RESUMEN
Enhancing electrocatalytic performance relies on effective phase control, which influences key catalytic properties, such as chemical stability and electrical conductivity. Traditional methods for manipulating the phase of transition-metal dichalcogenides (TMDs), including high-temperature synthesis, Li intercalation, and doping, involve harsh conditions and energy-intensive processes. This study introduces an innovative approach to crafting heterophase structures (2H-1T-WS2) in TMDs, using WS2 as a model compound, encompassing both semiconducting (2H) and metallic (1T) types through a straightforward potential activation method. Insights from in situ electrochemical Raman spectroscopy, HR-TEM, and XPS measurements reveal distinctive partial phase-transition behavior. This behavior enables the partially exposed basal plane of 2H-1T-WS2 to demonstrate superior activity in the hydrogen evolution reaction (HER), attributed to enhanced electrical conductivity and the exposure of highly active sites. The potential-induced phase transition presents promising avenues for the development of catalysts with heterophase structures.
RESUMEN
We report a case of subglottic narrowing caused by an extranodal deposit of sinus histiocytosis in a 55-year-old man. To the best of our knowledge, no previous reports have described diagnosis using sonographic-guided fine-needle aspiration cytology for Rosai-Dorfman disease of the subglottis. This patient was diagnosed by sonographic-guided fine-needle aspiration biopsy, which revealed lymphocytes, plasma cells, and many foamy, multinuclear histiocytes with preserved lymphocytes in their cytoplasm (emperipolesis). The patient underwent an incisional biopsy of the tumor and received postoperative steroids and low-dose chemotherapy. The subglottic tumor was markedly regressed 6 months later.
