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Episodic memory, working memory, emotional memory and attention are subject to dopaminergic modulation. However, the potential role of dopamine on the generation of false memories is unknown. This study defined the role of the dopamine D2 receptor on true and false memories. Twenty-four young, healthy volunteers ingested a single dose of placebo or 400 mg oral sulpiride, a dopamine D2-receptor antagonist, just before starting the recognition memory task in a randomized, double-blind, placebo-controlled trial. The sulpiride group made more false recognitions during visual and verbal processing than the placebo group although both groups had the same indices of true memory. These findings demonstrate that dopamine blockade in healthy volunteers can specifically increase the rate of false recognitions.

Introducción: el procedimiento de Deloyers es una técnica útil en la reconstrucción del tránsito intestinal posterior a una colectomía izquierda ampliada, colostomía tipo Hartmann o resecciones colónicas iterativas, pues asegura una anastomosis colorrectal o coloanal sin tensión. Presentación del caso: una mujer de 60 años acudió a consulta para el cierre de una colostomía, con antecedente de colectomía segmentaria del sigmoides y colon descendente derivada con colostomía tipo Hartmann por diverticulitis complicada. Fue llevada a cirugía laparoscópica, en la que se encontró un segmento de colon transverso con meso corto y al liberarse completamente no se logró realizar la anastomosis colorrectal, por lo que se decidió realizar el procedimiento de Deloyers como alternativa para conservar la válvula ileocecal y obtener la anastomosis colorrectal libre de tensión. Discusión: el procedimiento de Deloyers consiste en la unión del colon derecho y recto o ano libre de tensión después de realizar la movilización completa y rotación de 180° en sentido antihorario del ángulo hepático y el colon derecho, en el que se seccionan los vasos cólicos derecho y medio, con preservación del pedículo ileocólico y la válvula ileocecal, para evitar la necesidad de una colectomía total y una anastomosis ileorrectal, para la cual los resultados funcionales pueden ser insatisfactorios. Conclusión: el procedimiento de Deloyers es una alternativa viable a la anastomosis ileorrectal o ileoanal con resultados funcionales satisfactorios.

The present study reports the development and application of a flow injection analysis (FIA) system for the simultaneous determination of uric acid (UA) and caffeine (CAF) using cathodically pretreated boron-doped diamond electrode (CPT-BDD) and multiple-pulse amperometry (MPA). The electrochemical profiles of UA and CAF were analyzed via cyclic voltammetry in the potential range of 0.20–1.7 V using 0.10 mol L−1 H2SO4 solution as supporting electrolyte. Under optimized conditions, two oxidation peaks at potentials of 0.80 V (UA) and 1.4 V (CAF) were observed; the application of these potentials using multiple-pulse amperometry yielded concentration linear ranges of 5.0 × 10−8–2.2 × 10−5 mol L−1 (UA) and 5.0 × 10−8–1.9 × 10−5 mol L−1 (CAF) and limits of detection of 1.1 × 10−8 and 1.3 × 10−8 mol L−1 for UA and CAF, respectively. The proposed method exhibited good repeatability and stability, and no interference was detected in the electrochemical signals of UA and CAF in the presence of glucose, NaCl, KH2PO4, CaCl2, urea, Pb, Ni, and Cd. The application of the FIA-MPA method for the analysis of environmental samples resulted in recovery rates ranging between 98 and 104%. The results obtained showed that the BDD sensor exhibited a good analytical performance when applied for CAF and UA determination, especially when compared to other sensors reported in the literature.

A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO4) and sensitized by an electrodeposited bismuth sulfide (Bi2S3) film. The PEC response of the Bi2S3/BiVO4/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.6-fold higher than the response observed in the absence of Bi2S3. The cTnI antibodies (anti-cTnI) were immobilized on the Bi2S3/BiVO4/FTO platform surface to produce the anti-cTnI/Bi2S3/BiVO4/FTO immunosensor, which was incubated in cTnI solution to inhibit the AA photocurrent. The photocurrent obtained by the proposed immunosensor presented a linear relationship with the logarithm of the cTnI concentration, ranging from 1 pg mL−1 to 1000 ng mL−1. The immunosensor was successfully employed in artificial blood plasma samples for the detection of cTnI, with recovery values ranging from 98.0% to 98.5%.

Cattle ranching is widely spread in the foothills of the Eastern Cordillera of Colombia, and its impact on aerial insectivorous bats is unknown. We used passive-acoustic monitoring of these bats in a silvopastoral system (SSP) planted with Mimosa trianae, a conventional livestock system dominated by pasture (SC) and a forest (B) in the Eastern Cordillera foothill of Colombia. Species composition of B differed from SC and SSP, whereas there were no differences between SC and SSP. Species richness was higher in the SC than in the other land covers, whereas there were no differences between B and SSP. Myotis nigricans, Peropteryx macrotis, Saccopteryx leptura, Molossus cf. rufus, Eptesicus I and Cormura brevirostris had the highest activity in the landscape, and their habitat use depended on land cover. Most bat species used SC more than the other land covers. We found that the spatial heterogeneity associated with the studied cattle ranching landscape affects both the structure of the bat ensemble and the responses of its species.

O presente artigo é uma intervenção do sociólogo colombiano Orlando Fals Borda publicada na coletânea Participación popular: retos del futuro (ICFES, IEPRI, Colciencias, 1998). A coletânea é uma reunião de textos de intelectuais e pesquisadores que participaram do Congresso Mundial de Convergencia Participativa en Conocimiento, Espacio y Tiempo, ocorrido em 1997 em Cartagena de Indias (Colômbia). Na ocasião, além de Fals Borda, participaram nomes como Immanuel Wallerstein, Agnes Heller, Manfred Max-Neef, Paulo Freire e Fernando Henrique Cardoso. A retomada da proposta sociológica de Fals Borda em nossa coletânea é oportuna, na medida em que a reflexão sobre educação popular na América Latina implica também uma perspectiva de intervenção (expressa pela proposta da pesquisa-ação participativa de Fals Borda) junto às profundas assimetrias do continente, considerando perspectivas de mudança social que sintetizam os eixos para políticas de desenvolvimento socioeconômico e a participação política. Além disso, o presente texto oferece aportes metodológicos sugestivos para as diversas modalidades de pesquisa-ação participativa caras à educação popular. Tradução de Felipe Ziotti Narita.

Abstract Russula comprises more than 3,000 species worldwide and is a characteristic genus of the coniferous forests of the northern hemisphere. The forest plantations with non-native species in the northeastern Argentina, such as pine or eucalyptus, provide the biotic and environmental conditions for the establishment of ectomycorrhizal fungi associated with these forest plantations. Due to the complexity of identifying Russula at specific level, morpho-anatomical, scanning electron microscopy, and phylogenetic (ITS) analysis were used to identify the specimens. As result, three Russula species, R. recondita, R. sardonia, and R. sororia, are described in detail and illustrated, none previously known to Argentina. Also, two of them, R. recondita and R. sororia, represent new records for South America.

En la investigación y el desarrollo científico de la Universidad de las Ciencias Informáticas se propuso un sistema de superación profesional que contribuye al impacto en la utilización de las tecnologías informáticas como medios en el proceso de enseñanza-aprendizaje, logrando una experiencia en el impacto a nivel institucional y de los procesos universitarios que marcaron en los profesores y en los estudiantes una profesionalidad, que a partir del análisis documental y un estudio exploratorio proporcionó las deficiencias sobre el poco impacto de la utilización de las tecnologías informáticas en la docencia y producción, por lo que a partir de la operacionalización y parametrización de la variable de estudio se identificaron dimensiones e indicadores y se definió la población y muestra para el diagnóstico y validación de los resultados, utilizando como indagaciones empíricas los métodos de observación, encuesta y entrevista, elaboró tres instrumentos y obtuvo datos que reafirmó lo necesario de considerar el impacto en la utilización de las tecnologías informáticas en el proceso enseñanza-aprendizaje a nivel institucional primero y por parte de los profesores después para consolidar en los estudiantes desde los procesos docente y productivo

En la investigación y el desarrollo científico de la Universidad de las Ciencias Informáticas se propuso un sistema de superación profesional que contribuye al impacto en la utilización de las tecnologías informáticas como medios en el proceso de enseñanza-aprendizaje, logrando una experiencia en el impacto a nivel institucional y de los procesos universitarios que marcaron en los profesores y en los estudiantes una profesionalidad, que a partir del análisis documental y un estudio exploratorio proporcionó las deficiencias sobre el poco impacto de la utilización de las tecnologías informáticas en la docencia y producción, por lo que a partir de la operacionalización y parametrización de la variable de estudio se identificaron dimensiones e indicadores y se definió la población y muestra para el diagnóstico y validación de los resultados, utilizando como indagaciones empíricas los métodos de observación, encuesta y entrevista, elaboró tres instrumentos y obtuvo datos que reafirmó lo necesario de considerar el impacto en la utilización de las tecnologías informáticas en el proceso enseñanza-aprendizaje a nivel institucional primero y por parte de los profesores después para consolidar en los estudiantes desde los procesos docente y productivo.

A simple, rapid and low-cost electroanalytical method is proposed for the determination of acetaminophen (ACP) and codeine (COD) at nanomolar levels in pharmaceutical and biological samples. The analytical procedure is based on a flow injection analysis system coupled to electrochemical detection, which was multiple pulse amperometry (FIA-MPA). Boron-doped diamond was used as the working electrode for electrochemical detection. The electrode was subjected to a cathodic pretreatment and was selected in this work due its good electrochemical performance. By applying the FIA-MPA method, after a number of optimization assays, the analgesics were simultaneously determined at excellent linear concentration ranges. The analytical curves ranged from 80 nmol L−1 to 100 µmol L−1 for ACP and from 50 nmol L−1 to 10 µmol L−1 for COD, and the obtained limits of detection were 30 nmol L−1 and 35 nmol L−1 for ACP and COD, respectively. The practical applicability of the electroanalytical method was evaluated from the ACP and COD determination in two sample matrices: commercial pharmaceutical samples and biological fluids. In the case of pharmaceutical formulation samples, the obtained results were statistically similar to those obtained using a reference chromatographic method. In addition, these drugs were simultaneously quantified in biological fluid samples of urine and human serum with excellent recovery percentages. Keywords: Paracetamol, Codeine, Flow injection analysis, Boron-doped diamond, Multiple pulse amperometry

Earthquakes threaten humanity globally in complex ways that mainly include various socioeconomic consequences of life and property losses. Resilience against seismic risks is of high importance in the modern world and needs to be sustainable. Sustainable earthquake resilience (SER) from the perspective of structural engineering means equipping the built environment with appropriate aseismic systems. Shape memory alloys (SMAs) are a class of advanced materials well suited for fulfilling the SER demand of the built environment. This article explores how this capability can be realized by the innovative SMA-based superelasticity-assisted slider (SSS), recently proposed for next-generation seismic protection of structures. The versatility of SSS is first discussed as a critical advantage for an effective SER. Alternative configurations and implementation styles of the system are presented, and other advantageous features of this high-tech isolation system (IS) are studied. Results of shaking table experiments, focused on investigating the expected usefulness of SSS for seismic protection in hospitals and conducted at the structural earthquake engineering laboratory of the University of Bonab, are then reported. SSS is compared with currently used ISs, and it is shown that SSS provides the required SER for the built environments and outperforms other ISs by benefitting from the pioneered utilization of SMAs in a novel approach.

The present work reports the development and application of an amperometric biosensor based on carbon paste electrode modified with laccase enzyme, glutaraldehyde, and gold nanoparticles (Lac-Glu-AuNPs/CPE) for the determination of the neurotransmitter dopamine (DA). The materials were characterized morphologically and chemically using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and cyclic voltammetry. Optimization studies were performed in order to determine the optimal amount of enzyme and pH level that can yield the best conditions of analysis. The application of the biosensor in optimal conditions using the amperometric technique yielded a linear concentration range of 8.0 × 10−7–6.2 × 10−5 mol L−1 with a limit of detection of 6.0 × 10−8 mol L−1. The proposed biosensor was successfully applied for the determination of DA in biological and environmental samples. In addition, the application of the biosensor for the conduct of electrochemical measurements showed that the sensing device has good repeatability and stability, and it does not suffer from matrix interference effects. The proposed biosensor exhibited an analytical signal of 85% after 10 days of consecutive use.

O uso do ácido nitroso para determinação de paracetamol (acetoaminofenol) em formulações sólidas e líquidas empregando um sistema de análise por injeção em fluxo é descrito. A determinação da droga foi realizada pela reação do paracetamol com ácido nitroso gerado em linha e o produto dessa reação foi monitorado em 430 nm em meio alcalino. A curva analítica apresentou uma faixa de concentração de paracetamol variando entre 9,7x10 -5 a 6,2x10 -3 mol L -1 com um limite de detecção de 2,5x10 -5 mol L -1 . Os desvios padrão relativos foram menores que 2% para soluções contendo 1,2x10 -4 e 2,8x10 -4 mol L -1 de paracetamol (n=10) e uma freqüência de amostragem de 60 determinações por hora foram obtidos. Os resultados da determinação de paracetamol nas formulações farmacêuticas obtidas pelo procedimento em fluxo proposto estão em boa concordância com os resultados obtidos utilizando-se o procedimento da Farmacopéia Americana a um nível de confiança de 95% e dentro de uma faixa aceitável de erro.

A spectrophotometric flow injection method for the determination of Zn(II) in ophthalmic formulations was developed. In this work, Zn(II) ion was complexed with Alizarin red S in borate buffer solution (pH 9.0) and the chromophore produced was monitored at 520 nm. The analytical curve was linear in the Zn(II) concentration range from 6.05 x 10-6 to 1.50 x 10-4 mol L-1 with a detection limit of 3.60 x 10-6 mol L-1. Recoveries ranged from 96.3 to 105 % and a relative standard deviation of 1.2 % (n = 10) for 5.5x10-5 mol L-1 Zn(II) reference solution were obtained. The sampling rate was 60 h-1 and the results obtained of Zn(II) in ophthalmic products using this procedure are in close agreement with those obtained using a comparative spectrophotometric procedure at 95 % confidence level.

In this article the construction and adaptation of inexpensive and easily available materials in acidbase titration in the place of usual materials such as burette, volumetric flask, erlenmeyer and others were described. The viability of the use of those materials was demonstrated in the standardization of caustic soda solution using acetylsalicylic acid as primary standard.

Neste artigo é descrito a construção de um calorímetro simples para o desenvolvimento de um protocolo com o qual é possível determinar a entalpia de dissolução de sais. Para isto, foram utilizadas soluções de sais de carbonato de sódio, bicarbonato de sódio, sulfato de cobre e cloreto de sódio bem como termômetro e recipiente de poliestireno expandido (isopor). O experimento permite assimilar alguns conceitos sobre Termoquímica e pode ser aplicado em qualquer escola de ensino médio, visto que utiliza material de fácil aquisição e baixo custo.

A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10-6 to 2.51 x 10-4 mol L-1 with a detection limit of 5.0 x 10-6 mol L-1. The relative standard deviation was smaller than 1.2% for 1.20 x 10-4 mol L-1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.

In this article the construction of a simple calorimeter (with easily acquired materials) for the determination of the enthalpy of neutralization at constant pressure of acid-base reactions is described. Solutions of weak and strong acids and bases, one thermometer, and one expanded-polystyrene (Styrofoam) container were used in the development of the experiment. With this calorimeter, it was possible to determine the enthalpy of neutralization of reactions and compare the obtained values with the most accepted one of - 55.84 kJ mol-1, at 25 ° C [1].

In this paper the conductometric titration of propranolol hydrochloride in pharmaceutical formulations using silver nitrate as titrant is proposed. The method was based on the formation of an insoluble salt (AgCl(s)) between the chloride of propranolol hydrochloride molecule and Ag(I) ions of the titrant AgNO3. The effect of the PROP-AgNO3 concentrations and the interval of time between the successive additions of the titrant on the shape of the titration curve were studied. The obtained recoveries for four samples ranged from 96.8 to 105%. The proposed method was successfully applied in the determination of propranolol hydrochloride in several pharmaceutical formulations, with results in close agreement at a 95 % confidence level with those obtained using official spectrophotometric method.

This paper reports a flow injection chemiluminescence method involving multicommutation for rutin determination in pharmaceutical formulations. The method is based on the oxidation of rutin by sodium hypochlorite which decreases the signal magnitude when compared with the same reaction without the rutin. Under optimized conditions, an analytical curve was obtained for rutin concentration range from 5.0 × 10-6 mol L-1 to 1.0 × 10-4 mol L-1 (r = 0.9966) with detection limit of 9.7 × 10-7 mol L-1 and a sampling frequency of 120 h-1. Repeatability study for a 7.0 × 10-6 mol L-1 rutine concentration showed a relative standard deviation (RSD) less than 5.0% for ten consecutives determination. The proposed method was applied successfully for rutin determination in pharmaceutical products.

In this research, a boron-doped diamond (BDD) electrode has been explored to detect the chloroquine drug. The electrochemical performance of BDD electrode towards the irreversible anodic response of chloroquine was investigated by subjecting this electrode to the cathodic (−0.5 A cm−2 by 180 s, generating a predominantly hydrogen-terminated surface) and anodic (+0.5 A cm−2 by 30 s, oxygen-terminated surface) pretreatments. The cathodically pretreated BDD electrode ensured a better-defined anodic peak and higher current intensity. Thus, by applying the cathodically pretreated BDD electrode and square-wave voltammetry (SWV), the analytical curve was linear from 0.01 to 0.25 µmol L−1 (correlation coefficient of 0.994), with sensitivity and limit of detection of 12.2 µA L µmol−1 and 2.0 nmol−1, respectively. This nanomolar limit of detection is the lowest recorded so far with modified and unmodified electrodes.

La Colección Mastozoológica del Museo de Historia Natural-Unillanos (MHNU-M) alberga en el momento 422 especímenes pertenecientes a ocho órdenes, 16 familias, 46 géneros, y 66 especies. Los especímenes provienen de cinco departamentos de Colombia, principalmente de la región de la Orinoquía. El número de especímenes de la Colección se ha enriquecido con actividades académicas de la Universidad de los Llanos, tesis de pre y posgrado, convenios y proyectos de investigación.

The present work reports the degradation of 4-nitrophenol using BiVO4/CuO hybrid material synthesized by the precipitation of BiVO4 in the presence of CuO. Morphological and structural characterizations were performed using X-ray diffraction and scanning electronic microscopy coupled to energy dispersive X-ray spectroscopy. Through the calculation of the Kubelka−Munk function applied to diffuse reflectance spectrophotometry data, the hybrid material presented absorption edge of 1.85 eV. The formation of p-n heterojunction between BiVO4 and CuO renders the hybrid material suitable for the construction of a photoanode employed in hydroxyl radical generation. UV−vis spectrophotometry and high-performance liquid chromatography experiments were performed in order to monitor the degradation of 4-nitrophenol and the formation of secondary products. Additional information regarding the hybrid material was obtained through ion chromatography and total organic carbon analyses. The application of BiVO4/CuO-based photocatalyzer led to a 50.2% decrease in total organic carbon after the degradation of 4-nitrophenol. Based on the results obtained in the study, BiVO4/CuO has proved to be a promising material suitable for the removal of recalcitrant compounds in water treatment plants.

The objective is to report a rare case about rhabdomyosarconma in PUC Campinas Hospital. This was a retrospective case report. A 9-year-old boy which presented a superior tarsal conjunctival lesion of the left eye which had a rapid growth in days. The patient underwent a biopsy which revealed an embryonal rhabdomyosarcoma stage III. The patient was submitted chemotherapy according to the Intergroup Rhabdomyosarcoma Study IV protocol and radiotherapy. This is a report discussed about this unusual tumor presentation in the city of Campinas, São Paulo state, Brazil.

Empregou-se nesse trabalho alguns vegetais como fonte de peroxidase. Após a determinação de proteína total, atividade e atividade específica, selecionou-se o extrato bruto da abobrinha (Cucurbita pepo) como fonte dessa enzima para ser empregado em um sistema de análise por injeção em fluxo com detecção espectrofotométrica para a determinação de diversos compostos fenólicos (e.g. fenol, catecol, 2,4-diclorofenol, 4-cloro-3-metilfenol, 4-acetamidofenol, 4-clorofenol, 2,4,6-triclorofenol, o-cresol, m-cresol, p-cresol e hidroquinona). Após a otimização desse sistema em fluxo, o mesmo foi empregado na determinação de compostos fenólicos em águas residuárias de indústrias da região de São Carlos-SP, no intervalo de concentração de 2,0x10-4 a 4,0x10-3 mol L-1, com LD de 8,0x10-5 mol L-1 e freqüência analítica de 58 h-1. A recuperação de fenol em 3 amostras variou de 98,3 a 106, 2% e o RSD foi menor que 1,2% para soluções de fenol nas concentrações de 6,0x10-4 e 8,0x10-4 mol l-1 (n=10).

The great American sociologist C. Wright Mills noted in 1959 that in our time the problems of Western societies are almost inevitably universal problems (Mills 1959:164-180). He already spoke of postmodernity and pointed his ?nger to one of the foremost characteristics of contemporary globalisation: the tension between Reason and Liberty. According to Mills, this tension caused malaise and a certain indifference that led to the formation of a happy robot in contrast to the Enlightenment model of a creative human being.

Las TIC han irrumpido vertiginosamente en la mayor parte de las ramas de la actividad social, económica y política del mundo, por ello se considera que resulta una necesidad que, en las condiciones actuales de cambios, donde la educación no está exenta de esta influencia, el profesor se supere no solo para manejar estas tecnologías, sino para utilizarlas con fundamentos didácticos. Existen necesidades de aprendizaje en los profesores respecto al empleo de la tecnología en las aulas y laboratorios para desarrollar la docencia con la calidad que exige el Modelo del Profesional del Ingeniero en Ciencias Informáticas. Este trabajo tiene como objetivo presentar un entrenamiento en TIC como medio del proceso de enseñanza aprendizaje para los profesores de la Universidad de las Ciencias Informáticas.

A novel method for simultaneous voltammetric determination of the antihypertensive drugs, amlodipine besylate (AML) and hydrochlorothiazide (HTZ) in synthetic urine samples was developed. Determination was carried out with a cathodically pretreated boron-doped diamond electrode (CPT-BDD) using square-wave voltammetry (SWV) and Britton-Robinson buffer solution at pH 2 as the supporting electrolyte. AML and HTZ exhibited oxidation peaks at 0.88 V and 1.30 V, respectively. The difference in potentials of 0.42 V allowed the simultaneous determination of these two analytes. The analytical curve showed linear response in the concentration range from 0.200 to 9.09 µmol L-1 for AML and from 4.00 to 100 µmol L-1 for HTZ, with a limit of detection (LOD) of 60.0 nmol L-1 and of 2.00 µmol L-1 for AML and HTZ, respectively. Recoveries of these analytes ranged from 91.0 to 107%. The proposed method using SWV and a CPT-BDD electrode is simple, fast and low cost, representing a good alternative for simultaneous determination of AML and HTZ in urine samples.

We analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers have a tubular 3-lobed perianth, with bilayered and non vascularized tepals. The androecium consists of three stamens with filaments and thecae connated into a synandrium. It has adnate a free central pistillode without megagametophyte. Staminal filaments, fused at their base to the perianth tube and distally free along a short section, have a single vascular bundle. The distal portion of the synandrium is formed by nine pollen sacs: six outer sacs are located laterally to each filament and three longer inner sacs. The anther wall consists of the epidermis, two parietal layers (that collapse at anther maturity), and an uninucleate secretory tapetum. There is no endothecium. During microsporogenesis, the stem cells produce tetrads of microspores by meiosis. The cytokinesis is simultaneous, forming tetrahedrally arranged tetrads. When pollen grains are in the tricellular state, the synandrium emerges from the mass of filariae, and anthers dehiscence occurs apically through longitudinal slits. In conclusion, despite the extreme reduction of flowers, the anatomic characteristics and gametophyte development of staminate flowers of H. cayennensis are perfectly normal and functional. They are thus highly similar to other genera of the holoparasitic subfamily Helosidoideae. Sterile parts of flowers and inflorescence maintain the same distinctive and aberrant features of the plant vegetative parts.

In this paper conceptual aspects and practices of Mohr method in the determination of metformin hydrochloride in pharmaceutical formulations are described. This experiment is simple and might be a good alternative to be applied in an experimental subject in undergraduation courses.

A carbon composite electrode modified with copper (II) phosphate immobilized in a polyester resin (Cu3(PO4)2-Poly) for the determination of rutin in pharmaceutical samples by square-wave voltammetry is described herein. The modified electrode allows the determination of rutin at a potential (0.20 V vs. Ag/AgCl (3.0 mol L-1 KCl)) lower than that observed at an unmodified electrode. The peak current was found to be linear to the rutin concentration in the range from 9.9 × 10-8 to 2.5 × 10-6 mol L-1, with a detection limit of 1.2×10-8 mol L-1. The response of the electrode was stable, with no variation in baseline levels within several hours of continuous operation. The surface morphology of the modified electrode was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) system. The results obtained are precise and accurate. In addition, these results are in agreement with those obtained by the chromatographic method at a 95% confidence level.Descreve-se um eletrodo de carbono modificado com fosfato de cobre (II) imobilizado em uma resina de poliéster (Cu3(PO4)2-Poly) para a determinação de rutina em amostras farmacêuticas por voltametria de onda quadrada. O eletrodo modificado permite a determinação de rutina em potencial (0.20 V vs Ag / AgCl (3,0 mol L-1 KCl)) menor que o observado em um eletrodo não modificado. Verificou-se que a corrente de pico foi linear com a concentração de rutina na faixa de 9,9 × 10-8 a 2,5 × 10-6 mol L-1, com um limite de detecção de 1,2 × 10-8 mol L¹. A resposta do eletrodo foi estável, sem variação significativa dentro de várias horas de operação contínua. A morfologia da superfície do eletrodo modificado foi caracterizada por microscopia eletrônica de varredura (MEV) e pelo sistema de energia dispersiva de raios-X (EDX). Os resultados obtidos foram precisos e exatos. Ademais, estes resultados estão de acordo com aqueles obtidos pelo método cromatográfico a um nível de confiança de 95%.

A simple flow-injection analysis procedure was developed for determining captopril in pharmaceutical formulations employing a novel solid-phase reactor containing silver thiocyanate immobilized in a castor oil derivative polyurethane resin. The method was based on silver mercaptide formation between the captopril and Ag(I) in the solid-phase reactor. During such a reaction, the SCN- anion was released and reacted with Fe3+, which generated the FeSCN2+ complex that was continuously monitored at 480 nm. The analytical curve was linear in the captopril concentration range from 3.0 × 10-4 mol L-1 to 1.1 × 10-3 mol L-1 with a detection limit of 8.0 × 10-5 mol L-1. Recoveries between 97.5% and 103% and a relative standard deviation of 2% for a solution containing 6.0 × 10-4 mol L-1 captopril (n = 12) were obtained. The sample throughput was 40 h-1 and the results obtained for captopril in pharmaceutical formulations using this procedure and those obtained using a pharmacopoeia procedure were in agreement at a 95% confidence level.Um procedimento simples de análise por injeção em fluxo foi desenvolvido para a determinação de captopril em formulações farmacêuticas empregando um novo reator em fase sólida contendo tiocianato de prata imobilizado em resina poliuretana obtida a partir de óleo de mamona. O método foi baseado na formação de um mercapto composto de prata, no reator em fase sólida, obtido entre o captopril e Ag (I) imobilizada. Durante a reação, íons SCN- eram liberados e reagiam com Fe3+, gerando o complexo FeSCN2+, que foi continuamente monitorado em 480 nm. A curva analítica foi linear no intervalo de concentração de captopril entre 3,0 × 10-4 a 1,1 × 10-3 mol L-1 com um limite de detecção de 8,0 × 10-5 mol L-1. Recuperações entre 97,5-103% e desvio padrão relativo de 2% para uma solução contendo 6,0 × 10-4 mol L-1 de captopril (n = 12) foram obtidos. A frequência de amostragem foi de 40 h-1 e os resultados obtidos para captopril em formulações farmacêuticas utilizando este procedimento e o da Farmacopeia, estão de acordo em um nível de confiança de 95%.

This study reports on the construction of a turbidimeter employing light emitting diodes as radiation source at a wavelength of 405 nm, a photodiode as detector, a temperature sensor and a microcontroller used for data acquisition and processing. The turbidimeter was applied to determine sulfate concentrations in natural water employing barium chloride as reagent. Potential interferences and recovery studies were performed and an interference of 3.5 % and a recovery between 97.8 and 108 % were estimated. The analytical performance of in situ turbidimeter for the determination of sulfate was evaluated and compared with two commercial spectrophotometers and a good agreement was obtained.

The construction of a low cost mini sensor containing a bismuth-film electrode (BiFE), as work electrode, a silver electrode as pseudo reference electrode, and copper as counter electrode is proposed. The application of this mini sensor using a low cost electrochemical cell for in loco voltammetric determinations of inorganic and organic analytes is also described.

A factorial design applied in a voltammetric stripping method for the measurement of Ag(I) in natural water is described. The procedure is based on the effective pre-concentration of silver ions on electrode surface. The calibration graph was linear in the silver concentration range from 7.92 x 10"7 to 1.07 x 10"5 mol L"1 with a detection limit of 3.81 x 10-7 mol L-1. The determination of Ag(I) in natural water samples was carried out satisfactory with the proposed electrode.

This review reports the use of solid amalgam electrodes in the electroanalytical determination of organic and inorganic compounds. The different types of amalgam electrodes are presented, and attention is paid to solid amalgam electrode, and here is presented details about the pre-treatment for activation and renovation and also possible modifications in its surface. The wide potential range, higher signal-to-noise ratio, mechanical stability enabling their application in flowing systems, and principally their resistance toward passivation, indicate that the solid amalgam electrodes are environmentally friendly alternatives to mercury electrodes, without loss in the sensitivity and reproducibility in voltammetric responses.

Cuando el 10 de Diciembre de 1982, Salvador Camacho Roldán, al pronunciar el discurso de clausura de las actividades académicas de la Universidad Nacional, tomó como asunto la propuesta de una nueva cátedra, una sobre una novísima disciplina (tal como se le veía en ese momento): la Sociología, a la vez, inauguró un debate de largo alcance que llega a nuestros días. En aquel momento, dos de los participantes, Nicolás Tanco Armero y Rafael Núñez, presidente de la República, sustentaron con minuciosidad sus argumentos y, al hacerlo, ofrecieron sendas muestras del nivel cultural del momento, de la sintonía en la que se hallaban, en contraste con lo que en otras latitudes se discutía, así como con corrientes percibidas como universales. El valor documental de las piezas de ese debate inaugural ha hecho que se las reedite de cuando en cuando; incluso, el propio Departamento de Sociología lo ha realizado en dos ocasiones. Menos conocido es el debate que se produjera en un suplemento literario de circulación nacional, con motivo de la inauguración de la enseñanza de la sociología en 1959, que, visto de manera retrospectiva, guarda más de una analogía con el debate inicial. En respuesta al discurso inaugural de Orlando Fals Borda, un articulista (Óscar Delgado) discute la naturaleza de la disciplina, y la tradición de pensamiento en la que se ubica; y, a su vez, replican y controvierten, algunos de quienes se hallaban entonces como sociólogos en formación y hoy son ya figuras de trayectoria (como son Guillermo Varela, Rodrigo Parra y Francisco A. Correa). Como una contribución a que la conmemoración no sea un rito vano, creemos conveniente reeditar tales documentos.

Prospecto 1961.

Biosensors based on laccase immobilized on microparticles of chitosan crosslinked with tripolyphosphate (biosensor I) and glyoxal (biosensor II) obtained by spray drying for the determinations of rutin in pharmaceutical formulations were developed. Under optimized operational conditions (pH 4.0, frequency of 30 Hz, pulse amplitude of 40 mV and scan increment of 2.0 mV) two analytical curves were obtained for both biosensors showing a detection limit of 6.2x10-8 mol L-1 for biosensor (I) and 2.0x10-8 mol L-1 for biosensor (II). The recovery of rutin from pharmaceutical sample ranged from 90.7 to 105.0% and the lifetime of these biosensors were 4 months (at least 400 determinations).

A simple, precise, rapid and low-cost conductometric titration method for the determination of metformin hydrochloride (MET) in pharmaceuticals using silver nitrate as titrant is proposed. The method was based on the chemical reaction between the chloride of metformin hydrochloride molecule and Ag(I) ions, yielding the precipitate AgCl(s). The method was applied for MET determination in three pharmaceuticals and the obtained results with proposed method were in close agreement with those results obtained using an official method of the British Pharmacopoeia, at a 95% confidence level.

A flow injection chemiluminescence method for the determination of paracetamol in pharmaceutical formulations is described. It is based on the consumption of the sodium hypochlorite by paracetamol and decreases of the analytical signal. The analytical curve was linear in the paracetamol concentration range from 5.0 x 10-6 to 5.0 x 10-5 mol L-1, with a detection limit of 1.8 x 10-6 mol L-1. The RSDs were 2.0 and 1.2% respectively for 2.0 x 10-5 and 4.0 x 10-5 mol L-1 paracetamol solutions (n = 10) and a sampling frequency of 180 h-1 was obtained.

A multicommuted method for determination of chlorine in water samples using a 100-cm cell was developed. In this method, orto-Tolidine reacts with chlorine and the product was monitored at 438 nm. The analytical curve for chlorine was linear in concentration range from 1.34x10-6 to 2.01x10-5 mol L-1 with a detection limit of 9.40x10-8 mol L-1. A sampling rate of 45 h-1and a RSD of 1.0 % (n = 15) were obtained. The method was applied with success for chlorine determination in six water samples.

A simple, accurate and precise flow-injection turbidimetric procedure for the determination of fluoxetine hydrochloride in pharmaceutical formulations is reported. The procedure is based on the precipitation of chloride of fluoxetine hydrochloride with silver nitrate solution and the yielded insoluble AgCl(s) was monitored at 420 nm. The analytical curve was linear in the fluoxetine hydrochloride concentration range 3.0 x 10-5 - 5.0 x 10-4 mol L-1 with a detection limit of 10 µmol L-1 and, a sample throughout of 60 h-1.

A simple and rapid conductometric method for captopril determination using copper(II) sulphate solution as titrant was developed. The method was based on the chemical reaction between captopril and Cu(II) ions yielding a precipitate. The conductance of the solution was monitored as a function of the added volume of titrant. The method was applied with success for captopril determination in three pharmaceutical formulations. The relative standard deviation for six successive measurements was smaller than 0.5%. Recovery values from three samples, ranging from 97.7 to 103%, were obtained.

In this work we describe both a chromatographic purification procedure and a spot test for the enzyme peroxidase (POD: EC 1.11.1.7). The enzyme was obtained from crude extracts of sweet potatoes and the chromatographic enzyme purification procedure resulted in several fractions. Therefore a simple, fast and economic spot test for monitoring peroxidase during the purification procedure was developed. The spot test is based on the reaction of hydrogen peroxide and guaiacol, which is catalyzed by the presence of peroxidase yielding the colored tetraguaiacol.

In this work was developed a method for the determination of saccharin in dietary products by a biamperometric titration, using two silver electrodes as working electrodes and silver nitrate as titrant. It were used products as juices (light) and sweeteners with saccharin in concentrations ranged from 8.73 x 10-5 mol L-1 to 1.0 x 10-2 mol L-1, and the results were in close agreement with those data found using a HPLC method at a confidence level of 95%. The main advantages of the proposed method are its simplicity, rapid and low cost.

The use of square-wave voltammetry in conjunction with a cathodically pre-treated diamond electrode for the analytical determination of sodium cyclamate is described. The samples were analyzed as received in a 0.5 mol L-1 H2SO4 solution in the concentration range from 5.0 × 10-5 mol L-1 to 4.1 × 10-4 mol L-1, with a detection limit of 4.8 × 10-6 mol L-1. The RSD was smaller than 1.2 % and the proposed method was applied with success in the determination of sodium cyclamate in several dietary products.

In this work a method was developed for removing metallic ions from wastewaters by co-precipitation of Cu2+, Pb2+, Cd2+, Cr3+ and Hg2+ with chitosan and sodium hydroxide solution. Solutions of these metallic ions in the range from 0.55 to 2160 mg L-1 were added to chitosan dissolved in 0.05 mol L-1 HCl. For the co-precipitation of metal-chitosan-hydroxide a 0.17 mol L-1 NaOH solution was added until pH 8.5-9.5. A parallel study was carried out applying a 0.17 mol L-1 NaOH solution to precipitate those metallic ions. Also, a chitosan solid phase column was used for removing those metallic ions from wastewaters.