Approaches for multicopper oxidases in the design of electrochemical sensors for analytical applications

We report an effective approach for the construction of a biomimetic sensor of multicopper oxidases by immobilizing a cyclic-tetrameric copper(II) species, containing the ligand (4-imidazolyl)ethylene-2-amino-1-ethylpyridine (apyhist), in the Nafion (R) membrane on a vitreous carbon electrode surface. This complex provides a tetranuclear arrangement of copper ions that allows an effective reduction of oxygen to water, in a catalytic cycle involving four electrons. The electrochemical reduction of oxygen was studied at pH 9.0 buffer solution by using cyclic voltammetry, chronoamperometry, rotating disk electrode voltammetry and scanning electrochemical microscopy techniques. The mediator shows good electrocatalytic ability for the reduction of O(2) at pH 9.0, with reduction of overpotential (350 mV) and increased current response in comparison with results obtained with a bare glassy carbon electrode. The heterogeneous rate constant (k(ME)`) for the reduction of O(2) at the modified electrode was determined by using a Koutecky-Levich plot. In addition, the charge transport rate through the coating and the apparent diffusion coefficient of O(2) into the modifier film were also evaluated. The overall process was found to be governed by the charge transport through the coating, occurring at the interface or at a finite layer at the electrode/coating interface. The proposed study opens up the way for the development of bioelectronic devices based on molecular recognition and self-organization. (C) 2010 Elsevier Ltd. All rights reserved.

Synthesis Optimization of Hydroxymethylnitrofurazone, an Antichagasic Candidate, Using 3(2) Factorial Design

Hydroxymethylnitrofurazone presents in vitro activity against Trypanosoma cruzi. The optimization of the synthesis of this compound was performed through a 3(2) factorial statistical design. Quadratic model produced the best response surface predicting a maximum yield (82%) close to the center design point with a seven hours reaction and a 1:1.5 (NF:K(2)CO(3)) ratio.

Design of novel antituberculosis compounds using graph-theoretical and substructural approaches

The increasing resistance of Mycobacterium tuberculosis to the existing drugs has alarmed the worldwide scientific community. In an attempt to overcome this problem, two models for the design and prediction of new antituberculosis agents were obtained. The first used a mixed approach, containing descriptors based on fragments and the topological substructural molecular design approach (TOPS-MODE) descriptors. The other model used a combination of two-dimensional (2D) and three-dimensional (3D) descriptors. A data set of 167 compounds with great structural variability, 72 of them antituberculosis agents and 95 compounds belonging to other pharmaceutical categories, was analyzed. The first model showed sensitivity, specificity, and accuracy values above 80% and the second one showed values higher than 75% for these statistical indices. Subsequently, 12 structures of imidazoles not included in this study were designed, taking into account the two models. In both cases accuracy was 100%, showing that the methodology in silico developed by us is promising for the rational design of antituberculosis drugs.

Metal transport parameters of a gneiss saprolitic silty soil for liner design

Diffusion coefficients and retardation factors of two metal cations (Cd2+ and Pb2+) were measured for a compacted Brazilian saprolitic soil derived from gneiss, aiming to assess its geoenvironmental performance as a liner for waste disposal sites. This soil occurs extensively all over the country in very thick layers, but has not been used in liners because of its hydraulic conductivity, higher than 10(-9) m/s when compacted at optimum water content of standard Proctor energy, but which can be reduced by means of appropriate compaction techniques or additives. Batch, column, and diffusion tests were carried out with monospecies synthetic solutions at pH 1, 3, and 5.5. Measured diffusion coefficients varied between 0.5 and 4 X 10(-10) m(2)/s. Retardation factors show that cadmium, a very mobile cation, is not adsorbed at pH I but is significantly retained at pH 3 and pH 5.5, whereas lead is retained at all tested pH values though slightly at pH 1. Estimated retardation factors from batch tests were 1.3-2.3 times those resulting from column tests and at its highest when obtained by diffusion tests; whereas batch tests allow a more complete exposure of the soil grains to the solution, time-dependent nonspecific adsorption may take longer to occur. The importance of contact time was observed and should be considered in further investigations. Its significant retention of metals suggests a promising utilization of this soil as a bottom liner for wastes landfills.

Use of Experimental Design for the Optimization of the Production of New Secondary Metabolites by Two Penicillium Species

A fractional factorial design approach has been used to enhance secondary metabolite production by two Penicillium strains. The method was initially used to improve the production of bioactive extracts as a whole and subsequently to optimize the production of particular bioactive metabolites. Enhancements of over 500% in secondary metabolite production were observed for both P. oxalicum and P. citrinum. Two new alkaloids, citrinalins A (5) and B (6), were isolated and identified from P. citrinum cultures optimized for production of minor metabolites.

Type 2 Design L Port Side

Print No: 189

Trombose da veia porta em crianças e adolescentes : deficiência das proteínas C, S e Antitrombina e pesquisa das mutações fator V Leiden, G20210A da Protrombina e C677T da Metileno-tetraidrofolato redutase

Objetivo: A trombose da veia porta é uma causa importante de hiper-tensão porta em crianças e adolescentes, porém, em uma proporção importante dos casos, não apresenta fator etiológico definido. O objetivo desse estudo é determinar a freqüência de deficiência das proteínas inibidoras da coagulação – proteínas C, S e antitrombina − e das mutações fator V Leiden, G20210A no gene da protrombina e C677T da metileno-tetraidrofolato redutase em crianças e adolescentes com trom-bose da veia porta, definir o padrão hereditário de uma eventual deficiência das pro-teínas inibidoras da coagulação nesses pacientes e avaliar a freqüência da deficiên-cia dessas proteínas em crianças e adolescentes com cirrose. Casuística e Métodos: Foi realizado um estudo prospectivo com 14 crianças e adolescentes com trombose da veia porta, seus pais (n = 25) e dois gru-pos controles pareados por idade, constituídos por um grupo controle sem hepato-patia (n = 28) e um com cirrose (n = 24). A trombose da veia porta foi diagnosticada por ultra-sonografia abdominal com Doppler e/ou fase venosa do angiograma celíaco seletivo. A dosagem da atividade das proteínas C, S e antitrombina foi determinada em todos os indivíduos e a pesquisa das mutações fator V Leiden, G20210A da pro-trombina e C677T da metileno-tetraidrofolato redutase, nas crianças e adolescentes com trombose da veia porta, nos pais, quando identificada a mutação na criança, e nos controles sem hepatopatia. Resultados: Foram avaliados 14 pacientes caucasóides, com uma média e desvio padrão de idade de 8 anos e 8 meses ± 4 anos e 5 meses e do diagnóstico de 3 anos e 8 meses ± 3 anos e seis meses. Metade dos pacientes pertenciam ao gênero masculino. O motivo da investigação da trombose da veia porta foi hemorra-gia digestiva alta em 9/14 (64,3%) e achado de esplenomegalia ao exame físico em 5/14 (35,7%). Anomalias congênitas extra-hepáticas foram identificadas em 3/14 (21,4%) e fatores de risco adquiridos em 5/14 (35,7%) dos pacientes. Nenhum pa-ciente tinha história familiar de consangüinidade ou trombose venosa. A deficiência das proteínas C, S e antitrombina foi constatada em 6/14 (42,9%) (p < 0,05 vs con-troles sem hepatopatia), 3/14 (21,4%) (p > 0,05) e 1/14 (7,1%) (p > 0,05) pacientes com trombose da veia porta, respectivamente. A deficiência dessas proteínas não foi identificada em nenhum dos pais ou controles sem hepatopatia. A mutação G20210A no gene da protrombina foi identificada em um paciente com trombose da veia porta e em um controle sem hepatopatia (p = 0,999), mas em nenhum desses foi identificado a mutação fator V Leiden. A mutação C677T da metileno-tetraidrofo-lato redutase foi observada na forma homozigota, em 3/14 (21,4%) dos pacientes com trombose da veia porta e em 5/28 (17,9%) controles sem hepatopatia (p = 0,356). A freqüência da deficiência das proteínas C, S e antitrombina nos pacientes com cir-rose foi de 14/24 (58,3%), 7/24 (29,2%) e 11/24 (45,8%), respectivamente (p < 0,05 vs controles sem hepatopatia), sendo mais freqüente nos pacientes do subgrupo Child-Pugh B ou C, que foi de 11/12 (91,7%), 5/12 (41,7%) e 9/12 (75%), respectivamente (p < 0,05 vs controles sem hepatopatia). Conclusões: A deficiência de proteína C foi freqüente nas crianças e adolescentes com trombose da veia porta e não parece ser de origem genética. A deficiência de proteína S, antitrombina e as presenças das mutações G20210A da protrombina e C677T da metileno-tetraidrofolato redutase foram observadas mas não apresentaram diferença estatística significativa em relação ao grupo controle sem hepatopatia. O fator V Leiden não foi identificado. Os resultados deste estudo sugerem que a deficiência da proteína C pode ocorre como conseqüência da hiper-tensão porta. Os distúrbios pró-trombóticos hereditários não parecem apresentar um papel importante em relação à trombose nas crianças e adolescentes estudadas.

O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?

VALENTIM, R. A. M. ; SOUZA NETO, Plácido Antônio de. O impacto da utilização de design patterns nas métricas e estimativas de projetos de software: a utilização de padrões tem alguma influência nas estimativas?. Revista da FARN, Natal, v. 4, p. 63-74, 2006

Encapsulation of Local Anesthetic Bupivacaine in Biodegradable Poly(DL-lactide-co-glycolide) Nanospheres: Factorial Design, Characterization and Cytotoxicity Studies

Local anesthetic agents cause temporary blockade of nerve impulses productiong insensitivity to painful stimuli in the area supplied by that nerve. Bupivacaine (BVC) is an amide-type local anesthetic widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. in this study, we prepared and characterized nanosphere formulations containing BVC. To achieve these goals, BVC loaded poly(DL-lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by nanopreciptation and characterized with regard to size distribution, drug loading and cytotoxicity assays. The 2(3-1) factorial experimental design was used to study the influence of three different independent variables on nanoparticle drug loading. BVC was assayed by HPLC, the particle size and zeta potential were determined by dynamic light scattering. BVC was determined using a combined ultrafiltration-centrifugation technique. The results of optimized formulations showed a narrow size distribution with a polydispersivity of 0.05%, an average diameter of 236.7 +/- 2.6 nm and the zeta potential -2.93 +/- 1,10 mV. In toxicity studies with fibroblast 3T3 cells, BVC loaded-PLGA-NS increased cell viability, in comparison with the effect produced by free BVC. In this way, BVC-loaded PLGA-NS decreased BVC toxicity. The development of BVC formulations in carriers such as nanospheres could offer the possibility of controlling drug delivery in biological systems, prolonging the anesthetic effect and reducing toxicity.

H-infinity control design for time-delay linear systems: a rational transfer function based approach

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

GRIOT - sistema CAD inteligente para design de calçados

O presente trabalho é o estudo dos aspectos da metodologia projetual, face às novas tecnologias da informática, Inteligência Artificial (Sistemas Especialistas) e CAD, consideradas as reais possibilidades de automatização no processo de concepção em Design. Esse artigo propõe uma metodologia para a construção de sistema inteligente capaz de auxiliar o designer nas tarefas projetuais. A indústria de calçados foi utilizada como estudo de caso para a aplicação da metodologia, onde as reais possibilidades de automação são verificadas.

Assessment of the ergonomic design of diagnostic ultrasound transducers through wrist movements and subjective evaluation

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

Influence of door handles design in effort perception: accessibility and usability

The application of ergonomics in product design is essential to its accessibility and usability. The development of manual devices should be based on ergonomic principles. Effort perception analysis is an essential approach to understand the physical and subjective aspects of the interface. The objective of the present study was to analyze the effort perception during a simulated task with different door handles by Portuguese subjects of both genders and different ages. This transversal study agreed with ethical aspects. 180 subjects of both genders pertaining to three age groups have participated. Five door handles with different shapes were evaluated. A subjective numeric rating scale of 5 levels was used to evaluate the effort. For statistical analysis it was applied the Friedman non-parametric test. The results have showed no significant differences of effort perception in door handles "A" and "B"; "A" and "D"; and "D" and "C". Door handle "E" presented the lowest values of all. In general, there's an inverse relationship between the results of biomechanical studies and the effort perception of the same task activity. This shows that door handles design influence directly these two variables and can interfere in the accessibility and usability of these kinds of products.

Product functions: interfaces with ergonomic design

In addition to technical quality, increasing emphasis is being placed on the importance of elements such as the appearance and meaning of products. To be successful, therefore, attention must be paid to the aesthetic and symbolic functions of objects as well as to reliability and physical quality. Study of the interfaces of these functions may provide a theoretical basis for the ergonomic design of products. The objective of this review is to attempt to establish the nature of these interfaces.