Publications by authors named "Gregory Helton"

Objectives: Patients with a coronary artery arising from the wrong sinus are susceptible to ischemia and sudden death. Risk is higher when the artery courses interarterially--between the pulmonary artery and aorta--has an intramural course, or has an abnormal orifice. In single coronary ostium without intramural course, unroofing and coronary reimplantation are inappropriate, and coronary artery bypass grafting is suboptimal.

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We wish to report the first measurements of (199)Hg NMR chemical shift data for a series of homoleptic Hg(II) complexes with thiacrown ligands and related aza and mixed thia/aza macrocycles. In mercury(II) complexes containing trithiacrown through hexathiacrown ligands, we observed (199)Hg NMR chemical shifts in the range of -298 to -1400 ppm. Upfield chemical shifts in these NMR spectra are seen whenever (a) the number of thioether sulfur donors in the complex is decreased, (b) a thioether sulfur donor is replaced by a secondary nitrogen donor, and (c) the size of the macrocycle ring increases without a change in the nature or number of the donor atoms.

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