The role of the alkali metal cations in halide perovskite solar cells is not well understood. Using synchrotron-based nano–x-ray fluorescence and complementary measurements, we found that the halide distribution becomes homogenized upon addition of cesium iodide, either alone or with rubidium iodide, for substoichiometric, stoichiometric, and overstoichiometric preparations, where the lead halide is varied with respect to organic halide precursors. Halide homogenization coincides with long-lived charge carrier decays, spatially homogeneous carrier dynamics (as visualized by ultrafast microscopy), and improved photovoltaic device performance. We found that rubidium and potassium phase-segregate in highly concentrated clusters. Alkali metals are beneficial at low concentrations, where they homogenize the halide distribution, but at higher concentrations, they form recombination-active second-phase clusters.
The vast majority of patients with T2DM have multiple comorbidities. To ensure a comprehensive approach to patient management, the presence of multimorbidity should be considered in the context of clinical decision making.
BackgroundDelirium is a frequent complication after cardiac surgery and its occurrence is associated with poor outcomes. The purpose of this study was to investigate the impact of perioperative dexmedetomidine administration on the incidence of delirium in elderly patients after cardiac surgery.MethodsThis randomized, double-blinded, and placebo-controlled trial was conducted in two tertiary hospitals in Beijing between December 1, 2014 and July 19, 2015. Eligible patients were randomized into two groups. Dexmedetomidine (DEX) was administered during anesthesia and early postoperative period for patients in the DEX group, whereas normal saline was administered in the same rate for the same duration for patients in the control (CTRL) group. The primary endpoint was the incidence of delirium during the first five days after surgery. Secondary endpoints included the cognitive function assessed on postoperative days 6 and 30, the overall incidence of non-delirium complications within 30 days after surgery, and the all-cause 30-day mortality.ResultsTwo hundred eighty-five patients were enrolled and randomized. Dexmedetomidine did not decrease the incidence of delirium (4.9% [7/142] in the DEX group vs 7.7% [11/143] in the CTRL group; OR 0.62, 95% CI 0.23 to 1.65, p = 0.341). Secondary endpoints were similar between the two groups; however, the incidence of pulmonary complications was slightly decreased (OR 0.51, 95% CI 0.26 to 1.00, p = 0.050) and the percentage of early extubation was significantly increased (OR 3.32, 95% CI 1.36 to 8.08, p = 0.008) in the DEX group. Dexmedetomidine decreased the required treatment for intraoperative tachycardia (21.1% [30/142] in the DEX group vs 33.6% [48/143] in the CTRL group, p = 0.019), but increased the required treatment for postoperative hypotension (84.5% [120/142] in the DEX group vs 69.9% [100/143] in the CTRL group, p = 0.003).ConclusionsDexmedetomidine administered during anesthesia and early postoperative period did not decrease the incidence of postoperative delirium in elderly patients undergoing elective cardiac surgery. However, considering the low delirium incidence, the trial might have been underpowered.Trial RegistrationClinicalTrials.gov NCT02267538
Grain boundaries play a key role in the performance of thin‐film optoelectronic devices and yet their effect in halide perovskite materials is still not understood. The biggest factor limiting progress is the inability to identify grain boundaries. Noncrystallographic techniques can misidentify grain boundaries, leading to conflicting literature reports about their influence; however, the gold standard – electron backscatter diffraction (EBSD) – destroys halide perovskite thin films. Here, this problem is solved by using a solid‐state EBSD detector with 6000 times higher sensitivity than the traditional phosphor screen and camera. Correlating true grain size with photoluminescence lifetime, carrier diffusion length, and mobility shows that grain boundaries are not benign but have a recombination velocity of 1670 cm s−1, comparable to that of crystalline silicon. Amorphous grain boundaries are also observed that give rise to locally brighter photoluminescence intensity and longer lifetimes. This anomalous grain boundary character offers a possible explanation for the mysteriously long lifetime and record efficiency achieved in small grain halide perovskite thin films. It also suggests a new approach for passivating grain boundaries, independent of surface passivation, to lead to even better performance in optoelectronic devices.
Cognitive adaptation training (CAT) is a psychosocial treatment that uses environmental supports such as signs, checklists, alarms, and the organization of belongings to cue and sequence adaptive behaviors in the home. Ninety-five outpatients with schizophrenia (structured clinical interview for diagnosis, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) were randomly assigned to (1) Full-CAT (CAT focused on many aspects of community adaptation including grooming, care of living quarters, leisure skills, social and role performance, and medication adherence), (2) Pharm-CAT (CAT focused only on medication and appointment adherence), or (3) treatment as usual (TAU). Treatment lasted for 9 months, and patients were followed for 6 months after the withdrawal of home visits. Medication adherence (assessed during unannounced, in-home pill counts) and functional outcomes were assessed at 3-month intervals. Results of mixed-effects regression models indicated that both CAT and Pharm-CAT treatments were superior to TAU for improving adherence to prescribed medication (P < .0001). Effects on medication adherence remained significant when home visits were withdrawn. Full-CAT treatment improved functional outcome relative to Pharm-CAT and TAU (P < .0001). However, differences for functional outcome across groups decreased following the withdrawal of home visits and were no longer statistically significant at the 6-month follow-up. Survival time to relapse or significant exacerbation was significantly longer in both CAT and Pharm-CAT in comparison to TAU (.004). Findings indicate that supports targeting medication adherence can improve and maintain this behavior. Comprehensive supports targeting multiple domains of functioning are necessary to improve functional outcomes. Maintenance of gains in functional outcome may require some form of continued intervention.
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