A new class of biaryl chiral ligands derived from 1,2-diaminocyclohexane (1,2-DACH) has been designed to enable the asymmetric addition of aliphatic and, for the first time, aromatic Grignard reagents to ketones for the preparation of highly enantioenriched tertiary alcohols (up to 95% ee). The newly developed ligands L12 and L12' together with the previously reported L0 and L0' define a set of complementary chiral promoters, which provides access to the modular construction of a broad range of structurally diverse non-racemic tertiary alcohols, bearing challenging quaternary stereocenters. The present advancements bring to completion our asymmetric Grignard methodology by expanding the scope to aromatic organomagnesium reagents, while facilitating its implementation in organic synthesis thanks to improved synthetic routes for the straightforward access to the chiral ligands.
View Article and Find Full Text PDFDue to heightened fear surrounding the possibility of future terrorism involving nuclear weapons and radiological dispersive devices, compounded by nonroutine nuclear power plant releases such as from emergencies or accidents, interest in contamination levels of environmental radiation has spiked. This project sought to develop a continuously operational radiation-monitoring system, with graphically visualized data easily accessible to the public. Because this continuing project is housed at a university facility, it bears no connection to perceived political or commercial interests, generally increasing the credibility of the endeavor.
View Article and Find Full Text PDFThe transcription factor signal transducer and activator of transcription (STAT) 1 can mediate antiproliferative and proapoptotic effects in cancer cells, and a number of mechanisms have been found whereby STAT1 signaling is attenuated in tumors thereby increasing their malignant behavior. Thus, enhancing gene transcription mediated by STAT1 may be an effective approach to cancer therapy. A high-throughput screen was developed to identify molecules that could enhance STAT1-dependent gene expression.
View Article and Find Full Text PDFTo determine the role of the transcription factor signal transducer and activator of transcription (STAT) 1 on endothelial cell function, human umbilical vein endothelial cells (HUVEC) were treated with IFN-gamma, a potent activator of STAT1. IFN-gamma inhibited cell growth and tube formation of HUVECs. Although the potent proangiogenic protein vascular endothelial growth factor (VEGF) stimulated cell growth and tube formation, IFN-gamma could suppress these effects of VEGF.
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