Organic radicals for the enhancement of oxygen reduction reaction in Li-O2 batteries.

We examine for the first time the ability of inert carbon free-radicals as soluble redox mediators to catalyze and enhance the oxygen reduction reaction in a (TEGDME)-based electrolyte. We demonstrate that the tris(2,4,6-trichlorophenyl)methyl (TTM) radical is capable of chemically favoring the oxygen reduction reaction improving significantly the Li-O2 battery performance.

Chemical vs. electrochemical extraction of lithium from the Li-excess Li(1.10)Mn(1.90)O4 spinel followed by NMR and DRX techniques.

Lithium extraction from the Li-excess Li1.10Mn1.90O4 spinel has been performed by chemical and electrochemical methods in aqueous and in organic media, respectively. De-lithiated samples have been investigated by XRD, SEM, TG, (7)Li and (1)H MAS-NMR techniques. The comparative study has allowed demonstrating that the intermediate de-intercalated samples prepared during the chemical extraction by acid titration are similar to those prepared by the electrochemical way in a non-aqueous electrolyte. LiMn2O4 based spinel with a tailored de-lithiation degree can be prepared as a single phase by controlling the pH used in chemical extraction. (7)Li MAS-NMR spectroscopy has been used to follow the influence of the manganese oxidation state on tetra and octahedral Li-signals detected in Li-extracted samples. The oxidation of Mn(III) ions goes parallel to the partial dissolution of the spinel, following Hunter's mechanism. Based on this mechanism, a generalized chemical reaction has been proposed to explain the formation of intermediate Li(+) de-intercalated samples during acid treatment in aqueous media. By the (1)H MAS NMR study, no evidence of Li-H topotactic exchange in the bulk of the acid treated material was found.

A randomized double-blind study of low-molecular-weight heparin (parnaparin) for superficial vein thrombosis: STEFLUX (Superficial ThromboEmbolism and Fluxum).

BACKGROUND: Optimal doses and duration of low-molecular-weight heparin (LMWH) for the treatment of superficial vein thrombosis (SVT) are still uncertain. OBJECTIVES: To compare the efficacy and safety of different doses and durations of LMWH parnaparin for symptomatic lower limb SVT. PATIENTS AND METHODS: Outpatients with at least a 4-cm-long SVT of long or short saphenous veins or their collaterals were randomized to receive parnaparin either 8500 UI once daily ( o.d.) for 10 days followed by placebo for 20 days (group A) or 8500 UI o.d. for 10 days followed by 6400 UI once daily (o.d.) for 20 days (group B) or 4250 UI o.d. for 30 days (group C) in a double-blind fashion in 16 clinics. Primary outcome was the composite of symptomatic and asymptomatic deep vein thrombosis (DVT), symptomatic pulmonary embolism (PE) and relapse and/or symptomatic or asymptomatic SVT recurrence in the first 33 days with 60 days follow-up. RESULTS: Among 664 patients, primary outcome occurred in 33/212 (15.6%), 4/219 (1.8%) and 16/217 (7.3%) subjects in groups A, B and C, respectively (B vs. A: absolute risk reduction [ARR]: 13.7%, 95% confidence intervals [CI]: 8-18.9 P<0.001; B vs. C: ARR: 5.5%; 95% CI: 1.6-9.4 P= 0.011; C vs. A: ARR: 8.2%, 95% CI: 2-14 P=0.012). During days 0-93, the event rate was higher in group A (22.6%) than either in group B (8.7%; P=0.001) or C (14.3%, P=0.034). No major hemorrhages occurred. CONCLUSIONS: An intermediate dose of parnaparin for 30 days is superior to either a 30-day prophylactic dose or a 10-day intermediate dose for lower limb SVT treatment.

[Hyperlipemia and erythrocyte filterability]. / Iperlipemia e filtrabilità eritrocitaria.

The erythrocyte filterability was examined in 30 patients presenting identical values of fibrinogen and polymorphonuclear leucocytes (10 patients had normal values of lipemia, cholesterol and triglycerides and in the other 20 patients one or more of these parameters were altered). In the first group filterability values were homogeneous, while in the second group they were higher and widely dispersed. A close proportionality between the reduced filterability rate and cholesterolemic values was also found.