Se describen tres métodos para obtener hidroxiapatita (HA). La HA es una cerámica muy interesante por sus múltiples aplicaciones médicas. Los primeros dos métodos de precipitación parten de compuestos de calcio y fósforo, mientras que el tercer método es un proceso sol-gel que usa alcóxidos. Los productos fueron caracterizados y comparados entre sı́. Las diferencias observadas son importantes pa...

Dipeptidyl aminopeptidase activity was found in the culture medium of Bacteroides gingivalis 381. The enzyme, hydrolyzing glycylprolyl-4-methylcoumaryl-7-amide, was purified 750-fold from culture medium by ammonium sulfate precipitation, Sephadex G-200 gel filtration, and DEAE Bio Gel A column chromatography. The molecular weight, determined by gel filtration, was approximately 160,000. The iso...

Plasma from estrogenized, [32P] NaH2PO4-injected murrel, Channa punctatus was collected in the presence of proteolytic inhibitors and subjected to different separation procedures singly or in combination, viz., gel filtration chromatography on Ultrogel AcA 34, ion-exchange chromatography on DEAE sephacel, or selective precipitation with dimethylformamide or with Mg2+: EDTA in order to isolate v...

Formation and dynamics of an Al(OH)3 precipitation ring is studied by diffusing NaOH into a gel containing AlCl3. Limited feeding of the outer electrolyte (NaOH) is found to yield an intricate ring-dynamics which involves stopping and reversal of the direction of motion of the precipitation ring, and evolution into stationary multi-ring structures. A model of the ring-dynamics is developed by c...

Yttria-doped zirconia powders" with an extremely small crystallite size (8 nm) and a narrow size distribution have been prepared by gel precipitation methods. Precipitation of an alkoxide solution in water ("alkoxide" synthesis) results in weaker agglomerates when compared with a precipitation of a metal chloride solution in ammonia ("chloride" synthesis). Both types of agglomerate are fracture...

AIMS Bile is an important body fluid which assists in the digestion of fat and excretion of endogenous and exogenous compounds. In the present study, an improved sample preparation for human bile was established. METHODS AND MATERIAL The method involved acetone precipitation followed by protein extraction using commercially available 2D Clean-Up kit. The effectiveness was evaluated by 2-dimen...

Three different high-performance liquid chromatographic (HPLC) techniques, i.e. affinity, ion exchange, and gel filtration chromatography, have been used to purify polyclonal antibodies from bovine serum. Polyclonal antibodies were obtained from animals infected with bovine leukaemia virus, which was confirmed by AGID and ELISA tests. Precipitation of the antibodies by ammonium sulphate prior t...

The effect of the preparation method of Co/TiO2 catalysts on the performance in the liquid phase hydrogenation of cinnamaldehyde and crotonaldehyde has been studied. The Co/TiO2 catalysts were prepared by impregnation on titania (TiO2, P-25), sol-gel, and precipitation procedures. Different reduction-oxidation-reduction cycles were carried out in order to detect possible changes in the nature o...

Alzheimer's disease (AD), the most common form of dementia, is manifested in the brain by the aggregation of amyloid plaques and neurofibrillary tangles. The tangles are primarily composed of microtubule-associated protein tau that is aberrantly hyperphosphorylated, suggesting that deregulated phosphorylation may contribute to AD pathogenesis. However, systematic analysis of the phosphoproteome...