Urinary fluoride excretion in children exposed to fluoride toothpaste and to different water fluoride levels in a tropical area of Brazil

The aim of this study was to evaluate the urinary fluoride excretion of 2- to 7-year-old children exposed to different water fluoride concentrations in the city of Catolé do Rocha, PB, Brazil. Forty-two children were allocated to 3 groups according to the concentration of fluoride in the water: G1 (n=10; 0.5-1.0 ppm F), G2 (n=17; 1.1-1.5 ppm F) and G3 (n= 15; >1.51 ppm F). The study was carried out in two 1-week phases with 1-month interval between the moments of data collection: in the first phase, the children used a fluoride toothpaste (FT) (1,510 ppm F) for 1 week, whereas in the second phase a non-fluoride toothpaste (NFT) was used. The urine was collected in a 24-h period in each week-phase according to Marthaler's protocol. The urinary fluoride excretion data expressed as mean (SD) in ì g/24 h were: G1-FT= 452.9 (290.2); G1-NFT= 435.1 (187.0); G2-FT= 451.4 (224.0); G2-NFT= 430.3 (352.5); G3-FT=592.3 (390.5); and G3-NFT=623.6 (408.7). There was no statistically significant difference between the water fluoride groups, and regardless of the week phase (ANOVA, p>0.05). The use of fluoride toothpaste (1,510 ppmF) did not promote an increase in urinary fluoride excretion. There was a trend, though not significant, as to the increase of urine fluoride concentration in relation to fluoride concentrations in the water. The excretion values suggest that some children are under risk to develop dental fluorosis and information about the appropriate use of fluoride is necessary in this area.

Fractional order and dynamic simulation of a system involving an elastic wide plate

Numerous researchers have studied about nonlinear dynamics in several areas of science and engineering. However, in most cases, these concepts have been explored mainly from the standpoint of analytical and computational methods involving integer order calculus (IOC). In this paper we have examined the dynamic behavior of an elastic wide plate induced by two electromagnets of a point of view of the fractional order calculus (FOC). The primary focus of this study is on to help gain a better understanding of nonlinear dynamic in fractional order systems. © 2011 American Institute of Physics.

Nitrogen excretion during embryonic development of the green iguana, Iguana iguana (Reptilia; Squamata)

Development within the cleidoic egg of birds and reptiles presents the embryo with the problem of accumulation of wastes from nitrogen metabolism. Ammonia derived from protein catabolism is converted into the less toxic product urea or relatively insoluble uric acid. The pattern of nitrogen excretion of the green iguana, Iguana iguana, was determined during embryonic development using samples from allantoic fluid and from the whole homogenized egg, and in hatchlings and adults using samples of blood plasma. Urea was the major excretory product over the course of embryonic development. It was found in higher concentrations in the allantoic sac, suggesting that there is a mechanism present on the allantoic membrane enabling the concentration of urea. The newly hatched iguana still produced urea while adults produced uric acid. The time course of this shift in the type of nitrogen waste was not determined but the change is likely to be related to the water relations associated with the terrestrial habit of the adult. The green iguana produces parchment-shelled eggs that double in mass during incubation due to water absorption; the eggs also accumulate 0.02. mM of urea, representing 82% of the total measured nitrogenous residues that accumulate inside the allantois. The increase in egg mass and urea concentration became significant after 55. days of incubation then were unchanged until hatching. © 2012 Elsevier Inc.

The fractional and nonlinear magneto-flexible rod

This paper deals with a system involving a flexible rod subjected to magnetic forces that can bend it while simultaneously subjected to external excitations produces complex and nonlinear dynamic behavior, which may present different types of solutions for its different movement-related responses. This fact motivated us to analyze such a mechanical system based on modeling and numerical simulation involving both, integer order calculus (IOC) and fractional order calculus (FOC) approaches. The time responses, pseudo phase portraits and Fourier spectra have been presented. The results obtained can be used as a source for conduct experiments in order to obtain more realistic and more accurate results about fractional-order models when compared to the integer-order models. © Published under licence by IOP Publishing Ltd.

The fractional-nonlinear robotic manipulator: Modeling and dynamic simulations

In this paper, we applied the Riemann-Liouville approach and the fractional Euler-Lagrange equations in order to obtain the fractional-order nonlinear dynamics equations of a two link robotic manipulator. The aformentioned equations have been simulated for several cases involving: integer and non-integer order analysis, with and without external forcing acting and some different initial conditions. The fractional nonlinear governing equations of motion are coupled and the time evolution of the angular positions and the phase diagrams have been plotted to visualize the effect of fractional order approach. The new contribution of this work arises from the fact that the dynamics equations of a two link robotic manipulator have been modeled with the fractional Euler-Lagrange dynamics approach. The results reveal that the fractional-nonlinear robotic manipulator can exhibit different and curious behavior from those obtained with the standard dynamical system and can be useful for a better understanding and control of such nonlinear systems. © 2012 American Institute of Physics.

Photoelectrochemical properties of FTO/m-BiVO4 electrode in different electrolytes solutions under visible light irradiation

Photoelectrochemical properties of FTO/BiVO4 electrode were investigated in different electrolytic solutions, potassium chloride (KCl) and sodium sulphate (Na2SO4), and under visible light irradiation condition. In order to accomplish that, an FTO/BiVO4 electrode was built by combining the solution combustion synthesis technique with the dip-coating deposition process. The morphology and structure of the BiVO4 electrode were investigated through X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. Photoelectrochemical properties were analyzed through chronoamperometry measurements. Results have shown that the FTO/BiVO4 electrode presents higher electroactivity in the electrolyte Na2SO4, leading to better current stabilization, response time, and photoinduced current density, when compared to KCl electrolyte. Besides, this electrode shows excellent performance for methylene blue degradation under visible light irradiation condition. In Na2SO4, the electrode has shown higher degradation rate, 51 %, in contrast to 44 % in KCl, plus higher rate constant, 174 × 10-4 min-1 compared to 150 × 10-4 min-1 in KCl. Results presented in this communication leads to the indication of BiVO4 thin films as alternate materials to use in heterogeneous photoelectrocatalysis, more specifically in decontamination of surface water. © 2013 Springer-Verlag Berlin Heidelberg.

Role of acidic and basic electrolytes on the structure and morphology of cathodically reduced indium tin oxide (ITO) substrates

In this report we track the structural changes suffered by ITO along galvanostatic polarization at different current densities by X-ray diffraction and SEM micrographs. The XRD shown that cathodic treatment induces structural change in ITO, characterized by appearing peaks set distinct from ITO original structure associated to metallic phase of the solid solution of In-Sn. It is interesting to note that although the different ions present in the solution are not, at least to a noticeable degree, incorporated in the metallic phase, the SEM images show that they do influence its formation, pointing to some type of adsorptive mechanism of the inert ions during the lateral diffusion of the metallic ions. © 2013 Elsevier Ltd. All rights reserved.

Time-course morphological and functional disorders of the kidney induced by long-term high-fat diet intake in female rats

BackgroundEvidence is emerging that highlights the far-reaching consequences of a high-fat diet (HFD) on kidney morphology and function disorders.MethodsThe present study was performed on 3-, 5-, 7- and 9-week-old HFD female rats compared with the appropriate gender and age-matched animals. We evaluated the kidney expression of angiotensin type II receptor and fibrotic and epithelial-to-mesenchymal transition (EMT) markers, by immunoblotting and immunohistochemical and histological techniques, in parallel with kidney function.ResultsIn the current study, the time-course HFD-treated group showed, by immunoblotting and immunohistochemical analysis, an early time-course increase in the expression of transforming growth factor β-1 (TGFβ-1) in the entire kidney of HFD-treated rats, compared with that observed in the control group. Simultaneously, the study shows a transient increase in the expression of ZEB2 in the HFD whole kidney accompanied by a fall in the E-cadherin expression and increased collagen and fibronectin deposition. A pronounced decrease in fractional urinary sodium excretion was also demonstrated in the long-term HFD-treated rats. The decreased FENa + was accompanied by a fall in FEPNa + and FEPP Na +, which occurred in association with significantly decreased CCr and, certainly on the sodium-filtered load. The reduction in the glomerular filtration rate (GFR) occurred in parallel to proteinuria and glomerular desmin overexpression.ConclusionsThe results of the current study suggest that podocyte injury in parallel with observed proteinuria and evidence of EMT transformation are associated with long-term loss of kidney function and renal sodium and water retention. © 2013 The Author. All rights reserved.

Urolitíase em bovinos da raça Guzerá (Bos taurus indicus): estudo comparativo em animais oriundo de propriedades com e sem o problema

Pós-graduação em Medicina Veterinária - FMVZ

Acompanhamento laboratorial da função renal de cães sadios tratados experimentalmente com doses terapêuticas de anfotericina b

Pós-graduação em Medicina Veterinária - FMVZ

Manure production and mineral excretion in feces of gilts fed ractopamine

A study was conducted to evaluate the feces+urine produced per animal (FUPA), dry matter, mineral matter, organic matter, nitrogen, phosphorus, potassium and sulfur in feces of gilts fed diets with increasing levels of ractopamine (0, 5, 10 and 15 mg kg-1 of diet). A total of 468 finishing gilts were allotted into 36 pens. In two days of each week, feces and urine were daily sampled in four pens per treatment, quantifying the feces+urine. To determine the characterization of feces, two samples per week were taken daily, in nine pens per treatment. It was used a split plot design, considering the ractopamine level as the plot and the weeks as the subplots. There was no reduction in nitrogen amount in feces. An interaction was detected between ractopamine concentrations and weeks for FUPA and phosphorus, potassium and sulfur in feces. Ractopamine addition in diets for gilts has reduced the feces+urine production and nitrogen and phosphorus excretion. Higher values estimated for potassium content in feces of animals fed diets with 10 and 15 mg of ractopamine kg-1 were found between the second and third week. Increasing levels of ractopamine from 5 to 15 mg kg-1 promoted higher excretion of sulfur over the weeks of supply.

Fractional fermion charges induced by axial-vector and vector gauge potentials and parity anomaly in planar graphenelike structures

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Behavior of Triton X-114 cloud point in the presence of inorganic electrolytes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Protective film growth on tin in perchlorate and citric acid electrolytes

Voltammetry has been employed to study the influence of systematic additions of citric acid on the E-I curves of Tin in 0.5 M NaClO4, in order to verify the film growth in the presence of the organic acid and the inhibition of the pitting corrosion of the metal. The minimum concentration of the organic acid needed to change the GI curves is 10(-2) M, in the pH range 1.0-4.0. At pH 3.0 and 4.0, the scan rate dependence on current density, in the potential region of formation and reduction of the film, showed that in a first stage adsorption occurs. In a second stage, the v(1/2) dependence found can he explained by ohmic resistance control. The formation of tin/citric acid complexes, 10(-2) M, is suggested. The pitting inhibition may be due to the formation of a mixed layer of tin in citric acid concentrations higher than 10(-2) oxide and tin citrate complexes on the electrode surface. (C) 2001 Elsevier Science B.V. All rights reserved.

Sex and reproductive stage differences in the growth, metabolism, feed, fecal production, excretion and energy budget of the Amazon River prawn (Macrobrachium amazonicum)

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