MTHFR Polymorphism and Folic Acid Supplementation Influence Serum Homocysteine Levels in Psoriatic Patients Treated with Methotrexate.

BACKGROUND Hyperhomocysteinemia has been reported in psoriasis. We investigated the effect of methylenetetrahydrofolate reductase (MTHFR), polymorphism and folic acid supplementation on serum homocysteine levels in psoriasis. METHODS Serum homocysteine levels were detected at baseline and at week 12 in 201 patients who were genotyped with MTHFR rs1801133 without and 93 psoriatic patients with folate supplement. RESULTS TT genotype carriers of MTHFR rs1801133 had significantly higher serum homocysteine levels at baseline and at week 12, a better PASI 75 response rate at week 8, and a higher PASI 90 response rate at week 12 than the CT and CC genotype carriers. Multiple regression analysis demonstrated that serum homocysteine concentration at baseline was significantly associated with sex, weight, PASI score at baseline, and the rs1801133 genotype. The significant upregulation of serum homocysteine levels after treatment with methotrexate (MTX) was only observed in male CT and CC genotype carriers and female CC genotype carriers. In contrast, folic acid supplementation significantly decreased serum homocysteine levels after MTX treatment but only in male psoriatic patients. CONCLUSIONS The effect of MTX on serum homocysteine levels was associated with the polymorphism of MTHFR rs1801133 and sex. Folic acid supplementation only decreased serum homocysteine levels in male psoriatic patients

Electrochemical Corrosion Behavior of Ni-Fe-Co-P Alloy Coating Containing Nano-CeO2 Particles in NaCl Solution

In order to study the effect of nano-CeO2 particles doping on the electrochemical corrosion behavior of pure Ni-Fe-Co-P alloy coating, Ni-Fe-Co-P-CeO2 composite coating is prepared on the surface of 45 steel by scanning electrodeposition. The morphology, composition, and phase structure of the composite coating are analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of the coatings with different concentrations of nano-CeO2 particles in 50 g/L NaCl solution is studied by Tafel polarization curve and electrochemical impedance spectroscopy. The corrosion mechanism is discussed. The experimental results show that the obtained Ni-Fe-Co-P-CeO2 composite coating is amorphous, and the addition of nano-CeO2 particles increases the mass fraction of P. With the increase of the concentration of nano-CeO2 particles in the plating solution, the surface flatness of the coating increases. The surface of Ni-Fe-Co-P-1 g/L CeO2 composite coating is uniform and dense, and its self-corrosion potential is the most positive; the corrosion current and corrosion rate are the smallest, and the charge transfer resistance is the largest, showing the best corrosion resistance

Influence of Element Penetration Region on Adhesion and Corrosion Performance of Ni-Base Coatings

In this study, Ni–P/Ni–P–SiC coatings were prepared on pretreated 45 steel substrates by scanning electrodeposition. Prior to the electrodeposition, the substrates were subjected to two types of pretreatments: polishing and sandblasting. The 3D morphology of the pretreated substrates was characterized by laser scanning confocal microscopy. The micromorphology and section morphology of the coating surface were characterized by field emission scanning electron microscopy. The section element composition was characterized using an EDS energy spectrum analyzer. The adhesion and corrosion resistance of 15 coatings were analyzed using an automatic scratch tester and CS350 electrochemical workstation. The results showed the presence of an element penetration region between the coating and the substrate. The sandblasting pretreatment and SiC nanoparticle addition helped widen the penetration region of the elements. The Ni–P–SiC coating prepared by scanning electrodeposition on the sandblasted substrate exhibited the thickest penetration region, up to 28.39 µm. A scratch test conducted on this coating showed that it exhibits the best adhesion force, up to 36.5 N. In electrochemical corrosion experiments, its corrosion potential was found to be the highest, reaching −0.30 V, and the corrosion current density was the lowest, reaching 8.45 × 10−7 A·cm−2. The presence of the element penetration region increased the coating adhesion and improved the corrosion resistance

Influence of Heat Treatment on the Microstructure and Wear Properties of Arc-Sprayed FeCrAl/Al Coating

Intermetallic compounds formed during heat treatment of alloy coatings affect the coating structure and properties. In order to determine the phase changes and coating performance, FeCrAl (Fe Bal., Cr 26 wt.%, Al 6 wt.%) and Al (99.9 wt.%) coating was sprayed onto low carbon steel substrates and subsequently heat-treated at different temperatures. The effects of heat treatment on the microstructure, phase composition, tensile bonding strength, microhardness, and wear properties of the coatings were analyzed. The as-sprayed coating had a dense, layered structure with an average porosity of 3.6%. The microhardness of the as-sprayed coating was comprised of hard FeCrAl splats and ductile Al splats with an average microhardness value of 494 HV0.1. The coating at 300 °C had the highest tensile strength of 37.5 MPa. At 500 °C, FeAl intermetallic compounds formed at the phase boundaries due to the diffusion of elements. The coating microhardness and wear resistance were affected by the uniform coating structure and the precipitation of FeAl intermetallic compounds. Compared with the annealed coatings, the as-sprayed coating had the lowest wear rate

2D tribotronic transistors

Since the discovery of graphene, two-dimensional (2D) materials have been widely applied to field-effect transistors due to their great potential in optoelectronics, photodetectors, intelligent sensors, and neuromorphic devices. By integrating a 2D transistor with a triboelectric nanogenerator (TENG) into a tribotronic transistor, the induced triboelectric potential can readily regulate the charge carrier transport characteristics in the semiconductor channel. The emerging research field of tribotronics (mainly tribotronic transistors) has attracted extensive attention due to their significant applications in various sensation and human–machine interactions. Here, this review summarizes the recent developments of 2D tribotronic transistors. Firstly, the electrical, optoelectronic, and piezoelectric properties of typical 2D materials are introduced. Then, tribotronic tuning at the micro/nanoscale is discussed together with the methodologies of thermionic emission, triboelectricity tunneling, and atomic force microscope probe scanning, which is of great significance for the investigation of the underlying mechanism of the tribotronic effect. In addition, macroscale tribotronic regulation via TENG mechanical displacement is discussed in detail to explore the applications of 2D tribotronic transistors in intelligent sensors, logic devices, memory devices, and artificial synapses. Finally, the challenges and perspectives for 2D tribotronic transistors are discussed

Effect of Initial Surface Roughness on Cavitation Erosion Resistance of Arc-Sprayed Fe-Based Amorphous/Nanocrystalline Coatings

The arc spraying process was used to prepare Fe-based amorphous/nanocrystalline coating. The cavitation erosion behaviors of FeNiCrBSiNbW coatings with different surface roughness levels were investigated in distilled water. The results showed that FeNiCrBSiNbW coating adhered well to the substrate, and was compact with porosity of less than 2%. With increasing initial surface roughness, the coatings showed an increase in mass loss of cavitation erosion damage. The amount of pre-existing defects on the initial surface of the coatings was found to be a significant factor for the difference in the cavitation erosion behavior. The cavitation erosion damage for the coatings was a brittle erosion mode. The evolution of the cavitation erosion mechanism of the coatings with the increase of the initial surface roughness was micro-cracks, pits, detachment of fragments, craters, cracks, pullout of the un-melted particle, and massive exfoliations

Influences of sand concentration and flow velocity on hydro-abrasive erosion behaviors of HVOF sprayed Cr3C2–NiCr and WC–Cr3C2–Ni coatings

Improving the hydro-abrasive erosion (HAE) resistance of the existing flow-handling components has been a matter of continuous effort for the hydraulic machineries. In current work, the effects of sand concentrations (SC) and flow velocities (FV) on HAE behaviors of high-velocity oxygen-fuel (HVOF) sprayed carbide-based cermet (i.e. Cr3C2–NiCr and WC–Cr3C2–Ni) coatings were studied using a rotating disk rig facility. The obtained results revealed that the WC–Cr3C2–Ni coating possessed lower porosity value, higher hardness (H) and elastic modulus (E) values, superior HAE resistances, and appeared less influenced by SC as well as FV compared with the Cr3C2–NiCr coating. Higher SC and FV caused more severe HAE degradations for both carbide-based cermet coatings, while FV had a greater influence on HAE resistances for both coatings than SC. With the increase of the SC and FV, the Cr3C2–NiCr coating experienced the HAE process of the isolation of hard phase grains as well as the scouring, the connection of micro-cracks as well as severe plastic deformations, and the crater formation as well as deep scour marks, while the HAE process of the WC–Cr3C2–Ni coating mainly included the micro-cracks, the erosion pits, and the scour marks