Perovskite oxides such as LaFeO₃ are promising for various functional applications, with performance significantly enhanced by targeted doping strategies. This study reports the synthesis of La₀.₈Sr₀.₁Ba₀.₁Fe₁₋ₓNiₓO₃ (x = 0.05 and 0.1) compounds via the sol–gel method, followed by systematic structural, microstructural, electrical, and dielectric characterizations using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and impedance spectroscopy. XRD results confirmed the formation of a single-phase rhombohedral perovskite structure. SEM analysis revealed a homogeneous microstructure, with average grain size decreasing from 171 nm (x = 0.05) to 119 nm (x = 0.1), attributed to the grain growth pinning effect of Ni. Raman and FTIR spectroscopies indicated that Ni substitution induces local lattice distortion. Electrical characterization showed semiconducting behavior across compositions, with DC conductivity analysis revealing temperature-dependent conduction mechanisms: Mott Variable Range Hopping (VRH) at low temperatures, Greaves VRH at intermediate, and Small Polaron Hopping (SPH) at higher temperatures. Activation energy decreased with increasing Ni doping. AC conductivity analysis demonstrated correlated barrier hopping (CBH) conduction for x = 0.05 and overlapping large polaron tunneling (OLPT) for x = 0.1 at high frequencies. Dielectric measurements showed reduced dielectric constant and loss upon Ni substitution, while impedance spectroscopy revealed non-Debye relaxation processes dominated by grain and grain boundary contributions. These findings establish that Ni doping effectively modulates structural order, defect chemistry, and charge transport in La₀.₈Sr₀.₁Ba₀.₁FeO₃ perovskites, improving their electrical performance and dielectric properties and making them promising candidates for applications in solid oxide fuel cells, gas sensors, and electronic devices.
To assess the effectiveness and safety of intravenous efgartigimod in patients with myasthenia gravis (MG) and to compare treatment responses between anti-acetylcholine receptor antibody (AChR-Ab)-positive and -negative subtypes. A comprehensive search was conducted in the PubMed, Scopus, Web of Science, and Cochrane CENTRAL databases up to 15 October 2025. Clinical trials and cohort studies evaluating the effectiveness and safety of efgartigimod in patients with MG were included. A random-effects model was used to pool mean differences (MDs) for continuous outcomes and proportions for categorical outcomes, with corresponding 95
In this study, a gold-based electrocatalyst was developed for ethanol electrooxidation in alkaline medium as an alternative to oxygen evolution in water electrolysis to reduce the energy input required for hydrogen production. The catalyst consists of Au nanoparticles of 200 nm supported on a three-dimensional gas diffusion electrode (Au@GDE) prepared by galvanostatic pulse electrodeposition. Optimization revealed that a 1 s pulse duration and an Au loading of 150 µg/cm2 provided the best catalytic performance. In 1 M NaOH + 1 M ethanol, the optimized Au@GDE delivered a peak mass activity of 42.2 mA/mgAu with an onset potential of − 0.25 V vs. SCE. A current density of 10 mA/cm2 was achieved at an anodic potential approximately 800 mV lower than that required for oxygen evolution under identical conditions. The catalyst exhibited strong tolerance to poisoning (If/Ib = 3.5) and showed only 4
IntroductionCephalic tetanus of otitic origin is a well-documented clinical entity. It is characterized by trismus associated with damage to one or more cranial nerves. Although rare, this form poses a real diagnostic challenge because of its often atypical clinical picture, which justifies rapid and appropriate treatment to limit morbidity and mortality.Case PresentationWe report the case of a 31-year-old patient, working as a welder and whose tetanus vaccination status was not up to date with recommended booster doses, who developed purulent otitis following auricular trauma caused by a metallic projectile, which was not treated. The course was marked by the appearance of cephalic tetanus, manifested by trismus associated with the involvement of the third cranial nerve (ptosis). Management includes the administration of antitetanus serum, a first dose of tetanus vaccine, and a prescription of metronidazole. The outcome was favorable.ConclusionThis case highlights the importance of tetanus vaccination, which remains the cornerstone of prevention and underscores the need for increased community awareness and appropriate training for health professionals. Cephalic tetanus, a rare complication of auricular trauma, requires prompt management to prevent serious sequelae and ensure favorable outcomes.
The present contribution aims to study the structural, mechanical, dynamic, electronic, optical, and vibrational properties of the NiThSn half-Heusler compound. We used the density functional theory (DFT) as implemented in the Wien2k software. Our data on the elastic constants indicate that the NiThSn compound is mechanically stable with a small elastic anisotropy. The derived electronic energy band structure reveals that the NiThSn half-Heusler compound exhibits semiconductor properties with small indirect band gap, with energies of similar to 0.325 eV using the TB-mBJ functional and 0.294 eV using the PBE-GGA functional, respectively. Furthermore, we interpreted the optical properties, including both real and imaginary parts of the dielectric function as well as the absorption coefficient in the energy range from 0 to 14 eV. The phonon dispersion curve confirms the presence of dynamical stability of the NiThSn compound, with a band gap of similar to 0.5 THz between the optical and acoustic branches regions. To the authors' knowledge, no data have been found in the literature on the electronic and optical properties of the NiThSn half-Heusler compound.
