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Le traitement des eaux de raffinerie par le procédé des Iits bactériens constitue une solution intéressante. Néanmoins, il subsiste actuellement des problèmes pratiques d'exploitation, en particulier la tendance au colmatage des lits bactériens existants qui résulte d'un encrassement incontrôlé des garnissages en vrac. Après étude, il est confirmé que les hydrocarbures, les matières en suspension contenus dans l'effluent et une mauvaise évacuation de la biomasse sont à l'origine du problème. L'examen des possibilités de lutte contre ce phénomène permet de distinguer des mesures curatives et des mesure préventives. Les mesures curatives qui consistent à régénérer le garnissage par augmentation de la charge hydraulique, nettoyage chimique, ou nettoyage manuel ne donnent pas entière satisfaction. Parmi tes mesures préventives, l'une des méthodes consiset à réduire la charge polluante de l'effluent : les eaux usées phénolées sont dessalées, les eaux de désulfuration du gas oil (DGO) et fluid cracking catalytic (FCC) sont strippées, les soudes sont réinjectées dans le brut, les huiles récupérées juste en aval de leur rejet, les traitements primaires sont optimisés, notamment par installation de racleurs et de tambours oléophiles sur les séparateurs API et par un meilleur choix de floculants. Néanmoins, l'expérience montre que cette méthode ne permet que de retarder l'échéance du colmatage. Le meilleur moyen de lutte réside dans le choix du matériau de garnissage, ainsi que le montrent les essais pilotes comparatifs réalisés par l'Institut National de Recherche Chimique Appliquée (lRCHA) et Compagnie Française de Raffinage (CFR). Ces essais, qui ont portés sur l'évolution de la densité du garnissage, les performances épuratoires et la qualité des boues montrent que le Cloisonyle, garnissage tubulaire, est probablement le matériau le mieux adapté. Refinery waste-water treatment by trickling filtration process is an interesting solution. Nonetheless, practical operating problems currently exist, and in particular the tendency for existing fixed film systems to become plugged up, resulting in the uncontrolled fouling of bulk liners. A study has shown that improper evacuation of the biomass are the cause of the problem. An investigation of how to control this phenomenon shows a distinction between curative and preventive measures. Curative measures consisting in regenerating the filter packing by increasing the hydraulic loading and by chemical or mechanical cleaning do not give full satisfaction. Among preventive measures, one method consists in reducing the organic loading of the effluent: phenol-containing waste waters are desalinated, waters from DGO and FCC are stripped, alcaline waters are reinjected into the crude oil, oils are recovered. just downstream from where they are discharged, and primary treatments are optimized, in particular by the installation of scrapers and oleophilic drums on the API separators and by a better choice of flocculants. Nevertheless, experience shows that this method does not delay plugging. The best method is in choosing contact medium, as is shown by comparative pilot-plant texts performed by Institut National de Recherche Chimique Appliquée (lRCHA) and Compagnie Française de Raffinage (CFR). These tests were concentrated on the fate of the specific gravity of the packing on purifying performances and on sludge quality; they have showes that cloisonyle forming a tubular packing is probable the best suited material.

Results show that the interaction of acetylcholinesterase with different molecules of the anti-Alzheimer drug (-)-huperzine A and its homologues occurs at the 'anionic' subsite of the active site of the enzyme. Data indicate that rearrangement of the amino acid residues of the 'oxyanion' hole occurs due to a peptide flip.

Research reveals that the carbamate inhibitor rivastigmine is a 'pseudo-irreversible' inhibitor of acetylcholinesterase as indicated by slow decarbamylation. However, the kinetics of the enzyme inhibition shows species dependence in that the source of the enzyme influences the inhibitory profile. Further, the in vivo and in vitro inhibition patterns differ.

The kinetics of the binding of huprine X inhibitor to the Torpedo californica acetylcholinesterase reveal that it binds to the anionic site and obstructs access to the esteratic site as shown by molecular dynamics simulation of the huprine X inhibitor/enzyme complex crystal structure.

X-ray crystallography and photoaffinity labelling were used to examine the binding regions of Torpedo acetylcholinesteraes for quarterly ligands. The aromatic groups were revealed as binding sites for quarterly ligands by the structural and chemical information collected. This data provides proof for designating Trp-84 and Phe-330 to the 'anionic' subsite of the active region, and Trp-279 to the outer anionic region.

Strongyloidiasis, as a result of Strongyloides stercoralis (Rhabditida: Strongyloididae) infestation, is occasionally recognized in a range of vertebrate hosts, including humans and dogs and causes widespread clinical disease in infected individuals ranging from asymptomatic to fulminating respiratory or gastrointestinal disease. We describe a case of strongyloidiasis in a young Pomeranian puppy that presented after history of a seizure and gastrointestinal disease associated with inadequate weight gain. Blood and parasitological analyses, that included Baermann culture and fecal flotation, revealed severe leukocytosis, anemia and hypoglycemia, as well as the presence of Strongyloides spp. in feces. PCR targeting the nuclear ribosomal DNA and mitochondrial (cox1) genes followed by sequencing of the amplicons revealed 100% identity with S. stercoralis and HVR IV haplotype A, which is potentially zoonotic. After two repeated five-day treatments with oral fenbendazole, infection was cleared and the dog recovered. Small animal clinicians should be aware of this disease especially among the canine progeny of animal breeders and shelter dogs whereby ideal conditions for increased transmission cycles may likely take place. Moreover, due to its zoonotic potential, a correct diagnosis of Strongyloides is crucial in order to prevent infection of those people that are involved in the care of infected dogs. [ABSTRACT FROM AUTHOR]