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Estudos do meio reacional da síntese de polianilina e poli-o-toluidina; Studies of the reaction media of polyaniline and poly-o-toluidine synthesis

Machado, Douglas Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/04/2007 PT
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99.24464%
Foram realizadas análises por espectros absorção, fluorescência e excitação para anilina e orto-toluidina em água, com e sem a adição de HCl. Os resultados indicam que as propriedades do meio dependem das concentrações de amina e de HCl, sendo observado principalmente pelos espectros de excitação de fluorescência. Espectros de 1H RMN parecem indicar um efeito de agregação destas moléculas pelas mudanças observadas na forma e na posição dos sinais dos prótons. Foi realizada a síntese de polianilina e de poli-o-toluidina, sendo o acompanhamento efetuado por espectroscopia ultravioleta-visível e pela técnica de perfil de potencial, indicando similaridades entre os dois métodos. As sínteses de polianilina e de poli-o-toluidina também foram realizadas via fotoquímica, sendo os produtos de reação caracterizados por espectroscopia ultravioleta visível e por infravermelho.; The aim this work was to study aniline and orto-toluidine in aqueous solution with or without HCl addition. The analyses were realized by absorption and fluorescence spectrum. The results show that the proprieties are relation on amines and chloridric acid concentrations, especially it was observed by fluorescence excitation spectrum. Changes in protons sign position and in the form can be indicating an effect of aggregation with these molecules though 1H RMN spectrum. UV-Vis spectroscopy and open circuit potential measurements were used for monitor the synthesis of polyaniline and the poly-o-toluidine. Theses methods show similar results. Also...

Aspectos descritivos e quantitativos da anatomia macroscópica e microscópica do nervo vestíbulo-coclear de cobaias; Descriptive and Quantitative Aspects of macroscopic and microscopic anatomy of the vestibulocochlear nerve of guinea pigs

Vasconcelos, Carlos Augusto Carvalho de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/06/2005 PT
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17.691248%
O nervo vestíbulo-coclear da cobaia possui peculiaridades não encontradas em outros nervos periféricos. Não foram encontradas informações detalhadas sobre os aspectos morfométricos do VIII nervo craniano em cobaias adultas na literatura. A avaliação descritiva e quantitativa no presente estudo, evidencia informações que precedem o estudo das alterações que ocorrem em modelos experimentais de neuropatias do VIII nervo craniano e as doenças ou lesões que possam afetar o homem. Foram utilizadas 8 cobaias adultas, perfundidas com glutaraldeído a 2,5% em tampão cacodilato de sódio (0,025 M). Seus nervos direito e esquerdo (n=6, 4 nervos direito e 2 esquerdos) foram dissecados na região mediana do nervo e pós fixado com tetróxido de ósmio (OsO4) a 1% e incluídos em resina epóxi Poly/Bed 812®. Os fragmentos foram cortados em secções transversais semifinas seriadas (6 nervos) com uma espessura de 0,5 μm e corados com azul de toluidina para a microscopia de luz. Foram analisados os aspectos histológicos descritivos e topográficos do nervo vestíbulo-coclear em cobaias adultas, bem como os aspectos histométricos na parte mediana do nervo, no referente a densidade de fibras mielínicas, a distribuição dos diâmetros de tal tipo de fibras mielínicas...

Synthesis and characterization of poly-o-toluidine: Kinetic and structural aspects

De Moraes Cordeiro, Maria Angela; Gonçalves, Débora; De Sousa Bulhões, Luis Otavio; Cordeiro, João Manuel Marques
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 5-10
ENG
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99.14449%
Poly(o-methylaniline) (poly-o-toluidine, PTOL) was synthesized by chemical oxidation of o-toluidine with ammonium peroxydisulfate in an aqueous 1.0 mol L -1 HCl solution. The progress of polymerization was followed by measuring the open-circuit potential (OCP) of a Pt electrode immersed in the reaction medium with the polymerization time. The chemical synthesis of PTOL was carried out at different monomer:oxidant (M:O) molar ratios (4:1, 2:1, 1.5:1, 1:1, and 0.66:1), and the products obtained were characterized by infrared spectroscopy, gel permeation chromatography, and X-ray diffraction. The molecular weight and percentage of crystallinity of PTOL are higher for samples synthesized in an excess of the monomer, i.e. at higher M:O ratios. However, the yield of PTOL prepared at higher M:O ratios is considerably low, in particular at a 4:1 M:O ratio, which is the M:O ratio most commonly used in the literature to synthesize polyaniline and its derivatives.

Avaliação in vivo da degradação de proteses tubulares de poli (L-acido-latico) empregadas no reparo cirurgico do nervo ciatico de ratos

Anibal de Araujo Morais
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/05/2003 PT
Relevância na Pesquisa
17.649756%
O reparo de nervos periféricos usando próteses tubulares é uma técnica alternativa que pode produzir resultados similares ou melhores que outras técnicas cirúrgicas utilizadas. Entretanto, sua eficiência depende essencialmente da biocompatibilidade e das propriedades estruturais do material do tubo. Nesse trabalho foi avaliado a degradação in vivo de tubos (lOmm) de poli(ácido lático) PLLA adicionado 10% de plastificante tri-etil-citrato. Dezesseis ratos machos da linhagem Wistar, foram submetidos a tubulização e divididos em quatro grupos experimentais (n=4) segundo tempos de sobrevida de 30, 90, 180 e 430 dias após a intervenção cirúrgica. Todas as cirurgias foram precedidas de anestesia profunda com pentobarbital sódico (60mg/kg). O nervo ciático esquerdo foi exposto e seccionado na porção média da coxa. Os cotos proximal e distal foram introduzidos no tubo, deixando-se uma distância de 5mm entre eles, sendo ancorados à parede deste através de um ponto de sutura epineural. Após os tempos de sobrevida de 30, 90, 180 e 430 dias, os animais foram novamente anestesiados e o nervos tubulizado e contralateral foram fixados in situ, por um período de 20 minutos, com uma solução de glutaraldeído 5% (tampão fosfato 0...

Synthesis and characterization of poly-o-toluidine: kinetic and structural aspects

Cordeiro,Maria Angela de Moraes; Gonçalves,Débora; Bulhões,Luis Otavio de Sousa; Cordeiro,João Manuel Marques
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2005 EN
Relevância na Pesquisa
99.14449%
Poly(o-methylaniline) (poly-o-toluidine, PTOL) was synthesized by chemical oxidation of o-toluidine with ammonium peroxydisulfate in an aqueous 1.0 mol L-1 HCl solution. The progress of polymerization was followed by measuring the open-circuit potential (OCP) of a Pt electrode immersed in the reaction medium with the polymerization time. The chemical synthesis of PTOL was carried out at different monomer:oxidant (M:O) molar ratios (4:1, 2:1, 1.5:1, 1:1, and 0.66:1), and the products obtained were characterized by infrared spectroscopy, gel permeation chromatography, and X-ray diffraction. The molecular weight and percentage of crystallinity of PTOL are higher for samples synthesized in an excess of the monomer, i.e. at higher M:O ratios. However, the yield of PTOL prepared at higher M:O ratios is considerably low, in particular at a 4:1 M:O ratio, which is the M:O ratio most commonly used in the literature to synthesize polyaniline and its derivatives.

Decolorization of Azo, Triphenyl Methane, Heterocyclic, and Polymeric Dyes by Lignin Peroxidase Isoenzymes from Phanerochaete chrysosporium

Ollikka, Pauli; Alhonmäki, Kirsi; Leppänen, Veli-Matti; Glumoff, Tuomo; Raijola, Timo; Suominen, Ilari
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1993 EN
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17.71239%
The ligninolytic enzyme system of Phanerochaete chrysosporium decolorizes several recalcitrant dyes. Three isolated lignin peroxidase isoenzymes (LiP 4.65, LiP 4.15, and LiP 3.85) were compared as decolorizers with the crude enzyme system from the culture medium. LiP 4.65 (H2), LiP 4.15 (H7), and LiP 3.85 (H8) were purified by chromatofocusing, and their kinetic parameters were found to be similar. Ten different types of dyes, including azo, triphenyl methane, heterocyclic, and polymeric dyes, were treated by the crude enzyme preparation. Most of the dyes lost over 75% of their color; only Congo red, Poly R-478, and Poly T-128 were decolorized less than the others, 54, 46, and 48%, respectively. Five different dyes were tested for decolorization by the three purified isoenzymes. The ability of the isoenzymes to decolorize the dyes in the presence of veratryl alcohol was generally comparable to that of the crude enzyme preparation, suggesting that lignin peroxidase plays a major role in the decolorization and that manganese peroxidase is not required to start the degradation of these dyes. In the absence of veratryl alcohol, the decolorization activity of the isoenzymes was in most cases dramatically reduced. However, LiP 3.85 was still able to decolorize 20% of methylene blue and methyl orange and as much as 60% of toluidine blue O...

Effect of Cell-Photosensitizer Binding and Cell Density on Microbial Photoinactivation

Demidova, Tatiana N.; Hamblin, Michael R.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /06/2005 EN
Relevância na Pesquisa
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Photodynamic therapy involves the use of nontoxic dyes called photosensitizers and visible light to produce reactive oxygen species and cell killing. It is being studied as an alternative method of killing pathogens in localized infections due to the increasing problem of multiantibiotic resistance. Although much has been learned about the mechanisms of microbial killing, there is still uncertainty about whether dyes must bind to and penetrate various classes of microbe in order to produce effective killing after illumination. In this report, we compare the interactions of three antimicrobial photosensitizers: rose bengal (RB), toluidine blue O (TBO), and a poly-l-lysine chlorin(e6) conjugate (pL-ce6) with representative members of three classes of pathogens; Escherichia coli (gram-negative bacteria), Staphylococcus aureus (gram-positive bacteria), Candida albicans (yeast). We compared fluence-dependent cell survival after illumination with the appropriate wavelengths of light before and after extracellular dye had been washed out and used three 10-fold dilutions of cell concentration. pL-ce6 was overall the most powerful photosensitizer, was equally effective with and without washing, and showed a strong dependence on cell concentration. TBO was less effective in all cases after washing...

A comparative in vitro photoinactivation study of clinical isolates of multidrug-resistant pathogens

Tang, Hi M; Hamblin, Michael R.; Yow, Christine M.N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
17.404043%
Photodynamic inactivation (PDI) has been investigated to cope with the increasing incidence of multidrug-resistant (MDR) pathogens. In Hong Kong, methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are the two commonest MDR pathogens. Here, we studied the photodynamic inactivation (PDI) mediated by poly-L-lysine chlorin(e6) conjugate (pL-ce6) and toluidine blue O (TBO) in clinical MRSA and ESBL producing E. coli, together with their corresponding American Type Culture Collection (ATCC) strains. Both pL-ce6 and TBO mediated a light- and drug dose-dependent efficacy for the four pathogens. pL-ce6 was more effective. pL-ce6 at 8 µM, 30 Jcm−2, attained 5 log killing for ESBL-producing E. coli and E. coli (ATCC 25922); 4 log killing for MRSA, and 3 log killing for S. aureus (ATCC 25923). TBO at 80 µM, 30 Jcm−2, only exhibited 3 log killing in MRSA and 2 log killing in S. aureus (ATCC 25923). TBO (400 µM, 30 Jcm−2) induced equal killing for ESBL-producing E. coli and E. coli (ATCC 25922). Our studied MRSA isolate responded better than S. aureus (ATCC 25923). Thus, pL-ce6-mediated PDI in other MRSA isolates deserves further investigation.

CSA Doped Poly(aniline-co-o-toluidine) and Dispersed Zinc Oxide Nanoparticles: a Promising Material for Photovoltaics

Mahudeswaran,Arunachalam; Manoharan,Devarajan; Chandrasekaran,Joseph; Vivekanandan,Janakiraman; Vijayanand,Pachanoor Subbaian
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
Relevância na Pesquisa
47.99721%
Copolymerization of aniline and o-toluidine is achieved by chemical oxidative polymerization with equal molar ratio of monomers in the presence of hydrochloric acid and ammonium persulphate as an oxidant. The copolymer found to be more soluble in polar solvents such as NMP, DMF and DMSO. FTIR spectroscopy confirms the copolymer chemical structure. UV spectroscopy shows π to π* transition and excitonic transition of the copolymer film. The copolymer is doped with camphorsulfonic acid (CSA) in m-cresol and then zinc oxide nanoparticles are dispersed into the copolymer and spin coated on to a glass plate. The scanning electron microscope image shows the morphology of the copolymer matrix. X-ray Diffraction shows the characteristic peaks of CSA and zinc oxide. EDAX analysis confirms the presence of CSA and zinc oxide. The dispersion of zinc oxide nanoparticles show quenching property of photoluminescence indicating that the copolymer can be used in the opto-electronics.