Argilas bentoníticas da península de Santa Elena, Equador: pilarização, ativação ácida e seu uso como descolorante de óleo de soja

Two samples of calcic bentonite of the Santa Elena Peninsula, Ecuador, were pillared with Al13 ions in the ratio of 10, 15 and 20 meq of Al g-1 of clay, calcinated at 573, 723 and 873 ºK and acid activated with 4, 6 and 8 mol L-1 H2SO4. Analyses by X-ray diffraction, X-ray fluorescence, differential and gravimetric thermal, density, surface area and porosity, were applied in order to study the modifications occurred in the crystalline structure of the montmorillonite. The 8 mol L-1 H2SO4 acid-activated 15 meq of Al g-1 of clay at 573 ºK Al-pillared samples indicated the best results in the bleaching of the soybean oil measured by UV-visible spectrophotometer

PCR associated with agar gel immunodiffusion assay improve caprine arthritis-encephalitis (CAEV) control

Caprine arthritis-encephalitis (CAE) is a multi-systemic viral syndrome in goats caused by small ruminant lentivirus (CAEV). The control measures prescribed for CAEV control are based on the identification of infected animals through a suitable serological test. The aim of this work was to improve the CAE control measures through the association of indirect (agar gel immunodiffusion-AGID) and direct (PCR) assays to CAEV diagnosis. Thirty-nine kids born to AGID-seropositive dairy goats were separated from their dams immediately after birth, fed heat-treated colostrum from AGID-seronegative goats and then after pasteurized goat milk. AGID was performed at birth before colostrum, at 9 and 12 months, and the AGID-seropositive animals were segregated. Seronegative goats were also submitted to PCR to detect proviral DNA in blood, and the positives were isolated. A study of accumulated residual negativity was performed using a 95% confidence limit rate. During the 12 month experimental period no clinical signs of CAEV were observed. At the end of that period 34 animals remained ACID-seronegative to CAEV, corresponding to 87% accumulated residual negativity. When submitted to PCR, 4 of the 34 ACID-seronegative animals showed positive results, leading to a 77% final accumulated negativity rate with 64-90% confidence limits. We conclude that the classical management practices recommended for CAEV control are insufficient in CAEV eradication programs and that PCR may be a useful tool for decreasing the risk of breeding AGID false negative animals (CAEV carriers). (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq