Physicochemical analysis of Ti-Si-B powder aalloys

Titanium alloys of Ti-Si-B system were manufactured by blended elemental powder method using Ti, Si and B powders as starting materials. It was found that uniaxial and isostatic pressing followed by hot pressing at around 1000°C, for 20 minutes, provided good densification of such alloys. The physicochemical studies were performed by means of scanning electron microscopy, X-ray diffraction, atomic force microscopy and microindentation/wear tests. The investigations revealed a multiphase microstructure formed mainly by α-titanium, Ti6Si2B, Ti5Si3, TiB and Ti3Si phases. The phase transformations after pressureless sintering at 1200°C was also studied by X-ray diffraction for the Ti-18Si-6B composition. As stated in some other researches, these intermetallics in the α-titanium matrix provide high wear resistance and hardness, with the best wear rate of 0.2 mm3/N.m and the highest hardness of around 1300 HV. © (2012) Trans Tech Publications, Switzerland.

Blood Cues Induce Antipredator Behavior in Nile Tilapia Conspecifics

In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood. © 2013 Barreto et al.

Chemical characterization and flexural strength of a denture base acrylic resin with monomer 2-tert-butylaminoethyl methacrylate

Purpose: The objectives of this study were to investigate the flexural strength (FS) and chemical interaction between 2-tert-butylaminoethyl methacrylate (TBAEMA) and a denture base acrylic resin. Materials and Methods: Specimens were divided into five groups according to the concentration of TBAEMA incorporated in acrylic resin Onda-Cryl (0%, 1%, 2%, 3%, 4%) and were submitted to Fourier transform infrared spectroscopy (FTIR), electron spectroscopy for chemical analysis (XPS-ESCA), and differential scanning calorimetry (DSC) analyses. FS of the specimens was tested, and results were analyzed by ANOVA/Tukey's test (α < 0.05). Results: Different nitrogen ratios were observed on specimens' surfaces: 0.36%, 0.54%, 0.35%, and 0.20% for groups 1%, 2%, 3%, and 4%, respectively. FTIR indicated copolymerization of acrylic resin and TBAEMA, and DSC results demonstrated a decrease in glass transition temperature (Tg). Significant differences were found for FS (p < 0.05). The mean values were 91.1 ± 5.5,A 77.0 ± 13.1,B 67.2 ± 12.5,B 64.4 ± 13.0,B and 67.2 ± 5.9B MPa for groups 0%, 1%, 2%, 3% and 4%, respectively (same superscript letters indicate no significant difference). Conclusions: The incorporation of TBAEMA in acrylic resin resulted in copolymerization and the presence of amine groups on specimens' surfaces, and in decreases of Tg and FS. © 2012 by the American College of Prosthodontists.

Serotonergic neurons in the nucleus raphé obscurus are not involved in the ventilatory and thermoregulatory responses to hypoxia in adult rats

The medullary raphé is an important component of the central respiratory network, playing a key role in CO2 central chemoreception. However, its participation in hypoxic ventilatory responses is less understood. In the present study, we assessed the role of nucleus raphé obscurus (ROb), and specifically 5-HT neurons confined in the ROb, on ventilatory and thermoregulatory responses to hypoxia. Chemical lesions of the ROb were performed using either ibotenic acid (non-specific lesion; control animals received PBS) or anti-SERT-SAP (5-HT specific lesion; control animals received IgG-SAP). Ventilation (VE; whole body plethysmograph) and body temperature (Tb; data loggers) were measured during normoxia (21% O2, N2 balance) and hypoxia exposure (7% O2, N2 balance, 1h) in conscious adult rats. Ibotenic acid or anti-SERT-SAP-induced lesions did not affect baseline values of VE and Tb. Similarly, both lesion procedures did not alter the ventilatory or thermoregulatory responses to hypoxia. Although evidence in the literature suggests a role of the rostral medullary raphé in hypoxic ventilatory responses, under the present experimental conditions our data indicate that caudal medullary raphé (ROb) and its 5-HT neurons neither participate in the tonic maintenance of breathing nor in the ventilatory and thermal responses to hypoxia. © 2013 Elsevier B.V.

Avaliação dos efeitos citotóxicos, genotóxicos, mutagênicos, antigenotóxicos, antimutagênicos e anticarcinogênicos do Lupinus albus em camundongos Mus musculus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da suplementação intranasal de oxigênio em diferentes protocolos anestésicos em veados-campero (Ozotoceros bezoarticus, Linnaeus 1758) de vida livre

Pós-graduação em Cirurgia Veterinária - FCAV

Modelo experimental de urolitíase em ovinos: estudo clinico, laboratorial e hemogasométrico

Pós-graduação em Medicina Veterinária - FMVZ

Reutilization of chemical waste in methodologies for analyses of neutral detergent fiber and acid detergent fiber

The disposal of chemical waste and the precision of analyses of the neutral (NDF) and acid (ADF) detergent fiber contents were evaluated utilizing conventional (Van Soest) and alternative methods of analyses. The recovery of acetone promoted both economic and environmental gains, with a recovery rate of 84.12%. The precision of the analyses was not observed in most of the determinations with reutilization of chemical waste in all the analytical methods tested, in spite of promoting decrease in cost, time invested in the preparation of solutions and the disposal of chemical waste.

The chemical properties of soil for alfalfa production after biofertiliser application

The objective of this study was to evaluate the use of biofertilisers for the production of alfalfa shoot, root and nodule dry matter, and also, to evaluate the chemical properties of the soil. This study was conducted in the greenhouse of the Support Department, Animal Production and Health, Faculty of Veterinary Medicine/UNESP, Aracatuba - SP, from May to October 2010. The experimental design was completely randomised with six biofertiliser doses (0, 25, 50, 100, 200 and 400 m(3) ha(-1)) and five replicates. The biofertiliser doses were the primary treatments and the cuts (five) were subplots. The cuts were performed, on average, every 27 days at 10 cm above the soil. At the end of the experiment, the roots, nodules and soil from all experimental units were collected for chemical analysis. We observed a linear increase in dry matter production of the shoots relative to the doses studied. The dry matter production of the roots and nodules was not significantly different. The chemical properties of the soil significantly improved for calcium and magnesium as well as the sum of bases and base saturation with biofertiliser application. Biofertilisers can be used for agricultural production and favourably alter the soil characteristics.

Mechanical and chemical analyses across dental porcelain fused to CP titanium or Ti6Al4V

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

PHYSIOLOGIC EFFECTS OF THREE DIFFERENT PROTOCOLS OF ISOFLURANE ANESTHESIA IN CAPTIVE BROWN BROCKET DEER (MAZAMA GOUAZOUBIRA)

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

Chemical and morphological features of nanofilled composite resin: influence of finishing and polishing procedures and fluoride solutions

This study evaluated the influence of finishing and polishing procedures and differ-ent fluoride solutions on superficial morphology and chemistry of the nanofilled composite resinSupreme XT (3M) through the EDX analysis and SEM evaluation. Circular specimens (n 5 30) of 10mm diameter and 2 mm thickness were prepared, with half of the sample assays finished and polishedwith Super-Snap1sandpaper. The experimental groups were divided according to the presence or ab-sence of finishing and polishing and solutions (arti ficial saliva, 0.0 5% of manipulated sodium fluoridesolution, Fluordent Re ach, Oral B, Fluorgard). Specimens were immersed in each respective solutionfor 1 min per day, during 60 days and stored in artificial saliva at 37 6 18C between immersion peri-ods. Topography and chemical analysis was qualitative. It was observed that specimens submitted tofinishing and polishing procedures had lower superficial degradation. Fluoride solutio ns promoted su-perficial alterations on specimens, being the highest degradation obtained with Fluordent Reach. Itca n be concluded that finishing and polishing procedures and the immersion media influence the su-perficial morphology of composite resin tested; the Fluordent Reach was the flu oride solution thatmo st affected the material’s surface.

Chemical and morphological features of dental composite resin: influence of light curing units and immersion media

Aims: The study evaluated the influence of light curing units and immersionmedia on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M)through the EDX analysis and SEM evaluation. Light curing units with different power densitiesand mode of application used were XL 3000 (480 mW/cm2), Jet Lite 4000 Plus (1230mW/cm2), andUltralume Led 5 (790 mW/cm2) and immersion media were artificial saliva, Coke1, tea and coffee,totaling 12 experimental groups. Specimens (10 mm 3 2 mm) were immersed in each respectivesolution for 5 min, three times a day, during 60 days and stored in artificial saliva at 378C 6 18Cbetween immersion periods. Topography and chemical analysis was qualitative. Findings: Groupsimmersed in artificial saliva, showed homogeneous degradation of matrix and deposition of calciumat the material surface. Regarding coffee, there was a reasonable chemical degradation with loss ofload particles and deposition of ions. For tea, superficial degradation occurred in specific areaswith deposition of calcium, carbon, potassium and phosphorus. For Coke1, excessive matrix degra-dation and loss of load particles with deposition of calcium, sodium, and potassium. Conclusion:Light curing units did not influence the superficial morphology of composite resin tested, but theimmersion beverages did. Coke1affected material’s surface more than did the other tested drinks.Microsc. Res. Tech. 73:176–181, 2010.

Evaluation of zebu nellore cattle blood samples using the Cell-Dyn 3500 hematology analyzer

The Cell-dyn 3500 is a multiparameter flow cytometer, which may analyze samples from several species performing several simultaneous analyses. It is able to perform white blood cells, red blood cells and platelet counts, besides differential leukocyte counts, packed cell volume and hemoglobin determination. Cell-Dyn 3500 performs total leukocyte count both optically and by impedance. The equipment may choose one or other method, based on the reliability of the results. Erythrocyte and platelet counts are determined by impedance. Leukocyte differentiation is based on an optical principle, using separation in multiangular polarized light. The objective of this study was to compare the results of complete blood count of Zebu Nellore heifers from Cell-dyn 3500, with those obtained from a semi-automated cell counter (Celm CC 510) and the manual technique. Blood samples were collected from the jugular vein in 5 mL EDTA vacuum tubes from 58 Nellore heifers, at 24 months of age. Samples were processed in parallel in the three different techniques. Results were analyzed using paired t test, Pearson's correlation and the Bland-Altmann method. There was a strong correlation for all parameters analyzed by Cell-Dyn 3500, manual method and semi-automated cell counter, except for basophils and monocytes counts. These results confirm that this analyzer is reliable for blood samples analysis of zebu cattle.

In vivo evaluation of the genetic toxicity of Rubus niveus Thunb. (Rosaceae) extract and initial screening of its potential chemoprevention against doxorubicin-induced DNA damage

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