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Abstract: The photocatalytic behavior of magnetic SrFe12O19 and SrFe11.4Al0.6O19 under visible and sun lights was evaluated using Congo red (CR) as a model dye. Synthesis of pure and Al substituted SrFe12O19 by microwave combustion method followed by calcination at 950°C yielded single phase materials having particle sizes and surface areas in the ranges ∼120–180nm and 3.5–5.5m2/g, respectively. The experimental band gaps (1.5–1.56eV), derived from UV–Vis diffuse reflectance spectra, matched well with those calculated (1.86–1.91eV) theoretically from electronic structure data using density functional theory. Both the samples efficiently degraded CR under visible/sun lights and the low band gap of the materials was mainly responsible for the activity. Slightly higher (∼10%) activity of SrFe11.4Al0.6O19 was primarily attributed to Al doping which prevented the electron–hole recombination. Reasonably high values of magnetization (∼52emu/g at 300K) was beneficial in separating the catalysts from the reaction cell at a low strength magnetic field after the reaction. These magnetic photocatalysts may be exploited further for the degradation of other dyes for their possible use in remediation of wastewater. [Copyright &y& Elsevier]

Abstract: We have performed an X-ray photoelectron spectroscopy (XPS) study of SrFe12−x Al x O19 (0≤ x ≤2.4), and the results have been correlated to the magnetic properties measured using VSM technique. The coercivity of the parent compound increased from 5420Oe to 7340Oe with increasing the doping concentration of Al ions up to x =1.2. The XPS data of Fe 3s spectrum show that the intensity of majority peak decreased with the doping of Al ion and it is associated with the magnetic moment. The XPS analysis of Fe 2p data in conjugation with the Fe 3s data suggests that the Al ions occupy the 2a site of the crystal structure up to x =1.2, and beyond the dopant ions distribute at other occupation sites. The observed correlation between the spectral features of Fe 3s spectrum and the magnetic data suggests that XPS technique can also be used as a spectroscopic diagnostic tool to comprehend the influence of doping ion on the magnetic moment of spin up and spin down sublattice of ferrimagnetic structure. [Copyright &y& Elsevier]

The paper addresses the structural, crystallization, soft magnetic and Curie temperature behaviour of Co36Fe36Si4B20Nb4 alloy. The material, prepared in the form of ribbons by melt-spinning technique, was amorphous in the as-cast state. Differential scanning calorimetry (DSC) showed two stages of crystallization whereas thermal variation of electrical resistivity (TER) carried out to a higher range of temperature indicated three stages of crystallization. The first crystallization stage, which occurred at 845 K and 825 K in DSC and TER, respectively, was due to the formation of nanophase (CoFe)2Si as evidenced by X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The formation of these nanoparticles reduced the magnetocrystalline anisotropy, thereby revealing good soft magnetic properties in the samples annealed between 825 K and 875 K with coercivity less than 49.9 A m-1 (627 mOe) and susceptibility ∼ 0.72 × 103. In this optimum nanocrystalline state, the material also exhibited a high Curie temperature above 1100 K, opening the scope of the present nanocrystalline alloy for high temperature applications. [ABSTRACT FROM AUTHOR]

The effect of hydrogenation on the mechanical and magnetic response of amorphous Fe73.5Nb3Cu1Si13.5B9 alloys was studied. Hydrogen was charged electrochemically by varying charging current density. Magnetic Barkhausen emissions and coercivity were measured in charged and degassed samples. It was found that both responses were reversible. The hydrogen induced stress was responsible for these reversible effects. The kinetics of hydrogenation and of degassing are reported. [Copyright &y& Elsevier]

Mesosphaerum suaveolens (L.) Kuntze (Syn. Hyptis suaveolens (L.) Poit.) is a wild essential-oil-bearing plant having multiple uses in traditional medicine, perfumery, food, agriculture, and pharmaceutical industries. The present paper is the first report on the in vitro anti-inflammatory effects of the leaf essential oil of M. suaveolens (MSLEO) and unravels its molecular mechanism in LPS-stimulated RAW 264.7 macrophage cells. GC-MS analysis of the essential oil (EO) isolated from the leaves by hydro-distillation led to the identification of 48 constituents, accounting for 90.55% of the total oil, and β-caryophyllene (16.17%), phyllocladene (11.85%), abietatriene (11.46%), and spathulenol (7.89%) were found to be the major components. MSLEO treatment had no effect on the viability of RAW 264.7 cells up to a concentration of 100 μg/mL, and the EO was responsible for a reduction in proinflammatory cytokines like IL-6, IL-1β, and TNF-α, a decrease in intracellular ROS production, and the restoration of oxidative damage by elevating the levels of endogenous antioxidative enzymes like CAT, SOD, GPx, and GSH. RT-qPCR analysis indicated that MSLEO reduced the mRNA expression levels of iNOS and COX-2 as compared to the LPS-induced group. In addition, a confocal microscopy analysis showed that MSLEO inhibited the translocation of NF-κB from the cytosol to the nucleus. The results of this experiment demonstrate that MSLEO possesses significant anti-inflammatory potential by preventing the activation of NF-κB, which, in turn, inhibits the downstream expression of other inflammatory mediators associated with the activation of the NF-κB pathway in LPS-induced RAW 264.7 cells. Thus, the leaf essential oil of M. suaveolens may prove to be a promising therapeutic agent for the treatment of inflammation, and targeting the NF-κB signaling pathway may be considered as an attractive approach for anti-inflammatory therapies.

Neocinnamomum caudatum (Lauraceae) plant is used in the traditional system of medicine and is considered a potential source of edible fruits, spices, flavoring agents and biodiesel. The leaves, bark and roots of the species are used by local communities for the treatment of inflammatory responses, such as allergies, sinusitis and urinary tract infections. However, there is no scientific evidence to support the molecular mechanism through which this plant exerts its anti-inflammatory effect. The aim of the current research was to characterize the chemical constituents of bark (NCB) and leaf (NCL) essential oil of N. caudatum and to elucidate its anti-inflammatory action in lipopolysaccharide (LPS)-treated RAW 264.7 cells. Essential oils extracted by hydrodistillation were further subjected to gas chromatography mass spectrometry (GC-MS) analysis. The major constituents in bark essential oil identified as β-pinene (13.11%), α -cadinol (11.18%) and α -pinene (10.99%), whereas leaf essential oil was found to be rich in β-pinene (45.21%), myrcene (9.97%) and α-pinene (9.27%). Treatment with NCB and NCL at a concentration of 25 µg/mL exerted significant anti-inflammatory activity by significantly reducing LPS-triggered nitric oxide (NO) production to 45.86% and 61.64%, respectively, compared to the LPS-treated group. In the LPS-treated group, the production of proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, decreased after treatment with essential oil, alleviating the mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. The essential oil also inhibited the production of intracellular ROS and attenuated the depletion of mitochondrial membrane potential in a concentration-dependent manner. Pretreatment with NCB also reduced nuclear factor kappa-B (NF-κB)/p65 translocation and elevated the levels of endogenous antioxidant enzymes in LPS-induced macrophages. The present findings, for the first time, demonstrate the anti-inflammatory potential of both bark and leaf essential oils of N. caudatum . The bark essential oil exhibited a significantly more important anti-inflammatory effect than the leaf essential oil and could be used as a potential therapeutic agent for the treatment of inflammatory diseases.