Resumen: La síntesis y estudio de biomateriales con propiedades biomecánicas y de biocompatibilidad es un tema de continua investigación por parte de la comunidad científica. Compuestos como la hidroxiapatita (HA) y la brushita, que poseen interesantes propiedades y a la vez son biocompatibles, están siendo utilizados como capa barrera entre materiales como el acero 316L y medios biológicos, disminuyendo así el flujo de iones de hierro del acero hacia los fluidos biológicos. Si bien estudios recientes presentan avances en términos de la adherencia de estos materiales a diferentes metales, aún hay desafíos abiertos en pro de mejorar su adherencia sobre el metal deseado. En este trabajo se obtuvieron recubrimientos compuestos de bicapas de brushita y dióxido de titanio (TiO2). A continuación, se presentan los protocolos seguidos para síntesis de los recubrimientos de brushita, dióxido de titanio y sus bicapas sobre acero 316 L, así como la caracterización estructural mediante espectrometría infraroja (FTIR), difracción de rayos X (XRD), microscopia electrónica de barrido (SEM) y espectroscopia de energía dispersiva (EDS) de los recubrimientos obtenidos. Los resultados muestran que la combinación brushita/ TiO2 parece tener una buena efectividad, dado que el dióxido de titanio ayuda a la adherencia de la brushita.

Abstract: The synthesis and study of biomaterials possessing biomechanical and biocompatibility properties is a subject of continuous research by the scientific community. Compounds such as hydroxyapatite (HA) and brushite, which have interesting properties and are biocompatible, are being used as a barrier layer between materials such as 316L steel and biological media, thus reducing the iron ion flux from the steel to the Biological fluids. Although recent studies have presented advances regarding the adhesion of these materials to different metals, there are still open challenges to improve the adhesion of these materials to the desired metal. In this work, we have implemented coatings composed of brushite and titanium dioxide (TiO2) bilayers. Following are the protocols followed for synthesis of brushite, titanium dioxide and bilayer coatings on 316 L steel, as well as the structural characterization by infra-red spectrometry (FTIR), X-ray diffraction (XRD), electron microscopy of Scanning (SEM) and dispersive energy spectroscopy (EDS) of the coatings obtained.

Resumo: A síntese e o estudo de biomateriais com propriedades biomecânicas e de biocompatibilidade são objeto de contínua pesquisa pela comunidade científica. Os compostos, tais como hidroxiapatite (HA) e brushite, que têm propriedades interessantes e ainda sejam biocompatíveis, estão a ser utilizados como barreira entre a camada de materiais como o aço 316L e meios biológicos, diminuindo deste modo o fluxo de iões de ferro de aço para o fluido biológico. Embora estudos recentes apresentem avanços em termos de aderência desses materiais a diferentes metais, ainda existem desafios abertos para melhorar a aderência ao metal desejado. Neste trabalho, foram obtidos revestimentos compostos de bicamada de brushita e dióxido de titânio (TiO2). Em seguida, são apresentados os protocolos seguidos para a síntese dos revestimentos de brushita, dióxido de titânio e suas bicamadas de cerca de 316 L, bem como a caracterização estrutural por espectrometria de infravermelho (FTIR), difracção de raios-X (DRX), Microscopia Eletrônica de Varredura (MEV) e espectroscopia de energia dispersiva (EDS) dos revestimentos obtidos. Os resultados mostram que a combinação de brushita / TiO2 parece ter uma boa eficácia, uma vez que o dióxido de titânio auxilia na aderência da brushita.

Abstract: Quindío Department is the second tourist destination in Colombia; one fifth of its territory is part of the Coffee Cultural Landscape. The main aim of this study was to assess the effect of the human presence on the behavior of the torrent duck Merganetta armata (Birds: Anatidae) on the Quindío River (Boquía sector), Salento, Colombia. Samplings were made of two pairs of ducks between February and October 2016, spanning the high and low tourist seasons. At each visit the behavioral patterns of the torrent duck and the presence of humans was recorded. MANOVAs were used to determine whether the human presence caused changes in the ducks’ behavior. In addition, the ducks’ minimum tolerance range (MTR) was calculated. It was demonstrated that the human presence mainly affects the individuals’ feeding and resting, with no difference in the gender of the duck (p=0.0476 and p=0.041), as they devote less time to these activities. The MTR was 7.2 m. However, from 32 m and depending on the intensity of noise emitted by the people, the ducks manifested warning behavior. In the case of the imminent proximity of a human, 57.5% of the ducks had agonistic reactions, and if the human intervention continued, 17.5% of the ducks would move away from the area. The main implication of this study suggests it is necessary to design and implement tourism policies that include the wild fauna in the area studied.

Resumen: El departamento del Quindío es el segundo destino turístico de Colombia; una quinta parte de su territorio se hace parte del Paisaje Cultural Cafetero. El objetivo principal de esta investigación fue evaluar el efecto de la presencia humana sobre el comportamiento del Pato de Torrente Merganetta armata (Aves: Anatidae) en el río Quindío (sector Boquía), en Salento-Colombia. Se realizaron muestreos a dos parejas de patos entre febrero y octubre de 2016 abarcando temporadas altas y bajas de turismo. En cada visita se registraron los patrones comportamentales del Pato de Torrente y la presencia de humanos. Por medio de MANOVAS se determinó si la presencia humana generó cambios en el comportamiento de los patos. Además, se calculó la distancia mínima de tolerancia (DMT) de los patos. Se logró evidenciar que la presencia humana afecta principalmente la alimentación y el descanso de los individuos, sin importar el sexo de los mismos (p=0,0476 y p=0,041), ya que destinan menor tiempo a estas actividades. La DTM fue de 7,2 m. Sin embargo a partir de los 32 m y dependiendo de la intensidad de ruido emitido por las personas, los patos manifestaron comportamiento de alerta. Ante la cercanía inminente de un humano un 57,5% de los patos generó reacciones agonísticas, y de continuar la intervención humana un 17,5% de los patos se desplazaría del sitio. La principal implicancia de esta investigación sugiere que es necesario diseñar e implementar políticas turísticas que incluyan a la fauna silvestre en la zona de estudio.

En este trabajo se presenta un prototipo de potenciostato de bajo costo, que permite el control de las variables eléctricas en la obtención de recubrimientos por electrodeposición. Se empleó la metodología QFD (Quality Function Deployment) como herramienta de planificación con el fin de determinar las características que debe tener el prototipo de potenciostato. El desarrollo de la investigación se basó en el diseño e implementación de un prototipo de potenciostato que permita trabajar 3 funciones básicas de electrodeposición a saber: cronoamperometría, que consiste en mantener un voltaje constante en un rango de 0 V a 20 V y mide la corriente entregada al sistema; cronopotenciometría, que mantiene constante una corriente en un rango de 0 A a 2 A y mide el voltaje (potencial) y voltamperometría cíclica, la cual trabaja en los mismos rangos de la cronoamperometría (0 V a 20 V) y excita el sistema mediante señales de onda triangular, diente de sierra, senoidal, cuadrada, entre otras. Estas características implementadas son comparadas con las de un potenciostato comercial, demostrando su eficiencia en el control de procesos electroquímicos.

This article presents a low cost prototype potentiostat, which allows to control electrical variables in obtaining coatings by electrodeposition. The QFD (Quality Function Deployment) methodology was used as a planning tool in order to determine the characteristics that should have the potentiostat along the entire process of obtaining the prototype. The development of the research was based on the design and implementation of a prototype potentiostat that can handle three basic functions of electrodeposition. One first function, chronoamperometry lets to keep a constant voltage in the range of 0 V to 20 V and measures the current delivered to the system. A second function, chronopotentiometry maintains constant a current in a range of 0 A to 2 A and measures the voltage (potential). A third function, cyclic voltammetry, works in the same ranges of chronoamperometry (0 V to 20 V) and excites the system by signals as triangular wave, saw tooth, sine, and square, among others. These implemented features were compared to one conventional potentiostat, demonstrating its efficiency in controlling electrochemical processes.

Nesse trabalho se apresenta um protótipo de baixo custo potentiostat, que permite o controle das variáveis elétricas na obtenção de recobrimentos por eletrodeposição. Empregou-se a metodologia QFD (Quality Function Deployment) como ferramenta de planificação com o fim de determinar as características que devem ter o protótipo de um potentiostat. A pesquisa baseou-se na concepção e implementação de um protótipo de um potentiostat, permitindo trabalho 3 noções básicas de galvanoplastia, nomeadamente: cronoamperometria, que consiste em manter uma voltagem constante em um intervalo de 0V a 20V e mede a corrente entregada ao sistema; cronopotenciometria que mantem constante uma corrente de um rango de 0A a 2ª e mede a voltagem (potencial) e voltamperometria clinica, a qual trabalha nos mesmos intervalos que a conoamperometria (0V a 20V) e excita o sistema mediante sinais de onda triangular, dente de serra, senoidal, quadrada, entre os outros. Estas características implementadas são comparadas com as de um potensiostato comercial, demostrando sua eficiência no controle de processos eletroquímicos.

Activated carbons obtained from cane sugar bagasse (ACB), African palm pit (ACP) and sawdust (ACS) were prepared through an impregnated with HNO3 and thermal treatment in an atmosphere in N2/steam water at 1173 K. Adsorption isotherms of N2 at 77 K and of CO2 at 273 K were determined for the activated carbons for which surface area and pore volume values were from 868 to 1100 m²g-1 and from 0.27 to 0.55cm³ g-1, respectively. These results were correlated, with the ones obtained for adsorption the adsorption isotherms of Pb2+ in aqueous solutions. Impregnation of the lignocellulosic materials with nitric acid produced acid-type activated carbons with total acid site contents between 4.13 and 6.93 mmol g-1 and pH at the point of zero charge values between 2.7 and 4.1, which were within range of the adsorption, at different pH values, since they determined, the surface charge of the activated carbons. Adsorption isotherms of Pb2+ at different pH values (2-8) at 298 K were determined. The ion adsorption capacity on ACB, ACP and ACS were 13.7, 15.2 and 17.5 mg.g-1, respectively. Experimental data were fitted to the Langmuir and Freundlich models and all cases the former fit better. The highest values for the quantity adsorbed on the monolayer, qm, were at pH 4, whereas the surface, charge of activated carbons was negative and the lead species mainly present was Pb2+. For higher pHs, the quantity of Pb2+ adsorbed decreased, and this had an important effect on adsorption, the surface characteristics of the solids and the hydroxilated lead species that were formed in the system.

The case of 20-years female patient with the diagnosis of sarcoidosis associated to fibrolamellar carcinoma of the liver is presented. Clinical features, diagnosis and treatment of these entities are exposed. The criteria of several researchers about the relation between sarcoidosis and neoplasic diseases are stood out. Sarcoidosis associated to fibrolamellar hepatocarcinoma is very uncommon.

Se presenta el caso de una paciente de 20 años de edad con el diagnóstico de sarcoidosis asociada a carcinoma hepático fibrolamelar. Se exponen algunos aspectos clínicos de estas dos enfermedades, así como la conducta diagnóstica y terapéutica seguida. Se resaltan las opiniones de diferentes investigadores sobre la posible relación de la sarcoidosis con las enfermedades neoplásicas, las cuales hasta el momento actual son contradictorias. Se concluye que esta asociación es supremamente rara y debe tenerse en cuenta en el estudio de pacientes jóvenes con sintomatología compatible.

This paper reports on a case of a 34-year male patient diagnosed for splenic lymphoma of the marginal zone, a rare entity in our milieu. Features of the disease are described. Early diagnosis is a must for optimum treatment of such a pathology, whose onset can be giant splenomegalia. All possible causes are to be considered.

Se presenta el caso de un paciente de 34 años de edad con el diagnóstico de linfoma esplénico de la zona marginal, una entidad poco reconocida en nuestro medio. Se describen algunas de sus características y se resalta el diagnóstico, el cual debe ser precoz para el tratamiento óptimo de esta patología. Esta entidad puede debutar como una esplenomegalia gigante requiriendo tener presente todas las causas que son capaces de producirla.

Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of activated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fibers were physically prepared from the carbonization of the Kevlar and its later activation with CO2 and steam of water, by the other hand; the chemically activated fibers were obtained by means of the impregnation of the material with phosphoric acid and their later carbonization. Different conditions were used and preliminary analyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterized by N2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off were also evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strong conditions respect to the commonly used such as water steam, high phosphoric acid concentrations and methods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.

Specific combustion programs (Gaseq, Chemical equilibria in perfect gases, Chris Morley) are used to model dioxin and formation in the incineration processes of urban solid wastes. Thanks to these programs, it is possible to establish correlations with the formation mechanisms postulated in literature on the subject. It was found that minimum oxygen quantities are required to obtain a significant formation of these compounds and that more furans than dioxins are formed. Likewise, dioxin and furan formation is related to the presence of carbon monoxide, and dioxin and furan distribution among its different compounds depends on the chlorine and hydrogen relative composition. This is due to the fact that an increased chlorine availability leads to the formation of compounds bearing a higher chlorine concentration (penta-, hexa-, hepta-, and octachlorides), whereas an increased hydrogen availability leads to the formation of compounds bearing a lower chlorine number (mono, di-, tri-, and tetrachlorides).

Zorflex® activated carbon fibers (ACF), reference FM100 198B, are used before and after an oxidizing procedure with H3PO4 to study the adsorption of Pb2+. The point of zero charge was determined for the modified and unmodified fiber giving values of 2.3 and 4.3, respectively. After oxidizing the ACF, the fiber showed to have a greater Pb2+ adsorption capacity in comparison with the unmodified fiber, which is related with the acid sites increase, where lead was mainly adsorbed. Determination of the BET area was carried out by nitrogen physisorption at 77K. ACFs presented superficial areas between 1000 and 1500 m²/g showing mostly, a microporous structure. The preliminary design of an adsorbent using the modified fiber is presented where the fiber superior physicochemical properties over the unmodified one are observed.

The present work shows a simple way to design a process scale-up, for an adsorber, from laboratory to industrial level using breakthrough curves in fixed beds developed through the continuous detection of the Pb(II) ion concentration in the effluent of the bed. This procedure was developed in order to examine its efficiency and to be compared with an experimental method developed in the laboratory, which produced similar results. The feasibility of this design lies on the fact that neither tedious calculations nor mass transfer coefficients are required in order to plot the mentioned curves. The procedure was developed by applying concepts such as mass transfer zone (MTZ) and length of unused bed (LUB), which are the dynamic basis of the adsorption process in fixed beds. As a complement to the experimentation, within a pilot plan scale, a filter was developed to handle the most important adsorption parameters and to control the variables that change the operating conditions during the process.

Este trabajo describe una manera simple de diseñar un proceso de escalado, para un adsorbedor, desde nivel de laboratorio a escala industrial usando curvas de paso en lechos fijos, desarrollado a través de la detección continua de la concentración de Pb(II) en el efluente del lecho. El procedimiento fue medido con el objeto de examinar su eficiencia y para ser comparado con un método experimental desarrollado en el laboratorio que dio lugar a resultados similares. La factibilidad del diseño se basa en la ausencia de cálculos tediosos y coeficientes de transferencia en el graficado de las curvas mencionadas. El procedimiento fue desarrollado aplicando conceptos tales como los de zona de transferencia de masa (MTZ) y longitud del lecho no usado (LUB), que constituyen la base dinámica del proceso de adsorción en lechos fijos. Como complemento a la parte experimental en el proceso de escalado, se desarrolló un filtro para controlar los parámetros de adsorción más importantes y para observar las variables que modifican las condiciones de operación durante el proceso.

An activated carbon was obtained by chemical activation with phosphoric acid, CM, from a mineral carbon. Afterwards, the carbon was modified with 2 and 5 molL-1, CMox2 and CMox5 nitric acid solutions to increase the surface acid group contents. Immersion enthalpy at pH 4 values and Pb2+ adsorption isotherms were determined by immersing activated carbons in aqueous solution. The surface area values of the adsorbents and total pore volume were approximately 560 m².g-1 and 0.36 cm³g-1, respectively. As regards chemical characteristics, activated carbons had higher acid sites content, 0.92-2.42 meq g-1, than basic sites, 0.63-0.12 meq g-1. pH values were between 7.4 and 4.5 at the point of zero charge, pH PZC. The adsorbed quantity of Pb2+ and the immersion enthalpy in solution of different pH values for CM activated carbon showed that the values are the highest for pH 4, 15.7 mgg-1 and 27.6 Jg-1 respectively. Pb2+ adsorption isotherms and immersion enthalpy were determined for modified activated carbons and the highest values were obtained for the activated carbon that showed the highest content of total acid sites on the surface.

Objetivo: describir el consumo del medicamento metilfenidato-ritalina®, en el valle del Aburrá del departamento de Antioquia en el periodo de febrero a julio de 2003, en cuanto a la variación del consumo, las caracter ísticas sociodemográficas de los pacientes que la consumen, así como en función de las variables de salud, aseguramiento y de medicamentos acompañantes. Métodos: estudio descriptivo longitudinal retrospectivo que tomó como fuente de información 1.917 pacientes consumidores del medicamento reportados oficialmente en el Fondo Rotatorio de Estupefacientes (FRE), con un tamaño muestral de 100 historias clínicas, 93 de las cuales se captaron mediante un formulario que permitió recolectar las variables de interés. Resultados: el consumo mínimo mensual fue de 150 miligramos y el máximo ascendió a 900 miligramos por paciente, con promedios mensuales que van de 362,9 a 398,4 miligramos por paciente. La tendencia de este consumo promedio total es visiblemente ascendente, con estabilización en niveles altos en los dos últimos meses. El 96,8% de todos los diagnósticos correspondió al trastorno por déficit de atención con hiperactividad (TDAH). El Instituto Neuroló- gico y el Hospital Mental de Antioquia fueron las instituciones que más distribuyeron el medicamento o las que más fórmulas prescribieron a pacientes de ambos sexos, con 81,7%. El 46,2% son tratados simultáneamente con medicamentos alternos a la ritalina®. Conclusiones: con este estudio se contribuye a ampliar los conocimientos sobre las enfermedades y la medicación respectiva, adem ás de mejorar los procedimientos administrativos establecidos en las entidades públicas encargadas de controlar el medicamento, lo que acarrea beneficios a la subregión antioqueña en cuanto a la ilustración y comprensión del tema estudiado.

Objective: to describe the consumption of the medication Methylphenidate-ritalin® in Aburrá Valley in the department of Antioquia, Colombia, in the period of February- July 2003, as for the variation in the consumption, the socio-demographic characteristic of the patients that consume it, and according to the variables of health, insurance and of accompanying medications. Methods: longitudinal and retrospective descriptive study that took as source of information the 1.917 patient consumers of the medication officially reported in the Rotational Fund of Narcotics (FRE) with a sample size of 100 clinical histories from which 93 were gathered by means of a form that allowed to collect the information of interest. Results: the monthly minimum consumption was of 150 milligrams and the maximum ascended to 900 milligrams per patient, with monthly averages that ranged from 362.9 to 398.4 milligrams per patient. The marked tendency of this consumption average total is upward, being stabilized in high levels in the last two months. A total of 96.8% of all the diagnoses corresponded to the Attention Deficit Hyperactivity Disorder (ADHD). The Neurological Institute and the Mental Hospital of Antioquia were the institutions that mostly distributed the medication or that more prescriptions issued to patients of both sexes (81.7%). A total of 46.2% patients are simultaneously treated with alternating medications to ritalin®. Conclusions: this study contributes to enlarge the knowledge on the illnesses and its respective medication and to improve the administrative procedures adopted by public entities which are in charge of controlling the medication, all of which carries benefits to Antioquian area in terms of the illustration and understanding of the topic studied.