Fractionation and fluxes of metals and radionuclides during the recycling process of phosphogypsum wastes applied to mineral CO2 sequestration

The industry of phosphoric acid produces a calcium-rich by-product known as phosphogypsum, which is usually stored in large stacks of millions of tons. Up to now, no commercial application has been widely implemented for its reuse because of the significant presence of potentially toxic contaminants. This work confirmed that up to 96% of the calcium of phosphogypsum could be recycled for CO2 mineral sequestration by a simple two-step process: alkaline dissolution and aqueous carbonation, under ambient pressure and temperature. This CO2 sequestration process based on recycling phosphogypsum wastes would help to mitigate greenhouse gasses emissions. Yet this work goes beyond the validation of the sequestration procedure; it tracks the contaminants, such as trace metals or radionuclides, during the recycling process in the phosphogypsum. Thus, most of the contaminants were transferred from raw phosphogypsum to portlandite, obtained by dissolution of the phosphogypsum in soda, and from portlandite to calcite during aqueous carbonation. These findings provide valuable information for managing phosphogypsum wastes and designing potential technological applications of the by-products of this environmentally-friendly proposal.Junta de Andalucía P10-RNM-6300, P12- RNM-226

Bioactivity of wollastonite/aerogels composites obtained from a TEOS-MTES matrix

Organic-inorganic hybrid materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS), methyltrimethoxysilane (MTES), synthetic wollastonite powders and polydimethylsiloxane (PDMS) in an ethanol solution. Aerogels were prepared from acid hydrolysis of TEOS and MTES with different volume ratio in ethanol, followed by addition of wollastonite powder and PDMS in order to obtain aerogels with 20 wt% of PDMS and 5 wt% of CaO of the total silica. Finally, when the wet gels were obtained, they were supercritically dried at 260°C and 90 bar, in ethanol. In order to obtain its bioactivity, one method for surface activation is based on a wet chemical alkaline treatment. The particular interest of this study is that we introduce hybrid aerogels, in a 1 M solution of NaOH, for 30 s at room temperature. We evaluate the bioactivity of TEOS-MTES aerogel when immersed in a static volume of simulated body fluid (SBF). An apatite layer of spherical-shaped particles of uniform size smaller than 5 microns is observed to form on the surface of the aerogels after 25 days soaking in SBF.Ministerio de Ciencia e Innovación MAT2005-01583Junta de Andalucía TEP 79

New method for carbon dioxide mineralization based on phosphogypsum and aluminium-rich industrial wastes resulting in valuable carbonated by-products

A new carbon mineralization method was designed based on a sequestration agent synthesised exclusively from industrial wastes. Phosphogypsum waste from the fertiliser industry was dissolved into caustic aqueous waste from the aluminium anodising industry. The resulting precipitate consisted of katoite (Ca3Al2(OH)12, a Si-free hydrogrossular solid solution end-member of the Al-containing hydrogarnet) and thenardite (Na2SO4); the latter easily removed by rinsing with water. The carbonation performance of this katoite-rich sequestration agent was evaluated using two different methods, by bubbling in aqueous media and by weathering. Both procedures yielded high carbonation efficiencies (80% and 100%, respectively), and resulted in a solid precipitate composed primarily of calcite (CaCO3) and aluminium hydroxide (Al(OH)3). Priority attention was given to the transfer of trace elements and radionuclides of the uranium series typically present in the phosphogypsum. Results confirmed that the traces were transferred to resulting final solid carbonate at concentrations similar to those present in the raw phosphogypsum. In conclusion, these carbonated minerals would trap substantial amounts of CO2 and produce final materials with similar civil engineering uses to those proposed for current phosphogypsum wastes. This work offers new methods for jointly managing specific industrial wastes oriented to more sustainable industrial processes and controlling CO2 emissionsPeer reviewe

Tailoring Organic-Organic Poly(vinylpyrrolidone) Microparticles and Fibers with Multiwalled Carbon Nanotubes for Reinforced Composites

Polymeric-based microparticles and fibers are tailorable for a wide range of common industrial and biomedical applications, while multiwalled carbon nanotubes (MWCNTs) are among the most useful macromolecules based on their outstanding electronic, mechanical, and optical properties at the nanoscale. If one combines these nanostructures with various polymeric precursors, their range of potential applications becomes even greater. One of the simplest and most affordable methods for fabricating micro- and nanostructures is electrospinning. Herein we demonstrate how MWCNTs may be used to produce tailor-made organic-organic poly(vinylpyrrolidone) (PVP) microparticles and fibers via electrospinning by studying their structural, vibrational, rheological, and mechanical properties' dependence on their solvent (ethanol (EtOH) or dimethylformamide (DMF)) and resulting morphology. Specifically, we find clear differences in morphologies from perfectly spherical and isolated microparticles to fibers mats, or a combination of fibers with entangled beads, with solvent type and concentration. On the basis of our findings, we propose that the mechanism governing the shape and size of the particles is a competition between the solvent's surface tension, dielectric constant, and viscoelastic properties. We show, based on both our experimental results and density functional theory (DFT) calculations, that OH functionalization of the MWCNTs is essential for achieving high PVP coverages and promoting the stability of the resulting PVP/MWCNT nanocomposite. Finally, by fabricating PVP/MWCNT fiber mats, we demonstrate that low concentrations (0.01-0.1 wt %) of MWCNTs led to a qualitative improvement (â250%) in the resulting mechanical properties, i.e., a reinforced composite. These results show how by controlling the solvent's dielectric constant, surface tension, and polymer concentration, one may produce tailor-made polymeric nanomaterials in combination with other organic/inorganic nanoparticles, i.e., silver, gold, or carbon allotropes, for next-generation applications

Stability of excited states of a Bose-Einstein condensate in an anharmonic trap

We analyze the stability of non-ground nonlinear states of a Bose-Einstein condensate in the mean field limit in effectively 1D (``cigar-shape'') traps for various types of confining potentials. We find that nonlinear states become, in general, more stable when switching from a harmonic potential to an anharmonic one. We discuss the relation between this fact and the specifics of the harmonic potential which has an equidistant spectrum

New method for carbon dioxide mineralization based on phosphogypsum and aluminium-rich industrial wastes resulting in valuable carbonated by-products

A new carbon mineralization method was designed based on a sequestration agent synthesised exclusively from industrial wastes. Phosphogypsum waste from the fertiliser industry was dissolved into caustic aqueous waste from the aluminium anodising industry. The resulting precipitate consisted of katoite (Ca3Al2(OH)12, a Si-free hydrogrossular solid solution end-member of the Al-containing hydrogarnet) and thenardite (Na2SO4); the latter easily removed by rinsing with water. The carbonation performance of this katoite-rich sequestration agent was evaluated using two different methods, by bubbling in aqueous media and by weathering. Both procedures yielded high carbonation efficiencies (80% and 100%, respectively), and resulted in a solid precipitate composed primarily of calcite (CaCO3) and aluminium hydroxide (Al(OH)3). Priority attention was given to the transfer of trace elements and radionuclides of the uranium series typically present in the phosphogypsum. Results confirmed that the traces were transferred to resulting final solid carbonate at concentrations similar to those present in the raw phosphogypsum. In conclusion, these carbonated minerals would trap substantial amounts of CO2 and produce final materials with similar civil engineering uses to those proposed for current phosphogypsum wastes. This work offers new methods for jointly managing specific industrial wastes oriented to more sustainable industrial processes and controlling CO2 emissionsGobierno de España MAT2013-42934- RJunta de Andalucía P12-RNM-226

Composición en ácidos grasos y contenidos de vitaminas A y E de la leche de cabra de la raza Payoya en sistemas de pastoreo arbustivo-mediterráneo

Apenas hay trabajos sobre el consumo de pastos arbustivo-mediterráneos y su relación con la calidad de los productos caprinos. El objetivo del presente trabajo fue estudiar el efecto del nivel de pastoreo sobre la calidad de la leche de cabras de raza Payoya. Se seleccionaron 16 explotaciones situadas en la Sierra de Cádiz. De enero a mayo se realizó una monitorización para caracterizar el manejo alimenticio. Según el porcentaje de necesidades energéticas cubiertas por el pastoreo (NEP), las explotaciones se clasificaron en tres grupos: alto, medio y bajo pastoreo. Mensualmente se recogieron muestras de leche de tanque y fueron analizados la composición de ácidos grasos (AG) y los contenidos en vitaminas A (retinol) y E (α- y β+γ-tocoferol). Los porcentajes de AG deseables nutricionalmente (α-linolénico, total n-3 PUFA) fueron significativamente mayores, mientras que el índice n-6/n-3 fue menor en el grupo de pastoreo alto en comparación con el grupo de pastoreo bajo. Para el grupo de pastoreo medio estos valores fueron intermedios. Además, se obtuvo una correlación positiva entre el NEP y los contenidos de varios AG n-3 y el total de n-3 (r=0,33), mientras que se obtuvo una correlación negativa con el índice n-6/n-3 (r=-0,45). Los contenidos en los isó- meros CLA estudiados no se vieron afectados por el nivel de pastoreo. No se encontraron diferencias significativas entre grupos para la suma de las formas β- y γ-tocoferol, ni para el retinol. En cambio, sí ha habido diferencias significativas para el contenido de α-tocoferol (177 μg/100 g - alto pastoreo; 132 μg/100 g - medio; 93 μg/100 g - bajo). Además, existió una correlación positiva entre el NEP y el contenido de α-tocoferol (r=0.42). En conclusión, el mayor nivel de pastoreo ha tenido un efecto positivo sobre la calidad de la leche, con mayores contenidos en algunos componentes funcionales (α-tocoferol; AG n-3)Information about consumption of Mediterranean bush pastures and its relationship to the quality of goat products in Andalusia (southern Spain) is scarce. The aim of this study was to evaluate the effect of grazing level on fatty acid composition and vitamins A and E contents in milk of Payoya goats. 16 farms in the Sierra de Cádiz were selected and surveyed to characterize feeding systems from January to May. According to the percentage of energy needs covered by grazing (NEP), farms were classified into three groups: high, medium and low grazing. In this period, milk samples were monthly collected from the bulk tank and analyzed for fatty acids (FA) composition and vitamin A (retinol) and E (α- and β+γ-tocopherol) contents. Contents of the nutritionally desirable FA (α-linolenic, total n-3 PUFA) were significantly higher, while the n-6:n-3 ratio was lower in the high compared with the low grazing group, and with intermediate values in the medium group. In addition, a positive correlation was found between NEP and the contents of several n-3 FA and total n-3 (r=0.33), while a negative correlation was obtained with the n-6:n-3 ratio (r=-0.45). CLA isomers contents were not affected by the grazing level. Retinol and β+γ-tocopherol contents were not affected by the grazing level, whereas α-tocopherol content was higher in the high grazing group (177 μg/100 g for high grazing; 132 for medium; 93 for low). In addition, the NEP was positively correlated with the contents of α-tocopherol (r=0.42). In conclusion, the highest level of grazing had a positive effect on the quality of milk from Payoya breed, with higher amounts of some functional components (α-tocopherol; n-3 FA)

Validation of housekeeping genes for quantitative real-time PCR in in-vivo and in-vitro models of cerebral ischaemia

<p>Abstract</p> <p>Background</p> <p>Studies of gene expression in experimental cerebral ischaemia models can contribute to understanding the pathophysiology of brain ischaemia and to identifying prognostic markers and potential therapeutic targets. The normalization of relative qRT-PCR data using a suitable reference gene is a crucial prerequisite for obtaining reliable conclusions. No validated housekeeping genes have been reported for the relative quantification of the mRNA expression profile activated in in-vitro ischaemic conditions, whereas for the in-vivo model different reference genes have been used.</p> <p>The present study aims to determine the expression stability of ten housekeeping genes (Gapdh, β2m, Hprt, Ppia, Rpl13a, Oaz1, 18S rRNA, Gusb, Ywhaz and Sdha) to establish their suitability as control genes for in-vitro and in-vivo cerebral ischaemia models.</p> <p>Results</p> <p>The expression stability of the candidate reference genes was evaluated using the 2^-ΔC'Tmethod and ANOVA followed by Dunnett's test. For the in-vitro model using primary cultures of rat astrocytes, all genes analysed except for Rpl13a and Sdha were found to have significantly different levels of mRNA expression. These different levels were also found in the case of the in-vivo model of pMCAO in rats except for Hprt, Sdha and Ywhaz mRNA, where the expression did not vary. Sdha and Ywhaz were identified by geNorm and NormFinder as the two most stable genes.</p> <p>Conclusion</p> <p>We have validated endogenous control genes for qRT-PCR analysis of gene expression in in-vitro and in-vivo cerebral ischaemia models. For normalization purposes, Rpl13a and Sdha are found to be the most suitable genes for the in-vitro model and Sdha and Ywhaz for the in-vivo model. Genes previously used as housekeeping genes for the in-vivo model in the literature were not validated as good control genes in the present study, showing the need for careful evaluation for each new experimental setup.</p

Cerium Oxide Nanoparticles Protect against Oxidant Injury and Interfere with Oxidative Mediated Kinase Signaling in Human-Derived Hepatocytes

Cerium oxide nanoparticles (CeO2NPs) possess powerful antioxidant properties, thus emerging as a potential therapeutic tool in non-alcoholic fatty liver disease (NAFLD) progression, which is characterized by a high presence of reactive oxygen species (ROS). The aim of this study was to elucidate whether CeO2NPs can prevent or attenuate oxidant injury in the hepatic human cell line HepG2 and to investigate the mechanisms involved in this phenomenon. The effect of CeO2NPs on cell viability and ROS scavenging was determined, the differential expression of pro-inflammatory and oxidative stress-related genes was analyzed, and a proteomic analysis was performed to assess the impact of CeO2NPs on cell phosphorylation in human hepatic cells under oxidative stress conditions. CeO2NPs did not modify HepG2 cell viability in basal conditions but reduced H2O2- and lipopolysaccharide (LPS)-induced cell death and prevented H2O2-induced overexpression of MPO, PTGS1 and iNOS. Phosphoproteomic analysis showed that CeO2NPs reverted the H2O2-mediated increase in the phosphorylation of peptides related to cellular proliferation, stress response, and gene transcription regulation, and interfered with H2O2 effects on mTOR, MAPK/ERK, CK2A1 and PKACA signaling pathways. In conclusion, CeO2NPs protect HepG2 cells from cell-induced oxidative damage, reducing ROS generation and inflammatory gene expression as well as regulation of kinase-driven cell survival pathways

Obtención de cepas infectivas de Ustilago maydis para la producción de huitlacoche en la sociedad rural mexicana

Ustilago maydis is a dimorphic fungus with a non-pathogenic yeast-like form, and a pathogenic filamentous one that is responsible for the formation of tumors in maize. U. maydis is known in Mexico as huitlacoche and consumed since Pre-Hispanic times. Currently, its production is limited to collection in the wild for subsistence consumption and with assistance for market purposes, and for this reason it is necessary to have strains of U. maydis with a capacity for infection. In this study infectious sporidia were isolated from native huitlacoche from the Cholula region in Puebla, Mexico. The inoculum in liquid medium was prepared at a concentration of 1x106 and 5x106 sporidia mL-1; the concentration of the inoculum was measured in a UV spectrum with sporidia counts in Neubauer chamber. Six native sporidia were selected and crossed with two reference strains, CP-436 and CP-437, for the formation of infectious hybrids. The material selected was tested in vivo through the infection of maize seedlings of the variety HUE-CP-14. The native infectious strains were sporidia e7 and e11 of the strain CP-897, with formation of galls in the greenhouse at 7 days of maize seedling infection, and heterokaryons e7xCP-436, e7xCP-437, e11xCP-436, e11xCP-437, e14xCP-437, e7xe11, e14xe18 and CP-436xCP-437 as infectious hybrids at 14 days of inoculation on average.Ustilago maydis es un hongo dimórfico con una forma levaduriforme no patogénica, y una filamentosa patogénica que es la responsable de la formación de tumores en maíz. U. maydis es conocido en México como huitlacoche y consumido desde épocas prehispánicas. Actualmente, su producción se limita a la recolección silvestre para autoconsumo y de manera asistida con fines de mercado, para ello es necesario contar con cepas de U. maydis con capacidad de infección. En el presente trabajo se aislaron esporidias infectivas a partir de huitlacoche nativo de la región de Cholula, Puebla, México. Se preparó el inoculo en medio líquido a una concentración de 1x106&nbsp;y 5x106&nbsp;esporidias mL-1,&nbsp;la concentración del inoculo se midió en un espectro de UV y con el conteo de esporidias en cámara de Neubauer. Se seleccionaron 6 esporidias nativas y se cruzaron con dos cepas de referencia, la CP-436 y CP-437, para la formación de híbridos infectivos. El material seleccionado se comprobó in-vivo mediante la infección de plántulas de maíz de la variedad HUE-CP-14. Las cepas infectivas4&nbsp;nativas fueron las esporidias e7 y e11 de la cepa CP-897, con formación de agallas en invernadero a los 7 días de infección en plántulas de maíz, y los heterocariones e7xCP-436, e7xCP-437, e11xCP-436, e11xCP-437, e14xCP-437, e7xe11, e14xe18 y CP-436xCP-437, como híbridos infectivos a los 14 días de inoculación en promedio