Abstract The photoluminescent behavior of Eu-doped Sr3Al2O6 obtained by highly efficient solution combustion synthesis is reported. In order to understand the influence of the fuel on the synthesis, the stoichiometric quantity and an excess of fuel were evaluated. By adjusting the amount of fuel, different luminescence responses were obtained, allowing europium cations incorporation into the Sr3Al2O6 lattice to serve as effective luminescence activators in such a short time during the rapid combustion synthesis process. The higher amount of fuel in the presence of the oxidizing agent produced Sr3Al2O6:Eu particles with higher phosphorescence brightness, owing to the increase of the reduction process from Eu3+ to Eu2+. The synthesized phosphor showed an intense band emission centered at 515 nm and could be excited over a broad spectral range in the UV-visible region. Particles having nanostructured flake-type morphology were obtained, which was considered a micro-nanofunctional candidate for practical applications.

Abstract The purpose of this study was the development of a low-cost ceramic tubular membrane, using inexpensive materials, namely natural clay, and graphite as a porogenic agent. Such a low-cost membrane can be used as filters or porous supports for the preparation of multilayer ceramic membranes. Extrusion was used as a shape-forming method for this purpose. Graphite was selected as a porogenic additive. Raw materials were physicochemically and morphologically characterized. A comparative study of the influence of porogen content on membrane characteristics was carried out. Finally a graphite addition of 15 wt% and 850 °C as the sintering temperature were chosen. The obtained membrane had 41 vol% of porosity, diametral compression strength of 4 MPa, and relatively good corrosion resistance in basic and acid conditions. The performance of the membrane support was evaluated for diesel-in-water emulsion depuration as a function of pressure. Filtration test using 15% of porogen sample led to turbidity rejection factor of 95%. Therefore, it was considered that this membrane can be suitable for diesel/water emulsion treatment.

Abstract The objective of this work was to produce brushite cement for orthopedic applications, based on the system wollastonite/phosphoric acid with the incorporation of polyethylene glycol (PEG) as a setting and processing additive. Brushite/PEG cement was obtained by the dissolution-precipitation method and its physicochemical properties were characterized by X-ray diffraction, compressive strength, porosimetry, and biological behavior (cell adhesion and bioactivity tests). The results indicated the formation of brushite cement with 21.4 MPa of compressive strength and 30% porosity, similar to human trabecular bone. The surface was shown to be adequate for cell adhesion and growth and bioactive with the formation of apatite layers. The incorporation of PEG improved working conditions without causing undesirable changes in the physicochemical properties and biological behavior of developed cement, thus promising for the repair of bone tissue injuries.

Resumo Microesferas de α-TCP foram obtidas atomizando uma suspensão aquosa contendo 50% em massa de α-TCP com baixa cristalinidade e 1% em massa de ácido cítrico. Poli(etileno glicol) e poli(álcool vinílico) foram testados como ligantes. O processo de spray drying resultou em microesferas com diâmetros médios de aproximadamente 20 μm e esfericidade (razão de comprimentos na horizontal e na vertical) próxima a um, características essenciais para várias aplicações, como a liberação controlada de drogas e cimentos ósseos injetáveis. A adição dos ligantes foi necessária para reduzir a quantidade de partículas soltas e aumentar a fluidez do pó, mas também resultou em uma redução na molhabilidade e na área superficial das microesferas. Os melhores resultados foram obtidos com 3% de PVA já que as microesferas apresentaram a maior área superficial, molhabilidade e esfericidade. As microesferas preparadas neste estudo podem ser utilizadas como precursoras de cimentos ósseos injetáveis, já que a sua geometria esférica e sua fluidez favorecem a homogeneidade e injetabilidade das pastas sobrepujando as principais dificuldades dos cimentos injetáveis atuais.

Abstract a-TCP microspheres were obtained by atomizing aqueous slurries containing 50 wt% of low crystallinity α-TCP and 1 wt% of citric acid. Poly(ethylene glycol) and poly(vinyl alcohol) were tested as a binder. The spray drying process yielded to microspheres with mean diameter around 20 μm and sphericity (horizontal and vertical length ratio) closest to one, which is essential to many applications, such as drug delivery and injectability of cements. The addition of binders was necessary to decrease the amount of loose particles and to improve powder flowability but it also caused a reduction in wettability and surface area. Best results were achieved with 3 wt% of PVA, as the microspheres presented the highest specific surface area, wettability, and sphericity. The microspheres prepared in this study may be used as injectable bone cements precursor since their geometry and flowability would favor paste homogeneity and injectability overcoming many drawbacks of today’s injectable bone cements.

Pigmentation of fungiform papillae (PFP) is considered a physiological condition, although the pathogenesis remains unclear. PPF is relatively common in African or Asian patients. However, this condition does not usually appear reflected in principal dermatology’s textbooks. When the entity is known, its diagnosis is simple and exclusively clinical.

La pigmentación de las papilas fungiformes (PPF) es considerada una condición fisiológica, cuya etiopatogenia es desconocida. La PPF es relativamente frecuente en pacientes de raza negra o asiática, pese a lo cual, no suele aparecer reflejada en los principales tratados de dermatología o pediatría. Su diagnóstico es sencillo y exclusivamente clínico, si se conoce la entidad.

Objective: the importance of acute postoperative pain lies in its high frequency, where inadequate treatment and the impact it has on the evolution and the patient's recovery. Iliofascial block may be a suitable technique for postoperative analgesia after total knee arthroplasty. The aim of this study is to assess the efficacy and safety of the blockade iliofascial compared with epidural analgesia in postoperative effects in patients undergoing total knee arthroplasty under spinal anesthesia. We also evaluate if the iliofascial block is a safe analgesic technique, the complications, the adverse effects and the patient satisfaction. Material and methods: multicenter, prospective, randomized, observational, controlled, assessor blind, in 54 adult patients, ASA I-III, of both sexes, for total knee arthroplasty under spinal anesthesia. Patients included in the study were divided into two groups, BIF and BE. In the BIF group (n = 27), a iliofascial catheter was placed, while in the other group BE (n = 27), a lumbar epidural catheter (at L3-L4) was placed, both for continuous postoperative analghesia. Both groups received the same protocol with paracetamol and metamizol, and rescue with intravenous morphine bolus. Student t test was used to compare quantitative variables. p < 0.05 was considered significant. Results: There were no differences between groups in postoperative pain measured by VAS scale in the first hour after surgery and at 8, 12, 24 and 48 hours. The supplemental analgesia consumption was similar in both groups. Both techniques were easy and showed no complications related to any of them. No differences in side effects, motor block level, the degree of satisfaction with the analgesia received or sleep quality. Discussion: in our study as the epidural catheter as the catheter iliofascial provide good control of postoperative pain after total knee arthroplasty, with a degree of satisfaction of patients as good to very good. According to our results we think that the iliofascial block seems a safe and effective technique, so we could join to the analgesic protocol of knee arthroplasty.

Objetivo: la importancia del dolor agudo postoperatorio radica en su alta frecuencia, en su inadecuado tratamiento y en las repercusiones que tiene en la evolución y en la recuperación del paciente. El bloqueo iliofascial puede ser una técnica adecuada para analgesia postoperatoria en la artroplastia total de rodilla. El objetivo de este estudio es valorar la eficacia y seguridad del bloqueo iliofascial, en comparación con el bloqueo epidural, a efectos de analgesia postquirúrgica en pacientes sometidos a artroplastia total de rodilla bajo anestesia subaracnoidea. Se valoró además si la realización del bloqueo iliofascial es una técnica analgésica segura, las complicaciones derivadas de la misma, los efectos secundarios y el grado de satisfacción del paciente. Material y métodos: estudio multicéntrico, prospectivo, aleatorio, observacional, controlado, con evaluador ciego, en 54 pacientes, adultos, ASA I-III, de ambos sexos, sometidos a cirugía de artroplastia total de rodilla bajo anestesia intradural. Los pacientes incluidos en el estudio se dividieron en dos grupos, BIF y BE. En el grupo BIF (n = 27) se colocó un catéter iliofascial, mientras que en el otro grupo BE (n = 27) se colocó un catéter epidural lumbar (a nivel L3-L4), en ambos casos para la analgesia postoperatoria continua. Ambos grupos recibieron el mismo protocolo analgésico con paracetamol y metamizol pautados, y rescate con bolos de morfina intravenosa. Se utilizó t-Student para comparar las variables cuantitativas. Se consideró significativo (p < 0,05). Resultados: no hubo diferencias entre ambos grupos en el dolor postoperatorio, medido a través de la escala EVA en la primera hora tras la intervención y a las 8, 12, 24 y 48 horas. El consumo de analgesia suplementaria fue similar en ambos grupos. La facilidad para realizar ambas técnicas fue similar y no se evidenciaron complicaciones relacionadas con ninguna de ellas. Tampoco se encontraron diferencias en los efectos secundarios, en el nivel de bloqueo motor, en el grado de satisfacción por la analgesia recibida o en calidad de sueño. Discusión: según nuestro estudio, tanto el catéter epidural como el catéter iliofascial aportan un buen control del dolor postoperatorio en artroplastia total de rodilla, con un grado de satisfacción por parte de los pacientes de bueno a muy bueno. En base a nuestros resultados, parece que el bloqueo iliofascial es una técnica efectiva y segura, por lo que podría incorporarse al protocolo analgésico de artroplastia de rodilla.

The ASM1 model is accepted as a reference to predict and understand the processes of organic matter degradation, nitrification and denitrification in systems activated sludge. To calibrate the model, requires estimate kinetic parameters such as the maximum grow rate (µHMAX) and decay (bH) heterotrophic. These parameters have been studied for temperatures under 20°C. The objective of this investigation was to evaluate µHMAX and bH in a range of temperature of 20 at 32°C in the wastewater treatment plant "Dulces Nombres" in Monterrey, Nuevo León, México. The work was based on respirometric tests as part of the calibration of the model ASM1. The fraction of substrate readily biodegradable (S S) was low (34 mg/L) diffult tests for growth. For evaluate µHMAX was necessary to add sodium acetate to obtain a durable growth of the microorganisms and thus to estimate this parameter. The tests of respirometry, were made at temperatures of 20, 24, 28 and 32°C. The results average of µHMAX and bH for 20°C were 6.9 and 0.40 d-1 respectively. The correction factor by temperature change (θ) of Arrhenius for µHMAX and bH was 1,045 and 1.04 respectively, which can be applied to conditions of warm climate or tropical.

El modelo ASM1 es aceptado como referencia para predecir y comprender los procesos de degradación de materia orgánica, nitrificación y desnitrificación en sistemas de lodos activados. Para calibrar el modelo, se requiere estimar paréticos tales como la tasa máxima de crecimiento (µHMAX) y de decaimiento (bH) heterotróficos. Estos parámetros han sido estudiados para temperaturas menores a 20°C. El objetivo de esta investigación, fue evaluar µHMAX y bH en un rango de temperatura de 20 a 32°C en la planta de tratamiento de aguas residuales "Dulces Nombres" en Monterrey, Nuevo León, México. El trabajo se basó en pruebas respirométricas como parte de la calibración del modelo ASM1. La fracción de sustrato fácilmente biodegradable (S S) fue baja (34 mg/L) dificultándose las pruebas de crecimiento. Para evaluar µHMAX , fue necesario agregar acetato de sodio para obtener un crecimiento duradero de los microorganismos y así poder estimar este parámetro. Las pruebas de respirometría, se realizaron a temperaturas de 20, 24, 28 y 32°C. Los resultados promedio de µHMAX y bH para 20°C fueron de 6.9 y 0.40 d-1 respectivamente. El factor de corrección por cambio de temperatura (θ) de Arrhenius para µHMAX y bH fue de 1.045 y 1.04 respectivamente, los cuales se pueden aplicar para condiciones de clima cálido o tropical.

The analysis of electrochemical behaviour of carbon steel immersed in a sour water of the petroleum industry, varying the pH, was studied. Different techniques used show the presence of three important corrosion stages: adsorption, species diffusion and localised corrosion. MEB analysis showed the presence of corrosion products only at pH 8.5, while in all the pH tested there are cavities or pitting. The EDS study confirms the presence of oxygen, calcium and chlorides at pH 8.5, where the corrosion products are present.

En este trabajo se presenta el análisis del comportamiento electroquímico de acero al carbono inmerso en agua amarga de la industria del petróleo, variando el pH. Las diferentes técnicas utilizadas denotan la presencia de tres etapas importantes en el proceso de corrosión: adsorción, difusión de especies y corrosión localizada. El análisis por Microscopia Electrónica de Barrido (MEB) mostró la presencia de productos de corrosión únicamente a pH 8.5, mientras que en todos los pH's evaluados se tiene presencia de cavidades o picaduras. El estudio de EDS confirma la presencia de oxígeno, calcio y cloro a pH 8.5 donde se tienen productos de corrosión.

The home care to the terminal patients is a more and more frequent situation inside the environment of the Primary Health Care. A great number of these patients will evolve, for different reasons, to the loss of the oral route. In these cases, the election method is going to be the subcutaneous route. This it is a route of simple use, which presents few complications and it allows the patient to continue in his home, improving this way his quality of life.

La atención domiciliaria al enfermo terminal es una situación cada vez más frecuente dentro del ámbito de la Atención Primaria. Un gran número de estos pacientes va a evolucionar por diferentes motivos, a la pérdida de la vía oral como método de administración de fármacos. En estos casos, el método de elección va a ser la vía subcutánea. Ésta es una vía de utilización sencilla, que presenta pocas complicaciones y permite al enfermo continuar en su domicilio, mejorando así su calidad de vida.