Comparative Effects of Deferiprone and Salinomycin on Lead-Induced Disturbance in the Homeostasis of Intrarenal Essential Elements in Mice

Lead (Pb) exposure induces severe nephrotoxic effects in humans and animals. Herein, we compare the effects of two chelating agents, salinomycin and deferiprone, on Pb-induced renal alterations in mice and in the homeostasis of essential elements. Adult male mice (Institute of Cancer Research (ICR)) were randomized into four groups: control (Ctrl)—untreated mice administered distilled water for 28 days; Pb-exposed group (Pb)—mice administered orally an average daily dose of 80 mg/kg body weight (BW) lead (II) nitrate (Pb(NO₃)₂) during the first two weeks of the experimental protocol followed by the administration of distilled water for another two weeks; salinomycin-treated (Pb + Sal) group—Pb-exposed mice, administered an average daily dose of 16 mg/kg BW salinomycin for two weeks; deferiprone-treated (Pb + Def) group—Pb-exposed mice, administered an average daily dose of 20 mg/kg BW deferiprone for 14 days. The exposure of mice to Pb induced significant accumulation of the toxic metal in the kidneys and elicited inflammation with leukocyte infiltrations near the glomerulus. Biochemical analysis of the sera revealed that Pb significantly altered the renal function markers. Pb-induced renal toxicity was accompanied by a significant decrease in the endogenous renal concentrations of phosphorous (P), calcium (Ca), copper (Cu) and selenium (Se). In contrast to deferiprone, salinomycin significantly improved renal morphology in Pb-treated mice and decreased the Pb content by 13.62% compared to the Pb-exposed group. There was also a mild decrease in the renal endogenous concentration of magnesium (Mg) and elevation of the renal concentration of iron (Fe) in the salinomycin-treated group compared to controls. Overall, the results demonstrated that salinomycin is a more effective chelating agent for the treatment of Pb-induced alterations in renal morphology compared to deferiprone.     

Antibacterial and antifungal activities of selected microalgae and cyanobacteria

In vitro activity of nine cyanobacterial and ten microalgal newly isolated or culture collection strains against eight significant food‐borne pathogens has been evaluated and compared. Water extracts and culture liquids of Gloeocapsa sp. and Synechocystis sp. demonstrated the widest spectrum of activity with minimal inhibitory concentration (MIC) ranging from 1.56 to 12.5 mg mL^?1. Culture liquid of Anabaena sp. had the highest activity (MIC = 0.39 mg mL^?1) but only to Gram‐positive bacteria. Ethanol extracts and fatty acids from all cyanobacteria and microalgae were active against Streptococcus pyogenes and/or Staphylococcus aureus. The fatty acids of Synechocystis sp. inhibited the growth of Bacillus cereus, Escherichia coli and Candida albicans (MIC values of 2.5–1.25 mg mL^?1, respectively). Exopolysaccharides (EPS) of Gloeocapsa sp. were the sample that exhibited activity against all test pathogens with lowest MIC values (0.125–1 mg mL^?1). High activity with a narrower range of susceptible targets demonstrated the exopolysaccharides of Synechocystis sp. and Rhodella reticulata. Antimicrobial activity was proven for phycobiliproteins isolated from Synechocystis sp., Arthrospira fusiformis, Porphyridium aerugineum and Porphyridium cruentum, respectively. In conclusion Gloeocapsa sp. and Synechocystis sp. and especially their exopolysaccharides showed the most promising potential against the examined food pathogens.     

Liquid Chromatography Orbitrap Mass Spectrometry Method for Analysis of Homocysteine and Related Aminothiols in Cereal Products

Liquid chromatography Orbitrap mass spectrometry method for quantification of biological aminothiols (cysteine, homocysteine, and glutathione) in cereal products has been developed. The assay is based on preliminary derivatization with N-(2-acridonyl)maleimide and high resolution accurate mass spectrometry with utilization of dl-Homocystine-3,3,3′,3′,4,4,4′,4′-d₈ (homocystine-d₈) as internal standard. The limits of quantification for homocysteine, cysteine, and glutathione are 19.44, 40.78, and 338.93 pg, respectively, per 10 μl injection. Intra- and inter-day precision expressed as relative standard deviations are in the range of 1.76 to 2.94 % and 1.06 to 4.13 %, respectively. The average recoveries were 98 % for Hcy, 87 % for Cys, and 92 % for GSH. Wheat, maize, and bakery products with different origin were analyzed. The content of Hcy in the investigated samples was found to be in range of 9–436 μg/100 g, Cys in range of 29–6,895 μg/100 g and GSH in range of 259–14,795 μg/100 g.     

Particle size and support effects on the complete benzene oxidation by Co and Co–Pt catalysts

Monometallic cobalt and bimetallic Co–Pt samples of various particle sizes have been prepared using SiO₂ and synthetic kenyaite (layered silicate) as a support. They are characterized by elemental analysis, XRD, TPR, and XPS. Cobalt is introduced by two methods—classical impregnation and ammonia method. The ammonia method of preparation leads to the formation of finely dispersed Co₃O₄ on both supports. Besides, hardly reducible cobalt silicate phases appear predominantly on the SiO₂ support. The Co₃O₄ particle size varies between 5 and 20 nm, depending on the support. The monometallic Co samples prepared by ammonia method on both supports are more active in benzene combustion than the impregnated ones due to the finer dispersion of the easily reducible Co₃O₄. Addition of Pt improves the activity and the promoting effect is more evident for the impregnated sample. This is explained with the synergy effect of cobalt oxide species and Pt. The less promoting effect of Pt on the catalytic activity of the bimetallic kenyaite-supported samples is attributed to the stronger interaction between the Co oxide phase and Pt during the preparation process.     

LaTiOxNy Thin Film Model Systems for Photocatalytic Water Splitting: Physicochemical Evolution of the Solid–Liquid Interface and the Role of the Crystallographic Orientation

The size of the band gap and the energy position of the band edges make several oxynitride semiconductors promising candidates for efficient hydrogen and oxygen production under solar light illumination. Intense research efforts dedicated to oxynitride materials have unveiled the majority of their most important properties. However, two crucial aspects have received much less attention: One is the critical issue of compositional/structural surface modifications that occur during operation and how these affect photoelectrochemical performance. The second concerns the relation between electrochemical response and the crystallographic surface orientation of the oxynitride semiconductor. These are indeed topics of fundamental importance, since it is exactly at the surface where the visible‐light‐driven electrochemical reaction takes place. In contrast to conventional powder samples, thin films represent the best model system for these investigations. This study reviews current state‐of‐the‐art oxynitride thin film fabrication and characterization, before focusing on LaTiO₂N, selected as a representative photocatalyst. An investigation of the initial physicochemical evolution of the surface is reported. Then, it is shown that after stabilization the absorbed photon‐to‐current conversion efficiency of epitaxial thin films can differ by about 50% for different crystallographic surface orientations, and be up to 5 times larger than for polycrystalline samples.     

Barrier properties of poly(ethylene‐co‐vinyl acetate)/cellulose composite membranes

Poly(ethylene‐co‐vinyl acetate) (EVA)/cellulose composite membranes were prepared and their vapor permeation characteristics were studied. Two types of EVA [having vinyl acetate contents of 18% (EVA18) and of 40% (EVA40), respectively] were used for the composite fabrication. Cellulose, isolated from banana waste fibers, was used as the filler. It was observed that the EVA40 composites were more permeating than were the EVA18 composites. This observation is explained on the basis of more amorphous nature of EVA40 as compared to EVA18. The extent of vapor permeation decreased with increase in the cellulose content in the composites. The presence of voids in the polymer membranes that were designed to possess controlled behavior for the permeation was confirmed using scanning electron microscopic images to complement the observations made during the permeation studies. The influence of molecular weight, molar size, and polarity of the penetrants, on the permeation process, was also considered. The permeability of the membrane samples was calculated and the values obtained were compared with the theoretical values provided by using the modified Neilson permeability equation. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

A matheuristic for workforce planning with employee learning and stochastic demand

This paper focuses on the opportunity to direct the development of responsive capacity by recognising that individuals learn through experience when designing workforce plans. We focus on the operations of a product manufacturer that seeks to maximise profit by selling multiple products, while recognising that demands for each product is uncertain. As such, we study a stochastic integer program wherein an organisation can hedge against uncertainty in demand both by holding inventory (at a cost) and building a more responsive production process. Solving this stochastic program presents many computational difficulties, including the fact that quantitative models of human learning are non-linear and the explosion of instance size that result from modelling uncertainty with scenarios. As a result, we propose a matheuristic for this problem and with an extensive computational study demonstrate its ability to produce high-quality solutions in little time.     

Corrosion Behavior of Nitrogen Containing Hot Rolled 304LN in Nitric Acid Medium

The corrosion behaviour of 304LN stainless steels containing three different nitrogen content (0.132, 0.193, 0.406 wt% N) was investigated by potentiodynamic anodic polarization technique, in 1, 4, 6 M nitric acid and simulated high level waste (HLW) medium. The results showed that all three alloys exhibited good corrosion resistance in nitric acid and simulated HLW and the corrosion properties were found to be similar. Owing to the spontaneous formation of the protective chromium oxide passive film in nitric acid and simulated HLW, increasing the nitrogen content of the alloy did not indicate any discernable effect on the corrosion resistance in both media. It was also found that the oxidizing ions present in simulated HLW did not deteriorate the passive film stability of the nitrogen containing alloys. In chloride medium, the highest nitrogen content 304LN stainless steel showed a profound increase in pitting corrosion resistance when compared to the lower nitrogen content alloy. Optical and scanning electron microscopy was carried out to obtain information about the microstructure. The results of the investigation are discussed in the paper.