Desenvolvimento e caracterização de sistemas líquido-cristalinos para aplicação de um peptídeo com ação antimicrobiana

Atualmente o uso indiscriminado e não criterioso de antibióticos está causando um aumento alarmante de resistência bacteriana chegando a ser considerado um problema de saúde pública. Nesse contexto, a utilização do peptídeo antimicrobiano (PAM) Hylina-a1 proveniente de uma rã da fauna brasileira está sendo estudado. Sua atuação na membrana celular dificulta a ocorrência de resistência bacteriana. No entanto, o uso de PAMs ainda apresenta problemas principalmente relacionados à disponibilidade, eficácia e toxicidade. A fim de contornar esses problemas, este trabalho teve como objetivo principal avaliar a incorporação deste peptídeo a um sistema líquido cristalino nanoestruturado com capacidade de regular a liberação e proteger os peptídeos da degradação química e física mantendo a bioatividade. O sistema líquido cristalino foi preparado com fosfatidilcolina de soja (FS), oleato de sódio (OS) e Tween 20 (TW), colesterol (CHO) e tampão fosfato, sendo que alguns pontos apresentaram fases líquido-cristalinas do tipo lamelar. Para os estudos posteriores foi escolhido um ponto com características visuais de viscosidade apropriadas ao uso tópico e a este se incorporou o peptídeo. A obtenção do peptídeo por meio da SPFS foi viável, obtendo-se materiais com alto índice de pureza. No ensaio de reologia a formulação apresentou-se como fluido pseudoplástico não–Newtoniano, com a presença de tixotropia; sendo possível também confirmar a incorporação do peptídeo ao sistema. A espectroscopia UV e a CLAE comprovaram que a maior parte do peptídeo é incorporada à fase líquido-cristalina do sistema. Os ensaios biológicos mostraram que o sistema líquido-cristalino possui atividade contra bactérias muito menor que o peptídeo livre. Este fato foi atribuído à baixa liberação do peptídeo pelo sistema

Desenvolvimento de um sistema para caracterização de dispositivos eletroluminescentes

The materials designed to be used in electroluminescent (EL) devices construction are studied and improved since 1936. Great interests in the development of this kind of devices are mainly due to its low power consumption, flexibility, low cost and easy processing. One class of ELs devices with these characteristics are produced by employing a organic-polymeric/inorganic composite from a conductive polymer blend and an inorganic electroluminescent material (Zn2SiO4:Mn) dispersed in the polymeric matrix. This kind of device operates in d.c. or a.c. potentials, with EL of hundreds candela in the green region of the visible spectrum. However, few studies on the light emission were performed for these devices. In order to characterize devices made from composites, in this work is proposed a method of characterizing the electroluminescence associated with the impedance spectroscopy technique. To implement the technique of impedance spectroscopy was employ an experimental setup consisting of a source of a.c. voltage, an oscilloscope, and a reference resistor. Associated with this system, was use a photo diode and an analog electrometer to characterize the emitted light signal from the sample. The system was implemented allows characterization by impedance spectroscopy in the frequency range from 0.2 Hz up to 2 MHz and voltage amplitudes of 5 mV up to 20 kV. This system permits, at the same time, measurement of the RMS value of the luminance for devices in frequency range from 20 Hz up to 2 MHz. To test the system efficiency, an EL device was characterized showing analogous results to those reported in literature. By doing this, was demonstrated the efficiency of the system for electroluminescence characterization associated with the electrical characterization by impedance spectroscopy, for devices

Síntese e caracterização de ferritas de manganês e zinco visando aplicação como agente de contraste em diagnóstico médico

This work aims to synthesize the manganese and zinc ferrite, by the polymeric precursor method, in order to obtain materials with appropriate characteristics for the application in medical diagnosis techniques. The manganese and zinc ferrite powders with the composition of Mn(1-x)ZnxFe2O4, where x=0,23, were prepared and calcined in air at different times and temperatures. The X-ray diffraction (XRD) data show that the sample calcined at 400°C crystallize as ferrite (monophase), but in an inverted spinel structure (high content of iron occupying manganese tetrahedral site and manganese occupying the iron octahedral site). The samples calcined at temperatures between 600°C and 900°C shows the secondary phase of hematite and the sample calcined at 1100oC shows to be monophase in ferrite with normal spinel structure. The monophase powders of ferrite showed a reduction in the surface area and an increasing in the pore size for higher calcination temperatures. The magnetic analysis show that the sample calcined at 400°C presents satisfactory magnetization at room temperature, however, it behaves as diamagnetic material at low temperatures (10K). The powder containing hematite, without the partial substitution of iron ions by manganese, showed to have low transition temperature, and consequently low magnetization at room temperature. The hematite, when partially substituted, provides materials with irregular magnetization at the saturation region. The powder calcined at 1100°C shows high magnetization either at room temperature or low temperature (10K)

Tomografia por Biosusceptometria de Corrente Alternada (tBAC): desenvolvimento, caracterização, implementação

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 ...

Caracterização de plasmas através da espectrometria de massa

Mass spectrometry is a diagnosis that can aid in the understanding of the kinetics of chemical plasma environment. Through this you can get information about some species present in the environment and make inferences about the behavior of the plasma when parameters such as pressure and applied power changes. When analyzed plasmas generated by the discharge of argon and diglyme (both individually and mixtures of them in various proportions) could be found conditions in which the plasma behavior was different from what is often found in the literature. By the end some peculiar characteristics of plasmas generated by mixing argon / diglyme were raised and it was found that the noble gas is a good mediator of physical and chemical reactions that occur in the environment, and help in the understanding of chemical kinetics. Therefore mass spectrometry was shown highly important tool for the study of plasma environment

Caracterização dos reservatórios do grupo Macaé no Campo de Garoupa - Bacia de Campos - por meio de interpretação sísmica e perfis de poço

The study area is the Garoupa Field, located 75 km from the coast of Rio de Janeiro in bathymetric elevation of 125 m and it is the first important offshore discovery of the Campos Basin with hydrocarbon production in the Albian carbonates. The high significance of carbonate rock reservoirs for the global oil industry and its degree of complexity, combined with the fact that the Garoupa Field is a mature field, make this research project interesting to develop a re-exploratory vision of the study area. The objective of this paper is to characterize the physical properties of the Macae Group reservoirs in the Garoupa Field through well correlation techniques, petrophysical analysis and seismic interpretation (3D), in order to evaluate qualitatively and quantitatively the response of geophysical data to the presence of carbonate rock reservoirs. From the analysis of well profiles (gamma ray, resistivity, density and sonic) it was possible to identify six reservoir levels in the Quissamã Formation. As a result, the reservoirs have good correlation between the wells in the Garoupa Field and show lateral facies variation. In the seismic interpretation, structural contour maps were generated in time (ms) from the top of the Macae Group and two horizons that correspond to the reservoir levels. These maps show that the oil producing area of this field is a structural high located at the west of the interpreted seismic cube, and it was classified as a rollover limited by lateral faults forming a horst. The seismic attribute maps show a good response to the reservoirs of the Garoupa Field because they are associated with amplitude anomalies, verified by the correlation between the physical properties of the reservoir rock and seismic data through cross plots, with emphasis in a linear correlation between the resistivity profile and the values of Maximum Absolute Amplitude and RMS Amplitude attributes

Caracterização in vitro de técnica biomagnética empregando magnetômetros 3D para avaliar tempo de trânsito esofagiano

The biomagnetic techniques use different magnetic field detectors to measure parameters of the human physiology. Those techniques present the advantage of being noninvasive and radiation free. Among them we can show up the Superconducting Quantum Interference Device (SQUID), the Current Alternate Biosusceptometry (ACB) and, more recently, the employment of anisotropic magnetoresistive sensors. Those magnetic sensors have a low cost and good sensitivity to measure different physiological parameters using magnetic markers. The biomagnetic techniques have being used successfully through study on the characteristics of the gastrointestinal tract. Recent research, the magnetoresistors were used to evaluate the transit time and localization of magnetic sources in different parts of the gastrointestinal tract. The objective of this work is the characterization, with in vitro tests, of a biomagnetic instrumentation using two 3-axis magnetoresistors arranged in a gradiometric coplanar setup to evaluate esophageal transit time, analyze and compare the results of experimental signals and the magnetic theory, as well as evaluate the instrumentation gain with use of tri-axial sensor front to the mono-axial sensor. The instrumentation is composed by two three-axis sensing magnetometers, precision power supply and amplifier electronic circuits. The sensors fixed in a coplanar setup were separate by distance of 18 cm. The sensitivity tests had been carried through using a cylindrical magnet (ø = 4 mm and h = 4 mm) of neodymium-iron-boron (grid 35). The tests were done moving the permanent magnet on the sensors parallel axis, simulating the food transit in... (Complete abstract click electronic access below)

Caracterização de sensores nanoplasmônicos produzidos com os polímeros pdma e paa: Micaela Gisoldi Ribeiro. –

A combinação de polímeros com nanopartículas de metais nobres resultam na formação de filmes finos, que podem ser utilizado na fabricação de nanosensores. Esses filmes finos possuem propriedades exclusivas, que causam ressonância plasmônica de superfície pela mudança conformacional dos mesmos. Essa variação conformacional é causada pela interação com analito ou por estímulo externo, podendo ser analisada por espectroscopia de absorção na região do UV-vis. Este simples e econômico meio de transdução do sinal apresenta-se como uma ferramenta bastante promissora, e se combinado com a alta seletividade encontrada em reações biológicas, torna-se ainda mais promissora no desenvolvimento de sensores. Os esforços desse projeto foram concentrados para o desenvolvimento dos sensores que respondam a estímulos externo e baseado na utilização de polímeros escovas. Este trabalho de conclusão de curso foi baseada na produção de sensores nanoplasmônicos, que na presença de fatores externos causam modificação estrutural dos filmes finos poliméricos depositados sobre um substrato e dão um resposta altamente seletiva. As mudanças conduzirão à geração de sinais ópticos ou eletroquímico, que serão medidos por transmissão de ressonância plasmônica de superfície ou via eletroquímica. Foram realizados experimentos de voltametria cíclica e impedância eletroquímica em pH=3 para avaliar a capacidade de eletródica deste material. Também foram efetuados experimentos por espectrofotometria de absorção na região de ultravioleta-visível em pHs variando de 3 a 7 para se analisar o efeito plasmônico do material. Pode-se notar que em pH mais ácidos o polímero se mostrou mais condutor e de acordo com a literatura este efeito é causado pela expansão polimérica que deixa o mesmo em seu estado ativo ON (expandido). Já em pH mais básicos os polímeros demonstraram um comportamento inverso por os mesmo se contraem, ...

Confecção e caracterização de filmes finos de boro para a medida da taxa de reação 10B(N, a)7LI na terapia por captura de nêutrons pelo boro

The Boron Neutron Capture Therapy (BNCT), based on the 10B(n,α)7Li reaction, represents a promising modality for the treatment of cancers that are resistents to conventional treatments. So, it is necessary to find drugs (boron compounds) with high selectivity for each type of cancer, the neutrons source should be well characterized and the rate of 10B(n,α)7Li reaction should be measured with great accuracy as possible. This study aimed to develop a method for manufacturing thin films of boron, for measure the 10B(n,α)7Li reaction, and analyze the uniformity of the films. Five thin films of boron were manufactured with three different concentrations of boric acid, heated to transform the acid in boron, irradiated with thermic neutrons coupled to CR-39 detectors, in BNCT line at the reactor IEA-R1 IPEN/CNEN, São Paulo. After the irradiation, the detectors were chemically attacked with NaOH to reveal the tracks. The methodology presented is effective because it resulted in deposition of boron as thin film enabling the quantitative analysis of 10B(n,α)7Li reaction. The analysis of the uniformity of density of the induced tracks in CR-39 shows that, in most of the films, there is no uniformity in surface distribution of boron, but when the film is divided, we obtain some uniform sectors

Processo de esmerilhamento, polimento e caracterização de um Shear Plate

Shearplate is an optical glass plate having two flat surfaces and a small angle between them. The use of a high quality shear plate is essential to implement shear interferometric technique . The shear interferometry is a technique used to evaluate the light beam collimation. In order to guarantee the shearplate quality , the complete manufacturing process must be thoroughly monitored. In the manufacturing process, the first step consisted of the glass selection. The selected glass has been submitted to the process of cutting, gluing, chamfering, grinding and polishing. Each phase has been strictly monitored. The quality of the final result depends extremely on an appropriate starting condition, which arises from the grinding process, as the polishing process only recovers the brightness of the part, acting on a small scale on the wearing off of the part, as well as not changing the structured obtained in the grinding process. Respecting all stages of the manufacturing process, the quality of the part has evolved to a good result. The best result obtained showed PV distance of 162 nm, slightly less than λ / 4. This result is significant because the dimensions of the piece with respect to the dimensions of the polisher what interferes directly in the results. The closer are the dimensions of piece and the dimensions of the polisher, the greater the difficulty in controlling the propagation of errors

Caracterização da contribuição da albumina para a formação do espectro de ressonância magnética nuclear (RMN) do plasma sanguíneo

The plasma represents a average of the information referring biochemists to the physiology of the organism as a whole, therefore it indirectly or directly interacts with all tissues of the body. In such a way the plasma can be considered as a metabolic “soup”. Using the Nuclear Magnetic Resonance Spectroscopy sanguineous plasma spectra had been generated and using deconvolution techniques it was possible to know the contribution of the albumin for the formation of the spectra of the sanguineous plasma

Identificação e caracterização de fungos melanizados com potencial de degradação de tolueno

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diodo planar orgânico Schottky: construção e caracterização

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização e aplicação da Blenda PEDOT : PSS/PVA na construção de eletrodos transparentes e dispositivos eletroluminescentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização de estruturas de óxido de estanho modificado como sensores de gases

Pós-graduação em Química - IQ