structural analysis were used to elucidate the effect of divalent magnesium and iron cations on the structure of the protective Dps-DNA complex. Small-angle X-ray scattering (SAXS) and cryo-electron microscopy (cryo-EM) demonstrate that Mg$^{2+}$ ions block the N-terminals of the Dps protein preventing its interaction with DNA. Non-interacting macromolecules of Dps and DNA remain in the solution in this case. The subsequent addition of the chelating agent (EDTA) leads to a complete restoration of the structure of the complex. Different effect was observed when Fe cations were added to the Dps-DNA complex; the presence of Fe$^{2+}$ in solution leads to the total complex destruction and aggregation without possibility of the complex restoration with the chelating agent. Here, we discuss these different responses of the Dps-DNA complex on the presence of additional free metal cations, investigating the structure of the Dps protein with and without cations using SAXS and cryo-EM. Additionally, the single particle analysis of Dps with accumulated iron performed by cryo-EM shows localization of iron nanoparticles inside the Dps cavity next to the acidic (hydrophobic) pore, near three glutamate residues., Published by Molecular Diversity Preservation International, Basel

Background: One of the future applications of magnetic nanoparticles is the development of new iron-oxide-based magnetic resonance imaging (MRI) negative contrast agents, which are intended to improve the results of diagnostics and complement existing Gd-based contrast media.Results: Iron oxide nanoparticles designed for use as MRI contrast media are precisely examined by a variety of methods: powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, Mössbauer spectroscopy and zero-field nuclear magnetic resonance (ZF-NMR) spectroscopy. TEM and XRD measurements reveal a spherical shape of the nanoparticles with an average diameter of 5–8 nm and a cubic spinel-type crystal structure of space group Fd−3m. Raman, Mössbauer and NMR spectroscopy clearly indicate the presence of the maghemite γ-Fe2O3 phase. Moreover, a difference in the magnetic behavior of uncoated and human serum albumin coated iron oxide nanoparticles was observed by Mössbauer spectroscopy.Conclusion: This difference in magnetic behavior is explained by the influence of biofunctionalization on the magnetic and electronic properties of the iron oxide nanoparticles. The ZF-NMR spectra analysis allowed us to determine the relative amount of iron located in the core and the surface layer of the nanoparticles. The obtained results are important for understanding the structural and magnetic properties of iron oxide nanoparticles used as T2 contrast agents for MRI.

Chitin whiskers are promising reinforcing filler for composites due to their mechanical properties, renewable nature and low cost. A new method for preparation of β-chitin fibrils from squid pens in ascorbic acid aqueous solutions (AscA) was developed. Stirring of the solution with 2 g/l AscA for 2 h disperses the swollen chitin to individualized fibrils with an aspect ratio > 250. The optimal conditions of β-chitin exfoliation in acrylic acid (AcrA) aqueous solution were found (0.75–2 g/l, 3–4 h). TEMPO-oxidized β-chitin fibrils were chosen as a reference sample for comparison of different methods. 0.1% chitin suspensions exfoliated in AscA and AcrA solutions show similar gel-like behavior with a storage modulus (G′) of 98 ± 23 and 34 ± 12 Pa, respectively, whereas G′ of 0.1% dispersion of the TEMPO-oxidized β-chitin fibrils was 0.015 ± 0.005 Pa only. Composites based on poly(acrylic acid) comprising 1–3 wt% of β-chitin fibrils were fabricated by polymerization filling. Mechanical properties of the composites were investigated in dry state in the temperature range of 25–250 °C and at controlled relative humidity in the range from 53.6% to 100%. It was revealed that the maximum reinforcing effect is achieved at high temperature (>120 °C) and high relative humidity (≥75.3%RH).

The microstructure of GdBa2Cu3O7−δ based on superconducting tapes with BaSnO3 and BaZrO3 artificial pinning centers formed by high-rate pulse laser deposition in SuperOx Japan was studied by scanning/transmission electron microscopy. The artificial pinning centers have adopted columnar morphology with average diameter of about 8 nm (BaSnO3-doped sample) and 6.5 nm (BaZrO3-doped sample) and density of 500 μm−2 for the both samples. The average length of the BaSnO3 nanocolumns is about two times higher than the BaZrO3 nanocolumns. The angular dependences of critical current in magnetic field up to 1 Tesla at 77 and 65 K have been obtained. The critical current and its anisotropy depend on artificial pinning centers presence and their type. The angular dependence of resistivity in the field up to 9 Tesla was also studied and discussed.

One of the most important aspects of regenerative medicine is the selection of the scaffold—the biological skeleton of the tissue-engineering structure. To reproduce the structure and properties of damaged tissue and maintain the cell adhesion and proliferation, it is optimal to use scafflds obtained by decellularization of native organs with subsequent recellularization of various cell lines. Using the methods of environmental scanning electron microscopy and scanning pulsed ultrasound microscopy, the microstructure of native and decellularized matrixes of dermal tissues was determined.

Under severe or prolonged stress, bacteria produce a nonspecific DNA-binding protein (Dps), which effectively protects DNA against damaging agents both in vitro and in vivo by forming intracellular biocrystals. The phenomenon of protective crystallization of DNA in living cells has been intensively investigated during the last two decades; however, the results of studies are somewhat contradictory, and up to now, there has been no direct determination of a Dps-DNA crystal structure. Here, we report the in vitro analysis of the vital process of Dps-DNA co-crystallization using two complementary structural methods: synchrotron small-angle X-ray scattering in solution and cryo-electron tomography. Importantly, for the first time, the DNA in the co-crystals was visualized, and the lattice parameters of the crystalline Dps-DNA complex were determined.

Epitaxial thin-film growth enables novel functionalities, particularly if significant barriers to integration with existing technologies, scalability and excessive temperature of films, can be addr...

The microstructure of Al85Ni5Fe7La3 amorphous alloy after high-speed quenching, isothermal annealing, and flash lamp annealing (FLA) was studied by electron microscopy (including the high-resolution transmission electron microscopy), electron and X-ray diffraction, energy-dispersive X-ray microanalysis, and differential scanning calorimetry. A comparative analysis of the structures with respect to phase composition and phase morphology was performed. It was shown that, after the quenching, an X-ray amorphous structure is formed in the alloy. Critical parameters of heat treatment of the amorphous alloy which lead to single-phase or multiphase crystallization and volumetric or gradient structure were determined. The phase composition of the nanocomposite formed during crystallization was determined. The identity of the emerging structures with respect to the phase composition and phase morphology was determined for certain parameters of isothermal and flash lamp annealing to which close values of microhardness significantly exceeding the hardness of the alloy in the amorphous state correspond.

An inhomogeneity of material in W/Si multilayer structures was studied with grazing-incidence small-angle X-ray scattering. The experimental study revealed lateral density fluctuations in the Si spacer layers., A structural characterization of W/Si multilayers using X-ray reflectivity (XRR), scanning transmission electron microscopy (STEM) and grazing-incidence small-angle X-ray scattering (GISAXS) is presented. STEM images revealed lateral, periodic density fluctuations in the Si layers, which were further analysed using GISAXS. Characteristic parameters of the fluctuations such as average distance between neighbouring fluctuations, average size and lateral distribution of their position were obtained by fitting numerical simulations to the measured scattering images, and these parameters are in good agreement with the STEM observations. For the numerical simulations the density fluctuations were approximated as a set of spheroids distributed inside the Si layers as a 3D para­crystal (a lattice of spheroids with short-range ordering but lacking any long-range order). From GISAXS, the density of the material inside the density fluctuations is calculated to be 2.07 g cm−3 which is 89% of the bulk value of the deposited layer (2.33 g cm−3).

Low-temperature radiation hardening of prospective structural steel Eurofer 97 as the material for the first wall of the DEMO fusion reactor is studied in this work. Specimens of Eurofer 97 steel were irradiated with Fe ions up to 10 dpa at temperatures of 250, 300 and 400°C. Irradiated samples were studied by transmission electron microscopy and atom probe tomography. TEM study of irradiated samples showed preferential formation of dislocation loops at all temperatures of irradiation. Pair-correlation function analysis detected the initial stage of matrix solid solution decomposition of Eurofer 97 steel only at the temperature of 400°C. Detected microscopic changes and calculated hardening in the framework of the DBH (dispersed barrier hardening) model have shown that formation of dislocation loops is the main origin of low temperature radiation hardening of Eurofer 97 under irradiation with Fe ions with fluence up to 10 dpa.

The results of a comprehensive microstructural study of the ternary and quaternary phases in air-cast Al85Ni11−xFexLa4 (where x = 2 and 4 at. pct) polycrystalline alloys by means of optical microscopy, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction are presented. It was found that these alloys contain several phases, namely, fcc-Al, Al11La3, Al3Ni1−xFex, Al9Ni2−xFex, Al8Fe2−xNixLa, and Al3.2Fe1−xNix, in the form of δ-layers in Al8Fe2−xNixLa particles. A high density of other defects in the quaternary Al8Fe2−xNixLa particles was found, and the formation of these defects could be caused by the dendritic type of growth of this phase. The crystal structures of all these defects were revealed by high-resolution scanning transmission electron microscopy together with atomic-resolution energy-dispersive X-ray microanalysis. The thermal stability of the ternary and quaternary phases was also studied. The Al8Fe2−xNixLa phase is metastable and undergoes an irreversible transformation: Al8Fe2−xNixLa → Al9Ni2−xFex + Al11La3. Based on these data, a sequence of solid-phase reactions in these alloys during cooling and heating is proposed.

The fusion power density produced in a tokamak is proportional to its magnetic field strength to the fourth power. Second-generation high temperature superconductor (2G HTS) wires demonstrate remarkable engineering current density (averaged over the full wire), JE, at very high magnetic fields, driving progress in fusion and other applications. The key challenge for HTS wires has been to offer an acceptable combination of high and consistent superconducting performance in high magnetic fields, high volume supply, and low price. Here we report a very high and reproducible JE in practical HTS wires based on a simple YBa2Cu3O7 (YBCO) superconductor formulation with Y2O3 nanoparticles, which have been delivered in just nine months to a commercial fusion customer in the largest-volume order the HTS industry has seen to date. We demonstrate a novel YBCO superconductor formulation without the c-axis correlated nano-columnar defects that are widely believed to be prerequisite for high in-field performance. The simplicity of this new formulation allows robust and scalable manufacturing, providing, for the first time, large volumes of consistently high performance wire, and the economies of scale necessary to lower HTS wire prices to a level acceptable for fusion and ultimately for the widespread commercial adoption of HTS.

International journal of biomedicine 11(Suppl_1), S7 (2021). doi:10.21103/IJBM.11.Suppl_1.OR2, Background: The effect of Dps-DNA co-crystals formation, which occurs in stressed Escherichia coli cells exposed to extreme conditions, is well described in the literature. However, the exact mechanisms of co-crystals formation are yet to be postulated remaining largely unknown. Here we summarize the results obtained by our group over the last few years using cryo-Electron Microscopy (cryo-EM) and Small Angle X-ray Scattering (SAXS). Methods: Samples for cryo-EM were plunge frozen in liquid ethane with Vitrobot Mark IV and studied with Titan Krios (ThermoFisher Scientific, US) cryo-EM, equipped with Falcon 2 direct electron detector, Image corrector (CEOS, Germany), and Volta phase plate. Single Particle Analysis (SPA) and cryo-Electron Tomography (cryo-ET) studies were conducted with 300 kV accelerating voltage in low dose mode using EPU and Tomography software (ThermoFisher Scientific, US). Cryo-EM data processing was conducted using Warp, CryoSPARC, IMOD, EMAN, and Relion software packages..., Published by International Medical Research and Development Corporation, New York, NY

This work is addressed to the phenomenon of catalyst deactivation taking place during the repeated uses in the reaction of Suzuki-Miyaura (S-M) cross-coupling, which is widely applied in industry for C-C bond formation. Ligandless catalysts based on Pd(0) NPs supported on hyper-cross-linked polystyrene (HPS) of two types (non-functionalized and bearing tertiary amino groups) were studied in a model S-M reaction between 4-bromoanisole and phenylboronic acid. Synthesized catalysts were shown to be highly active under mild reaction conditions. HPS allows stabilization of Pd(0) NPs and prevents their agglomeration and detectable Pd leaching. However, the loss of catalytic activity was observed during recycling. The deactivation issue was assigned to the hydrophobic nature of non-functionalized HPS, which allowed a strong adsorption of cross-coupling product during the catalyst separation procedure. A thorough washing of Pd/HPS catalyst by hydrophobic solvent was found to improve to the big extent the observed catalytic activity, while the replacement of non-functionalized HPS by a one containing amino groups increased the catalyst stability at the expense of their activity.