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In this paper, we have tailored the structural, magnetic and dielectric properties of Ni0.5Zn0.3Cd0.2Fe2-yLayO4 (y = 0.0–0.21) nano-structured spinel ferrites by the substitution of La3+ ions. The investigated samples were synthesized by Sol-gel auto-combustion method and were characterized using XRD, SEM, VSM, FTIR and dielectric measurements. Single phase nanostructure formation of synthesized material was confirmed by XRD analysis. The effect of La3+ ions on crystallite size, grain size, lattice constant and bulk densities was calculated and it was found that lattice constant first increased upto concentration y = 0.105 then decreased with further substitution of dopant ions. FTIR results for all synthesized samples demonstrated two absorption bands at υ1 = 540.8 cm−1 and υ2 = 490.8 cm−1 corresponds to tetrahedral and octahedral sites of spinel structure respectively. With the increase in La3+ ions concentration, saturation magnetization and remanence both found to be decreased down to lowest Ms value of 34.1 emu/g which is not yet reported in the literature according to best of our knowledge. Dielectric results showed that by decreasing frequency, both dielectric loss and dielectric constant decreases. AC conductivity has two regions, at low frequency region ac conductivity increases while at high frequency region, it decreases with increasing frequency. The measured results for all synthesized nano-ferrites suggested that synthesized nanoferrites are recommended for high frequency and microwave absorbing applications.

Cerium oxide (CeO2) nanoparticles (also called nanoceria) have broad range of applications in various fields, especially in the biomedical sector. Doping of CeO2with different elements can vary the optical, structural, biomedical and electrical characteristics of cerium dioxide nanoparticles. In this study CeO2was doped with different concentrations of Manganese (Mn) and Iron (Fe). The characterization techniques used for analysis of CeO2nanoparticles were X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and I–V analysis. The particles were also tested for Antibacterial and Antifungal activity. For antibacterial activity test, gram-positive test was conducted by Staphylococcus aureus and gram-negative tested on E. coli. The antifungal activity was tested with Candida Albicans.

A series of Cd0·5Cu0.5-xMgxFe1.95La0·05O4 (x = 0.0, 0.125, 0.25, 0.375, 0.5) nano ferrites was synthesized via sol-gel auto combustion route. XRD analysis confirmed the development of spinel ferrites. Different structural parameters like lattice constant, tetrahedral and octahedral radii, oxygen ion parameter, tolerance factor, bond lengths, edge lengths and interionic distances were calculated from XRD data. It was observed that by increasing the Mg2+ concentration, lattice constant and crystallite size were increased. Energy band gap was measured using UV–vis spectroscopy and found in the range 1.79–2.36 eV. Dielectric properties of the prepared samples were also studied and it was found that dielectric constant and ac conductivity were decreased with increase in Mg2+ content. The study indicates that Cd0·5Cu0.5-xMgxFe1.95La0·05O4 nano ferrites have great potential to be utilized in high frequency devices as microwave absorbing material and in optoelectronic devices.

Herein, we developed and characterized pH responsive semi interpenetrating network (semi-IPN) of Pectin-g-poly(AA)/PVP by free radical polymerization. These hydrogels were developed to overcome hurdles associated with; i) mechanical strength of formed system which was dealt by the use of combination of natural (pectin) and synthetic (PVP) polymers and ii) oral administration of drugs requiring action in distal part of gastrointestinal tract which was addressed by employing pectin and acrylic acid which conferred pH sensitivity due to carboxylic group in their structure. Structurally and morphologically, developed semi-IPN hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Chemically, they were evaluated for swelling and release kinetics. Semi-IPN hydrogels restricted the swelling of system and therefore the release of dexamethasone sodium phosphate (DSP) at pH 1.2 but released it in controlled manner at pH 7.4 by non-Fickian diffusion. . Biologically, acute toxicity testing of developed semi-IPN hydrogels, revealed biocompatibility and safety of hydrogels after oral administration. Conclusively, prepared semi-IPN hydrogels showed good mechanical properties, swelling, biocompatibility, pH dependent DSP release for possible treatment of inflammatory bowel diseases.

Background Dual antiplatelet therapy causes gastric bleeding and requires incorporation of gastro protective agent. Objectives: Formulation and invitro evaluation of multistage release bilayer tablets containing three active ingredients (clopidogrel, aspirin & ranitidine) for site specific release i.e. stomach & duodenum. Method: Here, immediate release layer of multistage release matrices contains clopidogrel bisulphate granules and enteric coated aspirin pellets. Second layer is gastro retentive floating layer of ranitidine hydrochloride and developed by using HPMC K100 or xanthan gum as release retarding polymer along with Sorb-Cel M® for the very first time as floating agent. Results: Floating lag time, layer separation time, total floating time and swelling of floating layer increased with increasing concentration of polymer and decreasing concentration of Sorb-Cel M®. FTIR and DSC studies indicated absence of drug polymer interaction while XRD indicated amorphous nature of drugs. Cross section electron micrograph of optimized tablets confirmed our idea, showing stable interface between two layers and intact aspirin pellets in immediate layer. During drug release we demonstrated targeted release of three ingredients at their desired site i.e. clopidogrel and ranitidine HCl at pH 1.2 and aspirin at pH 6.8 to avoid its gastric irritating effect. In floating layer xanthan gum provided better controlled release of ranitidine HCl than HPMC K100. Conclusion: So, concisely our developed matrices could potentially delivers three active pharmaceutical ingredients (APIs) at desired site of action combined in single unit. It will not only reduce pill burden on patients but can also overcome the side effects of concomitant administration of aspirin and clopidogrel bisulphate.

We have performed FP-LAPW calculations in the framework of density functional theory (DFT) to compute ground-state electronic and optical properties of alkali metal selenides M2Se [M: Li, Na, K, Rb] in anti-CaF2 crystal structure. The generalized gradient approximation (GGA) parameterization schemes proposed by Wu and Cohen (WC) and Engel and Vosko (EV) have been utilized for these calculations and some trends in the electronic properties of alkali metal selenides have been analyzed in the light of available theoretical and experimental data of other group IA–VI crystals. Electronic density of states for these compounds has been obtained to elucidate contribution from different anion and cation states to the electronic structure. Optical properties such as complex dielectric function e(ω), absorption coefficient I(ω), refractive index n(ω), extinction coefficient k(ω) and reflectivity R(ω) for incident photon energy up to 35 eV and energyloss functions have been predicted for M2Se compounds. Various interband transitions and the possible contributions of the cation and anion states to these transitions have been presented. © 2010 Elsevier B.V. All rights reserved.

Awareness that some diseases are transmissible has existed for centuries. Hippocrates in 450 bc used wine or boiled water to irrigate wounds and, in the second century, Galen was reported to have boiled his instruments before use. In the middle ages, people suffering with leprosy and the severely ill were isolated from the local population. However, modern infection control was only started in the 19th century as a consequence of the work of Pasteur, Lister and other pioneers.