159 research outputs found
A Human Gut Commensal Ferments Cranberry Carbohydrates to Produce Formate
Commensal bifidobacteria colonize the human gastrointestinal tract and catabolize glycans that are impervious to host digestion. Accordingly, Bifidobacterium longum typically secretes acetate and lactate as fermentative end products. This study tested the hypothesis that B. longum utilizes cranberry-derived xyloglucans in a strain-dependent manner. Interestingly, the B. longum strain that efficiently utilizes cranberry xyloglucans secretes 2.0 to 2.5 mol of acetate-lactate. The 1.5 acetate:lactate ratio theoretical yield obtained in hexose fermentations shifts during xyloglucan metabolism. Accordingly, this metabolic shift is characterized by increased acetate and formate production at the expense of lactate. α-L-Arabinofuranosidase, an arabinan endo-1,5-α-L-arabinosidase, and a β-xylosidase with a carbohydrate substrate-binding protein and carbohydrate ABC transporter membrane proteins are upregulated (\u3e2-fold change), which suggests carbon flux through this catabolic pathway. Finally, syntrophic interactions occurred with strains that utilize carbohydrate products derived from initial degradation from heterologous bacteria
Detection of Inulin, a Prebiotic Polysaccharide, in Maple Syrup
Maple syrup is a widely consumed plant-derived natural sweetener produced by concentrating xylem sap collected from certain maple (Acer) species. During thermal evaporation of water, natural phytochemical components are concentrated in maple syrup. The polymeric components from maple syrup were isolated by ethanol precipitation, dialysis, and anion exchange chromatography and structurally characterized by glycosyl composition analysis, glycosyl linkage analysis, and nuclear magnetic resonance spectroscopy. Among the maple syrup polysaccharides, one neutral polysaccharide was characterized as inulin with a broad molecular weight distribution, representing the first isolation of this prebiotic carbohydrate from a xylem sap. In addition, two acidic polysaccharides with structural similarity were identified as arabinogalactans derived from rhamnogalacturonan type I pectic polysaccharides
Visualizing temperature-dependent phase stability in high entropy alloys
High entropy alloys (HEAs) contain near equimolar amounts of five or more elements and are a compelling space for materials design. In the design of HEAs, great emphasis is placed on identifying thermodynamic conditions for single-phase and multi-phase stability regions, but this process is hindered by the difficulty of navigating stability relationships in high-component spaces. Traditional phase diagrams use barycentric coordinates to represent composition axes, which require (N – 1) spatial dimensions to represent an N-component system, meaning that HEA systems with N \u3e 4 components cannot be readily visualized. Here, we propose forgoing barycentric composition axes in favor of two energy axes: a formation-energy axis and a ‘reaction energy’ axis. These Inverse Hull Webs offer an information-dense 2D representation that successfully captures complex phase stability relationships in N ≥ 5 component systems. We use our proposed diagrams to visualize the transition of HEA solid-solutions from high-temperature stability to metastability upon quenching, and identify important thermodynamic features that are correlated with the persistence or decomposition of metastable HEAs
mHealth in China and the United States: How Mobile Technology is Transforming Healthcare in the World's Two Largest Economies
In this paper, we explore ways mobile technology can help with these difficulties. Specifically, we look at avenues through which mobile devices boost productivity, aid communications, and help providers improve affordability, access, and treatment. Using data drawn from China and the United States as well as global trends, we look at recent developments andemerging opportunities in mobile health, or mHealth. We argue that mobile technology assists patients, health providers, and policymakers in several different respects. It helps patients by giving them tools to monitor their health conditions and communicate those results to physicians. It enables health providers to connect with colleagues and offers alternative sources of information for patients. It is also an important tool to inform policymakers on health delivery and medical outcomes
Navigating phase diagram complexity to guide robotic inorganic materials synthesis
Efficient synthesis recipes are needed both to streamline the manufacturing
of complex materials and to accelerate the realization of theoretically
predicted materials. Oftentimes the solid-state synthesis of multicomponent
oxides is impeded by undesired byproduct phases, which can kinetically trap
reactions in an incomplete non-equilibrium state. We present a thermodynamic
strategy to navigate high-dimensional phase diagrams in search of precursors
that circumvent low-energy competing byproducts, while maximizing the reaction
energy to drive fast phase transformation kinetics. Using a robotic inorganic
materials synthesis laboratory, we perform a large-scale experimental
validation of our precursor selection principles. For a set of 35 target
quaternary oxides with chemistries representative of intercalation battery
cathodes and solid-state electrolytes, we perform 224 reactions spanning 27
elements with 28 unique precursors. Our predicted precursors frequently yield
target materials with higher phase purity than when starting from traditional
precursors. Robotic laboratories offer an exciting new platform for data-driven
experimental science, from which we can develop new insights into materials
synthesis for both robot and human chemists
Expression of relative-protein of hypoxia-inducible factor-1α in vasculogenesis of mouse embryo
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