Solid-phase microextraction may catalize hydrogenation when using hydrogen as carrier in gas chromatography.

When hydrogen is used as carrier gas, carbon-carbon double bonds may be hydrogenated in the hot gas chromatograph (GC) injector if introduced by solid-phase microextraction (SPME). SPME fibers coated with polydimethylsiloxane (PDMS)/carboxen/divinylbenzene (DVB), PDMS/carboxen, polyacrylate, PDMS/DVB and PDMS on fused silica, stableflex or metal alloy core have been tested with fatty acid methyl esters (FAMEs) from olive oil. Using coatings containing DVB, hydrogenation took place with high conversion rates (82.0-92.9%) independently of the core material. With all fibers having a metal core, hydrogenation was observed to a certain extent (27.4-85.3%). PDMS, PDMS/carboxen and polyacrylate coated fibers with a fused silica or stableflex core resulted in negligible hydrogenation (0.2-2.5%). The occurrence of hydrogenation was confirmed also with other substances containing carbon-carbon double bonds (n-alkenes, alkenoic acids, mono- and polyunsaturated fatty acid methyl and ethyl esters).

Stereoselective synthesis of (E)-4-alkylidenecyclopent-2-en-1-ones by a tandem ring closure-Michael addition-elimination.

Reaction of (Z)-1,4-diketones with various functionalized nitroalkanes in the presence of DBU gives 4-alkylidenecyclopent-2-en-1-ones with E selectivity. A cyclopentadienone intermediate is probably formed by intramolecular aldol condensation, and this reacts with a nitroalkane giving a Michael addition-elimination.

The use of low-molecular-weight heparin in acute coronary syndromes.

The initiating event in unstable angina (USA) and non-Q-wave myocardial infarction (NQMI) is the rupture of an atherosclerotic plaque resulting in local thrombosis. The current standard treatment is the administration of aspirin and heparin. The introduction of low-molecular-weight heparin (LMWH) offers a potential alternative therapy. Clinical trials have begun to examine the efficacy and safety of using LMWH in the management of acute coronary syndromes. Two pivotal studies have evaluated the effects of LMWH preparations on patients with USA or NQMI: The ESSENCE and the TIMI 11B trials. These studies suggest that LMWH plus aspirin is more effective and safer than unfractionated heparin in preventing myocardial infarction, recurrent angina, or death. Because of these differences, the American College of Cardiology and the American Heart Association have updated their guidelines for the treatment of USA and NQMI.

Nutritional status of a group of institutionalized elderly people in Perugia (Italy).

In this group of institutionalized elderly people the anthropometry and body composition situation is much better than that observed in a noninstitutionalized group examined longitudinally on a previous occasion. On the other hand, as expected, indices of physical activity are lower. The diet is in general satisfactory, considering the very low physical activity of those individuals. Only a few foods and nutrients show marginal low intakes (fish, eggs and legumes; lipids, iron, thiamin and vitamin A).