Effects of pH and fluoride concentration of dentifrices on fluoride levels in saliva, biofilm, and biofilm fluid in vivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Median lethal concentration of formaldehyde and its genotoxic potential in bullfrog tadpoles (Lithobates catesbeianus)

In order to avoid that contaminated frog farms animals escaping in the environment and become potential vector of emergent diseases, studies with disinfection protocol are strictly necessary. The formaldehyde is one of the compounds tested in fungal disinfection protocols and also used in aquaculture. This study aimed to determine the median lethal concentration (LC50-96h) of formaldehyde in bullfrog tadpoles and to evaluate the possible genotoxic effects in acute exposition. Accordingly, the animals were exposed to formaldehyde in the concentrations of 6, 9, 12, 15, and 18 mg L(-1), and after 96 h blood samples were drawn for the micronucleus (MN) test. The LC50-96h was 10.53 mg L(-1), and the MN frequency increased in proportion to the formaldehyde concentrations, with an estimated frequency in the negative control being 1.35 MN/individual. We concluded that formaldehyde is genotoxic to tadpoles of bullfrogs in the tested concentrations, and the choice of this chemical should be contemplated before its use in animals in captivity.

Cassava root husks as a sorbent material for the uptake and pre-concentration of cadmium(II) from aqueous media

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Carbohydrate concentration in 'BRS Rubimel' peach trees during the annual cycle

The carbohydrate storage is necessary to support the plant growth in periods of stress, during the dormancy, in the beginning of the vegetative development and during the fruiting time. In this context, this work intended to evaluate the carbohydrate concentrations of the peach (Prunus persica (L.) Batsch) tree ‘BRS Rubimel’, cultivated under subtropical conditions. The experiment was performed at the experimental farm Lageado, of the Faculty of Agricultural Sciences of UNESP at Botucatu/SP. The evaluated peach trees were two years old and were cultivated in the spacing of 6.0 x 4.0 m. The adopted experimental delineation was in randomized blocks, making use of four plants per parcel with four repetitions. The treatments corresponded to the period of the collection of leaves and branches, during the annual cycle, corresponding to January to May and July to December 2012. The sample collection of the roots was performed in January, April, August, November and December 2012. Four fruits per plant were collected. The concentration of starch in the roots of the peach tree were superior to the ones from the branches, from August to December. The carbohydrate with the higher storage level in the peach tree ‘BRS Rubimel’ was starch.

Parameterization of bio-optical models for estimating chlorophyll-a concentration in a tropical eutrophic reservoir

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Geoquímica de radionuclídeos naturais e biomonitoramento em área de mineração de carvão no sul do Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)