Herein, we describe the effect of organic solvents on ozone solubility and the rate of ozonolysis reactions using rapid injection NMR spectroscopy. The tabulated solubility and kinetic data allowed for the design of a homogeneous ozonolysis flow reactor capable of delivering precise quantities of dissolved ozone to various olefin substrates.
View Article and Find Full Text PDFOzonolysis is a widely used and practical synthetic technique for the deconstructive oxidation of olefins using ozone. While there are numerous ozonolysis reactions that give a myriad of products and functionalities, almost all of them involve scission at the olefin double bond. Using ozone as a constructive reagent rather than a deconstructive one would open new domains of chemical reactivity and amplify molecular complexity in synthetic methodology.
View Article and Find Full Text PDFStatement Of Problem: When a cement-retained lithium disilicate crown needs to be removed, perforation is needed to reach the abutment screw. How this process affects its strength is unclear.
Purpose: The purpose of this in vitro study was to evaluate the fracture strength of milled lithium disilicate implant crowns with screw-access holes created before and after the firing stages.
Plant and essential oil extracts have been used for some time as antimicrobials and antioxidants, although little is known about the interactions between the main components of these plant materials. This knowledge could help to design more potent antimicrobial and antioxidant mixtures. Carvacrol and thymol, the main components of the essential oils of the Lamiaceae family of plants, were assessed in combination to evaluate their antioxidant activity and antimicrobial effect against 19 strains of () of different origins (clinical, meat, milk, and other) and mostly (12) enterotoxin producers.
View Article and Find Full Text PDFThe aim of this study was to compare the effectiveness of a novel assessment software system with the traditional grading protocol used in the University of Texas School of Dentistry at Houston operative dentistry preclinical curriculum. In the study, conducted in 2016, 98 Class I preparations were evaluated both traditionally and digitally by two teams of calibrated preclinical faculty members (two evaluators for each team). Scores from each faculty pair were averaged for the traditional and the digital grading systems, and the scores for the two grading systems were compared.
View Article and Find Full Text PDF