Highly efficient recyclable bismuth nanocatalysts fabricated using a facile one-step aqueous method for faster reduction of azo dye contaminants.

Easily accessible robust synthesis of metallic nanoparticles (NPs) and their colloidal stabilization via successive surface functionalization with desired molecules are crucial for catalytic applications. In this research, tannic acid (TA)-functionalized bismuth (Bi)-based novel NPs were prepared via a simple in situ aqueous reduction of Bi3+ ions for the catalytic reduction of azo groups. The synthesis, morphology, and structure of Bi/TANPs were confirmed through spectroscopic, electron microscopic and X-ray diffraction analyses. The Bi/TANPs comprise Bi, carbon, oxygen and sodium as building components and possess a high negative surface charge of -58 mV, colloidal dispersity, thermal stability and crystalline structure. The Bi/TANPs are almost spherical shaped with an average diameter of 33 nm. The surface of the catalyst is mesoporous with a high specific surface area of 267 m2 g-1. The designed Bi/TANPs exhibit pH-specific affinity for azo dye molecules and reduced azo moieties in the presence of aqueous NaBH4 without requiring any hydrogen gas supply. The catalytic reduction efficiencies of Bi/TANPs against methylene blue and Congo red are almost 100%. These reduction reactions are very fast owing to the presence of TA moieties on the catalyst surface, which facilitate direct electron transfer to azo groups, and follow a pseudo-first-order kinetic model. The catalyst is mechanically recyclable, and shows a minimal loss (<3%) of its initial efficiency until the fifth cycle. This study not only developed an efficient catalyst for the remediation of azo dye-contaminated water, but also offers novel insights into the synergistic effects of TA and glycerin on the reduction mechanism of aqueous Bi3+ ions and the concomitant colloidal stabilization of Bi NPs.

A cluster-randomized trial of water, sanitation, handwashing and nutritional interventions on stress and epigenetic programming.

A regulated stress response is essential for healthy child growth and development trajectories. We conducted a cluster-randomized trial in rural Bangladesh (funded by the Bill & Melinda Gates Foundation, ClinicalTrials.gov NCT01590095) to assess the effects of an integrated nutritional, water, sanitation, and handwashing intervention on child health. We previously reported on the primary outcomes of the trial, linear growth and caregiver-reported diarrhea. Here, we assessed additional prespecified outcomes: physiological stress response, oxidative stress, and DNA methylation (N = 759, ages 1-2 years). Eight neighboring pregnant women were grouped into a study cluster. Eight geographically adjacent clusters were block-randomized into the control or the combined nutrition, water, sanitation, and handwashing (N + WSH) intervention group (receiving nutritional counseling and lipid-based nutrient supplements, chlorinated drinking water, upgraded sanitation, and handwashing with soap). Participants and data collectors were not masked, but analyses were masked. There were 358 children (68 clusters) in the control group and 401 children (63 clusters) in the intervention group. We measured four F2-isoprostanes isomers (iPF(2α)-III; 2,3-dinor-iPF(2α)-III; iPF(2α)-VI; 8,12-iso-iPF(2α)-VI), salivary alpha-amylase and cortisol, and methylation of the glucocorticoid receptor (NR3C1) exon 1F promoter including the NGFI-A binding site. Compared with control, the N + WSH group had lower concentrations of F2-isoprostanes isomers (differences ranging from -0.16 to -0.19 log ng/mg of creatinine, P < 0.01), elevated post-stressor cortisol (0.24 log µg/dl; P < 0.01), higher cortisol residualized gain scores (0.06 µg/dl; P = 0.023), and decreased methylation of the NGFI-A binding site (-0.04; P = 0.037). The N + WSH intervention enhanced adaptive responses of the physiological stress system in early childhood.

Optical Properties of Azo-Benzothiazole Side Chain Liquid Crystalline Polymers: Effect of Solvents, Substituents and Temperatures.

The optical properties of a series of side chain liquid crystalline polymers (P1-P3) containing azo-benzothiazole mesogen with different terminal substituents (-H, -CH3 and -OCH2CH3) in four organic solvents of varying polarity have been investigated by absorption and fluorescence spectral analysis. Solvatochromic studies of P1-P3 did not show any regular variation on the absorption and emission intensities with changing the polarity of solvent. Theoretical studies were performed based on different solvent correlation methods such as Dimroth-Reichardt and Kamlet-Taft methods to investigate the solute-solvent interactions. Both absorption and emission maxima of investigated polymers were bathochromically shifted with the replacement of sixth position hydrogen atom by electron donating groups in benzothiazole moiety. The emission intensities of the studied polymers showed decreasing trend with increasing temperature.

Triethyl-ammonium bis-(2-oxido-2,2-diphenyl-acetato-κO,O)anti-monate(III).

The coordination around the Sb atom in the title compound, (C(6)H(16)N)[Sb(C(14)H(10)O(3))(2)], is fourfold in a pseudo-trigonal-bipyramidal pattern in which one of the equatorial sites is occupied by the stereoactive lone pair of electrons. The four ligating atoms comprise the hydoxylate and carboxyl-ate O atoms from two independent benzilate ligands, each of which forms a five-membered chelating ring, spanning an axial and an equatorial site about the Sb atom. The hydroxy-late atoms occupy the two equatorial sites, and the carboxyl-ate atoms are in the pseudo-axial sites; the O-Sb-O angle is 147.72 (5)°. One carboxyl-ate group shows quite different bond lengths from those of the other group; one O atom is clearly the carbonyl atom and the other O atom the hydroxy-late atom. In the other ligand, there is less distinction in the C-O bonds. This is presumably related to the carbonyl O atom being the acceptor atom of a strong N-H⋯O hydrogen bond, which links the ammonium cation to the Sb complex anion.