RESUMO
Reference electrode (RE) plays the core role in accurate potential control in electrochemistry. However, nanoresolved electrochemical characterization techniques still suffer from unstable potential control of pseudo-REs, because the commercial RE is too large to be used in the tiny electrochemical cell, and thus only pseudo-RE can be used. Therefore, microsized RE with a stable potential is urgently required to push the nanoresolved electrochemical measurements to a new level of accuracy and precision, but it is quite challenging to reproducibly fabricate such a micro RE until now. Here, we revisited the working mechanism of the metal-junction RE and clearly revealed the role of the ionic path between the metal wire and the borosilicate glass capillary to maintain a stable potential of RE. Based on this understanding, we developed a method to fabricate micro ultrastable-RE, where a reproducible ultrathin ionic path can form by dissolving a sandwiched sacrificial layer between the Pt wire and the capillary for the ion transfer. The potential of this new micro RE was almost the same as that of the commercial Ag/AgCl electrode, while the size is much smaller. Different from commercial REs that must be stored in the inner electrolyte, the new RE could be directly stored in air for more than one year without potential drift. Eventually, we successfully applied the micro RE in the electrochemical tip-enhanced Raman spectroscopy (EC-TERS) measurement to precisely control the potential of the working electrode, which makes it possible to compare the results from different laboratories and techniques to better understand the electrochemical interface at the nanoscale.
RESUMO
Intracranial primary chondrosarcomas are rare, accounting for <0.15% of all intracranial tumors, but exhibit a high risk of recurrence. Due to the rarity of this condition, it has proven difficult to establish efficacy-based treatment guidelines. The present study details a case of clivus chondrosarcoma exhibiting no recurrence following surgical resection using an endoscopic transsphenoidal approach and postoperative adjuvant radiotherapy. A 41-year-old female presented with primary symptoms of left eye esotropia, scotoma of the left nasal visual field and double vision. Preoperative cranial magnetic resonance imaging revealed a lesion on the clivus, which was initially diagnosed as chordoma. However, clivus chondrosarcoma was ultimately diagnosed based on intraoperative findings and postoperative histopathology. The tumor was totally resected and 25 doses of adjuvant radiotherapy with planning gross tumor volume (60 Gy) and planning clinical target volume (50 Gy) were administered for 5 weeks. The patient was discharged at 12 days post-surgery with no obvious postoperative complications. Over the 28-month follow-up period, there was no evidence of recurrence, which may be due to the successful use of combined gross total resection and adjuvant radiotherapy. Therefore, surgical resection using an endoscopic transsphenoidal approach and postoperative adjuvant radiotherapy is an effective method for treating intracranial clivus chondrosarcoma.