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Metal matrix composites containing nanoscale carbon (nanotubes, graphene, etc.) are of great interest from the viewpoint of developing materials with improved mechanical properties. In the present work, detonation spraying experiments were conducted to produce composite coatings containing in situ generated nanoscale carbon. The coatings were prepared by detonation spraying with the use of fuel-rich acetylene-oxygen mixtures. When C2H2 + kO2 mixtures with k < 1 detonate, together with gaseous detonation products, solid graphene-like carbon nanoparticles form in the detonation gun barrel. When spraying a powder, these particles enter the coating layer and affect its properties. The phase composition and mechanical properties of coatings obtained from Al, Cu, Ni and Ti powders in the mode of in situ carbon generation are reported. The microhardness of the carbon-containing composite coatings was higher than that of the pure metal coatings and bulk commercial metals. The cohesion of Al- and Cu-based coatings containing carbon and carbon-free coatings did not actually differ. However, the presence of carbon reduced the cohesion of the Ni-based coating by about 30% and, conversely, increased the cohesion of the Ti-based coating by 30%. This work opens a new avenue for research and applications in the area of coatings formed by detonation spraying.

The behavior of linear defects in n-and p-type silicon, generated by laser radiation is studied for pulse energy density 417 – 1083 mJ/cm2. The features of the nondestructive and destructive effects of the laser pulse on the surface defects formation of the semiconductor crystals are revealed. The formation and movement of dislocations in the crater region and the development of micro cracks, accompanied by acoustic waves are revealed.

The feasibility study of elaboration of metal composite coatings by detonation spray using the blends of iron, nickel, copper, cobalt, and aluminum powders was performed using different spray modes. The numerical simulation of particle parameters showed that the particles formed the coating in solid, semi-molten, or molten state depending on the spraying modes, particle material, and particle size. It was shown that successful formation of the coating containing all powder mixture components could be achieved in case of proper optimization of spraying parameters. Obtained Fe-Co-Ni, Fe-Co-Ni-Cu, and Fe-Co-Ni-Cu-Al coatings had the uniform lamellae structure. However, the composition of the coatings differed from the initial powder mixture composition due to different deposition efficiencies of the powders. It was also found the mutual influence of blend components on bonding. In particular, the deposition efficiency of iron particles was probably affected by copper.

We describe the advantages and disadvantages of infrared and electrochemical gas analyzers of carbon dioxide (CO2). We study the possibility of application of conductometric sensors with distilled water for the purposes of monitoring of the CO2 content in air. We manufactured two identical measuring systems each of which contains two open-type conductometric cells, a matching device, and a personal computer. With the help of these complexes, we performed the experiments aimed at simultaneous measurements of the CO2 content in air at two sites (in a laboratory room and in a building located in the forest at a distance of 15 km from the first site) with knowingly different daily dynamics of variations of the CO2 level. We carried out special experiments aimed at the determination of the time lag of conductometric cells and evaluation of the conversion factor of the obtained levels of CO2 content into the standard measurement units. It is shown that the daily dynamics of variations of the electric conductivity of distilled water in the open cells agrees with the expected dynamics of changes in the CO2 content in the rooms used for measurements. The serviceability of the analyzed measuring complex is confirmed and the possibility of creation of a device based on this complex and intended for the long-term monitoring of the CO2 content in the air mixture of gases is demonstrated. The high selectivity of the proposed measuring complex to the presence of CO2 (as compared with the other atmospheric gases) is established.

We suggest a new strategy for creating stimuli-responsive bio-integrated optical nanostructures based on Mie-resonant silicon nanoparticles covered by an ensemble of similarity negatively charged polyelectrolytes (heparin and sodium polystyrene sulfonate). The dynamic tuning of the nanostructures' optical response is due to light-induced heating of the nanoparticles and swelling of the polyelectrolyte shell. The resulting hydrophilic/hydrophobic transitions significantly change the shell thickness and reversible shift of the scattering spectra for individual nanoparticles up to 60 nm. Our findings bring novel opportunities for the application of smart nanomaterials in nanomedicine and bio-integrated nanophotonics.

Background Limited information exists regarding the factor IX (FIX) coagulant activity (FIX:C) measured by different assays following FIX‐Padua gene therapy. Objective Assess for the first time FIX:C in five commonly used coagulation assays in plasma samples from hemophilia B subjects receiving FIX‐Padua gene transfer. Methods FIX:C was compared between central (n = 1) and local laboratories (n = 5) in the study, and across four commonly used FIX:C one‐stage assays and one FIX:C chromogenic assay. For comparison, samples of pooled congenital FIX‐deficient plasma spiked with purified recombinant human FIX (rHFIX)‐Padua protein or rHFIX (nonacog alfa) to obtain FIX:C concentrations from ~20% to ~40% were tested. Results FIX:C results at local laboratories strongly correlated with central laboratory results. However, absolute values at the central laboratory were consistently lower than those at local laboratories. Across five different FIX:C assays, a consistent pattern of FIX:C was observed for subjects receiving fidanacogene elaparvovec‐expressed gene transfer. Use of Actin FSL activated partial thromboplastin time (APTT) reagent in the central laboratory resulted in lower FIX:C values compared with other APTT reagents tested. The chromogenic assay determined lower FIX:C than any of the one‐stage assays. The rHFIX‐Padua protein–spiked samples showed similar results. In contrast, FIX:C results for rHFIX‐nonacog alfa measured within 25% of expected for all one‐stage assays and below 25% in the chromogenic assay. Conclusions Assay‐based differences in FIX:C were observed for fidanacogene elaparvovec transgene product and rHFIX‐Padua protein, suggesting the variable FIX:C determined with different assay reagents is inherent to the FIX‐Padua protein and is not specific to gene therapy–derived FIX‐Padua.

This work is dedicated to a method for preionization of a laser medium (that is the most popular ones-CO2- and CO-lasers) using X-ray radiation created by a nanosecond sliding discharge (NSD). An experimental study has been carried out on the influence of the initial pressure and the composition of the gaseous medium on the intensity of X-ray bremsstrahlung. In order to estimate this intensity, a special sensor is used; it can measure free electron density that, in our, case is created during photoionization by X-ray radiation from an NSD. It is shown that in case an X-ray emitter is filled with argon, the photoelectron density in the vicinity of a cathode is about 15 times higher than in case the X-ray emitter is filled with helium. Moreover, when the gas volume of the X-ray emitter is filled with argon, the energy spectrum of the “runaway” electrons shifts to the region of lower values of their energy.

The behavior of linear defects in p-type silicon (111) carrying a direct current of density 0−15×105 A/m2 in the [110] direction are studied in the temperature range T=850–1000 K during isothermal annealing. The regularities of change in the linear density and maximum path of dislocations in slip lines are revealed. A model of linear defects displacement in silicon single crystals in the field of internal stresses under an electric current is proposed. Matching theory with experimental data has made it possible to reveal the dependence of this distribution on the internal stresses relaxation time.

The advantages and disadvantages of infrared and electrochemical gas analyzers for carbon dioxide CO2 are described. The possibility of using conductometric sensors with distilled water for monitoring the CO2 content in the air has been investigated. Two identical measuring systems were manufactured, each containing two open-type conductometric cells, a matching device and a personal computer. With the help of these complexes, experiments were carried out on the simultaneous measurement of the CO2 content in the air in two places (a laboratory room and a building in a forest, located at a distance of 15 km from each other) with deliberately different daily dynamics of the CO2 level change. A special experiment was carried out, which made it possible to obtain an estimate of the inertia of conductometric cells and a conversion factor for the values of CO2 content into standard units of measurement. It is shown that the daily dynamics of changes in the electrical conductivity of distilled water in open cells corresponds to the expected dynamics of changes in the CO2 content in the rooms where the measurements were carried out. The operability of the measuring complex and the possibility of creating on its basis a device for long-term monitoring of the CO2 content in the air mixture of gases has been confirmed. The principal high selectivity of the measuring complex to CO2 in relation to other gases of the atmosphere has been established.

A CCDS2000 detonator for acetylene, ethylene, propylene, and a multicomponent methylacetylene–allene fraction (MAF) fuel is used to perform experiments on measuring the detonation velocity and recording a detonation front cell in a tube 26 mm in diameter and 2 m in length. The experiments are carried out at atmospheric pressure in stoichiometric mixtures diluted by nitrogen to air concentrations and in air–fuel mixtures with a varying fuel content in them. In the case where the explosive mixture components are fed as a flow by stratifying an explosive charge in an initiation zone, a self-sustaining detonation is stably ignited up to limiting (spin) modes. The concentration limits of the detonation existence are determined. In the air–fuel mixtures of acetylene and ethylene, as the values become lower than the limits, there is multiheaded detonation. For propylene and MAF, a tube diameter of 26 mm is near-critical: only single- and two-headed spin is observed in the entire range of existence. Calculation results are in good agreement with the experiment.

The porous silicon film surface region containing silver particles is studied by scanning electron microscopy and Raman spectroscopy. The porous silicon film is formed by metal-assisted etching of a single-crystal silicon substrate. It is found that the distribution of silver particles is controlled by the porous layer morphology. The formation of silver particles by chemical deposition results in certain smoothing of the por-Si film surface relief. In this case, the silicon crystallite structure does not change significantly.

Metal nanopowders have a stimulating effect on the growth and development of plants. The biological activity of nanoparticles depends on size, concentration, and chemical composition. Nanoparticles require further study because they have a wide range of applications in medicine and agriculture. Being biocompatible, copper and cobalt can play the role of growth stimulant, are not toxic and can be used for contact with living systems. The object of study was rice, as an economically important culture. The study addressed the effect of cobalt and copper nanoparticles on the germination and development of rice seedlings. The optimal concentration of ultrafine solutions of these nanopowders for pre-sowing treatment of seeds was determined. Although copper and cobalt have different chemical nature, the nanoparticles show similar impact and doze-dependent effect. Minimum concentrations of the nanoparticles had a positive effect on the morphological and biometric indicators of sprouts. The activity of oxidase enzymes was measured and it showed a reversible nature of oxidative stress. An increase in superoxide dismutase activity and a decrease in catalase activity by less than 30% indicates the stress resistance of rice sprouts and the absence of phytotoxic effects of the nanopowders. The presence of these metals in the seedling homogenate was determined to define the toxic effect. The electron microscopic analysis of the partition of metals in the tissues of experimental plants did not reveal significant deviations from control values. The experiments were performed using scientific equipment of Regional Center for Collective Use of Probe Microscopy in Ryazan State Radio Engineering University.

A technique for analysis of secondary tungsten-containing raw materials (tungsten-containing sludge) using inductively coupled plasma atomic emission spectrometry in combination with microwave autoclave sample preparation has been developed. The composition of the acid mixture and algorithm of microwave heating of the autoclave are chosen to provide a complete quantitative transfer of the sample into a convenient analytical form for subsequent ICP-AES determination of the main components (sample heating to 220°C in the acid mixture of NH 4 F, HNO 3 , and HCl provides a quantitative transfer of the sample components to be determined, into the solution). Analytical lines free from spectral interference were selected to determine Ti, Cr, Fe, Co, Ni, and W We used real industrial samples of secondary raw materials obtained in product manufacture from VK-type hard alloys [solid solution of tungsten carbide grains (WC-phase) in cobalt (Co-phase)], presented in the form of tungsten-containing powders, grinding sludge of solid sintered alloys, dust waste, defective mixtures, waste ventilation systems, and carbide powders. Correctness of the element determination was proved in analysis of ferrotungsten standard samples upon determination of the matrix component (tungsten) and by the methods of additives and sample weight variation upon determination of the alloying elements and impurities. The method of internal standard (with Sc as the element of comparison) was used to improve the precision and accuracy of the tungsten determination. The relative standard deviation was thus reduced from 0.03 to 0.004. The developed precise rapid technique was tested in analysis of industrial samples of secondary tungsten-containing sludge of hard alloys. The technique is recommended to control the composition of the secondary tungsten-containing sludge of hard alloys in a wide range of concentrations.

Technological processes of processing of metal products and galvanic production are characterized by large volumes of wastewater containing ions of heavy metals, in particular as a result of Nickel plating products in wastewater in the predominant amount fall ions Ni2+. To assess the possibility of removing pollution from this type of wastewater, the process of adsorption purification of model Nickel-containing wastewater was investigated. As adsorbents modified nitrogen-containing polyvinyl alcohol, polycaproamide, hydrocellulose fiber were used. Modification of this type of fibers allows fixing functionally active groups on the surface of adsorbent. It is established that the fibrous adsorbents have a high adsorption capacity towards Nickel ion(II), the magnitude of adsorption is in the range of 80-100 mg/g. The predominant mechanism is monomolecular chemisorption. Adsorption proceeds at high speeds, the balance is achieved in the first 20 minutes of the process. The effect of pH on complex formation in the phase of adsorbents is revealed. It is shown that in a strongly acidic medium the purification efficiency is small, the increase in pH leads to increased adsorption properties of fibers. The optimal value of the acidity of the solution are pH values above 5. A decrease in the amount of coordinated nitrogen with an increase in pH was determined. In assessing the selectivity of fibers with respect to Ni2+ in the presence of Zn2+ and Cu2+, the influence of matrix polymer effect was revealed. Adsorption on polyvinyl alcohol and polycaproamide fibers showed that the influence of zinc ions(II) on the adsorption of Nickel (II) increases with its concentration in the solution, and hydrate cellulose fiber has a higher selectivity with respect to Zn2+ion. The presence of Cu2+ leads to a significant decrease in the efficiency of model wastewater treatment from Nickel ions (II) on all types of adsorbents studied

Gas detonation in ethylene– and propylene–oxygen explosive mixtures was studied over a wide range of equivalence ratio. Detonation parameters were calculated using the DETON code. The experiments were performed on an improved detonation facility in which the flow feed of the components of the explosive mixture and the intensification of deflagration-to-detonation transition (DDT) due to charge stratification was implemented in a long cylindrical channel using the systems of a CCDS2000 computerized detonation facility. Experimental data on the detonation velocity and cell size of the detonation front cell were obtained. The concentration limits of steady detonation in a cylindrical channel 26 mm in diameter were determined. Using propylene and ethylene as fuel for detonation spraying, coatings of tungsten carbide with a cobalt binder and alumina were obtained and their properties were investigated. Coatings based on propylene with stratification of the explosive mixture charge are comparable in properties and performance to coatings sprayed by dual-fuel (acetylene/propane) technology, which allows propylene to be considered as an acceptable fuel for detonation spraying.

The microstructure transformations in copper subjected to high-rate deformation via dynamic channel angular pressing (DCAP) have been examined after one and four DCAP passes using electron backscat...

An ecologically and economically effective technical solution has been developed for the production of hydrogen fluoride and fluorine hydrite by using fluorosulfonic acid in the decomposition technology of fluorspar. The stages of the technology of obtaining hydrogen fluoride and fluorine hydrite are shown: obtaining fluorosulfonic acid itself, decomposition of calcium fluoride with fluorosulfonic acid and hydrolysis of calcium fluorosulfonate with water vapor to form fluorosulfonic acid, recycled, hydrogen fluoride and fluorine hydrite. Experimental data have shown the promise of this technology.

We have optimised a hybrid mode-locked holmium-doped fibre laser and a holmium-doped fibre amplifier for obtaining stable pulses as short as possible. Temporal and spectral characteristics of pulsed light have been measured as functions of pump power. Lasing has been achieved in the wavelength range 2066 – 2068 nm, with a full width at half maximum of the emission spectrum from 3 to 4 nm. The pulse duration does not exceed 1 ps and the pulse energy ranges from 0.2 to 0.5 nJ. To raise the pulse energy, holmium-doped fibre amplifiers based on two types of active fibre have been used. We have demonstrated a decrease in the width of the central part of the pulse autocorrelation function and considerable broadening of the spectrum of the pulses. The maximum average power at the amplifier output exceeds 200 mW.

Hydroxyapatite (HA), the major mineral component of tooth enamel and natural bones, is a good candidate for bone tissue engineering. Synthetic HA is used for making coatings on metallic implants intended for medical applications. A HA coating renders the implant biocompatible and osteoinductive. In addition, it improves fixation and the overall performance of the implanted object. In the present work, HA coatings were deposited on a medical titanium alloy implant with mesh geometry and a developed surface by detonation spraying. The feedstock powder was HA obtained by the dry mechanochemical method. Single-phase HA coatings were obtained. The coatings were formed not only on the surfaces normal to the particle flow direction, but also on the sides of the mesh elements. Despite partial melting of the powder, no decomposition of HA occurred. This work demonstrates the prospects of detonation spraying for the production of HA coatings on metallic implants with complex geometries.

The temperature and dynamic pressure of the detonation products are parameters that determine the heating and acceleration of particles during the detonation spraying. These parameters depend on the composition of the explosive mixture. The present article reports the influence of the composition of the acetylene–oxygen explosive mixture on the structure and properties of detonation coatings obtained from a multi-component Fe-based alloy. A gas-atomized powder with a nominal composition of Fe66Cr10Nb5B19 was used for depositing the coatings. The O2/C2H2 molar ratio was 1.1; 1.5 or 2.0; the volume of the explosive mixture was constant. At an O2/C2H2 ratio of 1.1, the coating was 99% amorphous. As the O2/C2H2 ratio was increased, the content of the crystalline phase in the coatings increased. At higher oxygen contents, oxidation of the particle surfaces during spraying is more likely. Possibly, oxide films formed in-situ may act as heterogeneous nucleation sites for crystallization, which leads to a decrease in the content of the amorphous phase in the coatings. The increase in the O2/C2H2 ratio from 1.1 to 2.0 also leads to increased porosity and decreased coating microhardness.

The research has been carried out under production conditions on light gray forest soils with light particle-size composition at an area of 550 hectares where liquid pig manure (LPM) of a large pig breeding complex is annually used as an organic fertilizer at doses of 60 and 90 t/ha. The average characteristics of LPM are as follows: dry matter content is 9.5%, pH 7.7 units, nitrogen 0.22%, phosphorus 0.11%, and potassium 0.12%. The cultivated grain crops were presented by winter and spring wheat varieties, Moskovskaya 39 and Esther, respectively. It has been established that at the dose of 60 t/ha LPM for two years of research at an average a mean wheat yield was 3.0-3.75 t/ha, and at the dose of 90 t/ha - up to 4.75 t/ha. The return on investments for fertilizers in the “winter wheat → spring wheat” crop rotation link at the dose of 60 t/ha of LPM was 5.41 kg of grain per 1 kg of active substance of manure, at the dose of 90 t/ha - 4.57 kg / kg. A positive balance of nutritional elements developed on all fields, but it was better balanced when the dose of LPM was 60 t/ha and the yield was 3.0 t/ha of grain annually, or when the LPM dose was 90 t/ha and the yield of wheat was 4.75 t/ha. In this case, the estimated potassi-um supply of soil occurs at a lower rate than that of nitrogen and phosphorus. The application of 120 t of LPM during two years in total on loamy sand and of 180 t/ha on light loamy soil provided an increase in the content of mobile phosphorus compounds by 5-22 mg/kg, and potassium - by 11-30 mg/kg with a variation coefficient of 28-57% and 21-49%, respectively.

The microstructure of the surface region of the silicon photoelectric converter with an n+-p junction and an antireflection porous silicon film is studied by scanning electron microscopy and Raman spectroscopy methods. The n+-p junction was formed by laser irradiation of the surface of a porous silicon film containing a phosphorus impurity. It is shown that laser irradiation causes partial recrystallization of the porous silicon film and the n+-p junction formation within silicon crystallites.

The microstructures of a commercial aluminum foil and an aluminum foil alloyed by 0.001 wt % scandium are studied before and after electrochemical etching. The strength properties, the capacitance, and the weldability of the foils subjected to electrochemical etching are investigated. We are the first to show that the alloying of aluminum by such a low amount of scandium affects the microstructure of a foil and is sufficient for increasing the strength properties, the capacitance, and the weldability of the aluminum foil used for capacitors.

Solid-state reactions of refractory carbides MC (M = Hf, Ta, W) with iridium powder at 1600 °C result in the formation of the corresponding MIr3±x intermetallic solid solution. Vickers microhardness tests of MIr3 intermetallics were performed using the load of 10 gf (HV0.01), and the local elemental composition was determined by energy dispersive spectroscopy (EDS) for each indentation area. The results of indentation tests showed that MIr3 intermetallics are much harder than pure Hf, Ta, W, or Ir (top-hardness metals), with the hardness 900–1400 HV0.01. The hardness value is affected by the real elemental composition of MIr3±x solid solution. Free carbon released during the interaction of metal carbide with iridium can contribute to the microhardness values.

A relatively simple approach based on mixing WC and iridium powders, followed by heating to 1300–1600 °C in inert atmosphere, was proposed to synthesize refractory intermetallics in the tungsten – iridium system. The peculiarities of the solid-state interaction in the WC-Ir system were studied within the 1000–1600 °C temperature range using a set of modern analytical techniques. Intensive solid-state interaction in the WC – Ir system starts at 1300 °C. It was stated that this interaction can be described by two stages in the 1300–1600 °C temperature range. The first stage is the formation of Ir-rich disordered WxIr1-x solid solution with constant average composition W0.265Ir0.735. The second stage is the interaction of the obtained WxIr1-x solid solution with residual component (Ir or WC) that leads to the shift of the WxIr1-x phase composition on one side or the other in dependence on type of residual component. No ordered intermetallic phases are formed in the 1300–1600 °C temperature range. In the course of the solid-state reaction, free carbon is released as graphite-like phase on the surface of the intermetallic product.

New tetracyclic dispiro-1,2,4-trioxolanes (ozonides) were synthesized by reactions of 5–7-membered alicyclic 1,5-diketones with 30% hydrogen peroxide in diethyl ether or ethanol in the presence of boron trifluoride-diethyl ether complex or a strong mineral acid (HCl, H2SO4, HClO4). Mass spectrometric study of the title compounds under atmospheric pressure chemical ionization revealed specificity of fragment ion decomposition with respect to the ring size, which makes it possible to identify such compounds by their mass spectra.

Grain lattice fragmentation in heavily deformed metals is controlled by the formation of deformation-induced boundaries (DIBs) with misorientations evolving from low to high angles with increasing strain. A method is suggested allowing the separation of the contributions from DIBs and original grain boundaries to the overall misorientation angle distribution based on electron backscatter diffraction (EBSD) data. The peculiarities, accuracy and limitations of the method are considered by the example of copper under uniaxial compression at room temperature and 150 °C. It is shown that obtained distributions of DIB misorientation can be analyzed using their representation as a superposition of partial distributions. The partial distributions f1 and f2, which describe the low-angle interval, correlate with the distributions determined earlier by the transmission electron microscopy for two types of dislocation boundaries, while the third partial distribution f3 relates to the high-angle DIBs, whose misorientations go beyond the range of the first two distributions. The rise of deformation temperature does not affect the character of misorientation distribution development.

A method for ICP-AES determination of Ti, V, Cr, Fe, Co, Ni, Cu, Zn, and Ta in recycled cemented tungsten carbide is developed including preliminary microwave sample decomposition in a steam pressure vessel (autoclave). We have specified the composition of the reaction mixture for sample dissolution and optimized the parameters of microwave heating in the autoclave. Correctness of the results is proved by the method of sample weight variation and spike tests. The results of analysis are compared with the data obtained by standardless method of X-ray fluorescence spectrometry. The technique is characterized by good reproducibility and allows significant reduction of the analysis time owing to the combination of the multielement method of ICP-AES and microwave sample preparation.

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P-8), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution.A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.

Genome instability is associated with myriad human diseases and is a well-known feature of both cancer and neurodegenerative disease. Until recently, the ability to assess DNA damage—the principal driver of genome instability—was limited to relatively imprecise methods or restricted to studying predefined genomic regions. Recently, new techniques for detecting DNA double strand breaks (DSBs) and single strand breaks (SSBs) with next-generation sequencing on a genome-wide scale with single nucleotide resolution have emerged. With these new tools, efforts are underway to define the “breakome” in normal aging and disease. Here, we compare the relative strengths and weaknesses of these technologies and their potential application to studying neurodegenerative diseases.

Theoretical studies of graphene began long before the first real samples were obtained (Wallace, 1947). Calculations performed in the 1930s and 1940s showed that a free two-dimensional film must be thermodynamically unstable. For this reason monolayer structures were obtained only on the surface of bulk materials. The first steps to make single carbon layers were made in the 1960s and 1970s using the reduction of graphite oxide from colloidal solutions (Boehm et al., 1962a, b) and the method of chemical vapor deposition (CVD) of hydrocarbons on metal substrates (Eizenberg and Blakely, 1979) or on their carbides (Aizawa et al., 1990). It has been shown that a high-temperature treatment of silicon carbide with evaporation of silicon leads to the formation of carbon film, that is, the so-called epitaxial growth is realized (van Bommel et al., 1975; Forbeaux et al., 1998). However, in all the works listed above, carbon films with a thickness of at least 20–30 layers were obtained, which were not inherently graphene. A detailed review of early experiments on the preparation of thin graphite layers was given in Jang and Zhamu (2008).

We study active metasurfaces composed of arrays of split-nanodisk resonators made of InGaAs slab with embedded InGaAsP quantum wells. We demonstrate lasing from high-Q localized anapole modes with high coherence, narrow linewidth, and low threshold.

Chemical vapor deposition synthesis of graphene on copper foil from methane is the most promising technology for industrial production. However, an important problem of the formation of the second and subsequent graphene layers during synthesis arises due to the strong roughness of the initial copper foil. Here we demonstrate the various approaches to prepare a smooth copper surface before graphene synthesis to reduce the formation of multi-layer graphene islands. Six methods of surface processing of copper foils are studied, and the decrease of the roughness from 250 to as low as 80 nm is achieved. The correlation between roughness and the formation of multi-layer graphene is demonstrated. Under optimized conditions of surface treatment, the content of the multi-layer graphene islands drops from 9% to 2.1%. The quality and the number of layers of synthesized graphene are analyzed by Raman spectroscopy, scanning electron microscopy, and measurements of charge mobility.

The switching effect in the Au-Ta-Al 2 O 3 -Cr structure was revealed. The memristor properties with bipolar switching were revealed at switching voltages U set = 5.2 V and U reset = -3.5 V. The ratio of high resistance and low resistance states was 7.105 Ohms. Effect of the etching regimes on the memristor properties of Al 2 O 3 thin layers was studied. It was revealed that the best way to remove aluminum oxide is to etch the structures in a 20% HF solution without contact protection.

Background The C9ORF72 hexanucleotide repeat expansion is the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two fatal age-related neurodegenerative diseases. The C9ORF72 expansion encodes five dipeptide repeat proteins (DPRs) that are produced through a non-canonical translation mechanism. Among the DPRs, proline-arginine (PR), glycine-arginine (GR), and glycine-alanine (GA) are the most neurotoxic and increase the frequency of DNA double strand breaks (DSBs). While the accumulation of these genotoxic lesions is increasingly recognized as a feature of disease, the mechanism(s) of DPR-mediated DNA damage are ill-defined and the effect of DPRs on the efficiency of each DNA DSB repair pathways has not been previously evaluated. Methods and results Using DNA DSB repair assays, we evaluated the efficiency of specific repair pathways, and found that PR, GR and GA decrease the efficiency of non-homologous end joining (NHEJ), single strand annealing (SSA), and microhomology-mediated end joining (MMEJ), but not homologous recombination (HR). We found that PR inhibits DNA DSB repair, in part, by binding to the nucleolar protein nucleophosmin (NPM1). Depletion of NPM1 inhibited NHEJ and SSA, suggesting that NPM1 loss-of-function in PR expressing cells leads to impediments of both non-homologous and homology-directed DNA DSB repair pathways. By deleting NPM1 sub-cellular localization signals, we found that PR binds NPM1 regardless of the cellular compartment to which NPM1 was directed. Deletion of the NPM1 acidic loop motif, known to engage other arginine-rich proteins, abrogated PR and NPM1 binding. Using confocal and super-resolution immunofluorescence microscopy, we found that levels of RAD52, a component of the SSA repair machinery, were significantly increased iPSC neurons relative to isogenic controls in which the C9ORF72 expansion had been deleted using CRISPR/Cas9 genome editing. Western analysis of post-mortem brain tissues confirmed that RAD52 immunoreactivity is significantly increased in C9ALS/FTD samples as compared to controls. Conclusions Collectively, we characterized the inhibitory effects of DPRs on key DNA DSB repair pathways, identified NPM1 as a facilitator of DNA repair that is inhibited by PR, and revealed deficits in homology-directed DNA DSB repair pathways as a novel feature of C9ORF72-related disease.

We report the discovery and functional characterization of &alpha, M-Conotoxin MIIIJ, a peptide from the venom of the fish-hunting cone snail Conus magus. Injections of &alpha, M-MIIIJ induced paralysis in goldfish (Carassius auratus) but not mice. Intracellular recording from skeletal muscles of fish (C. auratus) and frog (Xenopus laevis) revealed that &alpha, M-MIIIJ inhibited postsynaptic nicotinic acetylcholine receptors (nAChRs) with an IC50 of ~0.1 &mu, M. With comparable potency, &alpha, M-MIIIJ reversibly blocked ACh-gated currents (IACh) of voltage-clamped X. laevis oocytes exogenously expressing nAChRs cloned from zebrafish (Danio rerio) muscle. &alpha, M-MIIIJ also protected against slowly-reversible block of IACh by &alpha, bungarotoxin (&alpha, BgTX, a snake neurotoxin) and &alpha, conotoxin EI (&alpha, EI, from Conus ermineus another fish hunter) that competitively block nAChRs at the ACh binding site. Furthermore, assessment by fluorescence microscopy showed that &alpha, M-MIIIJ inhibited the binding of fluorescently-tagged &alpha, BgTX at neuromuscular junctions of X. laevis, C. auratus, and D. rerio. (Note, we observed that &alpha, M-MIIIJ can block adult mouse and human muscle nAChRs exogenously expressed in X. laevis oocytes, but with IC50s ~100-times higher than those of zebrafish nAChRs.) Taken together, these results indicate that &alpha, M-MIIIJ inhibits muscle nAChRs and furthermore apparently does so by interfering with the binding of ACh to its receptor. Comparative alignments with homologous sequences identified in other fish hunters revealed that &alpha, M-MIIIJ defines a new class of muscle nAChR inhibitors from cone snails.

Bound states in the continuum, which exist in realistic samples in a form of high quality (Q) factor supercavity modes, catch a lot of attention due to their promising applications in optics. Here we study silicon metasurfaces supporting a number of supercavity modes. The metasurfaces consist of silicon rods with circular or rectangular profile. We analyze the array of circular rods by exploiting the multiple scattering theory. More practical metasurfaces with rectangular nanoblocks on a silicon substrate are examined using numerical simulations. We obtain Q factor dependences on geometric parameters of the metasurfaces. The rapid Q factor growth typical for supercavity mode is found for the systems under study.

Here, we study exceptional point and parity-time (PT) symmetry regimes in a dimer of rods supporting dipole Mie resonances. In order to achieve PT-symmetry, the significant radiative decay that is associated with dipole resonances has to be offset by internal gain in the rods. We suggest an approach to finding the parameters of a dimer that would have an exceptional point at a given real frequency. We then show that this dimer starts demonstrating PT-symmetry when its gain-loss contrast is decreased with respect to the exceptional point.

We study periodic lattices of silicon nanorods and introduce the concept of a phase diagram that characterizes a transition between the regimes of photonic crystals and the dielectric metamaterials when the lattice spacing and operational wavelength vary. We find the conditions when a hexagonal periodic lattice of silicon nanorods can operate as a metamaterial described by averaged parameters. In general, we reveal that the metamaterial regime can be achieved for dielectric permittivity exceeding the value e = 14, being commonly available for semiconductors in both visible and near-infrared frequency ranges. Thus, advanced semiconductor technologies can offer a versatile platform for novel designs of all-dielectric Mie-resonant metadevices.