Endogenous and exogenous polyamines in the organogenesis in Curcuma longa L.

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

Levels of copper in Nile tilapia from Brazil

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

Evolution of Substrate Preparation Behaviors for Cultivation of Symbiotic Fungus in Attine Ants (Hymenoptera: Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Planting of fungus onto hibernating workers of the fungus-growing ant Mycetosoritis clorindae (Attini, Formicidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants

We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix.

Yeasts and filamentous fungi carried by the gynes of leaf-cutting ants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ecology of microfungal communities in gardens of fungus-growing ants (Hymenoptera: Formicidae): a year-long survey of three species of attine ants in Central Texas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)National Science Foundation (NSF)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

COEVOLUTION BETWEEN ATTINE ANTS and ACTINOMYCETE BACTERIA: A REEVALUATION

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nitrogen-tixing and vesicular-arbuscular mycorrhizal symbioses in some tropical legume trees of tribe Mimoseae

Response to mineral fertilization and inoculation with rhizobia and/or arbuscular mycorrhiza fungi (AMF) of the Anadenanthera colubrina, Mimosa bimucronata and Parapiptadenia rigida (Leguminosae-Mimosoideae) native trees from Brazilian riparian forests, were studied in nursery conditions. Each species was submitted to seven treatments, varying nitrogen and phosphorous fertilization and inoculation with rhizobia (r), mycorrhiza (m) or both (rm): NP, P, P + r, P + rm, N, N + m and N + rm. Results showed that AMF inoculations did not enhance the mycorrhizal colonization, and P uptake was not sufficient to sustain good growth of plants. The level of P mineral added affected negatively the AMF colonization in A. colubrina and M. bimucronata, but not in P. rigida. Native fungi infected the three legume hosts. The absence of mineral N limited growth of A. colubrina and P. rigida, but in M. bimucronata the lack of N was corrected by biological nitrogen fixation. N mineral added inhibited the nodulation, although spontaneous nodulation had occurred in A. colubrina and M. bimucronata. Rhizobia inoculation enhanced the number of nodules, nitrogenase activity and leghemoglobin content of these two species. Thus, the extent of rhizobial and mycorrhizal symbiosis in these species under nursery conditions can affect growth and consequently the post-planting success. (C) 2004 Elsevier B.V. All rights reserved.

Effect of surfactants and polyethylene glycol on the activity and stability of a lipase from oilseeds of Pachira aquatica

Lipases from oilseeds have a great potential for commercial exploration as industrial enzymes. Lipases are used mixed with surfactants in cleaning and other formulated products, and accordingly, both components must be compatible with each other. This work presents the results of the effects of anionic, cationic and nonionic surfactants, polyethylene glycol and urea on the activity and stability of a lipase extracted of oilseeds from Pachira aquatica. The enzyme was purified and the spectrophotometric assays were done using p-nitrophenyl acetate (p-NPA) as substrate pH 7.5 and 25 degrees C. The activity was significantly enhanced by the cationic surfactant CTAB. Bile salts increased the lipase activity in the tested concentration range, whereas anionic and nonionic surfactants showed an inhibitory effect. Aqueous solutions of PEG activated the lipase and maximum activation (161%) occurred in PEG 12,000. This effect on lipase that can be due to exposition of some hydrophobic residues located in the vicinity of the active site or aggregation.

Oral Piercing Complications Among Teenage Students

Purpose: The aim of this study was to assess the use of oral piercings and their possible associated complications among students aged 14 to 18 years.Materials and Methods: A total of 927 students from private and state schools were invited to participate in this study. The participants were subjected to clinical examination, and a questionnaire was provided for collecting the following data: gender, piercing location, oral complications or alterations, and cleaning frequency.Results: Among the students who were analysed, 33 had oral piercings (3.6%); 69.70% were from state schools and 30.30% were from private schools. There was a slight predominance of males (54.55%) compared with females (45.45%). The tongue was the most common location for piercing (66.6%). The complications and alterations associated with the use of piercing were observed in 74.3% of the cases.Conclusions: In the population that was studied, oral piercing was observed in a small percentage of teenage students (3.6%) and there were local complications associated with its use.

Resin Bonding to a Feldspar Ceramic After Different Ceramic Surface Conditioning Methods: Evaluation of Contact Angle, Surface pH, and Microtensile Bond Strength Durability

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

Effects of Nd : YAG and Er : YAG lasers on the sealing of root canal fillings

Objective: the ability of the laser irradiation to promote the cleaning and disinfection of the radicular canal system has become this type of treatment in a viable and real alternative in endodontics. The purpose of this study was to evaluate the apical marginal sealing of root canal fillings after the irradiation with the laser of Nd:YAG or of Er:YAG. Materials and Methods: Forty-two human, extracted single-rooted teeth had their crowns sectioned and the root canals prepared with a no. 70 K-file. Then, they were dried and divided into three groups according to canal wall treatment: group 1: the canals were filled with EDTA for 3 min, followed by irrigation with 1% sodium hypochlorite solution; group 2: the canal walls were irradiated with Nd:YAG laser; and group 3: the canal walls were irradiated with Er:YAG laser. Afterwards, the root canals were obturated by the lateral condensation technique. The roots were externally waterproof, except in the apical foramen and immerged in 2% methylene blue aqueous solution during 48 hours. Results: the results showed that the largest infiltrations happened in the group 3-Er:YAG (7.3 mm), proceeded by the group 1-EDTA (1.6 mm) and by the group 2-Nd:YAG (0.6 mm). The group Er:YAG differed statistically of the others (p < 0.05). Conclusion: It was concluded that the Er:YAG laser intracanal irradiation previously to the root canal filling must be used with caution until future research is define the best parameters for it's use.

Effect of silica coating combined to a MDP-based primer on the resin bond to Y-TZP ceramic

The aim of this study was to evaluate the influence of silica coating and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based primer applications upon the bonding durability of a MDP-based resin cement to a yttrium stabilized tetragonal zirconia (Y-TZP) ceramic. Ninety-six Y-TZP tabs were embedded in an acrylic resin (free surface for adhesion: 5 x 5 mm(2)), ground finished and randomly divided into four groups (N = 24) according to the ceramic surface conditioning: (1) cleaning with isopropanol (ALC); (2) ALC + phosphoric acid etching + MDP-based primer application (MDP-primer); (3) silica coating + 3-methacryloyloxypropyl trimethoxysilane (MPS)-based coupling agent application (SiO(2) + MPS-Sil); and (4) SiO(2) + MDP-primer. The MDP-based resin cement was applied on the treated surface using a cylindrical mold (diameter=3 mm). Half of the specimens from each surface conditioning were stored in distilled water (37 C, 24 h) before testing. Another half of the specimens were stored (90 days) and thermo-cycled (12,000x) during this period (90d/TC) before testing. A shear bond strength (SBS) test was performed at a crosshead speed of 0.5 mm/min. Two factors composed the experimental design: ceramic conditioning strategy (in four levels) and storage condition (in two levels), totaling eight groups. After 90d/TC (Tukey; p < 0.05), SiO(2) + MDP-primer (24.40 MPa) promoted the highest SBS. The ALC and MDP-primer groups debonded spontaneously during 90d/TC. Bonding values were higher and more stable in the SiO2 groups. The use of MDP-primer after silica coating increased the bond strength. (C) 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part 8: Appl Biomater 95B: 69-74, 2010.

In Vitro Assessment of Chemical Activation Efficiency During In-office Dental Bleaching

Purpose: This study compared five types of chemical catalyzing agents added to 35% hydrogen peroxide gel, with regard to their capacity of intensifying in-office dental bleaching results.Methods: One-hundred and twenty bovine incisors were used, of which the crowns and roots were cut in the incisor-apical direction, to acquire the dimensions of a human central incisor. The specimens were sectioned in the mesiodistal direction by means of two longitudinal cuts, the lingual halves being discarded. The vestibular halves received prophylaxis with a bicarbonate jet, ultrasound cleaning and acid etching on the dentinal portion. Next, the specimens were stored in receptacles containing a 25% instant coffee solution for two weeks. After the darkening period, initial measurement of the shade obtained was taken with the Easy Shade appliance, which allowed it to be quantified by the CIELab* method. The samples were divided into six groups, corresponding to the chemical activator used: a) none (CON); b) ferric chloride (CF); c) ferrous sulphate (SF); d) manganese gluconate (GM); e) manganese chloride (CM); f) mulberry root extract (RA). Each group received three 10-minute applications of the gels containing the respective activating agents. Next, a new shade measurement was made.Results: The Analysis of Variance and Tukey tests (alpha=5%) showed statistically significant differences for the shade perception values (p=0.002). Groups GM, CM and RA showed significantly higher means than the control group.Conclusion: The presence of some chemical activators is capable of resulting in a significant increase in tooth shade variation.