Arsenic (V) removal with nanoparticulate zerovalent iron: Effect of UV light and humic acids

Results on As(V) removal in the presence of oxygen using the zerovalent iron technology with commercial iron nanoparticles (NanoFe^®) are presented, showing the effect of (NanoFe^®) mass, UV light and addition of humic acids. The nanosized iron particles (NZVI) were characterized in their particle size, surface area and constituent phases. As(V) removal was rapid and increased with NZVI mass (0.005–0.1 g L⁻¹) attaining more than 90% after 150 min of time contact with the optimal NanoFe^® concentration. The removal followed a biexponential kinetic decay, with rate constants increasing with NZVI mass. (NanoFe^®) presented an outstanding ability to remove As due to not only a high surface area and low particle size but also to a high intrinsic activity. Humic acids (HA) decreased around 50% the removal efficiency in the dark, indicating competition with As(V) for active surface sites. In contrast, UV light doubled removal rates, the process being even more enhanced in the presence of HA, with an almost total arsenic removal within 4 h. In all cases, adsorption on iron corrosion phases was found the main mechanism of As(V) removal, promoted by formation of Reactive Oxygen Species and enhanced under UV irradiation by the formation of multiple active species. Preliminary results with As-polluted groundwater of the Chacopampean Plain of Argentina (Tucumán Province) are also reported. Addition of NanoFe^® under UV irradiation for 3 h resulted in As contents well in agreement with the regulations (<10 μg L⁻¹).     

Alternaria toxins in Argentinean wheat,bran, and flour

Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg^?1 for AOH, AME and TeA, respectively. For bran, these data were 3.1, 4.5, and 12 µg kg^?1 and for flour 50, 70, and 14 µg kg^?1, respectively. The studied recoveries were higher than 70% and RSD was below 10%. Wheat and bran samples showed low AOH and AME contamination compared to TeA. The averages levels found for TeA in wheat, bran and flour were 19,190, 16,760, and 7360 µg kg^?1, respectively.     

Buckwheat honeys: Screening of composition and properties

The quality of 10 buckwheat honeys, collected from Italian and est European beekeepers declaring to produce monofloral honey, were evaluated by means of their pollen, physicochemical, phenolic and volatile composition data. The results of the traditional analyses and in particular electrical conductivity, optical rotation, pH and sugar composition revealed some poorly pure samples that could not fit in the buckwheat tipology. Honey volatiles, analysed by solid phase microextraction (SPME) and gas chromatography–mass-spectrometry (GC/MS), showed more than 100 volatile compounds, most of them present in all honey samples but with quantitative variation. Besides many furfural derivates, 3-methylbutanoic acid was the main volatile compound found in most of honeys. Also the presence of 2- and 3-methylbutanal and pheynalcetaldehyde confirmed the typical buckwheat aroma of some studied samples, corroborating physicochemical data. The HPLC phenolic profile was similar across the samples and p-hydroxybenzoic and p-coumaric acids proved to be the main components.     

Maximization of Fructooligosaccharides and β-Fructofuranosidase Production by Aspergillus japonicus under Solid-State Fermentation Conditions

The conditions of temperature, moisture content, and inoculum rate able to maximize the production of fructooligosaccharides (FOS) and β-fructofuranosidase (FFase) enzyme by solid-state fermentation were established. Fermentation assays were performed using the support material (coffee silverskin) moistened to 60, 70, or 80 % with a 240-g/l sucrose solution and inoculated with a spore suspension of Aspergillus japonicus to obtain 2?×?10⁵, 2?×?10⁶, or 2?×?10⁷ spores/gram dry material. The fermentation runs were maintained under static conditions at 26, 30, or 34 °C during 20 h. The moisture content did not influence the FOS and FFase production; however, temperature between 26 and 30 °C and inoculum rate of approximately 2?×?10⁷ spores/gram dry material maximized the results (FOS?=?208.8 g/l with productivity of 10.44 g/l h; FFase?=?64.12 units U/ml with productivity of 4.0 U/ml h). These results are considerably higher than those obtained under no optimized fermentation conditions and represent an important contribution for the establishment of a new industrial process for FOS and FFase production.     

Use of weak cation exchange resin Lewatit S 8528 as alternative to strong ion exchange resins for calcium salt removal

Softening of beet sugar juices using the weak cation exchange resin Lewatit® S 8528, both in hydrogen and sodium form has been studied. After analyzing the influence of the main operating parameters on decalcification efficiencies through a Taguchi approach, experimental runs were carried out at 40 BV/h and 80 °C to determine operation time, breakthrough point and resin capacity. The performance of the Lewatit S 8528 resin was compared with that of the industrially used Amberlite SR1L Na, a strong cation exchange resin. The experimental results showed that the use of Lewatit S 8528 in the acidic form is a feasible alternative to the classical strong cation exchange resins, providing calcium removal efficiencies higher than 80%. The mean calcium concentration in the softened thin juice was lower than 18 mg CaO/L. The breakthrough point corresponding to weak resin Lewatit S 8528 in H⁺ form, 700 bed volume, was considerable higher than that obtained for the strong resin Amberlite (300 BV). No considerably increase in the concentration of reducing sugars in the softened juice was observed. The consumption of chemical reagents in the regeneration stage was 3.2 ± 0.5 kg H₂SO₄/m³, considerably lower than the consumption of sodium chloride, 44 ± 1 kg NaCl/m³ when the strong Amberlite resin was used.     

Hybrid Self-Assembling Nanoparticles Encapsulating Zoledronic Acid: A Strategy for Fostering Their Clinical Use

Self-assembling nanoparticles (SANPs) promise an effective delivery of bisphosphonates or microRNAs in the treatment of glioblastoma (GBM) and are obtained through the sequential mixing of four components immediately before use. The self-assembling approach facilitates technology transfer, but the complexity of the SANP preparation protocol raises significant concerns in the clinical setting due to the high risk of human errors during the procedure. In this work, it was hypothesized that the SANP preparation protocol could be simplified by using freeze-dried formulations. An in-depth thermodynamic study was conducted on solutions of different cryoprotectants, namely sucrose, mannitol and trehalose, to test their ability to stabilize the produced SANPs. In addition, the ability of SANPs to deliver drugs after lyophilization was assessed on selected formulations encapsulating zoledronic acid in vitro in the T98G GBM cell line and in vivo in an orthotopic mouse model. Results showed that, after lyophilization optimization, freeze-dried SANPs encapsulating zoledronic acid could retain their delivery ability, showing a significant inhibition of T98G cell growth both in vitro and in vivo. Overall, these results suggest that freeze-drying may help boost the industrial development of SANPs for the delivery of drugs to the brain.     

Mydriatics release from solid and semi-solid ophthalmic formulations using different in vitro methods

The aim of the present paper was the development of semi-solid (hydrogels) and solid (film) ophthalmic formulations for the controlled release of two mydriatics: phenylephrine and tropicamide. The formulations – based on polyvinylalcohol and hyaluronic acid – were characterized, and release studies were performed with three different in vitro set-ups, i.e. Franz-type diffusion cell, vial method and inclined plane; for comparison, a solution and a commercial insert, both clinically used to induce mydriasis, were evaluated. Both gels and film allowed for a controlled release of drugs, appearing a useful alternative for mydriatics administration. However, the release kinetic was significantly influenced by the method used, highlighting the need for optimization and standardization of in vitro models for the evaluation of drug release from ophthalmic dosage forms.     

Influence of two structural phases of Fe3O4 and γ‐Fe2O3 on the properties of polyimide/iron oxide composites

Partially aliphatic polyimide/iron oxide composites based on the poly(amic acid) from 5‐(2,5‐dioxotetrahydro‐3‐furyl)‐3‐methyl‐3‐cyclohexene‐1,2‐dicarboxylic acid anhydride and 4,4′‐oxydianiline with iron oxide in different weight percentages were obtained. The structural phases of the transition of magnetite to maghemite occurring in these composites, at different temperatures, are discussed. The physical characteristics, including magnetic, thermal, structural and morphological properties, evaluated using X‐ray diffraction, scanning electron microscopy and thermal analysis, are influenced by the interplay of the filler content and the structural changes of the composite. The X‐ray diffraction patterns of all samples show a cubic structure indexed as magnetite (Fe₃O₄) or maghemite (γ‐Fe₂O₃). Quantification of these two phases was evidenced by the Rietveld method. The electrical properties analysed under different humidity conditions evidence the potential applicability of these polyimide/iron oxide materials as humidity sensors. © 2015 Society of Chemical Industry     

Production,mode of action and sequencing of the corresponding gene of a bacteriocin produced by Lactococcus lactis 19.3

Lactococcus lactis 19.3 produces a bacteriocin with a wide inhibitory spectrum, including the food pathogen Listeria monocytogenes. The producing strain was able to grow and produce similar amounts of bacteriocin in MRS medium, cow's milk and soya milk, respectively. The mode of action of this bacteriocin was further investigated using two indicator strains, Lactobacillus delbrueckii subsp. bulgaricus LMG 6901^T and Listeria monocytogenes ATCC 1911‐1. The bacteriocin displayed a bactericidal effect, causing a rapid decrease of the cell viability. Bacteriocin treatment of the sensitive strains resulted in major morphological changes, including pore formation, as shown by scanning electron microscopy. Finally, the bacteriocin‐encoding gene was identified by sequencing. The presence of nisin gene was confirmed. Based on all our data gathered so far, L. lactis 19.3 is a good candidate for a starter or protective culture in the manufacturing of both fermented dairy and vegetarian food products.