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To enhance the efficiency of catalysis, it is crucial to comprehend the behavior of individual nanowires/nanosheets. A developed on-chip microcell facilitates this study by creating a reaction window that exposes the catalyst region of interest. However, this technology's potential application is limited due to frequently-observed variations in data between different cells. In this study, we identify a conductance problem in the reaction windows of non-metallic catalysts as the cause of this issue. We investigate this problem using in-situ electronic/electrochemical measurements and atom-thin nanosheets as model catalysts. Our findings show that a full-open window, which exposes the entire catalyst channel, allows for efficient modulation of conductance, which is ten times higher than a half-open window. This often-overlooked factor has the potential to significantly improve the conductivity of non-metallic catalysts during the reaction process. After examining tens of cells, we develop a vertical microcell strategy to eliminate the conductance issue and enhance measurement reproducibility. Our study offers guidelines for conducting reliable microcell measurements on non-metallic single nanowire/nanosheet catalysts.
RESUMO
Prussian blue analogue (PBA), with a three-dimensional open skeleton and abundant unsaturated surface coordination atoms, attracts extensive research interest in electrochemical energy-related fields due to facile preparation, low cost, and adjustable components. However, it remains a challenge to directly employ PBA as an electrocatalyst for water splitting owing to their poor charge transport ability and electrochemical stability. Herein, the PBA/rGO heterostructure is constructed based on structural engineering. Graphene not only improves the charge transfer efficiency of the compound material but also provides confined growth sites for PBA. Furthermore, the charge transfer interaction between the heterostructure interfaces facilitates the electrocatalytic oxygen evolution reaction of the composite, which is confirmed by the results of the electrochemical measurements. The overpotential of the PBA/rGO material is only 331.5 mV at a current density of 30 mA cm-2 in 1.0 M KOH electrolyte with a small Tafel slope of 57.9 mV dec-1, and the compound material exhibits high durability lasting for 40 h.
RESUMO
OBJECTIVE: To provide pathological and clinical evidences in order to establish standardized diagnosis and treatment for MALT lymphoma. METHODS: Pathological characters, grade, stage, prognostic factors and treatment of 37 cases of MALT lymphoma were analyzed which were diagnosed from January 2000 to June 2002. RESULTS: The 39 patients(8.82%) were diagnosed as MALT lymphoma out of 442 NHL patients(37 patients were followed up, and two missing). Median age was 52 years. The percentage of patients older than 50 was 63.6%. The marjority of tumors were found in stomach, intestinal, thyroid, parotid gland, orbit and lung. Among 28 (71.8%) of 37 patients with gastro-intestinal(GI) Maltoma, low-grade was 70.3%, median-grade 27.0%, stage I 53.6%, stage II 28.6%, stage III 14.3%, and stage IV 3.6%. Of phenotype 35 cases were CD20 positive, and 4 cases were diagnosed as MALT lymphoma supported by PCR detecting IgH re-arrangement. Among 13 patients with gastric MALToma, 46.15% were helicobacter pylori (HP) positive. Patients with GI MALT lymphoma received 3-cycle antibiotic treatment. Most of GI patients received surgical operations. Most of patients received chemotherapy, with 4 plus local radiotherapy. Only one patient received antibiotic treatment alone. No one received radiation treatment alone. CONCLUSION: MALT lymphoma was often seen in older patients, most of whom were in low-grade with slow disease progression. The site, grade, stage and molecular genetic change are important prognostic factors, which can help us to make decision in choosing suitable treatment.