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An existing consistent set of model potentials for alkali halides formulated for convenient use in defect applications is extended to incorporate hydrides. The additional parameters required are fitted to the limited available experimental data for perfect alkali hydride crystals. Calculations of local-mode frequencies for isolated H-substitutional (Ucentre) and interstitial impurities, H-H-, H-D-, H-cation-impurity and H-anionimpurity pairs in alkali halides are reported. These calculations, which are based on large periodic defect cells, involve no further adjustable parameters and are in good agreement with results of infrared absorption measurements found in the literature.

Improvement in magnetic and electrical properties of multiferroic BiFeO3 in conjunction with their dependence on particle size is crucial due to its potential applications in multifunctional miniaturized devices. In this investigation, we report a study on particle size dependent structural, magnetic and electrical properties of sol-gel derived Bi0.9Ba0.1FeO3 nanoparticles of different sizes ranging from ∼ 12 to 49 nm. The substitution of Bi by Ba significantly suppresses oxygen vacancies, reduces leakage current density and Fe 2+ state. An improvement in both magnetic and electrical properties is observed for 10 % Ba-doped BiFeO3 nanoparticles compared to its undoped counterpart. The saturation magnetization of Bi0.9Ba0.1FeO3 nanoparticles increase with reducing particle size in contrast with a decreasing trend of ferroelectric polarization. Moreover, a first order metamagnetic transition is noticed for ∼ 49 nm Bi0.9Ba0.1FeO3 nanoparticles which disappeared with decreasing particle size. The observed strong size dependent multiferroic properties are attributed to the complex interaction between vacancy induced crystallographic defects, multiple valence states of Fe, uncompensated surface spins, crystallographic distortion and suppression of spiral spin cycloid of BiFeO3.

BackgroundChronic otitis media (COM) is characterized by middle ear fluid predominantly containing cytokines, Nontypeable haemophilus influenzae (NTHi), the mucin MUC5B, and neutrophil extracellular traps (NETs). NETs consist of extracellular DNA coated with antibacterial proteins such as myeloperoxidase (MPO) and citrullinated histone 3 (CitH3). NETs can damage tissues and sustain inflammation. Our study aimed to develop an in vitro model of NETosis, testing COM inductors.MethodsNETosis was evaluated in fresh blood human neutrophils attached to collagen‐coated plates and in suspension exposed to phorbol myristate acetate (PMA) as a control, and COM relevant mediators. Confocal microscopy, DNA fluorescence assay and flow cytometry were used to quantify NETosis.ResultsPMA exposure induced DNA, MPO, and CitH3 by immunofluorescence (IF) most significantly at 3 hours (3.8‐fold for DAPI, 7.6‐fold for MPO, and 6.9‐fold for CitH3, all P < .05). IL‐8 and TNF‐α cytokines showed milder increases of DAPI, MPO, and CitH3 positive cells. NTHi had no effect on these NETs markers. Purified salivary MUC5B (10 to 40 μg/mL) produced potent increases, comparable to PMA. A composite NET score summing the fold‐increases for DAPI, MPO, and CitH3 demonstrated PMA at 13.6 to 19 relative to control set at 1; and MUC5B at 8.6 to 16.3 (all P < .05). IL‐8 and TNF‐α showed scores of 5.4 and 3, respectively, but these were not statistically significant.ConclusionWe developed a reliable in vitro assay for NETosis which demonstrated that salivary MUC5B is a potent inductor of NETs whereas IL‐8, TNF‐α, live and lyzed NTHi demonstrated minimal to no NETosis.Level of evidenceNA.

The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi 1-x Ba x FeO 3 samples. Bi 1-x Ba x FeO 3 samples (x = 0.1, 0.2 and 0.3) were synthesized by the conventional solid-state reaction method using nano-powders of Bi 2 O 3 , Fe 2 O 3 , and BaCO 3 . Thereafter, field emission scanning electron microscope and X-ray diffraction (XRD) techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability (l 0 i and l 00 i ) measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant (k) was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi 0.8 Ba 0.2 FeO 3 sample due to reduction in leakage current at this composition.