RESUMEN
Developing efficient oxygen evolution reaction (OER) electrocatalysts is important for enhancing the water splitting efficiency. However, with the current catalysts containing one kind of active sites, it is challenging to achieve low overpotentials because of the four-electron transfer process. Herein is reported HZIF-2-CoMo, a new metal-organic framework with well-defined Co-Mo dual sites that can promote the OER process through an unconventional Mo6+/Co2+ dual-site relay mechanism. Theoretical calculations suggested that the Mo and Co sites stabilize the HO* and HOO* intermediates, respectively, and that the unique Co-O-Mo configuration induces the formation of a Co-O*-Mo transition intermediate, remarkably reducing the reaction free energy. As a result, HZIF-2-CoMo shows an overpotential of 277 mV at 10 mA cm-2 and a low Tafel slope of 70 mV dec-1 in alkaline solution, making it one of the best OER electrocatalysts reported to date.
RESUMEN
The hydrogen evolution reaction is a key half reaction for water electrolysis and is of great significance. Pt-based nanomaterials are promising candidates for HER electrocatalysts. However, the high price of platinum and poor durability impede their practical applications. Herein, a new CoMo-bimetallic hybrid zeolite imidazolate framework is employed to load Pt nanoparticles in a highly dispersed manner as a precursor to synthesize an efficient pH-universal HER electrocatalyst (PtCoMo@NC), which displays overpotentials of 26, 51, and 66 mV at a current density of 10 mA cm-2 in acidic, basic, and neutral media, respectively. The strong synergistic effect of highly dispersed multi-type catalytic species, including cobalt, molybdenum carbide, and platinum (4.7%) promotes the catalytic activity in the HER process. Meanwhile, the aggregation of Pt nanoparticles is greatly restrained by the carbon matrix so that a brilliant long-time durability of 12 hours and a negligible current decrease in the LSV curve after 10 000 CV cycles are achieved.
RESUMEN
AIM: To evaluate the benefit and harms of high-dose intravenous glucocorticoids (IVGC) as first-line treatment for Graves' ophthalmopathy (GO). METHODS: A systematic review and Meta-analysis of randomized clinical trials (RCTs) comparing IVGC for the treatment of GO, with placebo or other treatments, were conducted. Electronic databases were searched, and standard methodological guidance of Cochrane Handbook for Systematic Reviews of Interventions was used. The primary outcome was overall response, and secondary outcomes included the improvement and change in clinical activity score (CAS), and adverse events. RESULTS: Ten RCTs were included in the Meta-analysis. Low quality evidence (one trial) showed that participants receiving IVGC achieved significantly higher response compared to participants receiving placebo [risk ratio (RR) 7.50, 95% confidence interval (CI) 1.14 to 49.26]. Moderate quality evidence (four trials) support appreciable benefit of IVGC in response compared with oral glucocorticoids (OGC), with of RR being 1.51 (95%CI 1.25 to 1.83). There was low quality evidence (one trial) compatible with appreciable benefit for IVGC plus orbital radiotherapy in response (RR 1.38, 95%CI 1.07 to 1.79), compared with OGC plus orbital radiotherapy. One IVGC versus rituximab trial provided moderate quality evidence suggesting that participants using IVGC achieved significantly lower response compared to participants using rituximab (RR 0.70, 95%CI 0.50 to 0.98). One IVGC versus mycophenolate mofetil (MMF) trial provided moderate quality evidence suggesting that participants using IVGC achieved significantly lower response compared to participants using MMF (RR 0.74, 95%CI 0.63 to 0.88). Very low quality evidence (one trial) showed that participants with dysthyroid optic neuropathy (DON) receiving IVGC were more likely to achieve response compared to participants receiving orbital decompression (RR 3.33, 95%CI 0.51 to 21.89). CONCLUSION: The current evidence is moderate quality, which is sufficient to support IVGC to be as the first-line treatment for moderate-to-severe GO, and the use of rituximab or MMF to be the second-line treatment instead of IVGC. However, the evidence is very low quality, which is insufficient to support the use of IVGC or orbital decompression as the first-line treatment of DON.
RESUMEN
OBJECTIVE: To evaluate the efficacy of α2-adrenergic agonist (AA) brimonidine and topical carbonic anhydrase inhibitors (CAIs) dorzolamide and brinzolamide in reducing intraocular pressure (IOP) when used as adjunctive therapy to ß-blockers (BBs) or prostaglandin analogs (PGAs). RESEARCH DESIGN AND METHODS: Pertinent publications were identified through systematic searches of PubMed, EMBASE, and the Cochrane Controlled Trials Register. Randomized controlled trials comparing AA with CAIs in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) who had inadequate IOP control with monotherapy of a BB or PGA. The weighted mean differences (WMD) of IOP-lowering efficacy were calculated by performing meta-analysis. MAIN OUTCOME MEASURES: The main efficacy measures were the reduction from baseline to end of treatment in IOP at peak, trough, and diurnal curve. RESULTS: Eleven published randomized clinical trials involving 1493 patients were included in the meta-analysis. As adjunctive therapy, the IOP reduction was greater in the brimonidine group than in the CAI group at peak (WMD: 0.99 mmHg [95% confidence interval, 0.45 to 1.53]) and diurnal curve (WMD: 0.62 mmHg [0.07 to 1.18]). As adjunctive therapy to BBs, brimonidine was more effective than CAIs in reducing IOP at peak (WMD: 0.85 mmHg [0.42 to 1.29]) and trough (WMD: 0.47 mmHg [0.12 to 0.83]). As adjunctive therapy to PGAs, brimonidine resulted greater reduction in peak IOP than CAIs (WMD: 1.04 mmHg [0.08 to 2.00]). CONCLUSIONS: Brimonidine provides greater IOP-lowering efficacy than topical carbonic anhydrase inhibitors as adjunctive therapy to BBs or PGAs.