This in vitro study evaluated the efficacy of orthodontic adhesives with fluoride or amorphous calcium phosphate (ACP) in reducing bacterial adhesion and enamel demineralization. Forty human premolars each sectioned buccolingually into three parts were bracketed with control resin (Transbond XT) or adhesives containing ACP (Aegis Ortho) or fluoride (QuickCure). Artificial lesions induced by pH ...

This thesis is concerned with the synthesis of acid labile co-polymers. Two polymer systems were examined (1) polyacetals and (2) poly(ortho esters). As for poly(ortho esters), there is a need for better synthetic methods to prepare these polymers more easily without the need of stringent anhydrous conditions, with more broad structural variation, and in a more cost effective manner. Pendent fu...

Ortho-nitro- and ortho-alkoxy-oligo-meta-aniline units fold in solution through hydrogen bonds and aromatic stacking into compact structures that were characterized in the solid state as cylindrical beta-sheet like structures.

The data on the coordination and structure of iron(II) and iron(III) anthranilates in the solid state and in aqueous medium are presented and discussed, as studied using Mössbauer (for solid products and frozen solutions) and FTIR spectroscopy (for solid samples). Whereas, in slightly acidic nitrate solutions under aerobic conditions ferric ions can still be gradually reduced by anthranilic (o-...

A series of aluminium complexes containing anilido-pyrazolate ligands is described. Reactions of four anilido-pyrazolate ligand precursors, HNPhPz, HNPhTriMePz, HNPhOMePz, or HNPhSMePz [HNPhPz = ortho-C6H4(NH-phenyl)(1-pyrazole); HNPhTriMePz = ortho-C6H4(NH-2,4,6-trimethylphenyl)(1-pyrazole); HNPhOMePz = ortho-C6H4(NH-2-methoxyphenyl)(1-pyrazole); HNPhSMePz = ortho-C6H4(NH-2-methylthiophenyl)(1...

The addition and abstraction reactions of OH radical with benzoate anion are investigated by density functional theory calculations that include solvent effects using UB3LYP, UCAM-B3LYP, UmPW1PW91 and UM06-2X functionals with the 6-311++G(2d,2p) basis set. Geometry optimizations of the reactants, products and transition state species are performed for the possible reaction paths. For the additi...

Introduction An aromatics complex is a combination of process units that can be used to convert petroleum naphtha and pyrolysis gasoline (pygas) into the basic petrochemical intermediates: Benzene Toluene and Xylenes (BTX). Benzene is a versatile petrochemical building block used in the production of more than 250 different products. Ethylbenzene, cumene, and cyclohexane are the most important ...

BACKGROUND Polychlorinated biphenyls (PCBs) are ubiquitous environmental toxins. Although there is growing evidence to support an association between PCBs and deficits of neurodevelopment, the specific mechanisms are not well understood. The potentially different roles of specific PCB groups defined by chemical structures or hormonal activities e.g., dioxin-like, non-dioxin like, or anti-estrog...