Made available in DSpace on 2014-12-17T15:42:14Z (GMT). No. of bitstreams: 1 MarciaSL_TESE.pdf: 4842135 bytes, checksum: b5c017ecd503f8ac8f797fb07359e645 (MD5) Previous issue date: 2011-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The alginates are copolymers of 1→4-linked β-D-mannuronic acid (M) and α-Lguluronic acid (G) residues that are arranjed in a block structure along a linear chain. Titanium dioxide, TiO2, is a ceramic material and can exist in three distinct crystallography forms: anatase, brookite and rutile. composites of organic and inorganic materials have better properties than the components alone. Thus, this study aims to synthesize, characterize and analyze the composite NaAlg-TiO2 in the form of powder and film. The synthesis of composite powders was performed using the sol-gel process and obtain the composite film was performed using the slow evaporation process, then the composites were analyzed by infrared spectroscopy, fluorescence x ray, thermal analysis, attenuated total reflection (ATR), x ray diffraction and impedance spectroscopy. The X ray diffraction patterns of composite powders show that with increasing calcination temperature, there were no complete transition of rutile-anatase crystalline phase, since at all temperatures studied (300, 500, 700, 900 and 1100?C) were observed peaks of anatase phase. Thermal analysis shows that at 400?C caused the decomposition of sodium alginate in sodium carbonate and above 600?C, we observe an exothermic peak related to the decomposition of sodium carbonate and in the presence of titanium dioxide becomes sodium titanate. The XRD results confirm the formation of sodium carbonate at 700?C and the formation sodium titanate in the temperature range 900-1100?C. The sodium titanate influenced the electrical properties of the material, because with increasing temperature there was a decrease in conductivity, probably due to the creation of Ti vacancies, since the sodium can induce the reduction of surface Ti4+ ions into Ti3+ species. The infrared spectra of the composites in the form of powder and film showed a small shift in the bands compared to the spectrum of pure alginate, indicating that these shifts, even small ones, have evidence of miscibility between the polymer and ceramic material / O alginato de s?dio, NaAlg, ? um polissacar?deo formado por liga??es do tipo 1-4 entre os ?cidos β-D-manur?nico e α-L-gulur?nico arranjados em bloco ao longo de uma cadeia linear. O di?xido de tit?nio, TiO2, ? um material cer?mico e existe em tr?s formas cristalinas: anat?sio, bruquita e rutilo. Os comp?sitos de materiais org?nicos e inorg?nicos apresentam melhores propriedades do que os componentes isoladamente. Dessa forma, o presente trabalho teve objetivo sintetizar, caracterizar e analisar os comp?sitos, NaAlg-TiO2, em formas de p? e de membrana. A s?ntese dos p?s comp?sitos foi realizada atrav?s do processo sol-gel e a obten??o dos comp?sitos em forma de membrana foi realizada atrav?s do processo de evapora??o lenta. Em seguida, os comp?sitos foram caracterizados por espectroscopia de infravermelho, difratometria de raios X, espectroscopia de imped?ncia, fluoresc?ncia de raios X, an?lise t?rmica e espectroscopia de reflect?ncia total atenuada-ATR. Os difratogramas de raios X dos p?s comp?sitos mostraram que, com o aumento da temperatura de calcina??o, n?o houve a completa transi??o de fase anat?sio-rutilo, uma vez que, em todas as temperaturas estudadas (300, 500, 700, 900 e 1100?C) foram observados picos da fase anat?sio. A an?lise t?rmica mostrou que em 400?C ocorreu ? decomposi??o do alginato de s?dio em carbonato de s?dio e, acima de 600?C, se observa um pico exot?rmico referente ? decomposi??o do carbonato de s?dio que, na presen?a do di?xido de tit?nio, transforma-se em titanato de s?dio, confirmados, tamb?m, atrav?s dos difratogramas de raios X, em que na temperatura de 700?C observa-se picos referentes ao carbonato de s?dio e em 900 e 1100?C picos relacionados ao titanato de s?dio. O titanato de s?dio influenciou nas propriedades el?tricas do material, pois com o aumento da temperatura houve um decr?scimo na condutividade, provavelmente, devido ? cria??o de vac?ncias de Ti, uma vez que, o Na+ induz a redu??o dos ?ons Ti+4 para esp?cies Ti+3. Os espectros de infravermelho dos comp?sitos em formas de p? e de membrana mostraram um pequeno deslocamento nas bandas, quando comparados ao espectro do alginato de s?dio puro, indicando que estes deslocamentos, mesmo que pequenos, t?m ind?cios de miscibilidade entre o pol?mero e o material cer?mico

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-02T22:22:38Z No. of bitstreams: 1 RobertaTalitaStopilha_DISSERT.pdf: 9026948 bytes, checksum: 15e7a4c81ad84759d46e4d3ed6775c19 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-09T19:28:21Z (GMT) No. of bitstreams: 1 RobertaTalitaStopilha_DISSERT.pdf: 9026948 bytes, checksum: 15e7a4c81ad84759d46e4d3ed6775c19 (MD5) / Made available in DSpace on 2015-12-09T19:28:21Z (GMT). No. of bitstreams: 1 RobertaTalitaStopilha_DISSERT.pdf: 9026948 bytes, checksum: 15e7a4c81ad84759d46e4d3ed6775c19 (MD5) Previous issue date: 2014-09-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Os complexos polieletrol?ticos nanoparticulados foram obtidos usando quitosana e poli(metacrilato de s?dio). A forma??o dos complexos foi avaliada por turbidimetria, condutometria, viscosimetria e espalhamento din?mico da luz. A presen?a de excesso de cargas positivas pode ser evidenciada atrav?s da an?lise do potencial zeta. O di?metro das part?culas foi caracterizado pela t?cnica de espalhamento din?mico da luz e a morfologia por microscopia de for?a at?mica. Em todos os experimentos uma mudan?a abrupta de comportamento foi evidenciada no intervalo de raz?o molar (grupos carboxilato/amino) entre 0,7-0,8. Essas mudan?as de comportamento puderam ser relacionadas com uma proposta de mecanismo de forma??o dos complexos polieletrol?ticos, baseada na redu??o das dimens?es macromoleculares dos aglomerados de complexos polieletrol?ticos sol?veis seguidos de segrega??o de fase. / Polyelectrolyte complexes (PECs) nanoparticles were prepared using chitosan and sodium polymethacrylate. The complex formation was investigated using turbidimetry, conductometry, viscometry, and dynamic light scattering. The presence of excess positive charges was evidenced by zeta potential measurements. The particle diameter was characterized by dynamic light scattering and the morphology by atomic force microscopy. In all experiments an abrupt change in behavior was observed at a carboxyl:amino molar ratio around 0.7?0.8. Those changes in behavior were related to a proposed mechanism of complex formation based on the decrease of macromolecular dimensions of soluble polyelectrolyte complex clusters, followed by phase segregation

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-02T22:55:04Z No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-04T00:24:44Z (GMT) No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) / Made available in DSpace on 2016-03-04T00:24:44Z (GMT). No. of bitstreams: 1 GiselleKallineGomesCarvalho_DISSERT.pdf: 2257540 bytes, checksum: e731412b34e93ab422b0df96d21ad8b7 (MD5) Previous issue date: 2014-11-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Atividades industriais de minera??o, galvanoplastia e o processo de extra??o do petr?leo, vem aumentando os n?veis de metais pesados, tais como Cu, Fe, Mg e Cd, nos ecossistemas aqu?ticos. Este aumento est? relacionado ao descarte de efluentes contendo teores desses elementos acima do valor m?ximo permitido por lei. M?todos como troca i?nica, filtra??o por membranas e precipita??o qu?mica vem sendo estudados como meios de tratamentos de efluentes contaminados por esses metais. A precipita??o de metais utilizando tensoativos ani?nicos obtidos a partir de ?cidos carbox?licos surgiu como uma alternativa para a remo??o de metais de efluentes industriais. A rea??o entre ?ons bivalentes dos metais e esses tipos de tensoativos em solu??o aquosa leva a forma??o de carboxilatos de metais, que podem precipitar na forma de flocos e serem removidos, posteriormente, por um processo de decanta??o dos flocos formados ou por uma filtra??o simples. Neste trabalho, a extra??o de metais ? realizada por meio da utiliza??o do tensoativo hexadecanoato de s?dio como agente extrator. O objetivo principal ? estudar o efeito da varia??o da temperatura do meio, pH da solu??o de metal e concentra??o do tensoativo no processo de remo??o do metal. A modelagem estat?stica do estudo mostrou que o processo ? diretamente dependente das varia??es de pH e concentra??o do tensoativo, por?m inversamente proporcional e pouco dependente da varia??o de temperatura, sendo esse ?ltimo efeito considerado desprez?vel na maioria dos casos. O estudo individual do efeito da temperatura apresenta uma forte depend?ncia do processo ? temperatura de Kraft, tanto do tensoativo utilizado como agente extrator como do tensoativo obtido ap?s a rea??o desse tensoativo com o metal. A partir dos dados de temperaturas e concentra??es do tensoativo foi poss?vel o c?lculo da constante de equil?brio para a rea??o entre o hexadecanoato de s?dio e ?ons cobre. Posteriormente, foram determinados par?metros termodin?micos, comprovando que o processo ? exot?rmico e espont?neo. / Industrial activities like mining, electroplating and the oil extraction process, are increasing the levels of heavy metals such as Cu, Fe, Mg and Cd in aquatic ecosystems. This increase is related to the discharge of effluents containing trace of this elements above the maximum allowed by law. Methods such as ion exchange, membrane filtration and chemical precipitation have been studied as a means of treatment of these metals contamination. The precipitation of metals using anionic surfactants derived from carboxylic acids emerged as an alternative for the removal of metals from industrial effluents. The reaction between bivalent ions and these types of surfactants in aqueous solution leads to the formation of metal carboxylates, which can precipitate in the form of flakes and are subsequently removed by a process of decantation or simple filtration. In this work the metals extraction is performed by using the surfactant sodium hexadecanoate as extracting agent. The main purpose was to study the effect of temperature, solution pH, and concentration of surfactant in the metal removal process. The statistical design of the process showed that the process is directly dependent to changes in pH and concentration of surfactant, but inversely proportional and somewhat dependent to temperature variation, with the latter effect being considered negligible in most cases. The individual study of the effect of temperature showed a strong dependence of the process with the Kraft point, both for the surfactant used as extracting agent, as for the surfactant obtained after the reaction of this surfactant with the metal. From data of temperatures and concentrations of the surfactant was possible to calculate the equilibrium constant for the reaction between sodium hexadecanoate and copper ions. Later, thermodynamic parameters were determined, showing that the process is exothermic and spontaneous.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-27T12:21:51Z No. of bitstreams: 1 CamilaRenataMachadoDeLima_TESE.pdf: 10473326 bytes, checksum: 499183bf400adac799809def0c151a7f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-30T11:35:30Z (GMT) No. of bitstreams: 1 CamilaRenataMachadoDeLima_TESE.pdf: 10473326 bytes, checksum: 499183bf400adac799809def0c151a7f (MD5) / Made available in DSpace on 2017-01-30T11:35:30Z (GMT). No. of bitstreams: 1 CamilaRenataMachadoDeLima_TESE.pdf: 10473326 bytes, checksum: 499183bf400adac799809def0c151a7f (MD5) Previous issue date: 2016-06-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Polieletr?litos carregados opostamente interagem eletrostaticamente para formar os denominados complexos interpolieletrol?ticos (IPEC?s). Ao combinar diferentes tipos de polieletr?litos, estruturas distintas podem ser formadas, o que torna necess?rio a devida caracteriza??o f?sico-qu?mica desses complexos interpolieletrol?ticos. Dessa forma, neste trabalho, inicialmente, foram obtidos complexos interpolieletrol?ticos entre quitosana e poli (4-estireno sulfonato de s?dio) a diferentes raz?es molares, rSA (sulfonato/am?nio), atrav?s da simples mistura das solu??es desses polieletr?litos em meio ?cido: sendo a quitosana o polic?tion e o poli (4-estireno sulfonato de s?dio) o poli?nion. Posteriormente, esses IPEC?s foram caracterizados por medidas de viscosidade, turbidez, condutividade, potencial zeta, al?m das t?cnicas de espalhamento din?mico da luz (DLS) e espalhamento de raios-X a baixo ?ngulo (SAXS). A ampla faixa de dezessete raz?es molares, rSA (0,01; 0,03; 0,05; 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 1,4; 1,7; 2,0; 2,5; 3,3; 5,0 e 10), investigada neste trabalho gerou part?culas coloidais de natureza liof?lica e liof?bica. As medidas de turbidez e condutividade apresentaram um aumento dr?stico quando a raz?o molar teve seu valor igual a 1. O potencial zeta nesta regi?o de rSA = 1 foi de 0, confirmando a neutralidade de carga e uma estequiometria 1:1 entre os polieletr?litos. A partir dos par?metros obtidos pelo DLS e SAXS foi poss?vel caracterizar o processo de forma??o dos IPEC?s. As part?culas s?lidas de IPEC?s obtidas foram caracterizadas por TG, DRX e FTIR, indicando que a complexa??o interpolieletrol?tica inibiu a ocorr?ncia de regi?es cristalinas. Posteriormente, foram realizados experimentos a fim de monitorar e caracterizar o processo de adsor??o de dois f?rmacos, tetraciclina e cromoglicato, em part?culas s?lidas de IPEC?s obtidas a partir de duas raz?es molares diferentes, rSA = 0,7 e 1,43. Isotermas de adsor??o e um modelo cin?tico foram utilizados nos dados experimentais para descrever o processo de adsor??o. As part?culas de IPEC?s obtidas a partir da rSA = 0,7 e rSA = 1,43 mostraram ser bons adsorventes para a tetraciclina. Entretanto, nenhum processo de adsor??o do cromoglicato em part?culas obtidas a partir da rSA = 1,43 foi observado. / Oppositely charged polyelectrolytes interact electrostatically to form the so-called interpolyelectrolyte complexes (IPEC?s). By combining different types of polyelectrolytes, different structures may be formed, which makes necessary the physicochemical characterization of these interpolyelectrolyte complexes. Thus, in this study, initially, were obtained interpolyelectrolyte complexes between chitosan and poly (4-styrene sulfonate of sodium) at different molar ratios, rSA (sulfonate/aminium), by simply mixing the solutions of these polyelectrolytes in acid medium: it is the chitosan as the polycation and poly (4-styrene sulfonate of sodium) as the polyanion. Thereafter, the IPEC?s were characterized by measurements of viscosity, turbidity, conductivity, zeta potential, beyond techniques the dynamic light scattering (DLS) and scattering X-ray small angle (SAXS). The wide range of seventeen molar ratios, rSA (0.01; 0.03; 0.05; 0.1; 0.2; 0.3; 0.4; 0.5; 0.6; 0.7; 1.4; 1.7; 2.0; 2.5; 3.3; 5.0 e 10), investigated in this work generated colloidal particles of lyophilic and liophobic nature. The turbidity and conductivity measurements showed a drastic increase when the molar ratio had its value equal 1. The zeta potential in this region rSA = 1 was 0, confirming the neutral charge and a 1:1 stoichiometry between the polyelectrolytes. From the parameters obtained by DLS and SAXS it was possible to characterize the process of formation of IPEC?s. The solid particles obtained IPEC?s were characterized by TG, DRX and FTIR, indicating that complexation polyelectrolytic inhibited the occurrence of crystalline regions. Subsequently, experiments were conducted to monitor and characterize the adsorption process of two drugs, tetracycline and cromoglycate, in solid particulate IPEC?s derived from two different molar ratios, rSA = 0.7 e 1.43. Adsorption isotherms and a kinetic model were used in the experimental data to describe the adsorption process. The particles IPEC?s obtained from the rSA = 0.7 and rSA = 1.43 appeared to be good adsorbents for tetracycline. However, no adsorption process of the cromoglycate in particles obtained from the rSA = 1.43 was observed.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-17T21:58:31Z No. of bitstreams: 1 RobertaPatriciaMedeirosDeMaria_TESE.pdf: 6281151 bytes, checksum: 10964efe9eef6ffed08beadb31aa534f (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-19T19:38:24Z (GMT) No. of bitstreams: 1 RobertaPatriciaMedeirosDeMaria_TESE.pdf: 6281151 bytes, checksum: 10964efe9eef6ffed08beadb31aa534f (MD5) / Made available in DSpace on 2017-04-19T19:38:24Z (GMT). No. of bitstreams: 1 RobertaPatriciaMedeirosDeMaria_TESE.pdf: 6281151 bytes, checksum: 10964efe9eef6ffed08beadb31aa534f (MD5) Previous issue date: 2015-08-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / ? medida que demandas energ?ticas foram sendo apresentadas e requeridas pelo avan?o tecnol?gico, a s?ntese de novos materiais, capazes de suprir estas necessidades, foi e tem sido exaustivamente executada e estudada; dentre estes materiais, est?o filmes polim?ricos comp?sitos que t?m se destacado como uma alternativa qu?mica, f?sica, el?trica e econ?mica vi?vel. Neste trabalho filmes finos autossustent?veis de poli(metactrilato de metila) (PMMA) sob a forma de blendas, associado ao poli(etileno glicol) (PEG), e comp?sitos, dopados com tungstato de s?dio diidratado, foram obtidos pela associa??o dos m?todos sol-gel e ?casting?. A caracteriza??o el?trica, estrutural, qu?mica e morfol?gica dos filmes obtidos foi realizada usando-se espectroscopia de imped?ncia eletroqu?mica (EIS) para obten??o dos par?metros el?tricos, reflex?o total atenuada na regi?o do infravermelho (IV-ATR) e difra??o de raios X (DRX) para estudo da composi??o estrutural e qu?mica, enquanto que a estabilidade t?rmica foi analisada usando termogravimetria (TG/DTG), an?lise t?rmica diferencial (DTA) e calorimetria diferencial de varredura (DSC); as caracter?sticas morfol?gicas e topogr?ficas dos filmes foram analisadas por microscopia ?tica (MO) e eletr?nica de varredura (MEV). A adi??o do sal promoveu modifica??es do padr?o de disposi??o das cadeias polim?ricas, observado por difra??o de raios X e ratificado por altera??es das bandas relativas ? deforma??o angular ?CH2? em cadeia e estiramento assim?trico ?C?C? em cadeia, sugerindo mudan?as estruturais na cadeia polim?rica. A miscibilidade entre os pol?meros poli(metacrilato de metila) e poli(etileno glicol) foi resultado da presen?a de intera??es intermoleculares do tipo liga??o de hidrog?nio entre o ?CO? do PMMA e os grupos OH do PEG e do sal tungstato de s?dio, evidenciadas nas an?lises por IV-RTA, assim como, intera??es puramente eletrost?ticas. Os sistemas apresentaram melhores caracter?sticas capacitivas e maiores tempos de relaxa??o, favorecidos pelo aumento da concentra??o do tungstato de s?dio, resultado da melhora da sensibilidade do ac?mulo de cargas no eletrodo. / As energy demands were being presented and required by technological advances, the synthesis of new materials capable of meeting these needs, was and has been thoroughly studied and performed; among these materials are composite polymeric films that have stood out as an alternative chemistry, physics, electrical and economically viable. In this work self-supporting thin films of poly(methyl methacrylate) (PMMA) in the form of blends, linked to poly (ethylene glycol) (PEG), and composite doped with sodium tungstate dihydrate were obtained by combining the sol-gel methods and casting. The electrical, structural, chemical and morphological characterization of the films obtained was performed using electrochemical impedance spectroscopy (EIS) to obtain the electrical parameters, attenuated total reflection in the infrared (IR-ATR) and X-ray diffraction (XRD) to study the structural and chemical composition, while the thermal stability was evaluated using thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC); morphological and topographical characteristics of the films were analyzed by optical microscopy (OM) and scanning electron (SEM). The addition of the salt promoted standard modifications of the arrangement of the polymer chains, observed by X-ray diffraction and confirmed by the changes of the bands relative to the angular deformation -CH2- chain and asymmetric stretching -C-C-chain, suggesting structural changes in polymer chain. The miscibility between the polymers poly (methyl methacrylate) and poly (ethylene glycol) was a result of the presence of intermolecular interactions type hydrogen bonding between the PMMA and -CO- OH groups of the PEG and sodium tungstate salt, highlighted in analyzes by IR-ATR as well as purely electrostatic interactions. The systems showed better capacitive characteristics and larger relaxation times, favored by increasing the concentration of sodium tungstate, a result of improved sensitivity of the charges accumulated in the electrode.

Made available in DSpace on 2014-12-17T15:42:13Z (GMT). No. of bitstreams: 1 WilliamGM_DISSERT.pdf: 1986302 bytes, checksum: 71e6a449a8f77e2f64a9c3908ab5410d (MD5) Previous issue date: 2013-07-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / A new self-sustainable film was prepared through the sol-gel modified method, previously employed in our research group; sodium alginate was used as the polymer matrix, along with plasticizer glycerol, doped with titanium dioxide (TiO2) and tungsten trioxide (WO3). By varying WO3 concentration (0,8, 1,6, 2,4 and 3,2 μmol) and keeping TiO2 concentration constant (059 mmol), it was possible to study the contribution of these oxides on the obtained films morphological and electrical properties. Self-sustainable films have analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XDR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Electrochemical Impedance Spectroscopy (EIS). By the IR specters, it was possible identify the TiO2, and posteriorly WO3, addition has provided dislocation of alginate characteristics bands to smaller vibrations frequencies indicating an electrostatic interaction between the oxides and the polymer matrix. Diffractograms show predominance of the amorphous phase in the films. SEM, along with EDX, analysis revealed self-sustainable films showed surface with no cracks and relative dispersion of the oxides throughout the polymer matrix. From Impedance analysis, it was observe increasing WO3 concentration to 2,4 μmol provided a reduction of films resistive properties and consequent improvement of conductive properties / Um novo filme autossustent?vel foi preparado, atrav?s do m?todo sol-gel modificado, anteriormente empregado no nosso grupo de pesquisa, utilizando como matriz polim?rica o alginato de s?dio, juntamente com o plastificante glicerol, dopado com di?xido de tit?nio (TiO2) e tri?xido de tungst?nio (WO3). Variando as concentra??es do WO3 (0,8, 1,6, 2,4 e 3,2 μmol), e mantendo constante a concentra??o do TiO2 (0,59 mmol), foi poss?vel estudar a contribui??o destes ?xidos nas propriedades morfol?gicas e el?tricas dos filmes obtidos. Os filmes autossustent?veis foram caracterizados atrav?s das t?cnicas de Espectroscopia de Infravermelho com Transformada de Fourier (FTIR), Difratometria de Raios X (DRX), Microscopia Eletr?nica de Varredura (MEV), Espectroscopia de Raios X por Dispers?o de Energia (EDS) e Espectroscopia de Imped?ncia Eletroqu?mica (EIE). Atrav?s dos espectros de FTIR foi poss?vel identificar que a adi??o do TiO2 e, posteriormente, do WO3 proporciona deslocamento das bandas caracter?sticas do alginato para menores frequ?ncias de vibra??o, indicando uma intera??o eletrost?tica dos ?xidos com a matriz polim?rica. Os difratogramas evidenciaram a predomin?ncia do comportamento amorfo nos filmes. As an?lises de MEV, juntamente com as de EDS, revelaram que os filmes autossustent?veis apresentam uma superf?cie sem trincamento e de relativa dispers?o dos ?xidos ao longo da matriz polim?rica. Atrav?s da EIE observouse que o aumento da concentra??o de WO3 at? 2,4 μmol proporcionou uma redu??o do comportamento resistivo dos filmes, e consequente melhoria em suas propriedades condutoras

Made available in DSpace on 2016-04-28T20:18:34Z (GMT). No. of bitstreams: 1 2009 - Ana Paula de Magalhaes Nunes.pdf: 2100747 bytes, checksum: 71718bf8a01eaa5a22f6b041a009a396 (MD5) Previous issue date: 2009-03-13 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / In order to investigate the hypothesis of the influence of serotonergic system on the control of dipsogenic and sodium appetite, we examined the effects of chronicallytreated rats with the brain serotonin releaser, fenfluramine, the 5-HT1A agonist, 8-OHDPAT and the selective serotonin re-uptake inhibitor, sertraline. Animals treated with 5- HT1A agonist and brain serotonin releaser were sodium depleted and then their fluids intake analyzed. The first group decreased significantly the salt intake response while the second group intensified the sodium appetite 2 weeks after the first administration of fenfluramine. The water consumption was not altered in none of the groups when compared to their respective controls. Sodium-depleted animals that were treated with sertraline showed a more intense natriorexigenic response. On the other hand, water deprivation induced a lower water intake in SERT-treated rats than the controls. Osmotic simulation evoked a dipsogenic response significantly lower in SERT group. Fluids and food deprivation induced a weak dipsogenic response in SERT treated-rats compared to controls but without difference on saline intake. An increased urinary density and decreased plasma sodium levels in SERT-treated rats correlated with the highest plasma vasopressin and oxytocin levels at the 3rd week post-treatment. The obtained results in chronically-treated rats with the 5-HT1A agonist and the brain serotonin releaser, suggest that the alteration on the brain serotoninergic activity influences the sodium appetite expression, possibly after 5-HT1A autoreceptor desensitization produced by 8-OH-DPAT or brain serotonin depletion achieved with fenfluramine treatment. The results of chronically-treated rats with sertraline, constitute the first evidence of alterations on the threshold for thirst and sodium appetite response in SERT-chronically-treated rats. These alterations possibly are consequence of the hyponatremia provided by inappropriate secretion of AVP and OT. / Para investigar a hip?tese da influ?ncia do status do sistema seroton?rgico no controle da resposta dipsog?nica e do apetite ao s?dio, analisamos os efeitos de ratos tratados cronicamente com um liberador cerebral de serotonina, fenfluramina, um agonista 5-HT1A, 8-OH-DPAT e um inibidor da recapta??o pr?-sin?ptica de serotonina, sertralina (SERT). Animais tratados com agonista 5-HT1A e com liberador cerebral de serotonina, foram submetidos a deple??o de s?dio e, posteriormente, a ingest?o de fluidos foi aferida. O primeiro grupo diminuiu significativamente a ingest?o de salina hipert?nica, enquanto o segundo grupo intensificou o apetite ao s?dio 2 semanas ap?s o ?n?cio do tratamento com fenfluramina. O consumo de ?gua n?o foi alterado em nenhum dos grupos, quando comparados aos seus respectivos grupo controle. Os animais tratados cronicamente com SERT que sofreram deple??o de s?dio, obtiveram uma intensa resposta natriorexig?nica. Por outro lado, a priva??o de ?gua induziu uma menor ingest?o de ?gua em ratos tratados cronicamente com SERT quando comparado-os aos do grupo controle. O est?mulo osm?tico evocou uma resposta dipsog?nica significativamente menor no grupo SERT. A priva??o de fluidos e de alimentos induziu uma baixa resposta dipsog?nica em ratos tratados com SERT quando comparados aos controles, mas sem diferen?a significativa na ingest?o de salina hipert?nica. O aumento da densidade urin?ria em ratos tratados com SERT correlaciona-se com os maiores n?veis plasm?ticos do horm?nio anti-diur?tico e ocitocina na 4? semana p?s-tratamento. Os resultados obtidos em ratos tratados cronicamente, com o agonista 5-HT1A e com o liberador cerebral de serotonina, sugerem uma poss?vel altera??o da atividade cerebral serotonin?rgica, influenciando assim a express?o do apetite ao s?dio, pois possivelmente ocorreu uma dessensibiliza??o de autoreceptores 5-HT1A com o tratamento com 8-OH-DPAT, e deple??o cerebral de serotonina, obtida com o tratamento com fenfluramina. Os resultados relativos aos animais tratados cronicamente com sertralina, constituem as primeiras evid?ncias de altera??o no limiar de sede e de apetite ao s?dio. Essas altera??es s?o possivelmente conseq??ncia da hiponatremia gerada pela secre??o inapropriada de ADH e OT.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-24T15:47:47Z No. of bitstreams: 1 2016 - L?via da Rocha Natalino Monteiro.pdf: 1451629 bytes, checksum: c984d90970fa9192a11dedd19eb857df (MD5) / Made available in DSpace on 2017-01-24T15:47:47Z (GMT). No. of bitstreams: 1 2016 - L?via da Rocha Natalino Monteiro.pdf: 1451629 bytes, checksum: c984d90970fa9192a11dedd19eb857df (MD5) Previous issue date: 2016-02-17 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / The constant regulation of sodium and water balance is essential for the maintenance of life. From the simplest to the most complex organisms, conservation of such elements at appropriate levels is a vital issue for the homeostasis of the individual. In order to maintain this balance, organisms resort a set of neurohumoral mechanisms that constantly regulate the content of bodily water and sodium. In recent decades, studies of neural mechanisms involved in the regulation of sodium appetite have gained ground since the excessive intake of sodium chloride has been directly related to functional changes which can lead to diseases such as hypertension. Besides the high daily consumption of sodium chloride by occidental societies, there is also a growing number cases of hypertension, particularly the so-called ?salt-sensitive?. Therefore, it is necessary that the mechanisms involved in these changes are intensively studied in scientific models. Thus, through the use of an animal model, we investigated the functional changes arising from the modification of sodium content in the diet of animals. Wistar male rats were randomly divided into 4 groups: i) control (CTRL); ii) low-sodium diet (LSD); iii) furosemide (FURO); iv) saline overload (SO). From this division, we draw the hydroelectrolytic, cardiovascular and molecular profiles of these paradigms four days after the protocols beginning. We found that low-sodium diet and furosemide were able to induce a sustained sodium appetite 4 hours after reintroduction of fluids when compared to control group (LSD: 4.1 ? 0.8 and FURO: 8.5 ? 1.0 vs. CTRL 0.15 ? 0.08 mL/100g body weight, p<0.05, respectively). Besides we have confirmed the occurrence of hypernatremia in SO group (163.7 ? 1.6 vs. 143.2 ? 0.7 mEq/L, p<0.05) we surprisingly have found higher plasma sodium levels in LSD (148.7 ? 1.0 vs. 143.2 ? 0.7 mEq/L, p<0.05) when compared to control group. During the assessment of cardiac parameters, only the FURO group showed smaller mean arterial pressure than control after administration of phenylephrine at both 10 and 50 ?g/mL concentrations (Phe10: 142.6 ? 19.1 vs. 222.4 ? 14 bpm, p<0.05; Phe50: 261.0 ? 74.8 vs. 190.9 ? 19.6 mmHg, p<0.05, respectively), probably due to hypovolemia, a factor which could also explain the absence of hyponatremia in these animals. Concerning the molecular parameters within the PVN, SO group showed an increased mRNA expression of AVP (2.61 ? 0.16 vs. 1.04 ? 0.04 a.u., p<0.05) and OT (1.52 ? 0.12 vs. 1.01 ? 0.05 a.u., p<0.05), while in the LSD group, these parameters are reduced (AVP: 0.65 ? 0.07 vs. 1.04 ? 0.04 a.u., p<0.05; OT: 0.65 ? 0.06 vs. 1.01 ? 0.05 a.u., p<0.05), when compared to control group, respectively. Finally, we found increased levels of AT1 receptor mRNA in SO group (2.94 ? 0.26 vs. 1.14 ? 0.25 a.u, p<0.05) and FURO (3.08 ? 0.51 vs. 1.14 ? 0.25 a.u, p<0.05) compared to control, respectively. Thus, these results underscore the central role of neuroendocrine systems in the modulation of electrolyte and cardiovascular homeostasis / A regula??o constante do balan?o de ?gua e s?dio ? essencial para a manuten??o da vida. Desde os organismos mais simples at? os mais complexos, a conserva??o de tais elementos em n?veis adequados constitui ponto crucial para a homeostase do indiv?duo. Para tanto, os organismos lan?am m?o de uma s?rie de mecanismos neuro-humorais que regulam a todo momento o conte?do de ?gua e s?dio corporal. Nas ?ltimas d?cadas, estudos sobre mecanismos neurais envolvidos na regula??o do apetite ao s?dio t?m ganhado destaque, uma vez que o consumo exagerado de cloreto de s?dio est? diretamente relacionado a altera??es funcionais que podem gerar doen?as como a hipertens?o arterial. Al?m do alto consumo di?rio de s?dio pelas sociedades ocidentais, h? tamb?m um crescente n?mero de casos de hipertens?o arterial, particularmente do tipo denominado sal-sens?vel. Assim, ? necess?rio que os mecanismos envolvidos nessas altera??es sejam intensamente estudados em modelos cient?ficos. Desta forma, atrav?s do uso de modelo animal, investigamos neste trabalho as altera??es funcionais advindas da modifica??o do conte?do de s?dio presente na dieta dos animais. Para tanto, ratos Wistar machos foram randomicamente divididos em 4 grupos experimentais: i) controle (CTRL); ii) dieta pobre em s?dio (DP); iii) furosemida (FURO); iv) sobrecarga salina (SS). A partir desta divis?o, tra?amos os perfis hidroeletrol?tico, cardiovascular e molecular desses paradigmas de desafio ao balan?o hidroeletrol?tico. Verificamos que a dieta hiposs?dica e a furosemida foram capazes de induzir o apetite ao s?dio de forma sustentada at? 4 horas ap?s reapresenta??o de fluidos (DP 4,1 ? 0,8 de peso corporal; FURO 8,5 ? 1,0 vs. CTRL 0,15 ? 0,08 mL/100g; p<0,05). Confirmamos a ocorr?ncia de hipernatremia a partir da sobrecarga salina (SS 163,7 ? 1,6 vs. CTRL 143,2 ? 0,7 mEq/L; p<0,05) e, surpreendentemente, encontramos n?veis natr?micos maiores que o controle no grupo DP (DP 148,7 ? 1,8 vs. Ctrl 143,2 ? 0,7 mEq/L; p<0,05). Quanto ? avalia??o dos par?metros card?acos, somente o grupo furosemida apresentou PAM menor que o controle ap?s a administra??o de fenilefrina nas concentra??es de 10 e 50 ?g/mL ( Phe10 = Furo 142,6 ? 19,1 vs. Ctrl 222,4 ? 14,2 ; Phe50 = Furo 261,0 ? 74,8 vs. Ctrl 190,9 ? 19,6 mmHg; p<0,05), provavelmente devido ? hipovolemia nestes animais. Verificamos ainda que no grupo submetido ? sobrecarga salina ocorre aumento da express?o de mRNA para AVP (SS 2,61 ? 0,16 vs. CTRL 1,04 ? 0,04 a.u - unidades arbitr?rias; p<0,05) e OT (SS 1,52 ? 0,12 vs. CTRL 1,01 ? 0,05 a.u; p<0,05), enquanto que no grupo dieta pobre estes par?metros s?o reduzidos (AVP - DP 0,65 ? 0,07vs. CTRL 1,04 ? 0,04; OT - DP 0,65 ? 0,06vs. CTRL 1,01 ? 0,05 a.u; p<0,05). Por fim, encontramos n?veis aumentados de mRNA do receptor AT1 nos grupos sobrecarga salina (SS 2,94 ? 0,26 vs. CTRL 1,14 ? 0,25 a.u; p<0,05) e furosemida (Furo 3,08 ? 0,51 vs. CTRL 1,14 ? 0,25 a.u; p<0,05). Deste modo, estes resultados refor?am o importante papel dos sistemas neuroend?crinos centrais na modula??o da homeostase hidroeletrol?tica e cardiovascular

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2017-02-21T18:17:11Z No. of bitstreams: 1 Diana Roberta Pereira Grandizoli.pdf: 22186247 bytes, checksum: eda73530f877f7998ed73ea7c0033e18 (MD5) / Made available in DSpace on 2017-02-21T18:17:11Z (GMT). No. of bitstreams: 1 Diana Roberta Pereira Grandizoli.pdf: 22186247 bytes, checksum: eda73530f877f7998ed73ea7c0033e18 (MD5) Previous issue date: 2016-12-19 / The present study sought to evaluate the influence of protease inhibitors on the bond strength of a self-etch adhesive system during hybrid layer formation in caries-affected dentin. The occlusal thirds of 80 permanent third molars were ground down to flat dentin surfaces. Dentinal caries were induced artificially by the microbial method. Groups were divided as follows: G1 (n=20), application of Clearfil SE Bond adhesive system (CL) alone; G2 (n=20), pretreatment with 2% chlorhexidine (CLX)+CL; G3 (n=20), pretreatment with sodium bicarbonate (BIC)+CL; G4 (n = 20), BI +CLX+CL. Bond strength was assessed immediately and at 6 months. Composite resin (Z350) build-ups were made on the dentin surfaces, and beam-shaped specimens with a cross-sectional area of 1 mm? were obtained. Microtensile bond strength testing was performed. Only adhesive or mixed-mode fractures were taken into account for calculation of bond strength. The results were submitted to the Kruskal-Wallis test (Student-Newman-Keuls). There was no significant difference on bond strength between the control, bicarbonate and chlorhexidine groups in the immediate test (p> 0.05). After 6 months, adhesive resistance fell for all groups. The control group had higher bond strength (p <0.05). The predominant fracture was of the adhesive type independent of the period evaluated. It can be concluded that after six months, there was decrease on bond strength for all groups. This reduction was greater in the groups in which the inhibitors were used / O objetivo desse trabalho foi avaliar a influ?ncia do bicarbonato de s?dio na resist?ncia adesiva durante a hibridiza??o da dentina cariada utilizando o sistema adesivo autocondicionante. Foram selecionados 80 terceiros molares permanentes, feita a remo??o do ter?o oclusal e superf?cies dentin?rias planas foram obtidas. A les?o de c?rie dentin?ria foi confeccionada atrav?s do m?todo microbiol?gico. Os grupos foram: G1 (n=20): aplica??o do sistema adesivo Clearfil (CL), G2 (n=20): aplica??o de clorexidina 2% (CLX) + CL, G3 (n=20): aplica??o de bicarbonato de s?dio (BI) + CL, G4 (n=20): BI + CLX + CL. A resist?ncia adesiva foi avaliada imediatamente e ap?s seis meses. Um bloco de resina composta Z350 foi constru?do em dentina. Cada bloco dente/adesivo/resina foi seccionado com disco diamantado acoplado ? m?quina de corte em planos paralelos obtendo-se corpos de prova em forma de palito, com ?rea de sec??o transversal de 1 mm?. Foi realizado teste de resist?ncia de uni?o por meio do teste de microtra??o. Foi considerada apenas fratura adesiva/mista para c?lculo da resist?ncia de uni?o. Os resultados foram submetidos aos teste de Kruskal-Wallis (Student-Newman-Keuls). N?o houve diferen?a significante na resist?ncia de uni?o entre os grupos controle, bicarbonato e clorexidina no teste imediato (p>0.05). Ap?s 6 meses, houve queda da resist?ncia adesiva para todos os grupos. O grupo controle apresentou maior resist?ncia de uni?o (p<0.05). A fratura predominante foi do tipo adesiva independente do per?odo avaliado. Pode-se concluir que ap?s seis meses, houve diminui??o na for?a de uni?o para todos os grupos. Essa redu??o apresentou-se maior nos grupos em que os inibidores foram utilizados.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-10-16T18:19:32Z No. of bitstreams: 1 2013 - Gabriela Ferreira de Oliveira.pdf: 1149006 bytes, checksum: e5df0fd5e246ea685fd7bb50c7ab42d5 (MD5) / Made available in DSpace on 2018-10-16T18:19:32Z (GMT). No. of bitstreams: 1 2013 - Gabriela Ferreira de Oliveira.pdf: 1149006 bytes, checksum: e5df0fd5e246ea685fd7bb50c7ab42d5 (MD5) Previous issue date: 2013-08-12 / Sodium is the major electrolyte of the extra cellular space, essential for the control of plasma osmolality and blood pressure. In addition, sodium is the only mineral for which there is a defined appetite. For sodium homeostasis and for the regulation of extra cellular fluid, the reported physiological systems include the renin angiotensin aldosterone system, atrial natriuretic peptide and oxytocin. In mice the feeding behavior of sodium is well established and the central inhibition of sodium appetite has been demonstrated. However, in some domestic species, especially in horses, subject of this study, this behavior has not yet been clarified. This study aimed to evaluate the clinical and hematological effects, beyond the assessment of fluid and electrolyte balance and feeding behavior of fluids after the central administration of enalaprilat in horses experimentally dehydrated. Six adult, gelding horses, were used. The animals were subjected to water and food restriction for 72 hours prior the study, associated with the administration of three doses of furosemide in the first 24 hours. After the 72 hours fasting, the animals were divided into two experimental groups. The first group was called Control Group (CG) and the second, Treaty Group (TG). The animals of TG received 2.75 mg/animal of enalaprilat by intracarotideal route. After administration of enalaprilat, the animals had free access to water and hypertonic saline solution (1.8% of NaCl), with ingested volumes monitored. All animals were submitted to a regular and periodical physical examination, measured blood pressure and collected blood samples every 12 hours until the administration of enalaprilat, to evaluate the effects of dehydration; and 30, 60, 120, 180 minutes and 24 hours after administration, to evaluate the drug effects. Weight loss was the parameter that best reflected dehydration, which was estimated at 10.5% at the end of 72 hours of food and water restriction. When the animals had free access to water and saline, we observed a higher total water consumption in TG (13.7 ? 12 L) than in the CG (9.1 ? 7.9 L), with no significant difference between groups (p = 0.3522). There was no significant difference between GC and GT in clinical and hematological parameters, in all moments evaluated. Evaluating the sodium appetite, as evidenced by the ratio between salt intake and the amount of fluid consumed, it was observed that the TG showed lower sodium appetite than the CG (p = 0 0396), observed 120 minutes after the central administration of enalaprilat, demonstrating the centrally action of ACE inhibitor (enalaprilat) in inhibition of sodium appetite in horses. / O s?dio ? o principal eletr?lito do espa?o extracelular, fundamental para o controle da osmolaridade plasm?tica e press?o arterial, al?m de ser o ?nico mineral para qual existe um apetite claramente definido. Para a homeostase do s?dio e do fluido extracelular, os sistemas fisiol?gicos relatados incluem o sistema renina angiotensina aldosterona (SRAA), pept?deo natriur?tico atrial (ANP) e ocitocina (OT). O comportamento ingestivo de s?dio em ratos j? est? bem estabelecido e a inibi??o central do apetite por s?dio j? foi demonstrada. Por?m, em algumas esp?cies dom?sticas, especialmente nos equinos, tema deste trabalho, este comportamento ainda n?o foi esclarecido. O objetivo deste trabalho foi avaliar os efeitos cl?nicos e hematol?gicos, al?m da avalia??o do equil?brio hidroeletrol?tico e do comportamento ingestivo de l?quidos ap?s a administra??o central de enalaprilato em equinos experimentalmente desidratados. Foram utilizados seis equinos adultos, machos, castrados, que permaneceram em jejum h?drico e alimentar por 72 horas, associado ? administra??o de furosemida. Ap?s 72 horas de jejum, os animais foram divididos em dois grupos experimentais, o Grupo Controle (GC) e o Grupo Tratado (GT), que recebeu 2,75 mg/animal de enalaprilato por via intracarot?dea. Ap?s, os animais tiveram livre acesso a ?gua e a solu??o salina hipert?nica (1,8% de NaCl). Os animais foram avaliados atrav?s de exame cl?nico, a cada 12 horas durante as 72 horas de jejum e 30, 60, 120, 180 minutos e 24 horas ap?s o Enalaprilato. Foram avaliados o peso corporal, a quantidade de l?quidos ingeridos, a press?o arterial m?dia, par?metros bioqu?micos e eletrol?ticos sangu?neos. A perda de peso corporal foi o par?metro que melhor refletiu a desidrata??o, estimada em 10,5% ao final de 72 horas de jejum. Com o restabelecimento do acesso ? ?gua e solu??o salina, observou-se maior consumo total de ?gua no GT (13,7 ? 12 L) que no GC (9,1 ? 7,9 L), sem diferen?a significativa entre os grupos (p = 0,3522). N?o houve diferen?a significativa nos par?metros cl?nicos e hematol?gicos avaliados entre o GC e o GT. O apetite por s?dio foi reduzido significativamente (p = 0, 0396) no GT comparado ao GC, evidenciado 120 minutos ap?s a administra??o do enalaprilato, demonstrando a a??o central do inibidor de ECA (Enalaprilato) na inibi??o do apetite por s?dio em equinos.