The cloud points of various amorphous polyether, polyacrylate, and polysiloxane homopolymers, and a variety of commercially available block copolymers, were measured in CO2 at temperatures from 25 to 65 °C and pressures of ca. 1000−6000 psia. Almost without exception, the solubility of amorphous polymers increases with a decrease in the cohesive energy density, or likewise, the surface tension of the polymer. With this decrease in surface tension, the polymer cohesive energy density becomes closer to that of CO2. Consequently, solubility is governed primarily by polymer−polymer interactions, while polymer−CO2 interactions play a secondary role. The solubility is strongly dependent upon molecular weight for the less CO2-philic polymers. The solubilities of high-molecular-weight poly(fluoroalkoxyphosphazenes) in CO2 were comparable to those of poly(1,1-dihydroperfluorooctylacrylate), one of the most CO2-soluble polymers known.

However, the sluggish kinetics of oxygen evolution reaction (OER) in the electrolysis of water dramatically hinders its development for practical applications. [3] One of the challenges is to develop electrocatalysts with low-cost, abundance, high stability, and high catalytic activity for OER. Noble-metal oxides (such as IrO 2 and RuO 2) are most widely employed as efficient OER catalysts, but their scarcity and high cost limit their commercial application. [4] Therefore, tremendous efforts have been devoted to exploring low-cost earthabundant metals and their compounds for high-efficient and stable OER. [5] Nonprecious transition metal-based compounds, such as sulfides, [4c,6] (oxy)hydroxides, [4a,7] oxides, [4b,8] and phosphides, [4b,9] have been reported for OER owing to their tunable electronic structures and abundant active sites. Recently, 3d transition metal nitrides (TMNs) have been recognized to be promising for the OER process, which are superior to oxides, hydroxides, and sulfides, because of high electrical conductivity and enriched active sites. [10] It should be noted here that the surfaces of TMNs are easily oxidized into oxides and hydroxides. For example, the surface of catalyst was converted to metal oxyhydroxide (*OOH) owing to fast surface reconstruction and phase transition during the electrochemical The sluggish oxygen evolution reaction (OER) is a pivotal process for renewable energy technologies, such as water splitting. The discovery of efficient, durable, and earth-abundant electrocatalysts for water oxidation is highly desirable. Here, a novel trimetallic nitride compound grown on nickel foam (CoVFeN @ NF) is demonstrated, which is an ultra-highly active OER electrocatalyst that outperforms the benchmark catalyst, RuO 2 , and most of the state-of-the-art 3D transition metals and their compounds. CoVFeN @ NF exhibits ultralow OER overpotentials of 212 and 264 mV at 10 and 100 mA cm −2 in 1 m KOH, respectively, together with a small Tafel slop of 34.8 mV dec −1. Structural characterization reveals that the excellent catalytic activity mainly originates from: 1) formation of oxyhydroxide species on the surface of the catalyst due to surface reconstruction and phase transition, 2) promoted oxygen evolution possibly activated by peroxo-like (O 2 2−) species through a combined lattice-oxygen-oxidation and adsorbate escape mechanism, 3) an optimized electronic structure and local coordination environment owing to the synergistic effect of the multimetal system, and 4) greatly accelerated electron 1. Introduction Developing renewable and ecofriendly energy sources/technologies is urgently required to address environmental pollution and energy crisis. [1] Electrically driven water splitting for the production of hydrogen and oxygen has been considered as one

No abstract

Background: Accumulating evidence has shown that some environmental contaminants can alter adipogenesis and act as obesogens. Many of these contaminants act via the activation of the peroxisome proliferator-activated receptor γ (PPARγ) nuclear receptor.Objectives: Our goal was to determine the PPARγ ligand binding potency of several major flame retardants, including polybrominated diphenyl ethers (PBDEs), halogenated phenols and bisphenols, and their metabolites. Ligand binding activity of indoor dust and its bioactivated extracts were also investigated.Methods: We used a commercially available fluorescence polarization ligand binding assay to investigate the binding potency of flame retardants and dust extracts to human PPARγ ligand-binding domain. Rosiglitazone was used as a positive control.Results: Most of the tested compounds exhibited dose-dependent binding to PPARγ. Mono(2-ethylhexyl) tetrabromophthalate, halogenated bisphenols and phenols, and hydroxylated PBDEs were found to be potent PPARγ ligands. The most potent compound was 3-OH-BDE-47, with an IC50 (concentration required to reduce effect by 50%) of 0.24 μM. The extent of halogenation and the position of the hydroxyl group strongly affected binding. In the dust samples, 21 of the 24 samples tested showed significant binding potency at a concentration of 3 mg dust equivalent (DEQ)/mL. A 3–16% increase in PPARγ binding potency was observed following bioactivation of the dust using rat hepatic S9 fractions.Conclusion: Our results suggest that several flame retardants are potential PPARγ ligands and that metabolism may lead to increased binding affinity. The PPARγ binding activity of house dust extracts at levels comparable to human exposure warrants further studies into agonistic or antagonistic activities and their potential health effects.Citation: Fang M, Webster TF, Ferguson PL, Stapleton HM. 2015. Characterizing the peroxisome proliferator-activated receptor (PPARγ) ligand binding potential of several major flame retardants, their metabolites, and chemical mixtures in house dust. Environ Health Perspect 123:166–172; http://dx.doi.org/10.1289/ehp.1408522

Brain function is highly dependent upon controlled energy metabolism whose loss heralds cognitive impairments. This is particularly notable in the aged individuals and in age-related neurodegenerative diseases. However, how metabolic homeostasis is disrupted in the aging brain is still poorly understood. Here we performed global, metabolomic and proteomic analyses across different anatomical regions of mouse brain at different stages of its adult lifespan. Interestingly, while severe proteomic imbalance was absent, global-untargeted metabolomics revealed an energy metabolic drift or significant imbalance in core metabolite levels in aged mouse brains. Metabolic imbalance was characterized by compromised cellular energy status (NAD decline, increased AMP/ATP, purine/pyrimidine accumulation) and significantly altered oxidative phosphorylation and nucleotide biosynthesis and degradation. The central energy metabolic drift suggests a failure of the cellular machinery to restore metabostasis (metabolite homeostasis) in the aged brain and therefore an inability to respond properly to external stimuli, likely driving the alterations in signaling activity and thus in neuronal function and communication.