Light-Mediated Electrochemical Synthesis of Manganese Oxide Enhances Its Stability for Water Oxidation.

New methods are needed to increase the activity and stability of earth-abundant catalysts for electrochemical water splitting to produce hydrogen fuel. Electrodeposition has been previously used to synthesize manganese oxide films with a high degree of disorder and a mixture of oxidation states for Mn, which has led to electrocatalysts with high activity but low stability for the oxygen evolution reaction (OER) at high current densities. In this study, we show that multipotential electrodeposition of manganese oxide under illumination produces nanostructured films with significantly higher stability for the OER compared to films grown under otherwise identical conditions in the dark. Manganese oxide films grown by multipotential deposition under illumination sustain a current density of 10 mA/cm2 at 2.2 V versus reversible hydrogen electrode for 18 h (pH 13). Illumination does not enhance the activity or stability of manganese oxide films grown using a constant potential, and films grown by multipotential deposition in the dark undergo a complete loss of activity within 1 h of electrolysis. Electrochemical and structural characterization indicate that photoexcitation of the films during growth reduces Mn ions and changes the content and structure of intercalated potassium ions and water molecules in between the disordered layers of birnessite-like sheets of MnOx, which stabilizes the nanostructured film during electrocatalysis. These results demonstrate that combining multiple external stimuli (i.e., light and an external potential) can induce structural changes not attainable by either stimulus alone to make earth-abundant catalysts more active and stable for important chemical transformations such as water oxidation.

Radical cystectomy for bladder urothelial carcinoma with aggressive variant histology.

PURPOSE: The aim of this study is to report our experience in managing bladder cancer in patients with variant pathology. METHODS: Retrospective data collection for all patients managed by radical cystectomy over the last 3 years for a variant pathol-ogy was completed. We specifically included micropapillary and nested variants. RESULTS: Ten patients were identified, with eight having micropapillary carcinoma (MPC) and two having nested vari-ants. Nine patients were male. The median age was 75. The two patients with nested variant were 56 and 62 years old, respec-tively, whereas all patients with MPC were over the age of 70. Upon cystectomy of all micropapillary cases, three patients (37.5%) had positive lymph node invasion and the final patholo-gy was T2 (two patients), T3 (two patients), and T4 (four patients). Barring a grade III complication Clavien-Dindo classi-fication due to wound dehiscence that necessitated secondary surgical closure, there were no specific perioperative complica-tions. Given the urethral invasion, cystourethrectomy was per-formed on the female patient. Within a median 13-month fol-low-up, three patients developed local recurrence, including two urethral and one new lateral pelvic mass. CONCLUSIONS: Considering the muscle invasive nature of micropapillary and nested bladder cancer, aggressive surgical management should not be postponed. Moreover, due to notable prevalence of concurrent and/or recurrent urethral involvement, initial urethrectomy or early and frequent postoperative ure-throscopy should be provided. Patients with variant histology bladder cancer may benefit from early radical cystectomy when compared to bladder sparing protocols and prostate sparing cystectomy treatment options.