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Pt-transition metal oxides are emerging as new class of electrodes for alcohol oxidation reactions. We prepare at room temperature Pt-SnO2 nanocomposites of various surface morphologies onto carbon nanotubes for enhanced ethanol oxidation reaction (EOR) by cross-beam pulsed laser deposition technique. Synthesized nanocomposites are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), XRD, Raman spectroscopy, and transmission electron microscopy (TEM). It is observed that the interaction of SnO2 with Pt modifies the electronic structure of the latter inducing the formation of ionized Pt2+ and Pt4+ while Sn revealed mixed Sn4+ and Sn2+ cations. An optimum electrocatalytic performance toward EOR is obtained with a Pt-SnO2 grown under 0.5 Torr of He atmosphere. Versus a CNT/Pt electrode, this CNT/Pt-SnO2 electrode (i) oxidizes ethanol at much lower potentials (86 mV negative), and (ii) displays a superior specific mass activity of 1.6 times and 2.2 times by cyclic voltammetry and long-term stability, respectively. Such performance is ascribed to a combination of: (i) SnO2 has abundant hydroxyls on the surface and decrease the CO poisoning based on a bifunctional mechanism; (ii) modification of the electronic structure of Pt (electronic effect) and (iii) a semi-porous surface morphology favorable for the mass transfer of ethanol molecules. [ABSTRACT FROM AUTHOR]

Abstract: With the objective of lowering the potential oxidation of ethanol at PtSn nanocatalyst, we present the synthesis of free-standing catalyst layer comprising a current collector/carbon nanotubes (catalyst support)/SnO2/Pt75Sn25 (catalyst) nanostructured layers, each layer constructed upon the one below it. The CNTs are grown by chemical vapor deposition (CVD), whereas SnO2 and Pt75Sn25 are synthesized by pulsed laser deposition and cross-beam laser deposition, respectively. FESEM revealed that Pt75Sn25 nanoparticles assemble into cauliflower-like arrangement. TEM and HR-TEM showed that the Pt75Sn25 layer thickness is of ca. 25nm with a particle mean diameter of 4.3nm. It was found that addition of SnO2 to Pt75Sn25 promotes significantly the oxidation of ethanol at Pt75Sn25 nanoparticles relative to a carbon nanotubes support. Indeed, the electrooxidation of ethanol at CNTs/SnO2/Pt75Sn25 electrode starts at about 100mV negative with respect to that at CNT/Pt75Sn25. This decreased overpotential required to oxidize ethanol is very significant and has profound implications to developing high performing anodes for direct ethanol fuel cells technology. [Copyright &y& Elsevier]

BACKGROUND Trimethoprim/sulfamethoxazole and levetiracetam are commonly prescribed medications in the treatment of infections and seizures, respectively. Despite their known efficacy, each has a reputation for triggering severe and sometimes life-threatening cutaneous adverse drug reactions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Although the mechanism of such cutaneous adverse drug reactions cannot be fully explained, it is thought to be a type IV T cell and NK cells-mediated hypersensitivity reaction that leads to keratinocyte apoptosis and epidermal necrosis. It is also thought that cutaneous adverse drug reactions are also linked to a patient's genetic predispositions, especially the human leukocyte antigens profiles and the N-acetyl transferase 2 phenotypic variation. CASE REPORT We describe a case of Stevens-Johnson syndrome in a severely ill 51-year-old man who was treated in an outside health care facility simultaneously with Trimethoprim/sulfamethoxazole and levetiracetam. The patient presented to our Emergency Department with Stevens-Johnson syndrome believed to possibly be related to the combination of these 2 agents. CONCLUSIONS The concomitant use of Trimethoprim/sulfamethoxazole and levetiracetam might have been responsible for heightening the potential of these 2 medications to trigger an unfortunate adverse drug reaction, but no formal culprit was able to be identified and no in vivo study was performed, due to ethical considerations. Thus, through this case report we strive to increase awareness of the potential risk of simultaneously prescribing these 2 medications.