Sample records for thiophene
from WorldWideScience.org

Sample records 1 - 6 shown.



1

Oligômeros e polímeros derivados do tiofeno: síntese e aplicações/ Thiophene-based oligomers and polymers: syntheses and applications

Alves, Marcos Roberto de Abreu; Calado, Hállen Daniel Rezende; Matencio, Tulio; Donnici, Claudio Luis
2010-01-01

Resumo em inglês In this review we summarize recent synthetic investigations about the preparation of oligothiophenes and polythiophenes, the most important π-conjugated organic materials for applications in electrochromic and electroluminescent devices. It is showed that many interesting and novel functionalized oligothiophenes have been synthesized by convenient coupling strategies (Heck, Kumada, Negishi, Suzuki, Stille and Ullmann) and oxidative coupling methods. Synthesis of poly (mais) thiophenes are also presented and described according to chemical and electrochemical polymerization methodologies. The description of these noteworthy synthetic methods illustrates how important and promising are the interdisciplinary approaches in the obtaining of oligothiophenes and polythiophenes.

Scientific Electronic Library Online (Portuguese)

2

Pressão interna e refração molar dos sistemas dimetilsulfóxido + tiofeno, dimetilsulfóxido + piridina a 298,15K/ Internal pressure and molar refraction of dimethylsulfoxide + thiophene and dimetilsulfoxide + pyridine at 298.15K

AZNAREZ, Silvia Beatriz; POSTIGO, Miguel Ángelo; MARTINS, Adair
1999-01-01

Resumo em português Pressão interna, volume livre, refração molar e propriedades termodinâmicas de excesso de misturas líquidas binárias de dimetil sulfóxido + tiofeno e dimetil sulfóxido + piridina a 298.15K foram calculadas a partir de medidas experimentais de densidades, tensão superficial e índice de refração. A relação entre a pressão interna, volume molar de excesso, refração molar, e a interação molecular dos sistemas binários é examinada. Resumo em inglês Internal pressure, free volume, molar refraction and excess molar thermodynamic properties of binary liquid mixtures of dimethyl sulfoxide + thiophene and dimetil sulfoxide + pyridine at 298.15K have been evaluated from the experimental measurements of densities, surface tension and refractive index. The relationship between the internal pressure, excess molar volume, molar refraction, and the molecular interaction of the bianry sistems is examined.

Scientific Electronic Library Online (Portuguese)

3

Avaliação de uma sonda genética (Sistema Accuprobe, Gen Probe®) para identificação de organismos do complexo Mycobacterium tuberculosis, em comparação com métodos tradicionais de caracterização/ Evaluation of a genetic probe (Gen-Probe Accuprobe® system) in comparison to traditional methods for identifying members of the Mycobacterium tuberculosis complex

Spada, Delurce Tadeu de Araujo; Santos, Manoel Armando Azevedo dos; Almeida, Elisabete A.; Augusto, Marcos; Albarral, Maria Idemar Pedrosa; Melo, Fernando Augusto Fiuza de
2005-06-01

Resumo em português INTRODUÇÃO: O aparecimento da co-infecção tuberculose/síndrome da imunodeficiência adquirida, o aumento de doenças por micobactérias não tuberculosas e as confusões que estas podem ter com as emergentes cepas multirresistentes exigem respostas laboratoriais mais rápidas e de melhor rendimento, não só com isolamento das micobactérias, mas também com a sua identificação. OBJETIVO: Estudo comparativo entre uma nova ferramenta de identificação molecular com (mais) sonda genética baseada na unidade 16S do gene rDNA do Mycobacterium tuberculosis (Accuprobe Gen Probe®, Gen Probe Inc.) e a metodologia clássica. MÉTODO: Foram selecionados 55 isolados do gênero Mycobacterium, mantidos em bacterioteca, obtidos de escarros de pacientes de uma unidade de referência para tuberculose. Foram feitos repiques em três tubos: um destinado à identificação genética, outro para realização dos testes clássicos (produção e acumulação da niacina, e crescimento em meio de Lowenstein-Jensen com agentes inibidores - ácido p-nitrobenzóico e hidrazida do ácido tiofeno-2-carboxílico), e outro reserva. RESULTADOS: A sonda identificou 51 amostras do complexo M. tuberculosis (uma associada ao M. kansasii) e 4 como micobactérias não tuberculosas, posteriormente identificadas como M. kansasii (3) e M. avium (1). Os métodos tradicionais identificaram 47 amostras como do complexo M. tuberculosis, 4 com perfil de micobactérias não tuberculosas (concordante com o obtido pela sondagem genética) e 4 provas inconclusivas, uma delas exatamente a que associava duas espécies de micobactérias. CONCLUSÃO: Os benefícios da técnica de biologia molecular justificam sua implantação e uso rotineiro, associado aos métodos clássicos, numa unidade com alta demanda e que atenda casos de tuberculose de alta complexidade. Resumo em inglês BACKGROUND: The appearance of tuberculosis/human immunodeficiency virus co-infection and the growing number of diseases caused by nontuberculous mycobacteria, as well as the confusion that these can cause in relation to emerging multidrug-resistant strains, require more accurate and rapid laboratory results, not only in the isolation of strains but also in their identification. OBJECTIVE: A comparative study evaluating a new tool of molecular identification, which uses a (mais) genetic probe based on the 16S rDNA sequence of the Mycobacterium tuberculosis gene (Gen-Probe Accuprobe® Gen Probe, Inc.), and the classic methodology. METHOD: Fifty-five Mycobacterium strains, isolated from the sputum of patients treated at a tuberculosis reference clinic, were selected for study. Subcultures were performed in three tubes: one submitted to genetic identification, one analyzed through classical tests (production and accumulation of niacin; growth in the Lowenstein-Jensen medium with the inhibitor agents p-nitrobenzoic acid and thiophene-2-carboxylic acid hydrazide added), and one held in reserve. RESULTS: The probe identified 51 cases as belonging to the M. tuberculosis complex (one associated with M. kansasii) and the other 4 as nontuberculous mycobacteria, later identified as M. kansasii (3) and M. avium (1). Using traditional methods, 47 samples were identified as belonging to the M. tuberculosis complex, 4 were classified as fitting the profile of nontuberculous mycobacteria (in agreement with the genetic probe results), and 4 were unidentified, 1 of which presented the exact characteristics that 2 mycobacterium species have in common. CONCLUSION: The benefits of the molecular biology technique justify its implementation and routine use, in combination with classical methods, in a high-traffic clinic where complex cases of tuberculosis are treated.

Scientific Electronic Library Online (Portuguese)

4

Desenvolvimento de um sistema automatizado para a fabricação de filmes automontados/ Development of an automated device for fabrication of self-assembled films

Trivinho-Strixino, Francisco; Pereira, Ernesto C.; Lopes, Luis Roberto C.
2004-08-01

Resumo em inglês In this technical note, we describe the construction of a low-cost computer controlled device for layer-by-layer film fabrication. The software allows to control multiple material deposition, washing and drying steps and the time for each operation. To test the device, we produced and characterized self-assembled films of conductive polymers by alternating poly(o-methoxyaniline) (POMA) and poly(3-thiophene acetic acid) (PTAA) via the layer-by-layer technique.

Scientific Electronic Library Online (Portuguese)

5

Cyclic Voltammetry of Organometallic Acetylide Complexes

Mendes, Paulo J. G.; Silva, Tiago J. L.

We report herein the cyclic voltammetry behavior of the compounds [RuCp(L2)(CC{SC4H2}nA)] (L2=DPPE, 2 PPh3; A= NO2, CHO; n=1,2). The effect of the phosphines, length of the conjugated thiophene chain and acceptor (A) group will be addressed. Both the electrochemical and spectroscopic data will be co...

DRIVER (Portuguese)

6

Construção de uma célula espectroeletroquímica termostatizada e sua aplicação para estudar polímeros eletrocrômicos/ The application of a new temperature controllable spectroelectrochemical cell to the study of electrochromic polymers

Härtinger, Stefan; Machado, Dirnei Aparecido; De Paoli, Marco-A.
1998-06-01

Resumo em inglês The construction of a temperature controllable spectroelectrochemical cell is described. Its use in the analysis of the thermodynamic and structural parameters of the electrochromic process of poly(3-methyl thiophene) in the temperature range between -40ºC and 60ºC is given as an example of application.

Scientific Electronic Library Online (Portuguese)