Adsorption into the MFI zeolite of aromatic molecule of biological relevance. Investigations by Monte Carlo simulations.

Adsorption of paracresol and water into the silicalite-1 (MFI) zeolite has been investigated using canonical and grand-canonical Monte Carlo simulations. The most stable sites of adsorption of paracresol are found to be located at the channel intersections. Grand-canonical simulations have shown that at low loading, water molecules adsorb preferably at the vicinity of paracresol molecules, whereas they are also located in the sinusoidal channels as the loading increases.

Analysis of amitrole by normal-phase liquid chromatography and tandem mass spectrometry using a sheath liquid electrospray interface.

The coupling of normal-phase liquid chromatography to tandem mass spectrometry, previously developed in our laboratory, has been applied to the analysis of amitrole. This coupling utilizes an electrospray interface modified to accommodate the introduction of a make-up solution at the tip of the electrospray probe. A methanolic solution containing 3 mM ammonium acetate delivered at a flow rate of 10 microL .

Regulation of cuticular and postpharyngeal hydrocarbons in the slave-making ant Polyergus rufescens: effect of Formica rufibarbis slaves.

The purpose of this study was to compare cuticular hydrocarbon profiles of slave-making Polyergus rufescens ants reared alone or with their Formica rufibarbis slaves. Chemical analyses showed that due to the close contacts occurring when the Formica were tending the Polyergus, the synthesis of the cuticular hydrocarbons carried by the slaves was enhanced in the slave-makers. The postpharyngeal hydrocarbon levels increased during the first 15 days of life, whether or not the Polyergus were exposed to Formica.

The location of the ligand-binding site of carbohydrate-binding modules that have evolved from a common sequence is not conserved.

Polysaccharide-degrading enzymes are generally modular proteins that contain non-catalytic carbohydrate-binding modules (CBMs), which potentiate the activity of the catalytic module. CBMs have been grouped into sequence-based families, and three-dimensional structural data are available for half of these families. Clostridium thermocellum xylanase 11A is a modular enzyme that contains a CBM from family 6 (CBM6), for which no structural data are available.

Down regulation of hypertrophied follicular cell volume in thyroid hyperplastic gland.

In the present study, changes in thyroid follicular cell volume and its regulation have been investigated during the early involution of a hyperplastic goitre. Male Wistar rats were administered an iodine deficient diet for 6 months with propylthiouracil (PTU, 0.15%) during the last two months.