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Search Results: 1 - 10 of 217728 matches for " Ricardo N. Araujo "
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Sequential Injection Analysis of Ampicillin in Pharmaceuticals by Using Potentiometric Detectors Based on PVC and Sol-Gel Membranes  [PDF]
Nestor Zárate, Alberto N. Araujo, M. Concei?ao B. S. M. Montenegro, Ricardo Pérez-Olmos
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.24059
Abstract: This work describes the construction and the evaluation of the general performance of new ampicilli-nate-selective electrodes based on manganese (III) tetraphenylporphyrin [Mn(III) TPP-Cl] as ionophore, incorporated in both PVC and sol-gel membranes and directly applied onto a conductive graphite/epoxy resin support. The units were constructed without inner reference solution adopting conventional configuration and in the case of PVC membrane the tubular configuration was also adopted. The good working characteristics of these electrodes, made possible its application to the determination of ampicillin in pharmaceuticals formulations, both in conventional batch analysis and in flow conditions, when the electrodes were coupled to a SIA system. In the last case the potentiometric sensors presented linear response towards ampicillin concentration between 5.0 × 10–4 and 5.0 × 10–2 mol?l–1 with slopes of –57.4 and –63.5 mV?dec–1 for the PVC and sol-gel membranes, respectively. The developed procedures enable mean relative standard deviations better than 3% for all the samples analysed. The obtained results do not statistically differ from those furnished by applying the HPLC reference method.
Primary culture of Rhodnius prolixus (Hemiptera: Reduviidae) salivary gland cells
Rocha, Fernanda F;Araujo, Ricardo N;Silva, Luciana M;Gontijo, Nelder F;Pereira, Marcos H;
Memórias do Instituto Oswaldo Cruz , 2010, DOI: 10.1590/S0074-02762010000200004
Abstract: in the present paper, we developed a primary culture of rhodnius prolixus salivary gland and main salivary canal cells. cells remained viable in culture for 30 days. three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. the supernatants of salivary cultures contained mainly 16-24 kda proteins and presented anticoagulant and apyrase activities. secretion vesicles were observed budding from the cellular monolayer of the main salivary canal cells. these results indicate that r. prolixus salivary proteins may be produced in vitro and suggest that the main salivary canal may have a possible secretory role.
Efeitos de varia??es cambiais em uma abordagem de dinamica de mudan?a estrutural à teoria do crescimento restrito pelo balan?o de pagamentos
Araujo, Ricardo Azevedo;
Economia e Sociedade , 2012, DOI: 10.1590/S0104-06182012000300005
Abstract: in this paper it is shown that once-for-all variations at the level of the exchange rate can play an important role in the sectoral composition of the economy. this fact has important implications in terms of a disaggregated version of thirlwall's law, even when the argument of the quantitative unimportance of relative price movements holds. the growth rate of a country is therefore shown to be affected by once-for-all movements at the level of nominal exchange rates and the concept of a natural exchange rate is introduced.
Efeitos de varia es cambiais em uma abordagem de dinamica de mudan a estrutural à teoria do crescimento restrito pelo balan o de pagamentos The effects of exchange rate variations in a structural economic dynamic approach to the balance of payment constrained growth theory
Ricardo Azevedo Araujo
Economia e Sociedade , 2012,
Abstract: Neste trabalho, mostra-se que varia es once-for-all do nível da taxa de cambio podem desempenhar um papel importante na composi o setorial da economia e tal fato tem implica es importantes em termos de uma vers o desagregada da Lei de Thirlwall mesmo diante do argumento da insignificancia quantitativa dos movimentos de pre os relativos. Mostra-se, ent o, que a taxa de crescimento de um país compatível com o equilíbrio no balan o de pagamentos pode ser afetada por movimentos do nível de taxas de cambio nominal e o conceito de uma taxa de cambio natural é introduzida. In this paper it is shown that once-for-all variations at the level of the exchange rate can play an important role in the sectoral composition of the economy. This fact has important implications in terms of a disaggregated version of Thirlwall's law, even when the argument of the quantitative unimportance of relative price movements holds. The growth rate of a country is therefore shown to be affected by once-for-all movements at the level of nominal exchange rates and the concept of a natural exchange rate is introduced.
Soybean Seed Co-Inoculation with Bradyrhizobium spp. and Azospirillum brasilense: A New Biotechnological Tool to Improve Yield and Sustainability  [PDF]
Mariangela Hungria, Marco Antonio Nogueira, Ricardo Silva Araujo
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.66087
Abstract: Legume nodulation by rhizobia can supply crops with nitrogen and reduce environmental impacts caused by chemical fertilization. The soybean crop in Brazil is an impressive example of how biological N2 fixation can be employed with a plant species of high economic value. However, the development of more productive cultivars, along with the increasing global climatic changes demand agricultural practices to become more productive and yet more environmentally friendly. Plant growth-promoting rhizobacteria (PGPR) are highly beneficial to agriculture worldwide, acting in plant nutrition, protection, and growth stimulation. Azospirillum is, certainly, the most employed PGPR in the world, but little is known about its interaction with rhizobia, when both are applied to legume seeds. We have evaluated the co-inoculation of bradyrhizobia and azospirilla on soybean seeds under different soil and climate conditions in Brazil. Our results demonstrated that co-inoculation is efficient and beneficial to the crop, and promotes yield increases without adding any chemical N fertilizers even in soils where established populations of soybean bradyrhizobia exist. The strategy of co-inoculation thus represents a new biotechnological tool to improve soybean yield without adding any chemical N fertilizers, thus contributing to current practices of sustainability in agriculture.
Novos cenários das políticas públicas na quest o ambiental: os entornos eco-sócio-terrotoriais
Araujo, Paulo Ricardo da Rocha
Civitas , 2005,
Abstract: Este artigo trata das rela es entre o Estado-redimensionado em sua fun o social - e os novos espa os e atores da sociedade contemporanea contextualizados a partir das quest es ambientais. Entendo as políticas públicas como forma de express o das expectativas e necessidades desses agentes, sua concep o, implementa o e avalia o ocorreriam de modo complexo em suas fases de planejamento e gest o ambiental. Tal condi o seria agravada em se tratando das complexas rela es de negocia o entre os distintos espa os, a saber, econ mico, cultural, político e, ainda, o espa o territorial, propriamente dito, que caracterizam as quest es ambientais.
Estudo de seguran?a e eficácia da enoxaparina sódica na profilaxia e terapêutica antitrombótica
Lage, Silvia G;Carvalho, Ricardo T;Kopel, Liliane;Bastos, Jaime F;Ribeiro, Marcelo A;Fagundes Junior, Antonio AP;Araujo, Helia Beatriz N;Strunz, Célia C;
Revista Brasileira de Terapia Intensiva , 2007, DOI: 10.1590/S0103-507X2007000100009
Abstract: background and objectives: use of low molecular weight heparins (lmwh), either prophylactic or therapeutic, is of most importance in several syndromes and diseases in daily clinical practice. our objective in this clinical trial was to evaluate safety and efficacy of test sodium enoxaparin (enox-t) compared to the reference drug (enox-r). methods: we conducted a prospective, randomized, comparative, unicentric and open-labeled trial including patients with either prophylactic or therapeutic anti-thrombotic indications. a total of 100 patients were enrolled in two branches: prophylactic (n=50) and therapeutic (n=50) and two groups for each branch (group 1: enox-r and group 2: enox-t). we analyzed clinical and laboratory data in each segment. anti-factor xa was measured in three different moments: baseline (1st evaluation); 1st or 2nd day (2nd evaluation) and 5th to 7th day (3rd evaluation). doppler-sonography of inferior limbs was performed on all patients in prophylactic group on 2nd or 3rd evaluation. results: the data showed that both branches (prophylactic and therapeutic) were homogenous in regard of sex, age, body mass index (bmi), serum creatinine and apache ii severity score at admission. anti-factor xa results, in both prophylactic and therapeutic branches, showed expected efficacy to both drugs, without any clinical or statistical difference between them. adverse events incurred in both groups in a similar way, without any clinical or statistical difference between them. in prophylactic branch, doppler-sonography of inferior limbs added useful information on drugs efficacy. conclusions: we conclude that test sodium enoxaparin (enox-t) was effective and safe in our patient's cohort and equivalent to reference drug (enox-r).
Especialización Tecnológica en los países de la OCDE: patrones y tendencias
Xulia Guntín Araujo
Revista Galega de Economía , 2001,
Abstract: Tanto en las propuestas teóricas que surgen desde el marco analítico neoclásico, como en aquéllas emanadas desde enfoques más heterodoxos, el factor tecnológico y los perfiles de especialización tecnológica aparecen como elementos clave en la determinación del comportamiento comercial y de la competitividad de los países. Dada su relevancia, el presente trabajo pretende profundizar en el conocimiento de la dinámica de los patrones de especialización tecnológica en el período reciente. La metodología utilizada pretende evidenciar si en el período 1980-1994 ha tenido lugar un proceso de convergencia (divergencia) en los patrones tecnológicos de los países desarrollados, lo cual significaría que los países tienen pautas de especialización cada vez más semejantes, y si simultáneamente este proceso va acompa ado de un proceso de creciente desespecialización (especialización) dentro de los países. Ambos procesos pueden tener ritmos y direcciones diferentes. Las características del propio proceso de cambio tecnológico condicionan y limitan las posibilidades de homogeneización de los patrones tecnológicos.
Structural change and macrodynamic capabilities
Araujo, Ricardo Azevedo;Teixeira, Joanílio Rodolpho;
Nova Economia , 2011, DOI: 10.1590/S0103-63512011000300001
Abstract: in this paper we study some mechanisms that block a rapid diffusion of technological progress from advanced to underdeveloped countries. in order to accomplish this task we focus on two approaches that challenge the view that technological gaps between rich and poor nations are diminishing. the first is the structural economic dynamic approach and the second is the evolutionary view. both of them reveal that the elimination of technological gaps between rich and poor nations is more complex than what has been reported by the mainstream theory of economic growth.
Decisions on investment allocation in the post-keynesian growth model
Araujo, Ricardo Azevedo;Teixeira, Joanílio Rodolpho;
Estudos Econ?micos (S?o Paulo) , 2012, DOI: 10.1590/S0101-41612012000300007
Abstract: in this article the growth models of feldman (1928) and mahalanobis (1953) are extended to consider the analysis of decisions of investment allocation in the context of the post keynesian growth model. by adopting this approach it is possible to introduce distributive features in the feldman-mahalanobis model that allows us to determine the rate of investment allocation according to the equilibrium decisions of investment and savings. finally, an additional condition is added to the post keynesian growth model in order to fully characterise the equilibrium path in an extended version of this framework, where capital goods are also needed to produce capital goods.
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