10 research outputs found
Multimineral nutritional supplements in a nano-CaO matrix
ISSN:0884-2914ISSN:2044-532
Easy and Low-Cost Method for Synthesis of Carbon–Silica Composite from Vinasse and Study of Ibuprofen Removal
Vinasse was successfully utilized to synthesize carbon–silica composite with a low-cost silica source available in Thailand (sodium silicate, Na2SiO3) and most commonly used source, tetraethyl orthosilicate (TEOS). The composites were prepared by a simple one-step sol–gel process by varying the vinasse (as carbon source) to silica source (Na2SiO3 or TEOS) weight ratio. The resulting composites were characterized by N2 adsorption, moisture and ash contents, pH, pHpzc, bulk density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX). The composites had highest surface area of 313 and 456 m2/g, with average mesopore diameters of 5.00 and 2.62 nm when using Na2SiO3 and TEOS as the silica sources, respectively. The adsorption of a non-steroidal anti-inflammatory drug, ibuprofen, was investigated. The contact time to reach equilibrium was 60 min for both composites. The adsorption kinetics were fitted by a pseudo-second-order model with the correlation coefficient R2 > 0.997. The adsorption isotherms were well described by the Langmuir model (R2 > 0.992), which indicates monolayer adsorption. The maximal adsorption capacities of the Na2SiO3- and TEOS-based composites were as high as 406 and 418 mg/g at pH 2, respectively. The research results indicate that vinasse and a low-cost silica source (Na2SiO3) show great potential to synthesize adsorbents through a simple method with high efficiency
Easy and Low-Cost Method for Synthesis of Carbon–Silica Composite from Vinasse and Study of Ibuprofen Removal
Vinasse was successfully utilized to synthesize carbon–silica composite with a low-cost silica source available in Thailand (sodium silicate, Na2SiO3) and most commonly used source, tetraethyl orthosilicate (TEOS). The composites were prepared by a simple one-step sol–gel process by varying the vinasse (as carbon source) to silica source (Na2SiO3 or TEOS) weight ratio. The resulting composites were characterized by N2 adsorption, moisture and ash contents, pH, pHpzc, bulk density, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX). The composites had highest surface area of 313 and 456 m2/g, with average mesopore diameters of 5.00 and 2.62 nm when using Na2SiO3 and TEOS as the silica sources, respectively. The adsorption of a non-steroidal anti-inflammatory drug, ibuprofen, was investigated. The contact time to reach equilibrium was 60 min for both composites. The adsorption kinetics were fitted by a pseudo-second-order model with the correlation coefficient R2 > 0.997. The adsorption isotherms were well described by the Langmuir model (R2 > 0.992), which indicates monolayer adsorption. The maximal adsorption capacities of the Na2SiO3- and TEOS-based composites were as high as 406 and 418 mg/g at pH 2, respectively. The research results indicate that vinasse and a low-cost silica source (Na2SiO3) show great potential to synthesize adsorbents through a simple method with high efficiency
Nano- and Pheroid technologies for development of foliar iron fertilizers and iron biofortification of soybean grown in South Africa
Abstract Background Foliar iron (Fe) fertilization of crops may increase Fe concentrations in edible portions of plants and improve yield in soils with low available Fe. However, the role of foliar Fe fertilization in increasing seed Fe has not been studied in soybeans (Glycine max). In this study, the Pheroid® nutrient delivery technology was combined with FeSO4 or nanostructured FePO4 to develop potential new Fe foliar fertilizers. Eight different treatments including different combinations of FeSO4 and Pheroids were foliarly applied on field-grown soybeans in Northern Cape province in South Africa to investigate their influence on seed nutrient composition and yield. Results Confocal and optical microscopy images indicate that FeSO4 or FePO4 was not entrapped in the Pheroids but formed separate precipitates. The average seed Fe of the non-treated plants was 56 ± 3 mg kg−1, and none of the treatments (including the positive controls, FeSO4 and FeSO4 with citrate) significantly increased seed Fe over the control. There was also no significant change in yield or seed Zn, P, protein, or phytic acid. Thus, Pheroids as well as FeSO4 are not suitable as delivery system for Fe to soybean seeds due to Pheroid incompatibility with FeSO4 and poor dispersibility of FePO4. Conclusions Because none of the Fe treatments (including positive controls) affected seed Fe concentrations, foliar Fe application may not be effective to increase seed Fe in crops such as soybean that already have high native Fe
Proton-Promoted Iron Dissolution from Nanoparticles and the Influence by the Local Iron Environment
Nanostructured iron-containing compounds
are promising for food
fortification and supplementation to alleviate iron deficiency due
to their fast dissolution in dilute acid and high dietary iron bioavailability.
Furthermore, when such compounds are encapsulated in a nano-CaO matrix,
their dissolution rate is increased. Here the relation between that
rate and iron structure (amorphous/crystalline Fe<sub>2</sub>O<sub>3</sub>, crystalline Ca<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub>, or
monomeric Fe<sup>3+</sup> inside CaO) is investigated. We used X-ray
diffraction (XRD) and electron paramagnetic resonance (EPR) spectroscopy
as complementary techniques to study the local iron environment in
Ca/Fe oxides as a function of nanoparticle composition. Nanostructured
mixed Ca/Fe oxide-containing powders were prepared by flame spray
pyrolysis, and their dissolution over time in acidic solutions (pH
1 and 3) was monitored by EPR spectroscopy. Three types of Fe were
distinguished in these as-prepared powders: monomeric Fe<sup>3+</sup> and crystalline Ca<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub> at low
Fe content powders (Ca:Fe ≥ 3.6) and amorphous/crystalline
Fe<sub>2</sub>O<sub>3</sub> at Ca:Fe ≤ 0.7. During dissolution,
monomeric Fe<sup>3+</sup> and crystalline Ca<sub>2</sub>Fe<sub>2</sub>O<sub>5</sub> dissolved rapidly (<1 min), while crystalline Fe<sub>2</sub>O<sub>3</sub> was more stable and only slowly released Fe<sup>3+</sup> even at pH 1. The Fe release is discussed within a thermodynamic
model based on the nanoparticle lattice energy for each of the nanocrystalline
phases, revealing that Fe coordination and lattice dynamics play a
more dominant role than particle size. Thus, we demonstrate that control
of crystalline structure rather than “nanosizing” may
be a prerequisite for rapid dissolution of ferric iron from nanoparticles
Quantifying the Origin of Released Ag<sup>+</sup> Ions from Nanosilver
Nanosilver is most attractive for its bactericidal properties
in
modern textiles, food packaging, and biomedical applications. Concerns,
however, about released Ag<sup>+</sup> ions during dispersion of nanosilver
in liquids have limited its broad use. Here, nanosilver supported
on nanostructured silica is made with closely controlled Ag size both
by dry (flame aerosol) and by wet chemistry (impregnation) processes
without any surface functionalization that could interfere with its
ion release. It is characterized by electron microscopy, atomic absorption
spectroscopy, and X-ray diffraction, and its Ag<sup>+</sup> ion release
in deionized water is monitored electrochemically. The dispersion
method of nanosilver in solutions affects its dissolution rate but
not the final Ag<sup>+</sup> ion concentration. By systematically
comparing nanosilver size distributions to their equilibrium Ag<sup>+</sup> ion concentrations, it is revealed that the latter correspond
precisely to dissolution of one to two surface silver oxide monolayers,
depending on particle diameter. When, however, the nanosilver is selectively
conditioned by either washing or H<sub>2</sub> reduction, the oxide
layers are removed, drastically minimizing Ag<sup>+</sup> ion leaching
and its antibacterial activity against E. coli. That way the bactericidal activity of nanosilver is confined to
contact with its surface rather than to rampant ions. This leads to
silver nanoparticles with antibacterial properties that are essential
for medical tools and hospital applications
Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation
Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO(4)), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area approximately 190 m(2) g(-1)) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO(4) and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO(4) and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value
A Pan-Cancer Analysis Reveals High-Frequency Genetic Alterations in Mediators of Signaling by the TGF-β Superfamily
We present an integromic analysis of gene alterations that modulate transforming growth factor β (TGF-β)-Smad-mediated signaling in 9,125 tumor samples across 33 cancer types in The Cancer Genome Atlas (TCGA). Focusing on genes that encode mediators and regulators of TGF-β signaling, we found at least one genomic alteration (mutation, homozygous deletion, or amplification) in 39% of samples, with highest frequencies in gastrointestinal cancers. We identified mutation hotspots in genes that encode TGF-β ligands (BMP5), receptors (TGFBR2, AVCR2A, and BMPR2), and Smads (SMAD2 and SMAD4). Alterations in the TGF-β superfamily correlated positively with expression of metastasis-associated genes and with decreased survival. Correlation analyses showed the contributions of mutation, amplification, deletion, DNA methylation, and miRNA expression to transcriptional activity of TGF-β signaling in each cancer type. This study provides a broad molecular perspective relevant for future functional and therapeutic studies of the diverse cancer pathways mediated by the TGF-β superfamily. To date, there are no studies of the TGF-β superfamily of signaling pathways across multiple cancers. This study represents a key starting point for unraveling the role of this complex superfamily in 33 divergent cancer types from over 9,000 patients