RESUMEN
Ion migration is a major factor affecting the long term stability of perovskite light-emitting diodes (LEDs), which limits their commercialization potential. The accumulation of excess halide ions at the grain boundaries of perovskite films is a primary cause of ion migration in these devices. Here, it is demonstrated that the channels of ion migrations can be effectively impeded by elevating the hole transport layer between the perovskite grain boundaries, resulting in highly stable perovskite LEDs. The unique structure is achieved by reducing the wettability of the perovskites, which prevents infiltration of the upper hole-transporting layer into the spaces of perovskite grain boundaries. Consequently, nanosized gaps are formed between the excess halide ions and the hole transport layer, effectively suppressing ion migration. With this structure, perovskite LEDs with operational half-lifetimes of 256 and 1774 h under current densities of 100 and 20 mA cm-2 respectively are achieved. These lifetimes surpass those of organic LEDs at high brightness. It is further found that this approach can be extended to various perovskite LEDs, showing great promise for promoting perovskite LEDs toward commercial applications.
RESUMEN
PURPOSE: The purpose of this study was to compare the efficacy and safety of thoracoscopic-laparoscopic Ivor-Lewis surgery and McKeown surgery in the treatment of thoracic middle-lower segment esophageal cancer. METHODS: The clinical data of 136 patients with thoracic middle-lower segment esophageal cancer were divided into Ivor-Lewis group (n=68) and McKeown group (n=68). The perioperative indexes and the levels of tumor markers were observed. The patients' long-term survival condition was recorded via follow-up. Finally, the long-term quality of life of patients with a survival time >3 years was compared between the two groups after operation using EORTC QLQ-C30 and EORTC QLQ-OES18. RESULTS: The operation time was significantly shorter in Ivor-Lewis group than that in McKeown group. The hospitalization expenses were obviously higher in Ivor-Lewis group than those in McKeown group. The incidence rate of anastomotic fistula, anastomotic stenosis and pulmonary infection was evidently lower in Ivor-Lewis group than that in McKeown group. Moreover, the levels of serum CYFRA21-1, CA125 and CEA evidently declined in both groups after treatment compared with those before treatment. The follow-up results revealed that the 3-year survival rate was 72.1% and 64.7%, respectively. The analysis results of postoperative 3-year quality of life manifested that no statistically significant difference was observed in each index in QLQ-C30 between the two groups, but the dysphagia and reflux scores in QLQ-EOS18 were remarkably superior in Ivor-Lewis group to those in McKeown group. CONCLUSIONS: In the treatment of thoracic middle-lower segment esophageal cancer, minimally-invasive Ivor-Lewis surgery has shorter operation time, better life quality, and fewer postoperative complications (pulmonary infection, anastomotic fistula and anastomotic stenosis) than minimally-invasive McKeown surgery, while the treatment expenses are higher.
Asunto(s)
Neoplasias Esofágicas/cirugía , Laparoscopía/métodos , Toracoscopía/métodos , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
The microstructure at the interface of diffusion-bonded joints of oxygen-free high-conductivity copper for two kinds of surface conditions, with and without argon ion bombardment treatment, was investigated using scanning and high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that argon ion bombardment effectively removed the surface oxide film layer and lowered the height of the surface asperity, so that inclusion formation was decreased and void shrinkage time was shortened at the interface of the bonded copper joints, and the tensile strength of diffusion-bonded copper joints was improved obviously.