Quinoa Fiber and Quercetin Alter the Composition and Function of the Cecal Microbiome and Improve Brush Border Membrane Functionality and Morphology In-Vivo (Gallus gallus)

Objectives Assessment and comparison of the effects of various concentrations of soluble extracts of quinoa fiber (Chenopodium quinoa Willd.) and quercetin-3-glucoside on the zinc and iron status, brush border membrane (BBM) functionality, intestinal morphology, and cecal bacterial populations in-vivo (Gallus gallus). Methods The study utilized Gallus gallus intra-amniotic feeding, a clinically validated method to assess the effects of quinoa, quercetin, and control using seven groups (no injection, 18 Ω H2O, 5% inulin, 1% quercetin 3-glucoside, 2.5% quinoa fiber, 5% quinoa fiber, 1% quercetin 3-glucoside + 5% quinoa fiber). Upon hatch, the cecum, duodenum, pectoral muscle, liver, and blood samples were collected for the estimation of the relative abundance of the gut microbiome, mRNA gene expression Zn and Fe-related transporter proteins and brush border membrane functionality and morphology, glycogen, relative expression of lipid-related genes and hemoglobin levels, respectively. Results The results demonstrated an increase (P < 0.05) in villi height, weight, and surface area in the groups administered with quercetin, and a dose-dependent increase was observed with quinoa soluble fiber treatment. Additionally, an increase in ferroportin and duodenal cytochrome B (DcytB) was observed in the group injected with both quinoa and quercetin. Similarly, zinc transporter 7 (ZnT7) and sucrose-isomaltase (SI) gene expression was upregulated in this group. Further, the administration of quinoa soluble fiber altered the composition and function of the cecal microbiome. Conclusions The evidence suggests that quinoa and quercetin have a synergistic effect, together they are found to improve BBM morphology and functionality, affect the intestinal microbiome, increase short-chain fatty acid production, and thereby improving mineral solubility. Quinoa fibers, a polyphenol-rich superfood, may help fight micronutrient deficiencies in target populations. Funding Sources N/A.

Beyond dissolution: Xerostomia rinses affect composition and structure of biomimetic dental mineral in vitro

Xerostomia, known as dry mouth, is caused by decreased salivary flow. Treatment with lubricating oral rinses provides temporary relief of dry mouth discomfort; however, it remains unclear how their composition affects mineralized dental tissues. Therefore, the objective of this study was to analyze the effects of common components in xerostomia oral rinses on biomimetic apatite with varying carbonate contents. Carbonated apatite was synthesized and exposed to one of the following solutions for 72 hours at varying pHs: water-based, phosphorus-containing (PBS), mucin-like containing (MLC), or fluoride-containing (FC) solutions. Post-exposure results indicated that apatite mass decreased irrespective of pH and solution composition, while solution buffering was pH dependent. Raman and X-ray diffraction analysis showed that the addition of phosphorus, mucin-like molecules, and fluoride in solution decreases mineral carbonate levels and changed the lattice spacing and crystallinity of bioapatite, indicative of dissolution/recrystallization processes. The mineral recrystallized into a less-carbonated apatite in the PBS and MLC solutions, and into fluorapatite in FC. Tap water did not affect the apatite lattice structure suggesting formation of a labile carbonate surface layer on apatite. These results reveal that solution composition can have varied and complex effects on dental mineral beyond dissolution, which can have long term consequences on mineral solubility and mechanics. Therefore, clinicians should consider these factors when advising treatments for xerostomia patients.

The corundum conundrum: Constraining the compositions of fluids involved in metasomatic corundum formation.

<p>Corundum, including the variety ruby, is found in numerous locations in the Archaean North Atlantic Craton of southern Greenland. Corundum owes its occurrence to fluid-induced interaction among high-grade metamorphic lithologies of contrasting chemistry. Here, we present constraints on the conditions of corundum formation and the compositions of the fluids involved for the Storø and Maniitsoq ruby localities. We use thermodynamic modelling of mineral and mineral-fluid equilibria, and complement these with experimentally obtained data on mineral solubility to show that metasomatism took place at 650-725˚C and 7 kbar, involving a boron-rich, acidic fluid of low <em>f</em>O<sub>2</sub> and low X(CO<sub>2</sub>). Aqueous concentrations of aluminium are low and indicate that corundum saturation is the result of residual aluminium enrichment rather than aluminium mobilisation. Intrusion of the <em>ca.</em> 2.55 Ga Qôrqut granite and associated fluid release is the likely source of boron, and U-Pb dating of rutile inclusions is consistent with a temporal link between ruby formation and granite emplacement. Interaction with meta-dunite and Fe-sulfides modified the oxidized magmatic fluid, introduced SO<sub>4</sub>, and produced the reduced, high X<sub>Mg</sub> and K-rich fluid recorded by the corundum-bearing samples. These results highlight a complex interplay among lithologies involved in corundum-formation, but also demonstrate that corundum formation is a predictable part of the geological history where a magmatic intrusion expels a pulse of fluid through its lithologically heterogeneous carapace.</p>

Solubility Product of Vanadinite Pb5(VO4)3Cl at 25 °C—A Comprehensive Approach to Incongruent Dissolution Modeling

Although vanadinite (Pb5(VO4)3Cl) occurs in abundance in various terrestrial geochemical systems of natural and anthropogenic origin and is seriously considered as a potential nuclear waste sequestering agent, its actual application is severely limited by a lack of understanding of its basic thermodynamic parameters. In this regard, the greatest challenge is posed by its incongruent dissolution, which is a pivotal hurdle for effective geochemical modeling. Our paper presents an universal approach for geochemical computing of systems undergoing incongruent dissolution which, along with unique, long-term experiments on vanadinites’ stability, allowed us to determine the mineral solubility constant. The dissolution experiments were carried out at pH = 3.5 for 12 years. Vanadinite has dissolved incongruently, continuously re-precipitating into chervetite (Pb2V2O7) with the two minerals remaining in mutual equilibrium until termination of the experiments. The empirically derived solubility constant Ksp,V,298 = 10–91.89 ± 0.05 of vanadinite was determined for the first time. The proposed modeling method is versatile and can be adopted to other mineral systems undergoing incongruent dissolution.

Formation of chromitite seams and associated anorthosites in layered intrusion by reactive volatile-rich fluid infiltration

Drilling related to development of the platinum-group element deposit of the J-M Reef of the Stillwater Complex returned samples of a rare chromitite seam between anorthosite and norite in a discordant anorthositic body. Plagioclase core An concentrations are marginally higher and modestly reversely zoned on the norite side (average Ancore = 83.8; average Ancore-Anrim = -1.1) as compared with the anorthosite side (Average Ancore 82.5; Average Ancore-Anrim = +1.0). The anorthosites are also characterized by a slightly smaller average plagioclase grain size than plagioclase in the norite (1.41 mm and 1.54 mm, respectively). The chromite can contain single and polyphase inclusions of orthopyroxene, plagioclase, amphibole, biotite and Cl-rich apatite. These and other compositional and textural features, as well as inference from other discordant anorthositic bodies in the Banded series, are all consistent with a chromatographic model of chromite precipitation at a reaction front as a norite protolith reacts with a Cl-rich aqueous fluid saturated in plagioclase alone. Chromitite seam formation is modeled using an infiltration metasomatic model, in which a fluid becomes progressively undersaturated in pyroxene as it rises into the hotter part of the crystal pile. As this pyroxene-undersaturated fluid moves through a noritic protolith, it dissolves the Cr-bearing orthopyroxene to produce an anorthosite. Chromite precipitates at the reaction front between the anorthosite and the norite owing to liberation of Mg and Cr from pyroxene. Continuous redissolution and reprecipitation of chromite occurs as the pyroxene dissolution front moves in direction of fluid flow, collecting the Cr lost from the anorthosite. Owing to Cr dissolved mainly as a neutral divalent cation complex, (CrCl(OH)0, in the solution, but incorporated as a trivalent cation in chromite, the required redox reaction can involve concurrent precipitation of sulfide with chromite. This mechanism differs from some recent models in that the anorthosites are themselves replacement bodies and are not original precipitates from a magma nor formed by loss of mafic material by partial melting. The results show the need for experimental mineral solubility data at T and P conditions appropriate to upper crustal mafic/ultramafic intrusions.

An experimental approach to examine fluid-melt interaction and mineralization in rare-metal pegmatites

Niobium and tantalum, rare metals and high field strength elements (HFSEs) that are essential to modern technologies, are concentrated among others in lithium-cesium-tantalum (LCT) pegmatites and rare metal granites. The most important hosts for Nb-Ta in these types of deposits are the columbite group minerals (columbite-tantalite), but at some ore deposits significant Ta is also contained in wodginite, microlite, and tapiolite. Previous solubility experiments of HFSE minerals have been limited to high temperatures because of the slow diffusivities of HFSEs in granitic melts. An experiment protocol is described herein that allows HFSE mineral solubilities to be determined at lower temperatures, more in line with the estimated solidus temperatures of LCT pegmatites and rare metal granites. This is achieved through the interaction of a melt that is enriched in high field strength elements (e.g., P and Nb or Ta) with a fluid enriched in a fluid-mobile element (FME, e.g., Mn). A starting glass enriched in a slow diffusing HFSE was synthesized, and HFSE mineral saturation is obtained via the diffusion of a FME into the melt via interaction with a fluid. This interaction can occur at much lower temperatures in reasonable experimental durations than for experiments that require diffusion of niobium and tantalum. The solubility product of columbite-(Mn) from the fluid-melt interaction experiment in a highly fluxed granitic melt at 700 °C is the same as those from dissolution and crystallization (reversal) experiments at the same P-T conditions. Thus, both methods produce reliable measurements of mineral solubility, and the differences in the metal concentrations in the quenched melts indicates that the solubility of columbite-(Mn) follows Henry's Law. Results show that columbite-(Mn) saturation can be reached at geologically reasonable concentrations of niobium in melts and manganese in hydrothermal fluids. This experimental protocol also allows the investigation of HFSE mineral crystallization by fluid-melt interactions in rare-metal pegmatites. Magmatic origins for columbite group minerals are well constrained, but hydrothermal Nb-Ta mineralization has also been proposed for pegmatite-hosted deposits such as Tanco, Greenbushes, and granite-hosted deposits such as Cínovec/Zinnwald, Dajishan, and Yichun. This study shows that columbite-(Mn), lithiophilite, and a Ca-Ta oxide mineral (that is likely microlite) crystallized from experiments in fluid-melt systems at temperatures as low as 650 °C at 200 MPa. It is important to note that HFSE minerals that crystallize from fluid-melt interactions texturally occur as euhedral crystals as phenocrysts in glass, i.e., are purely magmatic textures. Therefore, crystallization of HFSE minerals from fluid-melt interactions in rare metal granites and pegmatite deposits may be more widespread than previously recognized. This is significant because the formation of these deposits may require magmatic-hydrothermal interaction to explain the textures present in deposits worldwide, rather than always being the result of a single melt or fluid phase.