Data Mining of Heterogeneous Electrical Conduction in the Electrode Components of Fuel Cells.

The electrodes of a polymer electrolyte membrane fuel cell (PEMFC) primarily contain a Pt/C catalyst and Nafion binder. Since these components play crucial roles in the redox reaction and proton transport, respectively, their distributions can directly affect the electrochemical reactivity and thus the device performance. Although analyzing the component distribution is important to understand its electrochemical reactivity and improve the device performance, determining it for the PEMFC electrode remains a challenging task. Herein, we propose a strategy for visualizing the spatial distribution of the electrode components and their heterogeneous electrical properties using multidimensional current-voltage (I-V) spectroscopy combined with data mining. The electrical properties of the electrode components, i.e., the Pt/C catalyst and Nafion binder, were explored by I-V spectroscopy, and their electrical heterogeneity was spatially classified based on the shapes of the measured I-V curves by cluster analysis. The results show that the components and their interfacial structure can be spatially visualized from the surface electrical heterogeneity. The proposed method is expected to be applicable for investigating in detail not only the spatial properties of PEMFC electrodes but also the properties of various material systems.

Palonosetron-Induced Anaphylaxis During General Anesthesia: A Case Report.

Palonosetron is a 5-hydroxytryptamine-3 (5-HT-3) receptor antagonist used for preventing postoperative nausea and vomiting. Compared with ondansetron and granisetron, it is a better drug because of prolonged action and minimal side effects. Some adverse effects of palonosetron have been reported. In this report, we describe a 37-year-old male who developed severe hypersensitivity reactions to palonosetron during surgery for kidney donation. His medical history was unremarkable, except for inguinal hernia with herniorrhaphy 8 years ago. The surgery was uneventful until 2 hours 20 minutes. After palonosetron injection, his blood pressure dropped to 80/50 mm Hg, and facial edema, rash, conjunctival swelling, and wheezing developed. The patient was resuscitated by administration of ephedrine, hydrocortisone, and peniramine. Following the surgery, the patient was monitored for 3 days, and there were no subsequent anaphylactic reactions or other complications. The skin test on postoperative day 54 was positive for hypersensitivity to palonosetron. Although palonosetron is known for its safety, other hypersensitivity events have been reported. Ondansetron is another widely used 5-HT-3 antagonist, which has been reported to cause anaphylaxis. Therefore, clinicians should be aware of the possibility of patients experiencing severe adverse reactions to palonosetron.