Ultrafast Detection of Arsenic Using Carbon-Fiber Microelectrodes and Fast-Scan Cyclic Voltammetry.

Arsenic contamination poses a significant public health risk worldwide, with chronic exposure leading to various health issues. Detecting and monitoring arsenic exposure accurately remains challenging, necessitating the development of sensitive detection methods. In this study, we introduce a novel approach using fast-scan cyclic voltammetry (FSCV) coupled with carbon-fiber microelectrodes (CFMs) for the electrochemical detection of As3+. Through an in-depth pH study using tris buffer, we optimized the electrochemical parameters for both acidic and basic media. Our sensor demonstrated high selectivity, distinguishing the As3+ signal from those of As5+ and other potential interferents under ambient conditions. We achieved a limit of detection (LOD) of 0.5 µM (37.46 ppb) and a sensitivity of 2.292 nA/µM for bare CFMs. Microscopic data confirmed the sensor's stability at lower, physiologically relevant concentrations. Additionally, using our previously reported double-bore CFMs, we simultaneously detected As3+-Cu2+ and As3+-Cd2+ in tris buffer, enhancing the LOD of As3+ to 0.2 µM (14.98 ppb). To our knowledge, this is the first study to use CFMs for the rapid and selective detection of As3+ via FSCV. Our sensor's ability to distinguish As3+ from As5+ in a physiologically relevant pH environment showcases its potential for future in vivo studies.

Systematic review of long-term effectiveness of endoscopic gastrojejunostomy in patients presenting with gastric outlet obstruction from periampullary malignancies.

BACKGROUND: Recently, endoscopic ultrasound-guided (EUS) gastrojejunostomy (GJ) has emerged as an alternative option to surgical palliation and endoscopic duodenal stenting for malignant gastric outlet obstruction (GOO). Although early success rates are commonly reported with the technique, there is a paucity of data regarding the long-term efficacy of this approach. In this study, we investigated long-term outcomes in patients that underwent EUS-guided GJ for palliation of periampullary malignancies. METHODS: From a total of 192 studies that were reviewed, 6 studies with a follow-up time frame of a minimum of 5 months were analyzed, totaling 238 patients. Outcome variables included technical success rate, clinical success rate, adverse events, symptom recurrence, and re-intervention rates. RESULTS: The cohort of 238 patients had a technical success rate of 93.7% and a clinical success rate of 92.9%. A total of 25 patients (10.5%) experienced adverse events associated with EUS-GJ. A total of 14 patients (5.9%) experienced recurrence of GOO symptoms within 5 months. A total of 14 patients (5.9%) underwent re-intervention with the first 5 months. CONCLUSIONS: This systematic review shows that data are scarce regarding long-term effectiveness of EUS-guided GJ. Even though early success rates have been reported, further studies are needed to focus on long-term efficacy of this approach. Until such studies become available, surgical palliation should continue to be the treatment of choice for patients with malignant GOO with a prolonged life expectancy.

Evaluation of helicene-derived 2,2'-bipyridine N-monoxide catalyst for the enantioselective propargylation of N-acylhydrazones with allenyltrichlorosilane.

Helicene-derived 2,2'-bipyridine N-monoxide was evaluated as a Lewis base catalyst for the enantioselective propargylation of N-acylhydrazones with allenyltrichlorosilane. The helicene-derived catalyst provided moderate-to-good reactivity and enantioselectivity for a range of acylhydrazones. This study represents the first example of the catalytic asymmetric propargylation of non-activated acylhydrazones.