Synergistic effects between alkali-free hydrotalcites and gold nanoparticles afford efficient heterogeneous catalysts for the cascade oxidation of 5-HMF to 2,5-FDCA.
Technetium incorporation into magnetite and its behavior during subsequent oxidation has been investigated at high pH to determine the technetium retention mechanism(s) on formation and oxidative perturbation of magnetite in systems relevant to radioactive waste disposal. Ferrihydrite was exposed to Tc(VII)(aq) containing cement leachates (pH 10.5-13.1), and crystallization of magnetite was induced via addition of Fe(II)aq. A combination of X-ray diffraction (XRD), chemical extraction, and X-ray absorption spectroscopy (XAS) techniques provided direct evidence that Tc(VII) was reduced and incorporated into the magnetite structure. Subsequent air oxidation of the magnetite particles for up to 152 days resulted in only limited remobilization of the incorporated Tc(IV). Analysis of both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data indicated that the Tc(IV) was predominantly incorporated into the magnetite octahedral site in all systems studied. On reoxidation in air, the incorporated Tc(IV) was recalcitrant to oxidative dissolution with less than 40% remobilization to solution despite significant oxidation of the magnetite to maghemite/goethite: All solid associated Tc remained as Tc(IV). The results of this study provide the first direct evidence for significant Tc(IV) incorporation into the magnetite structure and confirm that magnetite incorporated Tc(IV) is recalcitrant to oxidative dissolution. Immobilization of Tc(VII) by reduction and incorporation into magnetite at high pH and with significant stability upon reoxidation has clear and important implications for limiting technetium migration under conditions where magnetite is formed including in geological disposal of radioactive wastes.
A series of lanthanide(III) complexes with nitrogen donor extractant molecules, that exhibit potential for the separation of minor actinides from lanthanides in the management of spent nuclear fuel, have been directly synthesized and characterized in both solution and solid states.
Objective
To evaluate a multilevel cardiovascular disease (CVD) prevention program for rural women.
Methods
This six-month community-based randomized trial enrolled 194 sedentary rural women aged 40 or older, with a BMI ≥ 25 kg/m2. Intervention participants attended six months of twice-weekly exercise, nutrition, and heart health classes (48 total) that included individual-, social-, and environment-level components. An education-only control program included didactic healthy lifestyle classes once a month (6 total). The primary outcome measures were change in BMI and weight.
Results
Within group and between group multivariate analyses revealed that only intervention participants decreased BMI (−0.85 units; 95% CI 1.32, −0.39; p=0.001) and weight (−2.24 kg; −3.49, −0.99; p=0.002); compared to controls, intervention participants decreased BMI and weight (difference: −0.71 units; −1.35, −0.08; p=0.03 and 1.85 kg; −3.55, −0.16; p=0.03, respectively) and improved C-reactive protein (difference: −1.15; −2.16, −0.15; p=0.03) and Simple 7, a composite CVD risk score (difference=0.67; 0.14, 1.21; p=0.01). Cholesterol decreased in controls but increased among intervention (−7.85 versus 3.92; difference=11.77; 0.57, 22.96; p=0.04).
Conclusions
The multilevel intervention demonstrated modest but superior and meaningful improvements in BMI and other CVD risk factors compared to the control program.
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