Espectrofotometria de longo caminho óptico em espectrofotô metro de duplo-feixe convencional: uma alternativa simples para investigações de amostras com densidade óptica muito baixa

We describe the design and tests of a set-up mounted in a conventional double beam spectrophotometer, which allows the determination of optical density of samples confined in a long liquid core waveguide (LCW) capillary. Very long optical path length can be achieved with capillary cell, allowing measurements of samples with very low optical densities. The device uses a custom optical concentrator optically coupled to LCW (TEFLON® AF). Optical density measurements, carried out using a LCW of ̃ 45 cm, were in accordance with the Beer-Lambert Law. Thus, it was possible to analyze quantitatively samples at concentrations 45 fold lower than that regularly used in Spectrophotometric measurements.

Optimization of multipulse converters with delta and Y-differential connections

This work presents a study regarding the optimization of multipulse converters. A general expression for the connection (Δ or Y) for both 12 and 18-pulses is obtained and describes the output voltages on the secondary windings, depending on the voltage reference from the primary. These generalized expressions allows choosing different ratios between input and output voltages and as result an optimum operation point for the converter can be calculated. Considering Δ-connected converters the optimum point occurs when the magnetic core of the autotransformer processes 18% and 17% of the output power for 12 and 18-pulses, respectively. For Y-connected converters the optimum point occurs when the kVA rating is 13% and 18% for 12 and 18-pulses, respectively. Based on these results magnetic elements can be calculated and designed leading to a great weight and volume reduction and also to lower costs and losses. Finally an analysis is made to improve the kVA rating of the transformers for 12 and 18 pulses converters. © 2009 IEEE.

Ensaio randomizado, duplo-cego e controlado de anestesia tópica induzida por iontoforese de lidocaína

Introduction: Needle infi ltration of local anesthetic is a painful procedure, thus, a topical anesthetic is a comfortable alternative; however, it is diffi cult to deliver transcutaneous polar drugs. Iontophoresis is a noninvasive technique that uses electrical current for releasing electrically charged drugs through biological membranes. Objective: To evaluate the anesthesia induced by iontophoresis of lidocaine for a standardized painful stimulus. Material and methods: Randomized, controlled, double-blind study, involving 10 volunteers under the anesthetic effects of topical application of lidocaine gel 2% and noradrenaline 1:50,000, with or without iontophoresis of 1.85 milliamps for 13 minutes. Pain sensitivity was evaluated by the prick of a 21G needle in the arms posterior region, using a visual numerical scale. Results: Patients mean age was 50.8 ± 11.4 years. Nine of them were women. All had previously received infi ltrative anesthesia. Iontophoresis was well tolerated by volunteers. The median pain scores were 0 and 3 for the arm that received the iontophoresis and for the one that did not receive, respectively (p < 0.01). Conclusion: The anesthetic effect in the region subjected to iontophoresis suggests an effi cient and comfortable method for promoting local anesthesia in the surgical approach of pediatric, hyperalgic, or needlephobic patients.

Generalization of Wye and Delta auto-connections: Analysis of voltages and currents

Multipulse rectifier topologies based on autoconnections, or differential connections, are more and more applied as interface stages between the mains and power converters. These topologies mitigate many low-order current harmonics in the utility, reducing the THD (total harmonic distortion) and increasing the power factor. This paper presents a mathematical model based on phasor diagrams, that results in a single expression able to unify all differential topologies connections (Delta and Wye), for both step-up or step-down autotransformers, for 12 and 18-pulse AC-DC converters. The proposed family of converters can be designed for any relationship between the input voltage and the load voltage. An immediate application would be the retrofit, i.e. to replace a conventional rectifier with poor quality of the processed energy by the 12 or 18 pulses rectifier with Wye or Delta-differential connection. The design procedure, simple and fast, is developed and tested for a prototype rating 6 kW and 250 V on the DC load © 2010 IEEE.

A new design methodology for multipulse rectifiers with Delta auto-connected transformers and a retrofit application in Adjustable Speed Drives (ASDs)

Multipulse rectifiers can replace a conventional six pulse three-phase rectifier (diode bridge) providing a DC voltage with low ripple, low Total Harmonic Distortion of current (THDi) and a high Power Factor (PF). In this context is presented a multipulse rectifier with generalized Delta-differential autotransformer topology, which can provide any level of DC output voltage for any level of three-phase AC input voltage. This paper presents all the possible configurations for Delta topology in order to choose, through graphics, one configuration that presents reduced weight and volume. The average voltage on the DC bus must be compatible with the DC voltage in the six pulse rectifier used in commercial ASDs. Therefore, it is possible to apply the retrofit technique to replace the conventional bridge rectifier by the proposed multipulse rectifier. Based on mathematic models and simulation results, an 18-pulse rectifier with Delta topology, 220 V of line voltage, 315 V of DC output, and rating 2.5 kW of power was designed, implemented and applied for three different commercial ASDs. Experimental results as voltage and current waveforms and results about PF and THDi will be presented. © 2012 IEEE.

Estudo duplo cego com Isoconazol e Terbinafina tópicos no tratamento de um paciente com Tinea nigra plantaris bilateral e sugestões para novos diagnósticos diferenciais

The authors report a case of bilateral Tinea nigra plantaris treated through a double-blind study with the topical antifungal agents Isoconazole and Terbinafine. The objective of the study was to clinically compare the efficacy of these two topical antifungal agents on days 10, 20 and 30 of the treatment. No significant clinical differences were found, as all the plantar lesions regressed completely by the end of the treatment. Our conclusion was that in the case reported, the topical antifungal agents Isoconazole and Terbinafine demonstrated identical efficacy as a clinical cure. We also suggest the inclusion of injuries caused by arthropods of the Diplopoda Class in the differential diagnosis of Tinea nigra plantaris, due to the persistent acral hyperpigmentation.

Peripheral kappa and delta opioid receptors are involved in the antinociceptive effect of crotalphine in a rat model of cancer pain

Cancer pain is an important clinical problem and may not respond satisfactorily to the current analgesic therapy. We have characterized a novel and potent analgesic peptide, crotalphine, from the venom of the South American rattlesnake Crotalus durissus terrificus. In the present work, the antinociceptive effect of crotalphine was evaluated in a rat model of cancer pain induced by intraplantar injection of Walker 256 carcinoma cells. Intraplantar injection of tumor cells caused the development of hyperalgesia and allodynia, detected on day 5 after tumor cell inoculation. Crotalphine (6 μg/kg), administered p.o., blocked both phenomena. The antinociceptive effect was detected 1 h after treatment and lasted for up to 48 h. Intraplantar injection of nor-binaltorphimine (50 g/paw), a selective antagonist of κ-opioid receptors, antagonized the antinociceptive effect of the peptide, whereas N,N-diallyl-Tyr-Aib-Phe-Leu (ICI 174,864, 10 μg/paw), a selective antagonist of δ-opioid receptors, partially reversed this effect. On the other hand, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr amide (CTOP, 20 g/paw), an antagonist of μ-opioid receptors, did not modify crotalphine-induced antinociception. These data indicate that crotalphine induces a potent and long lasting opioid-mediated antinociception in cancer pain. © 2013 Elsevier Inc.

Solução da equação de Fokker-Planck para o potencial do oscilador harmônico duplo

Pós-graduação em Biofísica Molecular - IBILCE

Busca de parceiros físicos por duplo-híbrido das proteínas ADAM23 e MX1, codificadas por genes metilados em câncer de cabeça e pescoço

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Síntese e caracterização de cátodos de perovskitas 'La IND.0,6''Sr IND.0,4''Fe IND.y''Co IND.1-y''O IND.3-'delta'', para células a combustível de eletrólito sólido (SOFC) operando em temperaturas intermediárias

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aplicação do Método de Rietveld em caracterização estrutural e nanoestrutural do espinélio 'Ni IND. 1'- 'delta' Co'delta''Fe IND.2''O IND.4' preparado por reação de combustão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mobilidade de oxigênio intersticial em SM'BA IND.2' C IND.U 'IND.3' 'O IND. 7-'delta' medida através de espectroscopia mecânica

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Avaliação dos efeitos metabólicos da ingestão de quinoa (Chenopodium Quinoa) em um grupo de mulheres pós-menopausa - estudo prospectivo, randomizado, duplo cego

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ferritas 'MG IND. 1' - 'delta'ZN''delta''FE' IND. 2'O IND. 4' obtidas por síntese de reação de combustão: caracterização estrutural e nanoestrutural

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Osteotomia com brocas de alta e baixa rotação, com e sem refrigeração líquida: estudo histopatológico duplo cego em suínos

Pós-graduação em Odontologia - FOA