No abstract

Two 3,5-disubstituted sulfonamide catechol ligands were synthesized. Tris(ligand) iron(III) complexes were prepared and investigated as MRI contrast agents. Longitudinal relaxivity (r1) values were determined for the complexes. The r1 values in water were substantially higher than those of typical six-coordinate iron(III) complexes. The r1 values in plasma under the same conditions increased. The iron(III) complexes were administered to rats, and the kidney and liver signal intensities were measured by T1-weighted MR imaging experiments.

A series of tabletop models was built to demonstrate the interactions between a fictional cell-surface receptor, the receptor’s natural ligand, and eight potential therapeutic agents. Students assessed the eight therapeutic agents as agonists, antagonists, or neither agonists nor antagonists, first as a pencil-and-paper exercise and then subsequently using the three-dimensional models. Students found the activity to be engaging and were more accurately able to identify the correct roles of the agents when using the models.

We devised an activity to explore friction by testing some of the common theories on how ancient Egyptians moved the stones used to build the pyramids. The activity is suitable for a high school physics course or introductory college courses for both science majors and non-science majors. The students investigate dragging a 1-kg mass (representing a stone) on a small wooden sled under three conditions: over dry sand, using wooden rollers over dry sand, and over wet sand. This last condition has been recently proposed as a potential method used by the Egyptians. The force required to pull the sled at a constant velocity is measured and used to calculate the kinetic coefficient of friction for each of the three test conditions. Students then perform a similar activity pulling their professor across a sand volleyball court. Versions of this experiment have been done in four classes of science majors (general physics, two 2-hour lab periods) and in four classes of non-science majors (physical sciences for educators, one 2-hour lab period).