RESUMEN
Williams syndrome is caused by a deletion of the elastin gene on chromosome 7. One of the main roles of this gene is to maintain the strength and elasticity of the intestinal wall, and the absence of the elastin gene may predispose these patients to gastrointestinal pathology such as diverticulitis. Our patient was a 35-year-old Caucasian female with Williams syndrome who presented to the emergency department with diffuse abdominal pain for two days. A computed tomography (CT) scan of her abdomen and pelvis initially showed locally perforated sigmoid diverticulitis with pelvic abscess and acute peritonitis. Surgical management was indicated after the patient failed to respond to conservative treatment. She was treated with Hartmann's procedure which showed purulent peritoneal fluid intraoperatively. Her hospital course was complicated by postoperative ileus and a peri-incisional abscess. After a 15-day hospital stay, she was discharged home with plans for ostomy reversal in six months. Patients with Williams syndrome have an increased risk of developing diverticulitis at a younger age than the general population due to their propensity for chronic constipation stemming from their child-like eating habits and low dietary fiber. Thus, we emphasize the importance of treating constipation in patients with Williams syndrome to prevent diverticulitis. If these patients present to the emergency department with acute diverticulitis, aggressive surgical management may be beneficial because rapid progression could ensue.
RESUMEN
A series of 18 ruthenium(II) polypyridyl complexes were synthesized and evaluated under electrochemically oxidative conditions, which generates the Ru(III) oxidation state and mimics the harsh conditions experienced during the kinetically limited regime that can occur in dye-sensitized solar cells (DSSCs) and dye-sensitized photo-electrosynthesis cells, to further develop fundamental insights into the factors governing molecular sensitizer surface stability in aqueous 0.1 M HClO4. Both desorption and oxidatively induced ligand substitution were observed on planar fluorine-doped tin oxide (FTO) electrodes, with a dependence on the E1/2 Ru(III/II) redox potential dictating the comparative ratios of the processes. Complexes such as RuP4OMe ( E1/2 = 0.91 vs Ag/AgCl) displayed virtually only desorption, while complexes such as RuPbpz ( E1/2 > 1.62 V vs Ag/AgCl) displayed only chemical decomposition. Comparing isomers of 4,4'- and 5,5'-disubstituted-2,2'-bipyridine ancillary ligands, a dramatic increase in the rate of desorption of the Ru(III) complexes was observed for the 5,5'-ligands. Nanoscopic indium-doped tin oxide thin films (nanoITO) were also sensitized and analyzed with cyclic voltammetry, UV-vis absorption spectroscopy, and X-ray photoelectron spectroscopy, allowing for further distinction of desorption versus ligand-substitution processes. Desorption loss to bulk solution associated with the planar surface of FTO is essentially non-existent on nanoITO, where both desorption and ligand substitution are shut down with RuP4OMe. These results revealed that minimizing time spent in the oxidized form, incorporating electron-donating groups, maximizing hydrophobicity, and minimizing molecular bulk near the adsorbed ligand are critical to optimizing the performance of ruthenium(II) polypyridyl complexes in dye-sensitized devices.