No abstract available

[en] In spite of demonstrated application of nano barium titanate (BaTiO₃) in biomedical applications, its antibacterial/fungal activity and biocompatibility studies are hitherto unexplored. Present work reports synthesis, characterization and assessment of antimicrobial and hemolytic activity of nano BaTiO₃, owing to their potential futuristic biomedical applications. Nano BaTiO₃ is prepared by surfactant (Hexadecyltrimethylammonium bromide, CTAB) assisted hydrothermal synthesis and is characterized by various analytical and spectroscopic techniques. Morphology of the as synthesized nano BaTiO₃ is cubic in nature. Based on the characterization techniques, nano BaTiO₃ synthesised using 15 mM CTAB (15-CBT) were considered for antimicrobial activity against various multidrug-resistant pathogens. Good inhibition activity was observed against C. albicans with MIC value of 0.37 mg ml⁻¹ and MFC of 0.75 mg ml⁻¹. C. albicans treated with 10 mg of 15-CBT showed only 30% cell viability. The anticandidal mechanism of nano BaTiO₃ against C. albicans was attributed to decrease in ergosterol biosynthesis leading to cell death. Further, only 3% hemolytic activity on human blood RBCs was observed at 0.2 mg ml⁻¹ of 15-CBT. The anticandidal activity and hemolytic activity of the synthesised nano BaTiO₃ is systematically investigated and reported. (paper)

[en] A faster, simpler and sensitive method was developed for determination of aliphatic phthalates using differential pulse polarography (DPP) as standard technique. The choice and concentration of base electrolyte, solvent, initial potential, effect of water addition and interference by other phthalates were the main parameters to optimize for enhancement of peak current and to obtain well-defined polarograms with lower background current using 1.3 x 10/sup -4/ M di-butyl phthalate (DBP) solution. Best results were obtained in the presence of tetra methyl ammonium bromide (TMAB) as electrolyte in methanol solvent with initial potential, -1.4 V. A linear calibration plot was observed in the range of 3 x 10/sup -7/ - 1.6 x 10/sup -4/ M DBP solution as aliphatic phthalates with lower detection limit of 5.9 x 10/sup -8/ M and linear regression coefficient of 0.9987. The developed polarographic method was successfully applied for analysis of aliphatic phthalates in various samples of locally available polymer products such as baby toys, nipples, teethers, infusion blood bags and shopping bags. The results of the current method were compared with those obtained by a reported method and good agreement was found between them. (author)

[en] A theoretical model for evaluating the photoelastic constants of ionic solids is developed by taking into account the long-range Coulombian, van der Waals and three-body interactions as well as the electronic polarizabilities of cations and anions. Hafemeister Flygare type short-range overlap repulsive potential effective upto nearest and next nearest neighbours is taken into account. The model is applied to calculate the photoelastic constants of ammonium halides with CsCl and NaCl type structures for the first time. The results obtained show a systematic trend in this group of solids. (author)

No abstract available

[en] This paper demonstrates an array of SiNWs device was fabricated by Atomic Force Microscope-Local Anodic Oxidation (AFM-LAO) technique for Dengue virus deoxyribonucleic acid (DNA) oligomer detection. The SiNWs were wet etched by using 25 wt% tetramethylammonium hydroxide (TMAH) with addition of isopropyl alcohol (IPA) at various concentrations (10, 20 and 30 vol%). The produced SiNWs were in trapezoidal shape with different dimension and surface roughness. The surface of SiNWs was modified with 3-aminopropyltriethoxysilane and glutaraldehyde followed by the immobilized peptide nucleic acid, then hybridized with Dengue DNA oligomer. The hybridization procedure causes a current change due to accumulation of negative charges introduced on SiNWs surface which determines the performance of the device. The small width and rough surface of SiNWs device has high sensitivity (80.3 μAM⁻¹) and low detection limit (2.22 fM). (paper)

[en] Petroleum pollution is a common problem in industrial areas to such an extent that it poses a global threat. The wastes of oil refineries contain a wide variety of hydrocarbons. The aim of this study was to investigate the possibility to removal of total petroleum hydrocarbons (TPH) from the Behregan oil refinery, Bushehr, Iran, by granulated nanozeolite NaA particles (NaA-ZNPs) modified with cationic surfactants. Synthesized NaA-ZNPs with a silica source extracted from Hordeum vulgare were granulated by an alginate granulation method and were modified by the cationic surfactant hexadecyltrimethylammonium bromide (CTAB). The CTAB-modified granulated NaA-ZNPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and the Brunauer-Emmett-Teller theory. Adsorption of TPH was studied using both a batch process and a continuous-flow process in a fixed-bed column. The effect of various parameters, including time, pH, adsorbent dosage, flow rate, and column height, were investigated and the results were analyzed by gas chromatography - mass spectroscopy. The efficiency of the CTAB-modified granulated NaA-ZNPs was evaluated with one-way analysis of variance software SPSS 21. The highest TPH removal efficiency for batch processing (92.3%) was achieved at an adsorbent dosage 0.5 mg, pH = 7, and 20 min of contact time; the highest TPH removal efficiency for continuous processing (87.4%) was achieved at 15 cm column height and a 17.26 mL/min flow rate. The results indicated the potential of CTAB-modified granulated NaA-ZNPs for absorbing TPH in treating oil refinery waste. (author)

[en] The title compound is converted into the cyclic ethers 5 and the alcohol 6 upon treatment with ceric ammonium nitrate in acetone. Using methanol as a solvent the dimethoxy derivative 9 and the nitrate ester 10 are formed. No cross cycloaddition is observed in the presence of olefins such as ethyl vinyl ether, DMAD, or indene; however, with cyclopentadiene as co-reagent a mixture of the exo-endo Diels-Alder adducts 14 involving the vinylic system of 1 as 2π component is obtained. The results are rationalized through the intermediacy of the radical cation 1^.+, generated by single electron transfer (SET) from the neutral precursor 1 to Ce(IV)

No abstract available

No abstract available