Effect of Covalence and Degree of Cation Order on the Luminous Efficacy of Mn4+ Luminescence in the Double Perovskites, Ba2BTaO6 (B = Y, Lu, Sc).

The spectroscopic properties of the Mn4+ ion are investigated in the series of isostructural double perovskite compounds, Ba2BTaO6 (B = Y, Lu, Sc). A comparison of these properties highlights the influence of covalent bonding within the perovskite framework and the degree of order between the B3+-Ta cations on the energy and intensity of the Mn4+2E → 4A2 emission transition (R-line). These two parameters of the emission spectrum are of importance for practical application since they determine the phosphor luminous efficacy. The influence of covalent bonding within the corner shared BO6/2 and TaO6/2 perovskite framework on the energy of the R-line energy is investigated. From the spectroscopic data, we have derived information on the influence of the degree of order between the B3+ and Ta5+ cations on the intensity of the R-line. The lowest energy and the highest intensity of the R-line are found in the double perovskite, Ba2ScTaO6. The purpose of this work is to propose for first time an explanation of these effects in the considered double perovskites. The obtained results are useful guidelines for practical improvement and tuning of key parameters of phosphors to the desired values.

Taste and smell function in Wilson's disease.

OBJECTIVE: Wilson's disease (WD) is a metabolic disorder associated with abnormal copper metabolism that results in hepatic, psychiatric, and neurologic symptoms. No investigation of taste function has been made in patients with WD, although olfactory dysfunction has been evaluated. METHODS: Quantitative taste and smell test scores of 29 WD patients were compared to those of 790 healthy controls. Taste was measured using the 53-item Waterless Empirical Taste Test (WETT®) and smell using the 40-item revised University of Pennsylvania Smell Identification Test (R-UPSIT®). Multiple linear regression analysis controlled for age and sex. RESULTS: Average WETT® scores did not differ meaningfully between WD and control subjects (respective medians & IQRs = 32 [28-42] & 34 [27-41]); linear regression coefficient = 1.19, 95% CI [-0.81, 3.19], p = 0.242). In contrast, WD was associated with significantly reduced olfactory function [respective median (IQR) R-UPSIT® scores = 35 (33-37) vs. 37 (35-38); adjusted linear regression coefficient = -1.59, 95% CI [-2.34, -0.833]; p < 0.001)]. Neither olfaction nor taste were influenced by WD symptom subtype [23 (79.3%) were hepatic-predominant; 6 (20.7%) neurologic predominant]; R-UPSIT®, p = 0.774; WETT®, p = 0.912). No effects of primary medication or years since diagnosis (R-UPSIT®, p = 0.147; WETT®, p = 0.935) were found. Weak correlations were present between R-UPSIT® and WETT® scores for both control (r=0.187, p < 0.0001) and WD (r=0.237) subjects, although the latter correlation did not reach the 0.05 α level (p = 0.084). CONCLUSION: Although WD negatively impacts smell function, taste is spared. Research is needed to understand the pathophysiologic mechanisms responsible for this divergence.

Flap-based Closure of Acquired Tracheoesophageal Fistulas.

Iatrogenic tracheoesophageal fistulae management and repair are difficult to manage with few resourced describing management and repair. Two cases are presented describing the approach to and repair of a tracheoesophagea fistula; one with a free flap and one with local flap reconstruction. Both cases utilized allograft material to maintain separation between the alimentary and repiratory tracts. Laryngoscope, 134:3761-3764, 2024.