330 resultados para Tomografia de onda de superfície
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Atualmente são conhecidas aproximadamente 10.000 substâncias do metabolismo secundário de invertebrados e microorganismos marinhos. Dentre os organismos marinhos estudados do ponto de vista químico e farmacológico, destacam-se, as esponjas, as ascídias, os briozoários e os octocorais. No entanto, pouco se sabe quanto ao potencial imunomodulador de compostos isolados de microrganismos marinhos, em especial daqueles isolados da costa brasileira. A propriedade anti-inflamatória de diferentes extratos brutos foi inicialmente avaliada pelo potencial destes compostos quanto à inibição da produção de óxido nítrico (NO) em linhagem de macrófagos, RAW 264.7. Posteriormente as amostras que se mostraram promissoras foram também avaliadas em relação ao potencial imunomodulador quanto a expressão de moléculas de superfície relacionadas migração (Mac-1 ou CD11b) e ativação celular (CD80 e CD86) em linhagens de macrófagos estimulados com LPS. Nossos resultados mostram que dentre as 289 amostras testadas apenas o extrato DLM33 e as substâncias Ma(M3%)J-MeOH e Dr(M3%)6-MeOH/H2O foram inicialmente considerados promissores quanto capacidade de inibir a síntese de NO por macrófagos. O extrato DLM33 foi capaz de de modular apenas a porcentagem de macrófagos positivos para CD80 na presença de LPS. No entanto, a substância Dr(M3%)6-MeOH/H2O não se mostrou eficiente quanto a modulação da expressão de moléculas de superfície Mac-1, CD80 e CD86. Surpreendentemente, a substância Ma(M3%)J-MeOH apresentou um potencial imunoestimulador quanto a expressão de Mac-1+/CD80+, mas não de CD86, em macrófagos sugerindo um possível efeito adjuvante desta substância. O efeito imunoestimulador da substância Ma(M3%)J-MeOH será futuramente investigado utilizando diferentes abordagens in vitro e in vivo para validar os resultados obtidos... (Resumo completo, clicar acesso eletrônico abaixo)
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The computed tomography, devised by Godfrey Hounsfield and Allan Cormack, is in its fourth decade of the clinical use and has presented to be a very useful tool in the diagnosis of several pathologies. For this reason, its use is increasing each day, due to technological progress since its creation. Due to be more and more utilized, the equipment must be in good operating conditions, because it is subject to variance and wearing, damage the quality of diagnosis. To evaluate whether the performance of the scanner remains constant along the time and the dose received by the patient is within the desired limits, periodic tests of quality control must be performed. For this subject, the regulation 453 (June 01, 1998) was created, which determines the need of the implementation of a program for quality assurance (PGQ), where, in addition to the tests of quality control, are established the necessary measurements for the proper functioning of the equipment, generating a trustworthy diagnosis, reducing the dose for the patient and the costs. In this document, are presented tests of quality control carried out in hospitals of the city of Sao Paulo carried out together with the Technical Section of Applications by Imaging Diagnostic (STADI) of the Institute of Electrotechnics and Energy of the University of São Paulo (IEE/USP)
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This scientific research aimed at presenting a comparative analysis of softwares used to represent the processes of flood wave and debris flow. For this, a literature review was performed on these processes and on simulation models used to represent them. Then, a research on scientific database and developers’ websites was performed to identify the softwares used to simulate these processes. This step was performed based on specific criteria such as the type of simulation performed by the software, its practical applications and a user friendly interface. A free distribution and totally functional software was chosen and its simulation mechanisms were tested through a simulation exercise and the results interpreted based on data on measured in the Basin of Ribeirão Marins section Monjolinho located in Piracicaba - SP. With respect to the processes, it was sought to present the dynamics, constraints, parameters and variables used to understand them and for the simulation models were presented the conceptual aspects of mathematical modeling including the steps of the simulation process and the different types of simulation models used to represent them. In total, 20 softwares were identified, and the software object of analysis was the ABC 6 that performs simulation of flood wave. Through the simulation exercise, it was observed that were presented overestimated values of flow compared to measured data in the basin. For both hypotheses were raised about the causes of the discrepancy between the observed and simulated flow. It has been concluded that the simulation process consisted of a complex procedure where generalizations, misrepresentations and simplifications may occur due to the data used and the method adopted, but it is a useful tool in planning and decision making in various types of studies and environmental projects
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In this work were studied associations of ZnO with the natural products caffeic and feluric acids. Two preparation methods were used, that is, the sol-gel and a reflux procedure. In the sol-gel method, ZnO is produced by the basics hydrolysis of precursors in the presence of the organic filters (caffeic and feluric acids), which results in 30 nm (or less) ZnO particles with the organic filters (in dissociated form) bonded to the surface of ZnO. In the reflux method, a dispersion of ZnO in a water/ethanol mixture was kept under reflux (50oC/4h) in the presence of the organic acids. The ZnO particles used in the reflux method have a higher diameter than sol-gel ZnO particles, but the prepared associated product ZnO/Organic acids were similar. Despite of the difference in relation to crystallinity between the products, the preparation methods resulted in analogous associations with respect to the interaction of the organic filters with the ZnO surface. The caffeic/ZnO associations presented low photostability, which lead to the degradation of the organic filter. The other associations (feluric acid/ZnO) presented satisfactory results. The FT-IR spectroscopy confirmed the formation of the association, and the nature of the bond formed compared with the Zn-O bond in Zn2+/Felutic acid complexes. The isolated organic and inorganic filters, along with the associations were analyzed by diffuse reflectance spectroscopy and Uv-vis spectroscopy. The absorption edges and the critical wavelengths were analyzed and the effects of Zn-O bonds in feluric acid/ZnO associations described as a function of the relative position of the π/π* system of the organic filter. Finally the performance of the hybrid filters were investigated in terms of the absorption of UVA and UVB radiations, with the UVA/UVB ratio, an efficiency parameter largely used in the description of solar filters, sunscreen and suncare products
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Mesenchymal stem cells (MSCs) are adult multipotent cells with fibroblastoid morphology and adherent to plastic. Furthermore, they can be obtained from different sources. Besides bone marrow, these cells are taken from umbilical cord blood, umbilical vein, saphenous vein, peripheral blood, arteries, liver and fetal pancreas, placenta, dental pulp and adipose tissue. MSCs derived from adipose tissue are important because of the abundant number of cells that can be obtained from this tissue, easy access and little discomfort to the patient. This study compared two techniques for obtaining MSCs from adipose tissue: mechanical dissociation (MD) and enzymatic digestion (ED). We also analyzed the inter-species cross-reactions using commercial monoclonal antibodies directed against surface antigens of stem cells from different species: mouse, horse, rabbit, monkey and human. We found that MD technique is favorable in relation to ED within 15 days of culture, and ED is more efficient in the first days of culture. The data also showed that MD causes less damage to cellular DNA. About inter-species cross-reactions, the monoclonal antibody A69 directed against stem cells from rabbits, which can be used in veterinary medicine, particularly in research involving horses
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Several hormonal and physiological changes that occur during pregnancy directly affect gastrointestinal motility (GI), however, very little is known about the relationship between the electrical and mechanical activities of the stomach and its implications. The aim of this study was to compare the female sex hormones, with profiles of gastrointestinal motility using AC biosusceptometry (BAC) in pregnant rats. Seven female Wistar rats (weighing 250-350 g) were used and all procedures were approved by the local Ethics Committee of animal. Laparotomy was performed on anesthetized rats and a magnetic marker (3.5 mm in diameter and 3.0 mm height) was implanted in the distal stomach. After 10 days of recuperation, the mice were put to mate until confirmation of pregnancy. Fed animals were anesthetized (mg pentobarbital 30 / kg) and kept supine for recording the signal with a sensor 30 min BAC placed on the abdominal surface on days 0, 7, 14 and 20 of gestation. Statistical analysis was performed by Student's t test statistical Newman-Keuls and a P value of .05 was considered statistically significant. The frequency of contraction of the stomach was 74 mHz ± 3, 67 ± 7 mHz, 59 mHz ± 6 (p <0.05 vs day -1) and 71 ± 5 mHz on days -0, -7, -14, and -20, respectively. The values of 44 ± 15 pg / mL and 31 ± 9 pg / ml 25 ± 6 pg / ml, 22 ± 9 pg / ml on days -0, -7, -14 and -20, respectively, obtained by 17ß- estradiol were not statistically significant. The values of progesterone were 13 ± 6 pg / ml at 54 ± 15 pg / ml, 127 ± 42 pg / ml (p <0.05 vs day-1), 22 ± 13 pg / mL on day -0, - 7, -14 and -20, respectively. A linear correlation (Pearson's test) between the lower frequency gastric and increased levels of progesterone was 80% (p <0.0000001). Until then, the relationship between changes in motility and hormone were not described in detail, but with the work that we were able to demonstrate the high correlation between progesterone concentration ...
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The Biosusceptometry AC (BAC) is a research tool that has been extensively explored by the group Biomagnetism IBB-UNESP for monitoring of the gastrointestinal tract, its response to a known drug or in vivo performance of solid dosage forms. During this period the BAC, which has the characteristics of high sensitivity and low cost, has been developed primarily for recording signals contraction of activity and traffic human gastrointestinal tract. With the possibility of producing images with this instrumentation, it was possible to evaluate different situations in vitro and in vivo for physiological studies and pharmaceuticals. Considering the good performance of this system to produce planar images, the first aim of the BAC system tomography (TBAC) was to evaluate the system performance of BAC to produce tomographic images of phantoms ferromagnetic for a single channel system. All these applications were only possible because of their sensitivity to materials of high magnetic suscepitibility as ferrite, which allow to produce an electrical signal proportional to the variation of the magnetic flux generated by the presence of magnetic marker next to a first-order gradiometer. Measuring this variation at various points was possible to generate planar images that recently came to be produced in systems with multiple detectors, said multi-channels. From planar images, also producing tomographic images of simulators BAC bars in a system of 13 channels using only the center channel, with good results when applied to simple objects as one and two bars. When testing the resolution of the system with more elaborate forms the quality and resolution of images reconstructed is not satisfactory, which would be solved by increasing the spatial sampling rate and hence the acquisition time. The present system works with an acquisition time of about five hours. Whereas this system will be applied for in vivo experiments, the acquisition time became a ...
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This paper presents the study on the application of the electrolytic plasma for surface treatment of aluminum. A bibliographical study on the material of interest was preliminarily performed and later designed and built an electrolytic cell, including the excitation source. Unlike conventional electrolysis process, the plasma assisted carry on in the non-linear region of characteristic current/voltage curve. Therefore it requires for the on set of the process that the power supply operates on harder conditions than those on high current process. The plasma produced during the present investigation has temperatures in the range o 6,0.10 3 -7,0 .10 3 K, well above those found in conventional chemical process. It also shows a particular dynamic to promote changes on surface and to produce new materials. The plasma is generated by microdischarge in vapor or gas bubbles involved in physic-chemical processes in electrode regions of the electrolytic cell. The electrode material was the aluminum (7075). The Process Electrolytic Plasma Processing (EPP) is sensitive to various parameters such as operating voltage, current density, electrolyte, concentration of electrolyte, geometry of reactor, temperature of electrolytic solution and dynamic of the fluid in the cell. The experiments were carried on in order to find parameters for a stable abd steady operation. The choice for the electrolytic was silicate/alkali solution in various concentrations to operate in various voltage as well. Plasma was produced on negative (cathode) and positive (anode) electrode, in specific conditions. A stable operation on the cathode process was obtained with low concentration of the electrolytic in aqueous solution, current density around 250V effective voltage. For the evolution of plasma in anodic process it was required higher concentrations and higher... (Complete abstract click electronic access below)
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In this work, the influence of modifications of the cp-Ti and Ti 6Al 4V alloy, by treating the surface with NaOH and depositing titanium oxide and hydroxyapatite by sol-gel method, on their biocompatibility was studied. The coatings were characterized by scanning electron microscopy and X-ray diffraction which showed that the coatings on Ti 6Al 4V are better than on cp-Ti. Adhesion tests showed that adhesion strength of the coatings on cp-Ti substrate is less than on Ti 6Al 4V as well as cytotoxicity for L929 fibroblast cells is higher
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Fracture surfaces are the fracture process marks, taht it is characterized by energy release guieded by failure mode. The fracture toughness express this energy em stress and strain terms in pre-cracked samples. The strectch zone is the characteristic region forms by the transition of fatigue fracture and final fracture and it width demonstrate the relation with failure energy release.The quantitative fractography is a broadly tool uses in failure surfaces characterization that it can point to a material’s aspect or a fracture process. The image processing works like an investigation tool, guinding a lot of studies in this area. In order to evaluate the characterization effectivity and it respectivity studies, it used 300M steel that it was thermal treated by an aeronautical process known and it characterized by tensile test and energy dispersive spectroscopy (EDS). The tensile test of this material, made by ASTM E8, allowed the head treatment effectivity confirmation, beyond of mechanics porperties determination. The EDS confirmed the material composition, beyond of base the discussion about fracture mechanism presence. The fracture toughness test has also made, that it works to obtain the fracture surfeaces studies below self-similarity and self-affinity approaches. In front of all the exposed it was possible to conclude that the fractal dimension works like a study parameter of fracture process, allowinf the relation of their values with changes in thickness, which interferes directly in material’s behaviour in fracture toughness approach
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The equine locomotors system alterations are very frequent and corresponds a large portion of cases in equine medicine. The most equine veterinarian’s challenge is to do a precise diagnosis of lameness cause to perform a specific and proper treatment as early as possible. The navicular syndrome is considered responsible for one third of lameness causes and, although much studied, its etiology is still not fully understood. The most varied methods of diagnosis, such as x-ray, magnetic resonance, bursography, scintigraphy, computed tomography and ultrasound, have been used to assess podotrochlear apparatus situation in order to diagnose this syndrome. Among them transcuneal ultrasound can be used to observe some important structures such as the flexor surface of distal sesamoid bone, distal deep digital flexor tendon, distal sesamoid ligament entheses odd and the distal phalanx. The aim of this present paper is provide a brief review on the use and the technique of ultrasonography on third phalanx transcuneal region evaluation and its interpretation on navicular syndrome diagnosis in horses
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To evaluate the effect of surface treatment with Er:YAG and Nd:YAG laser on resin composite bond strength to recently bleached dentin. Material and Methods: In this study 120 bovine incisors were used and distributed into two groups: Group C: without bleaching treatment; Group B: with bleaching treatment (35% hydrogen peroxide). Each group was divided into three subgroups: Subgroup N: without laser treatment; Subgroup Nd: irradiation with Nd:YAG laser; Subgroup Er: irradiation with Er:YAG laser. Next, the adhesive system (Adper Single Bond 2) was applied and composite buildups were constructed with Z350 composite. The teeth were sectioned to obtain dentin-resin sticks (1x1mm) and analyzed by microtensile bond testing. The data were statistically analyzed by the ANOVA and Tukey tests. Results: The results showed that the bond strength values in the bleached control group (16.17 MPa) presented no significant difference in comparison with the group bleached and irradiated with Er:YAG laser (14.69 MPa). The non bleached control group (26.79 MPa) presented significant difference in bond strength when compared with the non bleached group irradiated with Er:YAG laser (22.82 MPa) and with the group treated by bleaching and irradiation with Nd:YAG laser (28,792 MPa). The group without bleaching treatment and irradiated with Nd:YAG (36.1 MPa) presented a significant increase in bond strength in comparison with the other groups. Conclusion: The use of Nd:YAG laser on bleached specimens was able of completely reversing the immediate effects of bleaching, obtaining bond strength values similar to those of the control group
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The goal of this work is to study the process of interaction of protons with matter through Monte Carlo simulation. For this purpose, it was employed the SRIM program (Stopping and Range of Ions in Matter ) and MCNPX (Monte Carlo N-Particle eXtended) v2.50. This work is going to support the development of a tomography system with protons. It was studied the interaction of proton with the follow materials: Polimethyl Mehacralate (PMMA), MS20 Tissue Substitute and water. This work employed energies in range of 50 MeV and 250 MeV, that is the range of clinical interest. The energy loss of proton after cross a material layer, the decreasing of its intensity, the angular and lateral de ection of incident beam, including and excluding nuclear interactions. This work is related with Medical Physics and Material Physics, like interaction of radiation with matter, particle transport phenomena, and the experimental methods in Nuclear Physics like simulation and computational by Monte Carlo method
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By the early 20th century, the blood vessels could only be seen by anatomical studies. Shortly after the discovery of X-rays by Conrad Roentgen in 1895, the first experiments with radiographic imaging were performed with blood vessels. In 1905, the first experiment involving catheterization of arterial and venous system in dogs was performed and only in 1914 performed on living human patients. Parallel to these landmarks, there were advances in diagnostic imaging devices and the evolution of contrast substances was of utmost importance to the current angiography occupy a prominent role not only in terms of diagnosis, but also in the treatment of various disorders. The main objective of this review is to weave historical considerations and comparisons between the different methodologies used in angiography, because its importance; that may be in future, a veterinary diagnostic decisive test
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The objective of the present work was to evaluate surface of experimental alloy Ti-7.5Mo after hydrothermal treatment. Ingots were obtained in arc melting furnace under an argon atmosphere and then homogenized under vacuum at 1100ºC for 86.4 ks to eliminate chemical segregation and after cold worked discs were cutting and grinding. For surface treatment, samples were immersed in a container with NaOH aqueous solution 5M, autoclaved, washed with distilled water. Followed, samples were heat treated and they were soaking in 5xSBF to form an apatite layer on the surface. Surfaces were investigated by, scanning electron microscopy, X-Rays powder diffraction, atomic force microscopy and contact angle, in order to evaluate the wettability of the alloy surface. The results were compared with our previous studies using the group of chemical surface treatments and results shows better condition is 120 minutes in the autoclave