Mosaic Targets Research Articles

Investigation of preference for local and global processing of Capuchin-monkeys (Sapajus spp.) in shape discrimination of mosaic arrangements.

Classical experiments using hierarchical stimuli to investigate the ability of capuchin monkeys to integrate visual information based on global or local clues reported findings suggesting a behavioral preference for local information of the image. Many experiments using mosaics have been conducted with capuchin monkeys to identify some of their perceptual phenotypes. As the identification of an image in a mosaic demands the integration of elements that share some visual features, we evaluated the discrimination of shapes presented in solid and mosaic stimuli in capuchin monkeys. Shape discrimination performance was tested in 2 male adult capuchin monkeys in an experimental chamber with a touchscreen video monitor, in three experiments: (i) evaluation of global and local processing using hierarchical stimuli; (ii) evaluation of target detection using simple discrimination procedures; (iii) evaluation of shape discrimination using simple discrimination and delayed matching-to-sample procedures. We observed that both monkeys had preferences for local processing when tested by hierarchical stimuli. Additionally, detection performance for solid and mosaic targets was highly significant, but for shape discrimination tasks we found significant performance when using solid figures, non-significant performance when using circle and square shapes in mosaic stimuli, and significant performance when using Letter X and Number 8 shapes in mosaic stimuli. Our results are suggestive that the monkeys respond to local contrast and partly to global contrast in mosaic stimuli.

NIa-Pro of sugarcane mosaic virus targets Corn Cysteine Protease 1 (CCP1) to undermine salicylic acid-mediated defense in maize.

Papain-like cysteine proteases (PLCPs) play pivotal roles in plant defense against pathogen invasions. While pathogens can secrete effectors to target and inhibit PLCP activities, the roles of PLCPs in plant-virus interactions and the mechanisms through which viruses neutralize PLCP activities remain largely uncharted. Here, we demonstrate that the expression and activity of a maize PLCP CCP1 (Corn Cysteine Protease), is upregulated following sugarcane mosaic virus (SCMV) infection. Transient silencing of CCP1 led to a reduction in PLCP activities, thereby promoting SCMV infection in maize. Furthermore, the knockdown of CCP1 resulted in diminished salicylic acid (SA) levels and suppressed expression of SA-responsive pathogenesis-related genes. This suggests that CCP1 plays a role in modulating the SA signaling pathway. Interestingly, NIa-Pro, the primary protease of SCMV, was found to interact with CCP1, subsequently inhibiting its protease activity. A specific motif within NIa-Pro termed the inhibitor motif was identified as essential for its interaction with CCP1 and the suppression of its activity. We have also discovered that the key amino acids responsible for the interaction between NIa-Pro and CCP1 are crucial for the virulence of SCMV. In conclusion, our findings offer compelling evidence that SCMV undermines maize defense mechanisms through the interaction of NIa-Pro with CCP1. Together, these findings shed a new light on the mechanism(s) controlling the arms races between virus and plant.

Coat protein of cassava common mosaic virus targets RAV1 and RAV2 transcription factors to subvert immunity in cassava.

Cassava common mosaic virus (CsCMV, genus Potexvirus) is a prevalent virus associated with cassava mosaic disease, so it is essential to elucidate the underlying molecular mechanisms of the coevolutionary arms race between viral pathogenesis and the cassava (Manihot esculenta Crantz) defense response. However, the molecular mechanism underlying CsCMV infection is largely unclear. Here, we revealed that coat protein (CP) acts as a major pathogenicity determinant of CsCMV via a mutant infectious clone. Moreover, we identified the target proteins of CP-related to abscisic acid insensitive3 (ABI3)/viviparous1 (VP1) (MeRAV1) and MeRAV2 transcription factors, which positively regulated disease resistance against CsCMV via transcriptional activation of melatonin biosynthetic genes (tryptophan decarboxylase 2 (MeTDC2), tryptamine 5-hydroxylase (MeT5H), N-aceylserotonin O-methyltransferase 1 (MeASMT1)) and MeCatalase6 (MeCAT6) and MeCAT7. Notably, the interaction between CP, MeRAV1, and MeRAV2 interfered with the protein phosphorylation of MeRAV1 and MeRAV2 individually at Ser45 and Ser44 by the protein kinase, thereby weakening the transcriptional activation activity of MeRAV1 and MeRAV2 on melatonin biosynthetic genes, MeCAT6 and MeCAT7 dependent on the protein phosphorylation of MeRAV1 and MeRAV2. Taken together, the identification of the CP-MeRAV1 and CP-MeRAV2 interaction module not only illustrates a molecular mechanism by which CsCMV orchestrates the host defense system to benefit its infection and development but also provides a gene network with potential value for the genetic improvement of cassava disease resistance.

Structure and Oxidation Resistance of Mo-Y-Zr-Si-B Coatings Deposited by DCMS and HIPIMS Methods Using Mosaic Targets

In this study, Mo-(Y,Zr)-Si-B coatings were obtained by direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HIPIMS) using mosaic targets. The results showed that the addition of Y and Zr into the composition of Mo-Si-B coatings led to the suppression of columnar grain growth, a decrease in the crystallite size of h-MoSi2 phase from ~50 to ~5 nm, and an increase in the amorphous to crystalline phases ratio Doping of the Mo-Si-B coating with Y and Zr promoted an increase in oxidation resistance at a temperature of 1000 °C. The introduction of yttrium into the composition of Mo-Si-B contributed to an increase in their crack resistance when heated to 1300 °C. High oxidation resistance of the coatings was provided by a defect-free SiO2 + MoO3 + Y2O3 surface layer. The transition from the DCMS mode to HIPIMS decreased the texture of the Mo-Si-B coatings. The use of an HIPIMS mode led to a decrease in the oxidation rate of Mo-(Y)-Si-B coatings at T = 1000 °C by 1.6–4.5 times compared to DCMS. In the case of Mo-Y-Si-B coatings, the use of HIPIMS led to a decrease of more than 50% in the thickness of the oxide layer at a temperature of 1300 °C.

NiAl Coatings Produced by Magnetron Sputtering from Mosaic Targets

NiAl Coatings Produced by Magnetron Sputtering from Mosaic Targets

Wheat yellow mosaic virus NIb targets TaVTC2 to elicit broad-spectrum pathogen resistance in wheat.

GDP-L-galactose phosphorylase (VTC2) catalyses the conversion of GDP-L-galactose to L-galactose-1-P, a vital step of ascorbic acid (AsA) biosynthesis in plants. AsA is well known for its function in the amelioration of oxidative stress caused by most pathogen infection, but its function against viral infection remains unclear. Here, we have identified a VTC2 gene in wheat named as TaVTC2 and investigated its function in association with the wheat yellow mosaic virus (WYMV) infection. Our results showed that overexpression of TaVTC2 significantly increased viral accumulation, whereas knocking down TaVTC2 inhibited the viral infection in wheat, suggesting a positive regulation on viral infection by TaVTC2. Moreover, less AsA was produced in TaVTC2 knocking down plants (TaVTC2-RNAi) which due to the reduction in TaVTC2 expression and subsequently in TaVTC2 activity, resulting in a reactive oxygen species (ROS) burst in leaves. Furthermore, the enhanced WYMV resistance in TaVTC2-RNAi plants was diminished by exogenously applied AsA. We further demonstrated that WYMV NIb directly bound to TaVTC2 and inhibited TaVTC2 enzymatic activity invitro. The effect of TaVTC2 on ROS scavenge was suppressed by NIb in a dosage-dependent manner, indicating the ROS scavenging was highly regulated by the interaction of TaVTC2 with NIb. Furthermore, TaVTC2 RNAi plants conferred broad-spectrum disease resistance. Therefore, the data indicate that TaVTC2 recruits WYMV NIb to down-regulate its own enzymatic activity, reducing AsA accumulation to elicit a burst of ROS which confers the resistance to WYMV infection. Thus, a new mechanism of the formation of plant innate immunity was proposed.

Structure and properties of ion-plasma deposited films of CoCrFeMiMn high-entropy alloy

High-entropy Co19Cr18Fe22Mn21Ni20 thin films were obtained by the modernized method of three-electrode ion-plasma sputtering of mosaic targets consisting of pure metals. The structure, electrical resistance, and magnetic properties of films were investigated. Single diffuse halo was seen on the XRD patterns of the as-deposited films, which confirms their amorphous structure. Some of the thin films, which were annealed at 900 K in a vacuum, were identified to be oxidized by a small amount of oxygen in the work chamber. After the heat treatment, the Co19Cr18Fe22Mn21Ni20 films were transformed from an amorphous state into a crystallized FCC solid solution with the lattice parameter a=0.3613 nm. Also, the cubic B2 phase of FeCo with a lattice parameter of 0.2857 nm was formed in the annealed films. As a result of oxidation processes, a dispersed phase of manganese oxide also arose after annealing. The temperature dependencies of electrical resistivity of films were measured by the four-point technique upon continuously heating in the high vacuum. Both as-deposited and annealed films clearly revealed a typical ferromagnetic behavior. The as-deposited high-entropy film exhibited the soft magnetic properties while the annealed films could be attributed to hard magnetic materials.

2D Particle-in-Cell/Monte Carlo Collision Simulation of Zn-C Mosaic Target Erosion

In this work, a simulation analysis of a commercial magnetron sputtering source was performed using the finite element method Particle-in-Cell/Monte Carlo Collision (PIC/MCC) to optimize the configuration of the Zn-C mosaic target. The magnetic field distribution was solved in a two-dimensional cylindrical coordinate system, and particles such as electrons, atoms, and charged ions of argon, zinc, and carbon were tracked in a DC magnetron sputtering system. The sputtering yield profile and particle flux for the eroded target were studied considering the ion and electron density distributions. The maximum sputtering flux of zinc and carbon was 1.975´1021 m-2.s-1 and 3.7´1018 m-2.s-1 respectively. The erosion position of a target was predicted based on the maximum power density distribution at the surface of the target. The accuracy of the simulation was checked by comparing it with the measurement of the target eroded after several hours of sputtering. However, as for the Zn-C mosaic target, the racetrack was identical to the analysis predicted by the numerical simulation process. The results of this work can be used as a guide for designing mosaic targets and optimizing their use for fabricating nanohybrid thin film structures.

Multi-component low and high entropy metallic coatings synthesized by pulsed magnetron sputtering

This paper presents the findings of the synthesis of multicomponent (Al, W, Ni, Ti, Nb) alloy coatings from mosaic targets. For the study, a pulsed magnetron sputtering method was employed under different plasma generation conditions: modulation frequency (10 Hz and 1000 Hz), and power (600 W and 1000 W). The processes achieved two types of alloy coatings, high entropy and classical alloys. After the deposition processes, scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy techniques were employed to find the morphology, thickness, and chemical and phase compositions of the coatings. Nanohardness and its related parameters, namely H3/Er2, H/E, and 1/Er2H ratios, were measured. An annealing treatment was performed to estimate the stability range for the selected coatings. The results indicated the formation of as-deposited coatings exhibiting an amorphous structure as a single-phase solid solution. The process parameters had an influence on the resulting morphology—a dense and homogenous as well as a columnar morphology, was obtained. The study compared the properties of high-entropy alloy (HEA) coatings and classical alloy coatings concerning their structure and chemical and phase composition. It was found that the change of frequency modulation and the post-annealing process contributed to the increase in the hardness of the material in the case of HEA coatings.

Metastable states and physical properties of Co-Cr-Fe-Mn-Ni high-entropy alloy thin films

In this study, Co19Cr18Fe22Mn21Ni20 HEA thin films have been obtained by the modernized method of three-electrode ion-plasma sputtering of mosaic targets consisting of pure metals. The structure, electrical resistance and magnetic properties of films were investigated. Single diffuse halo is observed on the XRD patterns of the as-deposited films, which confirms their amorphous structure. Some of the thin films, which were annealed at 900 K in a vacuum were identified to be oxidized by the small amount of oxygen in the work chamber. After the heat treatment, the Co19Cr18Fe22Mn21Ni20 films are transformed from an amorphous state into a crystallized FCC solid solution with the lattice parameter a = 0.3613 nm. Also, the cubic B2 phase of FeCo with a lattice parameter of 0.2857 nm is formed in the annealed films. As a result of oxidation processes, a dispersed phase of manganese oxide is also arising after annealing. Calculation of the activation energy of the beginning of phase transition was carried out by the generalized Kissinger method. The temperature dependencies of electrical resistivity of films were measured by the four-point technique upon continuously heating in the high vacuum. Both as-deposited and annealed films clearly reveal a typical ferromagnetic behavior. The as-deposited HEA film exhibits the soft magnetic properties while the annealed films can be attributed to hard magnetic materials.

Nial-Based Coatings Produced by Magnetron Sputtering of Mosaic Targets

Nial-Based Coatings Produced by Magnetron Sputtering of Mosaic Targets

Plasmon-enhanced photoluminescence from TiO2 and TeO2 thin films doped by Eu3+ for optoelectronic applications.

In this work we study the luminescence properties of europium-doped titanium dioxide and tellurium oxide thin films enhanced by gold plasmonic nanostructures. We propose a new type of plasmon structure with an ultrathin dielectric film between plasmonic platform and luminescent material. Plasmonic platforms were manufactured through thermal annealing of the gold thin film. Thermal dewetting of gold film results in spherical gold nanostructures with average dimensions of 50 nm. Both, luminescent TiO2:Eu and TeO2:Eu films were deposited by RF magnetron sputtering from mosaic targets. The morphology of the gold nanostructures was investigated by SEM and TEM, while the composition of oxides film was analyzed by XPS. Luminescence properties were studied on the basis of excitation and emission spectra. The experiments show that the additional dielectric layer enhances the luminescence intensity. Such structures could be potential candidates as phosphors in white LEDs.

Electrical and optical properties of (Ta2O5)1−x–(TiO2)x films, x = 0.035, prepared by sputtering of ceramic and mosaic (Ta, Ti) metal targets

(Ta2O5)1−x–(TiO2)x, with x = 0.035, thin films were deposited onto p-type silicon and quartz substrates following two different routes: first, by the sputtering of the ceramic target and, second, by sputtering of mosaic (Ta, Ti) metal target in the presence of oxygen (hereafter referred to as CT and MT, respectively). The deposited films were found to crystallize on annealing at and above 700 °C. The dielectric constant of the prepared films was found to increase with increasing annealing temperature, up to 700 °C, and on annealing at 800 °C, it was found to decrease. The dielectric constant of the CT was observed to be higher than that of the MT film structures at each annealing temperature. From the transmittance measurements, different optical parameters of the deposited crystalline films were calculated. The leakage current density of the CT films was found to increase with the annealing temperature, whereas in the MT films, it drastically decreased by an order of ∼3 when the annealing temperature was increased from 700 to 800 °C. Different conduction mechanisms were observed in the different applied field regions in the prepared film structure. The observed electrical properties of the prepared film structure seem to depend on the status of the growing interfacial oxide layer on annealing.

Pulsed Laser Deposition of Epitaxial Non-Doped PbTiO3 Thin Films from PbO–TiO2 Mosaic Targets

PbTiO3 (PTO) suffers from difficulty in preparing high-density robust bulk ceramics, which in turn has been a bottleneck in thin films growth with physical vapor deposition (PVD) methods. In the present work, we prepared non-doped PTO thin films by a pulsed laser deposition (PLD) method with either a single PTO target or a mosaic target consisting of PbO and TiO2 pie-shaped pieces. On the PTO single target, laser irradiation caused selective ablation of Pb, resulting in Ti-rich cone-shaped pillar structure on the surface, whereas the irradiated surface of PbO and TiO2 pieces was smoother. Epitaxial PTO films deposited on SrTiO3 (001) substrates from the pie-chart targets with PbO:TiO2 areal ratio from 3:5 to 5:3 resulted in composition, crystallinity, flatness, and ferroelectric properties almost independent of the areal ratio. The averaged composition of each film was close to stoichiometric, suggesting a compositional self-control mechanism. For growing epitaxial and high-quality non-doped PTO films, a PbO–TiO2 pie-chart target is advantageous in easiness of handling and stable surface structure.

Effect of the Degree of Aluminum Doping on the Mechanical and Tribological Characteristics of Titanium–Aluminum Nitride Films

The mechanical and tribological characteristics of titanium–aluminum nitride films deposited by the reactive magnetron sputtering of Ti–Al mosaic targets with different aluminum concentrations were studied. The dependences of the elemental composition, microhardness, and friction coefficient on the degree of doping of the films with aluminum and nitrogen concentration in the Ar/N2 gas mixture during film deposition were obtained. It was found that an increase in the aluminum content in the film results in an increase in film hardness and decrease in the friction coefficient. The optimum nitrogen concentration in the film was achieved at maximum hardness and low values of the friction coefficient. A maximum hardness of 23.5 GPa and a minimum friction coefficient of 0.082 were obtained for films of the composition Ti5AlN1.33, which had a Ti/Al ratio of 5 : 1 and a nitrogen deficiency.

Hydrogen permeability of surface-modified Pd-Ag membranes at low temperatures

Hydrogen-permeable membranes of the Pd77% Ag33% alloy were obtained. Membranes were modified with a catalytically active coating, which consist of a crystalline nanostructured palladium black. Membranes were obtained by magnetron sputtering using mosaic targets. The surface modification with a catalytically active coating was performed by electrochemical deposition from an aqueous solution of H2PdCl4. The low-temperature kinetic characteristics of the hydrogen permeability of metallic Pd77% Ag23% membranes with a modifying coating of crystallized palladium black were analysed. During the analysis of the obtained experimental data about the kinetic characteristics of the obtained membranes, it was revealed that the surface effects are the limiting stage of hydrogen transport through palladium membranes at low temperatures. It was experimentally confirmed that the high specific surface of the synthesized catalysts causes the acceleration of the kinetic characteristics of hydrogen transport. The possibility of intensifying the processes of hydrogen transport through metallic membranes by creating active centers of chemisorption and dissociation on their surface is shown.

Microstructure, mechanical and physical properties of FeCoNiAlMnW high-entropy films deposited by magnetron sputtering

Ferromagnetic Fe33Co30Ni16Al7Mn9W5 high-entropy films of BCC-structure solid solution were synthesized by RF magnetron sputtering with mosaic targets at different substrate temperature of 20 °C, 200 °C, 400 °C and 600 °C. Hardness and resistivity were measured by the methods of nanoindentation and four-point probe, respectively. Magnetization hysteresis loops were obtained by a vibrating sample magnetometer. Oriented grain growth of (2 1 1) was observed in the films deposited at 400 °C and 600 °C. Substrate-temperature elevation led to the variation of film-growth mode. The films showed high hardness and electrical resistivity. Electron-surface scatter generated by mesoscopic-scale roughness played a decisive role in the monotone increase of the films’ resistivity as substrate temperature rose. The optimal balance of magnetic and electrical properties was achieved at substrate temperature of 400 °C.

Creation of thin superconducting MoCN thin film by cathode sputtering technique as a basic material for functional cryogenic nanoelements

Thin MoCN films were synthesized by a method of cathode sputtering of mosaic Mo-C targets by nitrogen ions at temperature of 800°C on substrates of the oxidized silicon. The temperature dependences of electrical resistance of the films in the range of 4.2–300°K were measured. Volt-ampere characteristics of the films and critical current density vs film thickness were obtained at a temperature of 4.2°K. The microstructure and film-depth chemical composition profiles of thin films were investigated by analytical techniques of the transmission electron microscopy (HRTEM, EELS) on a cross-section samples made by the focused ion beam (FIB). It was established that MoCN thin film at a thickness of 8 nm contained MoC and Mo5N6 layers. The high density of critical current in these films indicated prospects of their application in the field of cryogenic nanotechnologies.

Relation between carriers hopping rate and structural constants in amorphous carbon nickel films with different nickel nanoparticles distributions

In this paper, the films were prepared by radio frequency magnetron co-sputtering technique. The effect of different mosaic targets made of nickel strips and graphite pure on the dielectric relaxation time, the carriers hopping rate, the fractal dimensions and the optical loss of films were studied. The values of the optical band gap of films using the cross-point between the tangent of the plot of lower and higher values of the photon energy were calculated. The films deposited at 4.64% have maximum hopping rate of about 8.6 × 1012 S−1. It can be seen that the films deposited at 3.92% have minimum value of fractal dimension of 2.27. With increasing Ni content of films a nonmetal–metal transition is observed which it is explainable by the power law of percolation theory. Critical metal content and the critical exponent of films were 87.25% and 1, respectively. With increasing Ni content, the carriers effective mass of films decreased and average lattice separation values of films increased. Films deposited at 3.92% have minimum value of Debye frequency νD of about 1.09 × 1012 Hz. The value of energy loss by free charge carriers when traversing the bulk and surface of films at 3.92% has maximum value and it has an increasing function behavior with energy.

Effects of complex graphite-like carbon coating on gear vibration noise

Abstract In this paper, the effects of substrate surface roughness and the addition of yttrium, cerium and tantalum on thickness uniformity of graphite-like carbon (GLC) coatings on gears were studied by magnetron sputtering method using mosaic targets. And noise reduction effects of gear pump deposited with complex GLC coatings were evaluated at different rotate speeds. The results showed that target-substrate distance, sputtering angle and surface roughness had influences on thickness uniformity of GLC coatings on gear. The introduction of elements Y, Ce and Ta into GLC coatings could effectively improve their thickness uniformity. The complex GLC coating with optimal thickness uniformity on gear exhibited significantly reduction effect for gear noise and the reduction effect for axial vibration was better than that of radial vibrations. Compared with uncoated gears, the noise for the coated gears was decreased by 10 dB at 2000 rpm. Good high-frequency noise reduction was obtained, which could be decreased by 19 dB in the range of 4000–10,000 Hz.