First Report of Puccinia kuehnii, Causal Agent of Orange Rust of Sugarcane, in Brazil.

In December 2009, on a farm located near the city of Rincão, state of São Paulo, Brazil, uredinial leaf lesions typical of a rust disease were observed to be affecting sugarcane (a complex Saccharum L. hybrid). Lesions were observed in a nursery plot of a precommercial cultivar (cv. Centauro) known to be resistant to brown rust caused by Puccinia melanocephala Syd. & P. Syd. Leaf samples, inspected under a light microscope, revealed spores identical morphologically to those described for the fungus P. kuehnii E.J. Butler, causal agent of sugarcane orange rust (1,3). Telia and teliospores were not observed. The Ministry of Agriculture was notified on 7 December 2009 in accordance with current Brazilian quarantine legislation. On 9 December, a specialized team from the Federal Phytosanitary Defense Department (DSV/MAPA) started a survey at the farm, collected leaf samples for additional analyses, and confirmed the presence of P. kuehnii E.J. Butler in Brazilian territory. During the following weeks, the disease was observed in several sugarcane-growing areas of the southern states of São Paulo and Paraná. It affected a small proportion of clones under selection in several breeding programs and the commercial cultivars SP89-1115, RB72454, and SP84-2025, which are now considered to be highly susceptible to the disease and currently cover less than 10% of the country's commercial sugarcane area. To our knowledge, this is the first report of P. kuehnii infecting sugarcane in Brazil, the largest world producer with more than 8 million ha of this crop. Orange rust is expected to expand to other important Brazilian sugarcane-producing areas, including the northeastern states and a new sugarcane expansion area in the central part of Brazil. The disease is widespread in the Asia-Pacific Region, caused a major epidemic in Australia in 2000, and was reported in the Western Hemisphere in 2007-2008 in several countries in North (1,2) and Central America (2,3) prior to this detection in South America. References: (1) J. C. Comstock et al. Plant Dis. 92:175, 2008. (2) R. C. Flores et al. Plant Dis. 93:1347, 2009. (3) W. Ovalle et al. Plant Dis. 92:973, 2008.

Sonochemical synthesis of calcium phosphate powders.

beta-tricalcium phosphate (beta-TCP) and biphasic calcium phosphate powders (BCP), consisting of hydroxyapatite (HA) and beta-TCP, were synthesized by thermal decomposition of precursor powders obtained from neutralization method. The precursor powders with a Ca/P molar ratio of 1.5 were prepared by adding an orthophosphoric acid (H(3)PO(4)) solution to an aqueous suspension containing calcium hydroxide (Ca(OH)(2)). Mixing was carried out by vigorous stirring and under sonochemical irradiation at 50 kHz, respectively. Glycerol and D-glucose were added to evaluate their influence on the precipitation of the resulting calcium phosphate powders. After calcination at 1000 degrees C for 3 h BCP nanopowders of various HA/beta-TCP ratio were obtained.

In vivo evaluation of hydroxyapatite foams.

Hydroxyapatite (HA) is widely applied as bone graft material due to its osteoconductive potential and well-established biocompatibility. In this work, macroporous hydroxyapatite structures made through foaming of aqueous suspensions and gelcasting were tested for in vivo osteointegration. These foams are composed of a three-dimensional array of spherical pores with diameters of approximately 100-500 microm, interconnected by windows of smaller size in the range of 30-120 microm. The HA foams were implanted in the tibia of albino New Zealand rabbits and removed after a period of 8 weeks. Histological analysis revealed that the pores in the foams were partially or completely filled progressively with mature new bone tissue and osteoid after the implanted period. No immune or inflammatory reactions were detected. The high osteoconductive potential of the HA foams provides a potential structure for use as bone substitute in orthopedic, oral, and cranio-maxillofacial reconstructive surgery, and as dento-alveolar implants.

Use of steel converter slag as nickel adsorber to wastewater treatment.

Magnetite, the main component of converter slag in the steel industry, can be used for the adsorption of Ni(II) from aqueous solutions, over a range of conditions: initial metal concentration (10-100 mg 1(-1)), stirring times (2-240 min), adsorbent dosage (1 g for 0.5 1 of metal solution) and temperatures (20, 30 and 38 degrees C). The adsorption rate increased with initial concentration but decreased with increase in temperature, due to competition of the dissolution process. The adsorption process obeyed the Freundlich isotherm model.

Production of porous hydroxyapatite by the gel-casting of foams and cytotoxic evaluation.

This study presents the manufacture of highly porous hydroxyapatite by a novel technique that employs the foaming of suspensions prior to the in situ polymerization of organic monomers contained in the compositions. This method produces strong gelled bodies with up to 90% porosity that can withstand machining in the green state. Complex-shaped components can be obtained if the process comprises casting in one of the processing steps. The organic additives are eliminated at temperatures above 300 degrees C, and sintering is carried out for consolidation of the ceramic matrix. Spherical interconnected cells with sizes ranging from 20 to 1000 micrometer characterize the porous structure, depending on the specimen density. Cytotoxicity tests were conducted on extracts from sintered HA foams based on a quantitative method of cell colony formation and the determination of cell death after indirect contact of the porous material with mammalian cells. This in vitro test of biological evaluation revealed that the original purity of the biomedical-grade hydroxyapatite powder was affected neither through processing nor by the employed reagents.

The interaction of blood proteins with alpha-alumina.

The use of alumina (alpha-Al2O3) as a material for cardiovascular applications was investigated on the basis of protein adsorption and thrombus formation on the material. The adsorption of 125I-labelled albumin and fibrinogen from phosphate buffered saline (pH 7.35, 0.100 M NaCl, 8.66 mM KH2PO4 and 41 mM Na2HPO4) solution on ceramic discs of alumina was studied. Both albumin and fibrinogen presented affinity for ceramic surfaces, with adsorptions of 1.47 +/- 0.06 ng/cm2 and 0.198 +/- 0.01 ng/cm2, respectively. Scanning electron micrographs of the alpha-Al2O3 surfaces after contact of the discs with whole human blood showed a thrombogenic behavior of alumina alpha. These results indicate a hemoincompatible property. Although critical surface tension (gamma C: 21.8 dynes/cm) of the disc surfaces determined by contact angle technique of sessile drops indicates that alumina alpha is a biocompatible material, by this criterion, the data reported here indicate that alpha-Al2O3 cannot be used for cardiovascular applications.

The interation of blood proteins with alpha-alumina

The use of alumina (Ó-Al2O3) as a material for cardiovascular applications was investigated on the basis of protein adsorption and thrombus formation on the material. The adsorption of 125I-labelled albumin and fibrinogen from phosphate buffered saline (pH 7.35, 0.100 M NaCl, 8.66 mM KH2PO4 and 41 mM Na2HPO4) solution on ceramic discs of alumina was studied. Both albumin and fibrinogen presented affinity for ceramic surfaces, with adsorptions of 1.47 + or - 0.6 ng/cm2 and 0.198 + or - 0.01 ng/cm2, respectively. Scanning electron micrographs of the Ó-Al2O3 surfaces after contact of the discs with whole human blood showed a thrombogenic behavior of alumina alpha. These results indicate a hemoincompatible property. Although critical surface tension (YC: 21.8 dynes/cm) of the disc surfaces determined by contact angle technique of sessile drops indicates that alumina alpha is a biocompatible material, by this criterion, the data reported here indicate that Ó-Al2O3 cannot be used for cardiovascular applications