The Impact of Different Surface Treatments on Topography and Bond Strength of Resin Cement to Lithium Disilicate Glass Ceramic.

OBJECTIVE: To evaluate the influence of different surface treatments on topography, surface roughness, surface energy, and microtensile bond strength stability of resin cement to lithium disilicate glass ceramic. METHODS AND MATERIALS: Seventy disc-shaped specimens of IPS e.max Press were divided into seven groups according to the surface treatment: NT - non-treated (control); FSil - hydrofluoric acid (HF) + silane; FPSil - HF + phosphoric acid (HP) + silane; FUSil - HF + ultrasonic bath (U) + silane; FPUSil - HF + HP + U + silane; MEP - Monobond Etch and Prime (MEP); and MEPH - MEP + heating. Topography and surface roughness were evaluated using a 3D laser confocal microscope (3DLCM) and scanning electron microscopy (SEM) and surface energy with a goniometer. The microtensile bond strength (µTBS) was evaluated after storage in distilled water at 37°C for 24 hours and after thermocycling (5,000 cycles, 5°-55° C, 30-second dwell time). Data were analyzed using one-way ANOVA (surface roughness and surface energy), two-way ANOVA (µTBS), Tukey's HSD post-hoc test, and Student t-test (α=0.05). RESULTS: FUSil, FPSil, and FSil presented similar and highest surface roughness, whereas NT, FPUSil, MEP, and MEPH showed similar, and lowest, roughness values (p<0.05). FPUSil, FPSil, FUSil, and FSil presented a similar and highest surface energy. NT, MEP, and MEPH showed similar and lowest surface energy. CONCLUSION: Only FSil, FPSil, and MEPH maintained bond strength stability after thermocycling, with FPSil leading to less bond strength reduction, suggesting this protocol is more reliable for bonding resin cements to lithium disilicate glass ceramics.

Characterization of novel human intragenic antimicrobial peptides, incorporation and release studies from ureasil-polyether hybrid matrix.

Intragenic antimicrobial peptides (IAPs) are internal sequences of proteins with physicochemical similarities to Antimicrobial Peptides (AMPs) that, once identified and synthesized as individual entities, present antimicrobial activity. Many mature proteins encoded by the genomes of virtually any organism may be regarded as inner reservoirs of IAPs, conferring them ample biotechnological potential. However, IAPs may also share shortcomings with AMPs, such as low half-life in biological media and non-specific adsorption in eukaryotic cells. The present manuscript reports a translational approach that encompasses the uncovering of two novel IAPs from human proteins as well as the first results concerning the incorporation and sustained release of one of these peptides from ureasil-polyether hybrid polymeric films. For such, the software Kamal was used to scan putative IAPs in the human proteome, and two peptides, named Hs05 and Hs06, were identified, synthesized, and tested as antimicrobials. Biophysical assays were conducted using model phospholipid vesicles and 1H NMR solution structures in phospholipid micelles were obtained for the IAP Hs05. This peptide was incorporated in a polymeric matrix composed of the ureasil/PPO-PEO-PPO triblock copolymer, and the resulting films were evaluated by atomic force microscopy and imaging mass spectrometry. The release rate of Hs05 from the polymeric matrix was assessed and the antimicrobial activity of Hs05-loaded hybrid polymeric films was evaluated against the bacterium Escherichia coli. This study represents the first steps towards the development of polymeric films enriched with IAPs obtained from the human proteome as sustained release devices for topical application.

Manufacturing ceramic bricks with polyaluminum chloride (PAC) sludge from a water treatment plant.

The objective of this research work is to assess the viability of manufacturing ceramic bricks with sludge from a water treatment plant (WTP) for use in real-world applications. Sludge was collected from settling tanks at the Bolonha WTP, which is located in Belém, capital of the state of Pará, Brazil. After dewatering in drainage beds, sludge was added to the clay at a local brickworks at different mass percentages (7.6, 9.0, 11.7, 13.9 and 23.5%). Laboratory tests were performed on the bricks to assess their resistance to compression, water absorption, dimensions and visual aspects. Percentages of 7.6, 9.0, 11.7 and 13.9% (w/w) of WTP sludge presented good results in terms of resistance, which indicates that technically, ceramic bricks can be produced by incorporating up to 13.9% of WTP sludge.

Techniques for restoring enlarged canals: an evaluation of fracture resistance and bond strength.

AIM: To verify the influence of fibreglass post diameter, as well as use of accessory posts on fracture resistance and bond strength, when used for restoring enlarged root canals. METHODOLOGY: One hundred maxillary single-rooted canine human teeth were decoronated and root canals were prepared using a No.4 drill (White Post, FGM, Joinville, SC, Brazil). The roots were assigned to five groups: (EC1) post No.1 (Exacto Cônico, Angelus, Londrina, PR, Brazil); (EC2) post No.2 (Exacto Cônico, Angelus); (EC3) post No.3 (Exacto Cônico, Angelus); (ECA) post No.1 (Exacto Cônico, Angelus) plus two accessory posts (Reforpin, Angelus); (WP) post No.4 (White Post, FGM). Posts 1-4 have a crescent diameter. Posts were luted (Rely X-Arc, 3M ESPE, USA) and composite resin filling cores were prepared for the fracture resistance test (n = 10). For the push-out test (n = 10), roots were sectioned into 1 mm thick slices. Both tests were performed in a universal testing machine. Data were analysed using anova and Tukey's test. RESULTS: Groups WP and EC3 had higher fracture resistance than the other groups (P < 0.05), which were statistically similar. Root fractures occurred in 14% of the specimens. Groups EC1 and EC2 had lower bond strength values than Groups EC3 and ECA which were lower than the WP Group (P < 0.05). Bond strength was lower in the apical and middle third than in the cervical third of root canals (P < 0.05). CONCLUSIONS: Thicker posts were associated with higher resistance to fracture and bond strength to root canals. Using a post plus two accessory posts improved the bond strength but not the fracture resistance.

Seasonal variation of natural mortality factors of the guava psyllid Triozoida limbata.

It is important to understand how components of the agroecosystem interfere with the attack of a pest species and their seasonality in order to use these components in IPM programs. This study focused on the evaluation of the seasonality of natural control factors associated with the guava psyllid Triozoida limbata (Enderlein) in Brazil. Life-table data were collected from an experimental guava orchard during four periods that roughly represented four seasons. Natural mortality was monitored daily through the immature stages, and the relative importance of each natural mortality factor and its seasonality was determined. Significant statistical differences were observed in the mortality during the four periods (P < 0.05). Several factors contributed to the mortality of T. limbata, including rainfall, physiological disturbance, the parasitoid Psyllaephagus sp. (Hymenoptera: Encyrtidae) and specific predators: syrphids, predatory wasps and other generalist predators. Depending on the location of nymphs (exposed or inside galls), the relative importance of the different natural mortality factors changed. The principal component analysis (PCA) showed some trends in the relationship of natural control agents and weather conditions. For example, the occurrence of predatory wasps was positively correlated with temperature and occurrence of winds; the occurrence of syrphids and Psyllaephagus sp. were negatively correlated with temperature and winds; and the occurrence of other generalist predators were negatively correlated with the occurrence of rainfall and photoperiod. The results showed the importance of natural mortality factors for the management of T. limbata and their changes through the different seasons which should be considered when implementing IPM programs in guava orchards.

Atividade antimicrobiana in vitro de extratos etanólicos de própolis de três estados brasileiros sobre Aeromonas hydrophila isoladas de peixes

The present study was aimed to evaluate the in-vitro susceptibility of Aeromonas spp. to ethanolic extracts of propolis (one green and two brown) from three Brazilian states (Minas Gerais, Ceará and Pernambuco). In order to verify the antimicrobial activity of the propolis in vitro, 15 Aeromonas spp. isolates were tested to determine the minimal bactericidal concentration (MBC) of the extracts. Ethanol at 70% was used as a control. Survival curves for the bacterial growth were determined by incubation of the isolates in ethanolic extracts of propolis at 15% for 24 hours. The averages of the MBC of propolis extracts were 1.68% for the green propolis of Minas Gerais, 2.31% for the brown propolis of Ceará, and 3.75% for the brown propolis of Pernambuco. The survival curve of the isolates showed partial inhibition until three hours of incubation. This result is compatible with the bacteriostatic effect of propolis that may be useful to antibiotic therapy in aquaculture, as an alternative to few available antimicrobial drugs.

O presente estudo teve como objetivo avaliar a sensibilidade in vitro de Aeromonas hydrophila frente a extratos etanólicos de própolis (uma verde e duas marrons) obtidos em três estados brasileiros (Minas Gerais, Ceará e Pernambuco). Para verificar a atividade antimicrobiana in vitro da própolis, 15 isolados de A. hydrophila foram testados para determinar a Concentração Bactericida Mínima (CBM) dos extratos. Curvas de sobrevivência para o crescimento bacteriano foram determinadas pela incubação dos isolados em extratos etanólicos de própolis a 15% por 24 horas. As médias da CBM dos extratos de própolis foram 1,68% para a própolis verde, 2,31% para a própolis marrom do Ceará e 3,75% para a própolis marrom de Pernambuco. A curva de sobrevivência dos isolados demonstrou uma inibição parcial com até três horas de incubação. Este resultado é compatível com o efeito bacteriostático da própolis, o que pode ser de interesse para a terapia em aquicultura, como alternativa às poucas drogas antimicrobianas disponíveis.

Modulatory effects of Duguetia furfuracea (A. St. Hil) Benth. and Hook. f. in Drosophila melanogaster somatic and germinative cells.

Mutagenic and antimutagenic activities of the medicinal plant Duguetia furfuracea were assessed using SMART/wing and ring-X-loss tests. For the ring-X-loss test, 2- to 3-day-old Drosophila melanogaster ring-X-lineage males and virgin ywsn³ females received D. furfuracea infusion at doses of 0.085, 0.042, or 0.014 g/mL for 24 h. We found that D. furfuracea did not produce any mutagenic effects in D. melanogaster germinative cells. The somatic cells of D. melanogaster were analyzed using the SMART/wing test involving three lineages - mwh, flr³, and ORR - and the same doses of D. furfuracea infusion employed in the ring-X-loss test, as well as 20 mM urethane. The results of both standard (ST) and high bioactivation (HB) crosses showed absence of mutagenic activity of D. furfuracea. In contrast, in both ST and HB crosses, we observed a modulatory effect of D. furfuracea against the genotoxic activity of urethane.

Potential re-colonisation by cladocerans of an acidic tropical pond.

To predict how re-colonisation of acidified lakes will proceed, at least two approaches are possible: (i) to compare the life history traits of candidate species and determine which one has the highest fitness, and (ii) to simulate a more realistic scenario carrying out experiments with the grouping of the candidate species, so that the intrinsic rate of natural increase of each species is integrated with its sensitivity to low pH and its ability to compete with the other candidate populations. The objective of the present study was to investigate the future re-colonisation of such acidified systems, taking as case-study a tropical pond (Lagoa das Dunas, Camaçari, BA, Brazil) and four species of cladocerans occurring in nearby water bodies (Ceriodaphniacornuta, Ceriodaphniasilvestrii, Latonopsisaustralis and Macrothrix elegans), by comparing the two above mentioned approaches. The second approach included two sets of in situ microcosms experiments, one simulating the re-colonisation by immigrating ephippia, thus using neonates of each species as colonisers, and another simulating the immigration of adults. Both these simulations followed nearly the same trends. The integration of the effects of a higher temperature, a different photoperiod and species competition determined differences in the species densities ranking between the two approaches: life history versus microcosms. The densities of C. cornuta in the microcosms matched the biphasic concentration/response hormetic model, in the simultaneous presence of two increasingly intense stressors (interspecific competition and acidity), with a low-dose stimulation and a high-dose inhibition. The present study provided, thus, a further support to the acceptance of hormesis in ecotoxicology, also at the population level in multispecies experiments.

Insulin resistance among Brazilian schoolchildren: association with risk factors for cardiovascular diseases.

AIM: Our purpose was to evaluate Insulin Resistance (IR) and its association with risk factors for cardiovascular diseases (CVDs) among 161 (6- to 10-year-old) schoolchildren. METHODS: This two-stage cross-sectional study evaluated: BMI, blood pressure, personal history (birth weight) and family history of CVDs. Children with at least one of the following criteria participated in the second stage: obesity, personal or family history. Insulin resistance was determined using Homeostasis Model Assessment (HOMA). RESULTS: The HOMA distribution in terciles showed mean values for the first, second and third tercile of 0.41, 0.79 and 2.11 respectively. The HOMA distribution in the third tercile demonstrated statistically significant associations with overweight/obesity (p = 0.007), hypertension (p = 0.008) and low HDL (p = 0.02). Analysis of mean birth weight in each tercile and between terciles did not present any positive correlation (p = 0.213). CONCLUSION: Higher levels of HOMA (IR) were positively associated with risk factors for CVD among schoolchildren.

Cardiorespiratory responses to stationary running at different cadences in water and on land.

AIM: The aim of the current study was to analyze the heart rate (HR), oxygen uptake (V.O(2)), and percentage of maximal HR (%HR(max)) and V.O(2) (%V.O(2max)) responses to stationary running exercise performed at different cadences on land (LA) and in water (WA). METHODS: The sample comprised 12 apparently healthy women (mean age 22.33+/-0.57 years). The exercise was performed in WA and LA environments (interval of 2 hours) at submaximal cadences of 60, 80 and 100 bpm for a period of 4 min at each cadence (interval of 5 min). HR and V.O(2) data were collected using a Polar S610TM and Aerosport KB1-C gas analyzer, respectively. The data were analyzed using factorial ANOVA for mixed models, Tukey's post hoc and Pearson's correlation test, with P<0.05 (SPSS version 13.0). RESULTS: Significant differences were found between the environments for all variables (HR, V.O(2), %HR(max) and %V.O(2max): P<0.001), with higher values for LA. Significant differences were found between the cadences for all variables (HR, V.O(2), %HR(max) and %V.O(2max): P<0.001). The effect of the interaction environment cadence was only significant for %HR(max) (P=0.041). The correlations between HR and V.O(2) (WA: r=0.857; P<0.001 and LA: r=0.556; P<0.001) and %HR(max) and %V.O(2) (WA: r=0.860; P<0.001 and LA: r=0.798; P<0.001) exhibited high and significant correlation coefficient values, especially for WA, suggesting that variable increased linearly with increases in cadence. CONCLUSIONS: The results suggest that cardiorespiratory responses to stationary running exercise are lower in WA, though they can be maximized by increasing the execution cadence.

Reproduction of Cubaris murina (Crustacea: Isopoda) under laboratory conditions and its use in ecotoxicity tests.

Reproduction of the isopod Cubaris murina was studied in the laboratory in order to observe the offspring number per brood, the number and duration of the incubation periods, and the influence of repeated mating on number of young per brood. An experiment was conducted with two different groups: female/male pairs and females that were isolated after mating. No significant difference was found between the two reproductive female groups for the mean number of young per brood (x = 25) and the duration of the incubation periods (x = 17 days). One mating was enough for at least five broods, with no reduction in brood size. There was no significant difference between the number of adult males and females. Low-density cultures had a significantly higher growth rate compared to high-density cultures. Furthermore, the experimental results for optimization isopod culture conditions for terrestrial ecotoxicity testing are reported.

Light transmission on dental resin composites.

OBJECTIVES: The purposes of this study was: (1) to examine the light transmittance characteristics of two light-cured resin composites, for different thickness, (2) to correlate the light transmittance through the resin composites and the filler contents, and (3) to determine the penetration depth of the light as a function of the wavelength. METHODS: Two resin composites (Filtek Z250, shade A2 and Filtek Supreme XT, shade A2E) were used. Specimens of six different thicknesses (0.15, 0.25, 0.30, 0.36, 0.47 and 0.75 mm) were prepared (n=3). The transmittance at wavelengths from 400 to 800 nm was measured using a UV-visible spectrophotometer, before and after light polymerization. RESULTS AND SIGNIFICANCE: Significant differences were found in the wavelength dependence of transmittance between the two materials, and between the unpolymerized and polymerized stages of each resin composite. At lower wavelengths, the light transmittance of the Filtek Supreme XT resin composite was lower than the Filtek Z250. At the higher wavelengths, however, Filtek Supreme XT presented higher light transmittance. For both resin composites, the penetration depth was higher after polymerization. However, Filtek Supreme XT showed a higher gain in transmittance at the 0.15 mm thickness. The difference in light transmittance characteristics of the resin composites may affect their depth of polymerization.

Influence of different dentinal substrates on the tensile bond strength of three adhesive systems.

PURPOSE: To evaluate the influence of the method and duration of storage for different types of teeth prior to their use in dentin bonding tests with three adhesive systems. MATERIALS AND METHODS: Recently extracted sound human molars, bovine incisors, and human caries-free molars obtained from exhumed bones 5 years postmortem were used. The latter group of teeth was kept dry for 6 months, and then rehydrated in distilled water over a period of 30 days. The adhesive systems used were Prime&Bond 2.1. Single Bond, and Etch&Prime 3.0. Human teeth were embedded longitudinally in PVC cylinders; bovine incisors were embedded leaving the buccal surface exposed. Flat dentin surfaces were cut with a diamond disk and ground with up to 600-grit SiC paper. Adhesives were applied following manufacturers' instructions. A silicone mold with a cone-shaped perforation (4.5 mm high and 2 mm diameter at the smallest) was fixed on the dentin surface and filled with TPH composite resin. The specimens were stored in distilled water for two weeks before testing. RESULTS: ANOVA did not detect statistical differences either in the main factors (substrate and adhesive system) or in their interaction (p > 0.05). Tensile bond strength averages ranged from 11.6 to 14.2 MPa. The dentinal substrates showed similar performances, regardless of the adhesives tested. CONCLUSION: The differences among the three dentin substrates do not appear to be critical for the tensile bond strength test for the three adhesive systems. The adhesive systems presented similar bond strengths.

Impact of the application of neurolinguistic programming to mothers of children enrolled in a day care center of a shantytown.

CONTEXT: Of the members of a family, the mother is without doubt the most important one, which provides justification for including an evaluation of her mental health as one of the variables to be considered as determining factors in each child's level of development. OBJECTIVE: To assess the impact of the application of Neurolinguistic Programming (NLP) on child development, home environment and maternal mental health. DESIGN: Randomised controlled trial. SETTING: The study included children enrolled in the municipal day care center of a shantytown in the City of São Paulo. PARTICIPANTS: 45 pairs of mothers and respective children between 18 and 36 months of age. MAIN MEASUREMENTS: Children's development (Bayley scales); home environment variation (HOME); and maternal mental health (SRQ). Comparison between before and after the intervention was made in terms of children's psychomotor development, home environment and maternal mental health. INTERVENTION: Application of the NLP technique to the experimental group and comparison with a control group. 1--Experimental (EG), consisting of 23 children submitted to intervention by NLP; and 2--Control (CG), with 22 children with no intervention. Length of intervention: 15 sessions of NLP. RESULTS: 37 children remained in the study (EG = 10, CG = 27). Variations in mental development (OR 1.21, IC 95% 0.0 to 23.08) in their home environment (Wilcoxon): p = 0.96 (before) and p = 0.09 (after); in maternal mental health: p = 0.26, 2 df. CONCLUSIONS: There was a trend that indicated positive effects on the home environment from the intervention.

The use of the mitochondrial transmembrane electric potential as an effective biosensor in ecotoxicological research.

In this work, the mitochondrial transmembrane electric potential (delta psi) of isolated mitochondria was used to evaluate the toxicity of some chemicals (endosulfan, 3,4-dichloroaniline, parathion, tributyltin and cadmium) and wastewater. Mitochondria were isolated from rat liver, and the delta psi measured in a suitable assay medium, using a sensitive tetraphenylphosphonium (TPP+) electrode. The test substance was pre-incubated in a rotenone-containing medium during 3 min with 1.0 mg of mitochondrial protein. Mitochondria were energised with succinate and after the establishment of a constant maximal potential ADP was added to induce the phosphorylative cycle. Chosen endpoints were the membrane potential from mitochondria oxidising succinate and the depolarisation induced by ADP. After the appropriate transformations the EC50 (effective concentration) was calculated for each toxicant. Even very low concentrations of a toxicant were able to affect the delta psi, thus showing its suitability as a biosensor in ecotoxicology and results were reproducible between tests. The utilisation of delta psi in screening tests of pure substances and wastewater seems to be very effective and can be carried out routinely.

[Outbreak of acute toxoplasmosis transmitted thru the ingestion of ovine raw meat]. / Surto de toxoplasmose aguda transmitida através da ingestão de carne crua de gado ovino.

The authors present 17 cases of symptomatic acute toxoplasmosis acquired by the ingestion of raw mutton offered during a party in September 1993. The incubation period carried from 6 to 13 days (10.9 +/- 7.0). Sixteen (94.5%) patients presented fever, headache, myalgia, arthralgia, and adenopathy (cervical or cervical/axilar). Hepatomegaly was found in 6 patients, splenomegaly in 4 and rash in 2. One patient presented clinical picture of chorioretinitis confirmed by ophthalmological exam. All patients showed increased serum levels of specific antibodies (IgG and IgM) on indirect immunofuorescence assay evidencing acute phase of toxoplasmosis. The patients were treated with specific drugs for toxoplasmosis and presented satisfactory clinical and laboratory response.