Energy of formation, lattice parameter and bulk modulus of (Ni,X)Ti alloys with X = Fe, Pd, Pt, Au, Al, Cu, Zr, Hf

An analysis of the ternary ‘bridge’ Ni_50−yX_yTi₅₀ alloys with X = Fe, Pd, Pt, Au, Al, Cu, Zr, and Hf was performed using the BFS method for alloys. The lattice parameter, bulk modulus and energy of formation were determined for all the intermediate states in the (B2) transition NiTi to XTi.     

A simple method for the differentiation of Listeria monocytogenes based on induction of lecithinase activity by charcoal

The PlcB phospholipase C, or lecithinase, is an important listerial virulence factor of potential use as a pathogenicity marker for Listeria spp. food isolates. However, wild-type strains of Listeria monocytogenes express virulence factors very poorly in vitro and their lecithinase activity is normally difficult to detect on agar plates. We recently reported that the production of listerial virulence factors is strongly induced if L. monocytogenes is grown in the presence of activated charcoal. We report here a simple method for the rapid differentiation of L. monocytogenes from other Listeria spp. based on a comparison of lecithinase reactions in egg yolk agar plates with and without charcoal supplementation. All L. monocytogenes wild-type isolates tested showed a clear induction of lecithinase activity in charcoal-supplemented medium (CEYM), while nonpathogenic Listeria spp. remained negative in CEYM. The animal pathogen L. ivanovii was easily differentiated from L. monocytogenes because it showed a strong lecithinase reaction independently of the presence or absence of charcoal in the medium.     

Comparative Bioavailability of Diltiazem in Prolonged-Release Oral Preparations

This study was conducted to compare the bioavailability of two prolonged-release pharmaceutical forms containing 300 mg of diltiazem. The test formulation is a new design of tablets with a hydrophilic matrix, and the reference formulation is capsules containing prolonged liberation microgranules, in the same dose, that are commercially available in the pharmaceutical market. Diltiazem plasma concentrations were analyzed by high-performance liquid chromatography (HPLC), which involves solid-phase extraction for plasma sample preparation. Twelve healthy volunteers participated in the study, which had a single-dose, two-treatment, two-sequence-crossover, randomized design. The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration-time curve AUC_(0-36), peak plasma concentration C_max, and C_max/AUC_(0-36) ratio as a measure for the absorption rate. No statistically significant difference was observed for any of the parameters, and the 90% confidence intervals calculated for the ratio of the logarithmically transformed AUC_(0-36) and C_max/AUC_(0-36) values of both formulations were within the bioequivalence limit of 0.80-1.25. Moreover, an in vitro study of dissolution according to USP 23 was conducted, and the in vitro parameters were calculated.     

Band structure analysis in SiGe nanowires

One of the main challenges for Silicon-Germanium nanowires (SiGe NWs) electronics is the possibility to modulate and engine their electronic properties in an easy way, in order to obtain a material with the desired electronic features. Diameter and composition constitute two crucial ways for the modification of the band gap and of the band structure of SiGe NWs. Within the framework of density functional theory we present results of ab initio calculations regarding the band structure dependence of SiGe NWs on diameter and composition. We point out the main differences with respect to the case of pure Si and Ge wires and we discuss the particular features of SiGe NWs that are useful for future technological applications.     

Physico-chemical and toxicological assessment of liquid wastes from olive processing-related industries

BACKGROUND: In the last few years, agricultural uses of waste waters from olive processing‐related industries have been gaining interest mainly with a view to composting or bio‐fertilizers. The present work examines physico‐chemical, toxicological and geno‐toxicological properties of three liquid wastes, namely olive mill wastewater (OMWW), olive wet husk and olive brine. The effect of OMWW spreading on soil microbial activity and biomass was also evaluated. RESULTS: Data from Artemia salina and Lactuca sativa toxicity tests indicated high levels of lethality, and inhibitory effects on seed germination and seedling growth of all olive wastes. The genotoxicity assays using Allium cepa tests showed contrasting results. At high concentrations, olive wastes caused inhibition or suppression of mitosis. However, they did not produce induced anaphase aberrations. Data on reversion of Salmonella thyphimurium strains using the Ames test indicated that the olive wastes did not present mutagenic activity. Results from the field experiment showed that OMWW at a 500 m³ ha^?1 had the highest values of both soil microbial activity and biomass after 3 months of the amendment application. CONCLUSION: This work adds new data for environmental risk assessment of olive industrial wastes. Direct use of olive wastes for agricultural purposes should be limited owing to their possible chemotoxic, phytotoxic and antimicrobial effects. Copyright © 2011 Society of Chemical Industry     

Effect of damaged starch on the rheological properties of wheat starch suspensions

The influence of damaged starch content on particle size distribution and rheological properties of unheated starch suspensions and pasting properties were investigated. Four samples containing different amounts of damaged starch were studied. Particle size distribution curves shifted toward higher diameters, and a greater overlap of both populations of particles (A- and B-type granules) and a decrease of both peak heights were produced. The flow curves of unheated starch suspensions were fitted using the power law model. The flow behavior indexes were higher than the unit. The consistency coefficient increased with the increment of damaged starch content. Unheated starch suspensions showed time-dependent rheological behavior and were described by the Weltman model. The unheated suspensions exhibited a thixotropic behavior. With regard to the pasting process, the increment of damaged starch content produced gradual reductions in peak viscosity, final paste viscosity, breakdown and setback. Results demonstrated the importance of the presence of physically damaged granules in wheat starch rheological characteristics.     

Fetal Bovine Serum Concentration Affects Δ<Superscript>9</Superscript> Desaturase Activity of <Emphasis Type="Italic">Trypanosoma cruzi</Emphasis>

Fetal bovine serum (FBS) is an important factor in the culture of Trypanosoma cruzi, since this parasite obtains and metabolizes fatty acids (FAs) from the culture medium, and changes in FBS concentration reduce the degree of unsaturation of FAs in phosphoinositides. When T. cruzi epimastigotes were cultured with 5% instead of 10% FBS, and stearic acid was used as the substrate, ∆⁹ desaturase activity decreased by 50%. Apparent K _m and V _m values for stearic acid, determined from Lineaweaver–Burk plots, were 2 μM and 219 pmol/min/mg of protein, respectively. In studies of the requirement for reduced pyridine nucleotide, ∆⁹ desaturase activity reached a maximum with 8 μM NADH and then remained constant; the apparent K _m and V _m were 4.3 μM and 46.8 pmol/min/mg of protein, respectively. The effect of FBS was observed only for ∆⁹ desaturase activity; ∆¹² desaturase activity was not affected. The results suggest that decreased FBS in culture medium is a signal that modulates ∆⁹ desaturase activity in T. cruzi epimastigotes.