In this study, tubular ceramic membranes were prepared from a mixture of ball clay, talc and alumina. The mixture was characterized by the following techniques: particle size analysis, X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD) and thermal analysis. Tubular membranes were produced by extrusion process and thermal treated at temperatures between 1025 °C and 1175 °C. The membranes were characterized by XRD, linear shrinkage, apparent porosity, flexural strength, mercury porosimetry, scanning electron microscope (SEM) and contact angle. To evaluate the efficiency of the membranes, permeability tests with distilled water and oil-in-water emulsion were conducted in a tangential flow system. The results showed that the sintering of the specimens promoted the formation of α-cordierite phase and directly influenced the physical and mechanical properties such as linear shrinkage, porosity and flexural strength. Separation tests revealed that these membranes promoted high oil-water separation efficiency with values above 99.0%.

Resumen El objetivo principal de la investigación fue conocer la relación entre el estrés parental y las actitudes de las madres solteras hacia la relación con sus hijos. El trabajo tuvo un enfoque cuantitativo, con alcance correlacional, diseño no experimental transversal y una muestra conformada por 104 madres solteras de la ciudad de Lima, Perú. La información fue recolectada con el cuestionario de estrés parental y con el inventario de relaciones padre-hijo, ambos instrumentos adaptados al contexto peruano. Los resultados indican que la correlación entre el estrés parental y la actitud hacia la relación con sus hijos es negativa (-.65), esto indicaría que a mayor estrés las madres solteras manifiestan menos apoyo a los hijos, baja satisfacción, compromiso, comunicación y autonomía, no establecen limites y presentan baja deseabilidad social. Se observó que las mujeres con educación superior, con más de 40 años y con apoyo externo en la crianza presentan menos estrés. Además, las madres con educación superior y apoyo externo presentan más actitudes positivas hacia la crianza.

Resumo A finalidade da investigação foi a de conhecer a relação entre o estresse parental e as atitudes de mães solteiras em relação a dos filhos. A investigação foi quantitativa, correlacional, não experimental, transversal e com uma amostra de 104 mães solteiras de Lima, Peru. As informações foram coletadas com o questionário de estresse parental e com o inventário das relações pai-filho, ambos instrumentos adaptados ao contexto peruano. Os resultados indicam que a correlação entre o estresse parental e as atitudes de mães solteiras em relação a dos filhos é negativa (-.65), isso indicaria que quanto maior o estresse das mães solteiras, elas mostram menos apoio aos filhos, baixa satisfação, comprometimento, comunicação e autonomia, não estabelecem limites e têm baixa desejabilidade social. Observou-se que mulheres com ensino superior, com mais de 40 anos e com apoio externo na criação têm menos estresse. Além disso, mães com ensino superior e apoio externo têm atitudes mais positivas em relação a criação.

Abstract The main purpose of the research was to know the relation between parental stress and the attitudes of single mothers towards relationship with children. The research was quantitative, correlational, non-experimental, cross-sectional and with a sample of 104 single mothers from Lima, Peru. The information was collected with the Parenting Stress Index and with the Parent-child relationship inventory, both questionnaires adapted to the Peruvian context. The results indicate that the correlation between parental stress and the attitudes of single mothers towards relationship with children is negative (-.65), this would indicate that the greater the stress of single mothers, they show less support for their children, low satisfaction, commitment, communication and autonomy, they don't set limits and have low social desirability. It was observed that women with higher education, with more than 40 years and with external support in raising have less stress. Furthermore, mothers with higher education and external support have more positive attitudes towards parenting.

ResumenEn este artículo los autores presentan resultados de curvas de compactación de suelos finos que fueron determinadas con un compactador giratorio. Se muestra cómo varía la curva de compactación dependiendo de las variables controladas en el equipo giratorio durante la compactación (presión vertical, ángulo de giro y velocidad a la que se aplican los giros). Se llevaron a cabo comparaciones entre las curvas de compactación obtenidas por métodos tradicionales y las obtenidas con el compactador giratorio, encontrándose que la curva de compactación Proctor estándar se puede obtener si el suelo colocado en el equipo giratorio se densifica con 200 giros, con 1.25 grados de inclinación del molde y si se aplica una presión vertical de 200 kPa.Con respecto a la curva Proctor modificada, ésta no se logró obtener para ningún suelo con la combinación de variables estudiadas, al parecer se requiere de una presión vertical mayor a 800 kPa para alcanzar los pesos volumétricos secos de dicha curva. En la investigación también se estudió el efecto del tipo de compactación (dinámica y por medio del compactador giratorio) en el módulo de resiliencia y la resistencia en compresión simple de muestras compactadas en el óptimo, 2% debajo del óptimo y 2% por arriba del óptimo. Los resultados indicaron que ambos parámetros dependen del tipo de compactación cuando las muestras compactadas tienen un contenido de agua inferior al óptimo.

AbstractThe authors present a series of compaction curves obtained in fine-grained soils through use of a gyratory compactor. The effect on compaction curves of variables such as vertical pressure, angle of gyration, and speed of gyration is shown. The curves obtained with the gyratory compactor were compared with those obtained using traditional methods of compaction (Proctor standard and modified compaction). It was observed that the standard compaction curve can be obtained with 200 gyrations, 1.25 degrees of angle of gyration, and a vertical pressure of 200 kPa. On the other hand, with the combination of variables studied in this research, modified compaction curves could not be reached. Tests were also performed to measure resilient modulus and unconfined compression strength on specimens prepared at optimum compaction conditions, 2% below the optimum and 2% above the optimum (for Proctor standard tests) using two methodsofcompaction.The results indicate that unconfined compression strengths and resilient modulus are related to the compaction method when samples are compacted at water content below optimum.

O Brasil é o maior produtor de citros do mundo, sendo responsável por mais de 20% de sua produção. No entanto, a produção ainda é baixa, em decorrência de problemas fitossanitários, como o Declínio do Citros que é uma anomalia cuja causa ainda não foi determinada e, consequentemente, não existem medidas de controle para minimizar as perdas na produção. O uso de variedades resistentes é considerado como a medida de controle mais adequada. Contudo, pouco se conhece sobre os genes envolvidos na resposta de defesa das plantas a essa anomalia. Considerando que muitas alterações fisiológicas associadas com respostas a estresses em plantas são controladas em nível transcripcional, neste estudo objetivou-se a identificação e caracterização dos produtos de expressão gênica diferencialmente expressos na resposta ao Declínio dos Citros. Por meio da técnica de hibridação subtrativa supressiva, bibliotecas de cDNAs expressos foram construídas utilizando mRNAs isolados de raízes de limoeiro "Cravo" (Citrus limonia L. Osbeck) sob laranja "Pera" (Citrus sinensis L. Osbeck) de plantas sadias e doentes. Cento e vinte e nove clones foram obtidos por subtração e suas sequências foram comparadas em bancos de dados. Trinta e quatro delas relacionaram-se a proteínas associadas a processos de estresses, enquanto as outras foram similares a sequências de funções desconhecidas ou não apresentaram similaridade com sequências depositadas nos bancos de dados. Três genes foram selecionados e suas expressões foram estudadas por RT- qPCR em tempo real. Plantas com Declínio dos Citros apresentaram um aumento no nível de expressão em dois desses genes, sugerindo que estes podem estar diretamente envolvidos com essa anomalia.

Brazil is the largest citrus producer in the world, being responsible for more than 20% of its production, which is, however still low due to phytosanitary issues such as citrus blight. Citrus blight is an anomaly whose causes still have not yet been determined, therefore there are no efficient control measures to minimize the production losses with the use of resistant varieties being considered the most appropriate method. However, little is known about the genes involved in the defense response of the plants to this anomaly. Considering that many physiological alterations associated with plant stress responses are controlled at a transcriptional level, in this study we sought the identification and characterization of the gene expression products differentially expressed in the response to the citrus blight. Through the suppressive subtractive hybridization technique, expressed cDNA libraries were built using mRNAs isolated from "Cravo" lemon tree roots (Citrus limonia L. Osbeck) under "Pera" orange (Citrus sinensis L. Osbeck) of healthy and sick plants. 129 clones were obtained by subtraction and their sequences were compared in databases. 34 of them linked to proteins associated to stress processes, while the others were similar to sequences of unknown functions or did not present similarity with sequences deposited in the databases. 3 genes were selected and their expressions were studied by RT - qPCR in real-time. Plants with citrus blight presented an increase of the expression level in two of those genes, suggesting that these can be directly involved with this anomaly.

A study on the interactions among the sociocultural context, science and technology in the emergence and development of a novel therapeutic scientific procedure: Continuous Arteriovenous Hemodyalisis is carried out, as well as the possible social, economic and scientific impacts of the application of this new technology. It is concluded that the technological-scientific development reached around the Second World War, as well as the high mortality among wounded soldiers with acute renal insufficiency played an important role in the emergence of hemodialysis. The economic advantages that the application of this procedure offers makes very useful its application in Cuba and other developing countries that don't have access to expensive capitalist technologies. The Cuban pattern for the construction of socialism, with its wide vision of science, technology and society, offers effective answers to the technological-scientific challenge that underdeveloped countries face

Se realiza un estudio sobre las interacciones entre el contexto sociocultural, la ciencia y la tecnología en el surgimiento y desarrollo de un novedoso procedimiento científico terapéutico: La Hemodiálisis Arteriovenosa continua, así como los posibles impactos sociales, económicos y científicos que traería consigo la aplicación de esta nueva tecnología, se concluye que el desarrollo científico tecnológico alcanzado alrededor de la segunda guerra mundial, así como la alta mortalidad en heridos con Insuficiencia renal aguda jugaron un importante papel en el surgimiento de la hemodiálisis. Las ventajas económicas que ofrece la aplicación de este proceder hace muy útil su aplicación en Cuba y otros países en vías de desarrollo que no tienen acceso a las caras tecnologías capitalistas. El modelo cubano de construcción del socialismo con una visión amplia en ciencia, tecnología y sociedad, ofrece respuestas efectivas al desafío científico tecnológico que hoy enfrentan los países subdesarrollados

The results of the analysis of the literature and the experience of the authors on the approach of the evaluation of the quality of the medical interview are dealt with. The following theoretical foundations are defined: 1) the points of view on the dimensions to be evaluated in Donabedian's medical care quality; 2) the triangulation in the objectives of the anaylisis of quality (aids, methods and results); 3) the priority of the model of interview centered in the patient, a model that is more compatible with Engel's biopsychosocial paradigm; 4) the priority given to the educative function and the taking of the own student as a pattern, in addition to the objectives emerging from the social demands. All this is expressed in the evaluative objectives and in the selection of the evaluation method. It is recommended the direct observation with the utilization of other techniques guaranteeing a better evaluation of the internal medicine resident.

Se exponen los resultados del análisis de la literatura y la experiencia de los autores sobre el enfoque de la evaluación de la calidad de la entrevista médica. Se definen como fundamentos teóricos: 1) los puntos de vista sobre las dimensiones a evaluar en la calidad de la atención médica de Donabedian; 2) la triangulación en los objetivos de análisis de la calidad (medios, métodos y resultados); 3) la prioridad del modelo de entrevista centrado en el paciente, modelo más compatible con el paradigma biopsicosocial de Engel; 4) la priorización de la función formativa y la toma como patrón al propio educando, además de los objetivos que surgen de las exigencias sociales. Todo ello se traduce en los objetivos evaluativos y en la selección del método de evaluación.Se recomienda la observación directa con la utilización de otras técnicas que garanticen una mejor valoración de las actitudes del residente de Medicina Interna.

A study was conducted in a number of 219 patients who died due to bronchopneumonia at the clinical area of "Carlos J. Finlay" Central Military Hospital during the first semester of 1989 and 1994. The study was aimed at knowing the number of diagnoses made of this condition. The number of cases accounted for 28.9 % in 1989, 28.6 % in 1994, and 28.8 % in general. These values are found to be higher than those reported in the International Literature reviewed. It is concluded that it is necessary to increase the index of suspicion regarding bronchopneumonias in elderly patients in whom systemic manifestations predominate over the respiratory ones.

Se estudiaron 219 pacientes fallecidos por bronconeumonía en el área clínica del Hospital Militar Central "Carlos J. Finlay" durante el primer semestre de los años 1989 y 1994, para conocer el grado de error diagnóstico de esta afección. Este fue del 28,9 % en 1989, 28,6 % en 1994 y 28,8 % globalmente, valores que se encuentran algo por encima de lo reportado en la literatura internacional revisada. Se concluye que es necesario incrementar el índice de sospecha de las bronconeumonías en pacientes ancianos en quienes predominan las manifestaciones generales sobre las respiratorias.