Rhodium effects on Pt anode materials in a direct alkaline ethanol fuel cell

The development of efficient catalysts for ethanol oxidation in alkaline medium requires a synthetic approach that may prevent the surfactant molecules from being adsorbed at the catalytic sites and decreasing the electrochemical performance of the final direct ethanol fuel cell. Toward this goal, the recently reported surfactant-less Bromide Anion Exchange (BAE) method, appears as a promising route to conveniently aim at preparing PtRh alloys dispersed on carbon substrates. The catalysts prepared herein by the BAE method were characterized physicochemically to obtain structural information on the PtRh/C nanomaterials, their morphology (size and shape), and their chemical and surface composition. Electrochemical behavior and properties of these electrodes were then investigated in a half-cell before the implementation of a direct ethanol fuel cell (DEFC) in a home-made anion exchange membrane Teflon cell. The analysis of the electrolytic solution in the anodic compartment by chromatography revealed that acetate was the major reaction product and the carbonate amount increased with the Rh content in the bimetallic composition. With 2.8–3.6 nm particle sizes, the Pt₅₀Rh₅₀/C catalyst exhibited the highest activity towards the ethanol electrooxidation.

The development of efficient catalysts for ethanol oxidation in alkaline medium requires an approach that avoids surfactant molecules from being adsorbed at active sites and decreasing the electrochemical performance of the direct ethanol fuel cell.     

Problems in the management of thyrotoxicosis in Black Africa: the Tongolese experience

In black Africa, and particularly in Togo, management of thyreotoxicosis is not simple. The intervention of several specialists and effective patient collaboration is needed. In a majority of cases, the patient's apprehensions, financial problems, and taboos prevent correct management. We report 30 cases of thyreotoxicosis in 82 patients with thyroid disease seen over a 5-year period in the Internal Medicine and Cardiology Department of the Lomé teaching hospitals. Graves' disease was the most frequent (83.33%), followed by multinodular goiter (10%) and toxic nodule (6.67%). Diagnosis was strictly clinical in 53.33% of the cases. The main complication was cardiothyreosis in 46.67% of the patients. Drug treatment was used. Short-term results (4 - 6 weeks) was favorable in 96.67% of the cases. A percentage (65.41%) were lost to follow-up after discharge. The main impairment encountered for the management of thyreotoxicosis was financial and economical difficulties not specific to the disease. Other problems included the lack of diagnostic and therapeutic means and insufficient cooperation between the surgeon, the cardiologist and the endocrinologist.     

Phase II,randomized, open,controlled study of AS03‐adjuvanted H5N1 pre‐pandemic influenza vaccine in children aged 3 to 9 years: follow‐up of safety and immunogenicity persistence at 24 months post‐vaccination

Background

An AS03-adjuvanted H5N1 influenza vaccine elicited broad and persistent immune responses with an acceptable safety profile up to 6 months following the first vaccination in children aged 3–9 years.

Methods

In this follow-up of the Phase II study, we report immunogenicity persistence and safety at 24 months post-vaccination in children aged 3–9 years. The randomized, open-label study assessed two doses of H5N1 A/Vietnam/1194/2004 influenza vaccine (1·9 μg or 3·75 μg hemagglutinin antigen) formulated with AS03_A or AS03_B (11·89 mg or 5·93 mg tocopherol, respectively). Control groups received seasonal trivalent influenza vaccine. Safety was assessed prospectively and included potential immune-mediated diseases (pIMDs). Immunogenicity was assessed by hemagglutination-inhibition assay 12 and 24 months after vaccination; cross-reactivity and cell-mediated responses were also assessed. ({"type":"clinical-trial","attrs":{"text":"NCT00502593","term_id":"NCT00502593"}}NCT00502593).

Results

The safety population included 405 children. Over 24 months, five events fulfilled the criteria for pIMDs, of which four occurred in H5N1 vaccine recipients, including uveitis (n = 1) and autoimmune hepatitis (n = 1), which were considered to be vaccine-related. Overall, safety profiles of the vaccines were clinically acceptable. Humoral immune responses at 12 and 24 months were reduced versus those observed after the second dose of vaccine, although still within the range of those observed after the first dose. Persistence of cell-mediated immunity was strong, and CD4⁺ T cells with a T_H1 profile were observed.

Conclusions

Two doses of an AS03-adjuvanted H5N1 influenza vaccine in children showed low but persistent humoral immune responses and a strong persistence of cell-mediated immunity, with clinically acceptable safety profiles up to 24 months following first vaccination.     

Electro-oxidation of C1 molecules at Pt-based catalysts highly dispersed into a polymer matrix: effect of the method of preparation

The electro-oxidation of oxygenated molecules containing one carbon atom (methanol, formaldehyde and formic acid) was systematically studied at highly dispersed Pt-based electrodes. The method of preparation appeared to be a key point, particularly for PtSn catalysts. An important decrease of the poisoning phenomena was systematically found, mainly with this latter electrode, but also with PtRu and PtRuSn electrodes. In the case of methanol oxidation, ruthenium-modified Pt electrodes are the best electrocatalysts, displaying the weakest poisoning. Conversely, for formic acid and formaldehyde oxidation, PtSn alloys give the most interesting results, better than those obtained with PtRu.     

Intraventricular thrombosis complicating peri-partum idiopathic myocardiopathy

Ventricular thrombosis can complicate the development and worsen the prognosis in any case of hypokinetic dilated cardiomyopathy. In the present article, a study has been made of 6 reports of ventricular thrombosis selected out of 58 medical files on women with peri-partum idiopathic cardiomyopathy. Patient age ranged from 22 to 55 years. The clinical picture showed hypokinetic dilated cardiomyopathy, complicated by cardiac failure; with its onset during the last trimester of gestation or in the 6 months post-partum. In all patients, overall cardiac failure was observed, and in all cases the diagnosis of intracardiac thrombosis was made by echocardiography. In all 6 patients, a left ventricular apical thrombosis was detected. In 2 subjects, 2 and 3 left ventricular thrombi were respectively found. In 1 case, a left ventricular thrombosis was present. In another case, a right thrombosis associated with a left ventricular thrombosis was detected. Treatment was initiated with a combination of anticoagulants (heparin and K antivitamins), diuretic and vasodilatory treatment. The clinical outcome was favorable, with the disappearance of thrombi and signs of cardiac failure (between the 15th and 54th day). No embolic complication was observed. These findings clearly show the importance of prescribing an anticoagulant treatment as a preventive measure during PPICM. Even if severe embolic complications are a potential risk, anitcoagulant treatment can ensure a favorable outcome.