Volume overload influence on hypertrophied myocardium function

The aim of this study was to demonstrate that hypertrophied cardiac muscle is more sensitive to volume-overload than normal cardiac muscle. We assessed the mechanical function of isolated left ventricular papillary muscle from male spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats (WKY) Submitted to volume overload caused by aortocaval fistula (ACF) for 30 days. Muscles were perfused with Krebs-Henseleit solution at 28degreesC and Studied isometrically at a Stimulation rate of 0.2 Hz. The ACF increased the right and left ventricular weight-to-body weight ratio in WKY rats; it also promoted right ventricular hypertrophy and further increased the basal hypertrophy in the left ventricle from SHR. The arterial systolic pressure was greater in SHR than in WKY rats, and decreased with ACF in both groups. Developed tension (DT) and maximum rate of DT (+dT/dt) were greater in the SHR-control than in the WKY-control (P<0.05); the time from peak tension to 50% relaxation (RT1/2) was similar in these animals. ACE did not change any parameters ill the SHR group and increased the resting tension in the WKY group. However, the significant difference observed between myocardial contraction performance in WKY-controls and SHR-controls disappeared when the SHR-ACF and WKY-controls were compared. Furthermore, RT1/2 increased significantly ill the SHR-ACF in relation to the WKY-controls. In conclusion, the data lead LIS to infer that volume-overload for 30 days promotes more mechanical functional changes in hypertrophied muscle than in normal cardiac muscle.

Analysis of camphorquinone in composite resins as a function of shade

Objective. To identify and quantify the camphorquinone (CQ) used in different brands of composite resins as a function of the shade analyzed.Materials and methods. Filtek Z250 A3 (FZA3), Filtek Z-250 Incisal (FZI), Pyramid Enamel A1 (PEA1), Pyramid Enamel Translucent (PET), Filtek Supreme A3E (FSA3) and Filtek Supreme GT (FSGT) were used. Five hundred milligrams of each resin were weighed and then dissolved in 1.0 ml of methanol. The samples were centrifuged to accelerate the sedimentation of the inorganic particles. 0.8 ml of the supernatant solution was collected with a pipette and assessed under gas chromatography coupled to the mass spectrometer (GC-MS). The results were compared to pure CQ solutions, used as a standard. Student's t-test, (p = 0.05) significant at the level of 5%, compared the results of each brand shade.Results. A smaller amount of camphorquinone was found in Filtek Z-250 (FZI) resin incisal shade when compared to (FZA3) A3 shade. on the other hand, Filtek Supreme resin featured a statistically larger camphorquinone amount in the incisal shade. in Pyramid Enamel resin camphorquinone was found only in shade Al, while the photoinitiator used in the Translucent shade was not identified.Significance. Based on the data obtained, it is possible to conclude that a single composite resin brand may feature differences in amount and type of photoinitiator used. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Spatial distribution of solutes and water in sucrose solution dehydrated apples

Half-fresh apples were immersed in sucrose solution (50% w/w, 27 degrees C) during different times of exposition (2, 4, and 8 h). Then each fruit was sliced from the transversal exposed surface. Density, water, and sugar content were determined for each slice. A mathematical model was fitted to experimental data of water and sucrose content considering the global flux and the tissue shrinkage. By numerical analysis, the binary effective diffusion coefficients as a function of concentration were calculated, using material coordinates and integrating simultaneously two differential equations (for water and sucrose). The coefficients obtained are one or even two orders of magnitude lower than the ones for pure solutions and present an unusual concentration dependence. This comparison shows the influence of the tissue resistance to the diffusion.

Three-dimensional finite element analysis of MHD duct flow by the penalty function formulation

A numerical scheme based on the Finite Element Method (FEM) is presented to calculate the full solution of a three-dimensional steady magnetohydrodynamic (MHD) flow with moderately high Hartmann numbers and interaction parameters. An incompressible, viscous and electrically conducting liquid-metal is considered. Assuming a low magnetic Reynolds number, the solution method solves the coupled Navier-Stokes and Maxwell's equations through the use of a penalty function method. Results are presented for Hartmann numbers in the range 10(2)-10(3).

Skin water uptake and renal function in the toad

1. 1. Water balance in the toad Bufo marinus ictericus was studied by evaluating cutaneous water uptake and renal excretion. 2. 2. The permeability of the skin to water was 78 ± 6 nl min -1 cm -2 atm -1 in 60 toads anaesthetized by chloralose and preincubated in water for 3 hr. Injection of Ringer's solution did not reduce the water uptake by the skin, while hemorrhage, or injection of vasopressin, or oxytocin approximately doubled the rates of water transport. In vivo values of skin water permeability were similar to those observed in vitro. 3. 3. The renal parameters of the water balance were significantly reduced by hemorrhage and by injection of vasopressin. Injection of Ringer's solution promoted a significant increase of the urinary flow and osmolar clearance. 4. 4. It is suggested that the fight against water deprivation could proceed initially by the triggering of the urinary mechanisms of water retention, while the increase of the skin water permeability would occur in a later stage. © 1981.

2-Mercaptobenzothiazole clay as matrix for sorption and preconcentration of some heavy metals from aqueous solution

2-Mercaptobenzothiazole loaded on previously polystyrene treated clay was prepared, characterized and used for sorption and preconcentration of Hg(II) Pb(II), Zn(II) and Cd(II) from an aqueous solution. The support used was a natural clay previously treated with sulphuric acid solution. Adsorptiou isotherms of metal ions from aqueous solutions as function of pH were studied at 298 K. Conditions for quantitative retention and elution were established for each metal by batch and column methods. The chemically treated clay was very selective to Hg(II) in solution in which Zn(II), Cd(II), Pb(II) and some transition metal ions were also present.

On the solution of bounded and unbounded mixed complementarity problems

A reformulation of the bounded mixed complementarity problem is introduced. It is proved that the level sets of the objective function are bounded and, under reasonable assumptions, stationary points coincide with solutions of the original variational inequality problem. Therefore, standard minimization algorithms applied to the new reformulation must succeed. This result is applied to the compactification of unbounded mixed complementarity problems. © 2001 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint, a member of the Taylor & Francis Group.

Stability of the null solution of the equation ẋ(t) = -a(t)x(t) + b(t)x([t])

The asymptotic stability of the null solution of the equation ẋ(t) = -a(t)x(t)+b(t)x([t]) with argument [t], where [t] designates the greatest integer function, is studied by means of dichotomic maps. © 2010 Academic Publications.

Dispersing carbon nanotubes in phenolic resin using an aqueous solution

The ability to control the carbon nanotube (CNT) dispersion in polymers is considered the key to most applications of nanotube/polymer composites. The carbon nanotube dispersion into water with different surfactants, as well as its incorporation into phenolic resins, was investigated. Ultrasonication of liquid suspensions was used to prepare stable dispersions. In order to evaluate the best surfactant to be used, light scattering and UV-Visible spectroscopy were employed. The structure of CNT reinforced of phenolic resin was analyzed in function of the concentration and type of surfactant, sonication power and time. It was also evaluated the influence in the dispersion by using the glass temperature transition properties being obtained by dynamic mechanical analyses and impact energy. © 2011 Sociedade Brasileira de Química.

Optimal trajectory and solution of the inverse kinematics of a robotic manipulator by genetic algorithms

This paper presents the generation of optimal trajectories by genetic algorithms (GA) for a planar robotic manipulator. The implemented GA considers a multi-objective function that minimizes the end-effector positioning error together with the joints angular displacement and it solves the inverse kinematics problem for the trajectory. Computer simulations results are presented to illustrate this implementation and show the efficiency of the used methodology producing soft trajectories with low computing cost. © 2011 Springer-Verlag Berlin Heidelberg.

Heparin and penicillamine-hypotaurine-epinephrine (PHE) solution during bovine in vitro fertilization procedures impair the quality of spermatozoa but improve normal oocyte fecundation and early embryonic development

The presence of heparin and a mixture of penicillamine, hypotaurine, and epinephrine (PHE) solution in the in vitro fertilization (IVF) media seem to be a prerequisite when bovine spermatozoa are capacitated in vitro, in order to stimulate sperm motility and acrosome reaction. The present study was designed to determine the effect of the addition of heparin and PHE during IVF on the quality and penetrability of spermatozoa into bovine oocytes and on subsequent embryo development. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes and mitochondrial function, was diminished (P < 0.05) in the presence of heparin and PHE. Oocyte penetration and normal pronuclear formation rates, as well as the percentage of zygotes presenting more than two pronuclei, was higher (P < 0.05) in the presence of heparin and PHE. No differences were observed in cleavage rates between treatment and control (P > 0.05). However, the developmental rate to the blastocyst stage was increased in the presence of heparin and PHE (P > 0.05). The quality of embryos that reached the blastocyst stage was evaluated by counting the inner cell mass (ICM) and trophectoderm (TE) cell numbers and total number of cells; the percentage of ICM and TE cells was unaffected (P > 0.05) in the presence of heparin and PHE (P < 0.05). In conclusion, this study demonstrated that while the supplementation of IVF media with heparin and PHE solution impairs spermatozoa quality, it plays an important role in sperm capacitation, improving pronuclear formation, and early embryonic development. © 2013 The Society for In Vitro Biology.

Structural and electrical properties of LaNiO3 thin films grown on (100) and (001) oriented SrLaAlO4 substrates by chemical solution deposition method

LaNiO3 thin films were deposited on SrLaAlO4 (1 0 0) and SrLaAlO4 (0 0 1) single crystal substrates by a chemical solution deposition method and heat-treated in oxygen atmosphere at 700° C in tube oven. Structural, morphological, and electrical properties of the LaNiO 3 thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and electrical resistivity as temperature function (Hall measurements). The X-ray diffraction data indicated good crystallinity and a structural preferential orientation. The LaNiO3 thin films have a very flat surface and no droplet was found on their surfaces. Samples of LaNiO3 grown onto (1 0 0) and (0 0 1) oriented SrLaAlO4 single crystal substrates reveled average grain size by AFM approximately 15-30 nm and 20-35 nm, respectively. Transport characteristics observed were clearly dependent upon the substrate orientation which exhibited a metal-to-insulator transition. The underlying mechanism is a result of competition between the mobility edge and the Fermi energy through the occupation of electron states which in turn is controlled by the disorder level induced by different growth surfaces. © 2013 Elsevier Ltd and Techna Group S.r.l.

Biosorption of cadmium (II) and lead (II) from aqueous solution using exopolysaccharide and biomass produced by Colletotrichum sp.

The biosorption of Cd(II) and Pb(II) ions on biomass and exopolysaccharide (EPS) produced by Colletotrichum sp. fungus has been investigated as a function of contact time, initial pH, initial metal ion concentration, and initial adsorbent concentration in a batch system. Adsorption equilibrium was described by Freundlich and Langmuir isotherms. Adsorption was characterized through granulometry, SEM and EDX analysis. Then, studies were performed to regenerate the adsorbent. Biosorption of metals by biomass and EPS were best described by the Langmuir and Freundlich isotherm, respectively. Results of thermodynamic investigations showed that adsorption reactions were spontaneous (ΔG° < 0), exothermal, and mainly physical. The EPS was able to remove 79 and 98% of cadmium and lead, respectively, and the biomass removed 85 and 84% of cadmium and lead, respectively, in a solution with initial concentration 100 mg L-1, and the four adsorption-desorption cycles of all adsorbents showed up with great regenerative capacity and relative stability after these four cycles, the high potential of these biological materials in sorption has been shown. © 2013 Copyright Balaban Desalination Publications.

Color degradation of acrylic resin denture teeth as a function of liquid diet: ultraviolet-visible reflection analysis

The effect of different beverages on acrylic resin denture teeth color degradation is evaluated. Ten acrylic resin denture teeth brands were evaluated: Art Plus (AP), Biolux (BX), Biotone IPN (BI), Magister (MG), Mondial 6 (MD), Premium 6 (PR), SR Vivodent PE (SR), Trilux (TR), Trubyte Biotone (TB), and Vipi Dent Plus (VP). Teeth were immersed in staining solutions (coffee, cola, and orange juice) or artificial saliva (control) (n = 6) for 1, 7, 15, or 30 days. Specimen colors were evaluated spectrophotometrically based on the Commission Internationale d'Eclairage L*a*b* system. Color differences (Delta E) were calculated between the baseline and post-staining results. Data were evaluated by analysis of variance and Tukey test (alpha = 0.05). BI (1.82 +/- 0.95) and TR (1.78 +/- 0.72) teeth exhibited the greatest Delta E values, while BX (0.88 +/- 0.43) and MD (1.09 +/- 0.44) teeth were the lowest, regardless of solution and measurement period, and were different from BI and TR teeth (P < 0.05). Cola and coffee promoted higher denture teeth color alterations than orange juice and saliva (P < 0.05). Saliva generated the lowest denture teeth color alterations. Greater immersion times caused higher denture teeth color changes. The lifespan of removable dentures and the aesthetic satisfaction of several edentulous patients may be increased with the use of stain-resistant artificial denture teeth. (C) The Authors.

Aspergillus niger beta-Glucosidase Has a Cellulase-like Tadpole Molecular Shape INSIGHTS INTO GLYCOSIDE HYDROLASE FAMILY 3 (GH3) beta-GLUCOSIDASE STRUCTURE AND FUNCTION

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