Uso de métodos químicos para obtener polvos cerámicos del sistema (Sn, Ti)O2

The (Sn,Ti)O2, system has a great interest due to its technological applications such as gas sensor and varistor. Although the thermodynamic properties and the kinetics of spinoidal decomposition in this system have been extensively studied, the general properties and applications of SnO2 - TiO2 binary compositions have been not investigated yet in depth. On the other hand, little work has been done to optimize the synthesis methods to obtain (Sn,Ti)O2 cerallmic powders, with pre - determinate physical and chemical characteristics. In this work the ceramic powders has been obtained by coprecipitation and polymeric precursor (Pechini) methods. The different physical chemistry phenomena that occurred during the synthesis were discussed. The (Sn,Ti)O2, ceramic powders were characterized with X- ray diffraction (XRD), thermal analysis (DTA/TG) and scanning electron microscopy (SEM). The knowledge about of steps and variables of synthesis process acquired with development of this work, we permited to obtain (Sn, Ti)O2, nanometers particles to low temperatures: to 450°C for coprecipitation method and to 600°C for Pechini method. The spinodal decomposition that ocurr to 900°C was discussed also.

Respuesta eléctrica de películas gruesas del sistema SnO2-TiO2, conformadas con polvos cerámicos obtenidos a través del método pechini

Tin oxide is the compound more used in the gas sensor production, mainly to reduce gases like CO and H2. Their electrical properties are strongly dependent of its surface. For this is of great importance to synthesize nanoscale tin oxide particles to use they later in the films conformation. The synthesis of SnO2-TiO2 nanoparticles by polymeric precursor method is reported in this work. The particles were characterized by DTA/TG, FT-IR, XRD and SEM. Also, the electrical response of thick films measured under oxygen and carbon monoxide atmospheres is was analyzed.

Material de risco específico no abate de bovinos

La Encefalopatía Espongiforme Bovina (EEB) es una enfermedad degenerativa mortal y transmisible del sistema nervioso central del ganado, con largo período de incubación y clínicamente se caracteriza por sintomas nerviosos, la reacción exagerada a los estímulos externos y dificultad locomoción. La EEB es una enfermedad del grupo de las Encefalopatías Espongiformes Transmisibles (EET), y consiste en una enfermedad zoonótica transmitida por comer alimentos contaminados con una proteína llamada príon. Se discute el control de enfermedades, celebrada en la carne de vacuno refrigerada masacre a través de las Material Especificado de Riesgo (MER) que son el cerebro, cráneo, ojos, amígdalas, médula espinal, gânglio del trigémino, gânglios de la raiz dorsal y el íleon distal. Estos organismos pueden contener el agente de la EEB y transmitir la enfermedad. Los controles se basan en la ley brasileña y las normas internacionales que dictan la recogida y destrucción de estos materiales, sino también las normas para la comercialización de productos procedentes de rumiantes, así como la prohibición de alimentar rumiantes com productos de origen animal

Evaluación comparativa in vitro de la capacidad de sellado del sistema de conductos radiculares por diferentes técnicas

The aim of this study was to evaluate in vitro the sealing ability of the root canal using different techniques: cold lateral compaction, modified Hybrid Tagger, Thermafil and System B. Material and methods. Were used 116 human single-roots, included in resin blocks, sectioned longitudinally, attached to a device with screws and divided into four groups (n=29). After instrumentation using a bur, depression was made in each third of the root canal in each of the halves. Teeth were filled upon the different techniques. For evaluation of the quality, pictures were taken with a 1.5X magnification, photos and radiographs were utilized. After statistical analysis, were performed both macroscopic and radiographic evaluation, by Chi-square test (χ2). Results. The Thermafil technique showed better results in terms of sealing capacity, failures and homogeneity followed by modified Hybrid Tagger, the System B and cold lateral compaction. Conclusions. Thermafil was the technique that shown to be macroscopic, radiographic and homogeneously best over the other techniques evaluated in regard to the filling of the depressions made (AU)

Acogimiento en el proceso de formación de los odontologos en Brasil: un analisis en el contexto del Sistema Unico de Salud (SUS)

To define the profile of Dentistry’s academics, on the welcoming reception of patients/users attended in the Public Institution, under the guidelines of the SUS. Methods: A structured questionnaire was applied to 163 students, which contained questions that covered five variables (reception, dialogue and listening, action and care first contact, professional identity) and conducted an interview to associate to responses obtained during the first phase. Quantitative data were tabulated and analyzed by descriptive statistics in SPSS 16.0 and qualitative data analyzed through discourse of the collective subject. Results: It was observed that, intellectually, the most of student (70.7%) understand the concept and the repercussion of the welcoming reception process in health and many have caring characteristics. However, the pedagogic system formation makes it difficult or systemizes an integral and spontaneous welcoming action. Conclusions: The academics have the embracement profile but it is need more motivation in the humanization of the university teaching.

Doença cerebelar em cães e gatos

Diseases of the cerebellar system are common in small animals, and result in a clinical syndrome characterized by hypermetria, base-wide stance and intentional tremors of the head and body. All movements of the limbs are spastic and awkward. The neurological examination assists in the localization of lesions restricted to the cerebellum or in the detection of disorders relating to other parts of the nervous system, which characterizes a multifocal disease process. Neurological disorders in dogs and cats may suggest a very extensive list of differential diagnoses, since they may be caused by infectious, degenerative and traumatic processes, among others. The possible etiologies for cerebellar syndrome include: aplasia and hypoplasia, abiotrophy, cancer, vascular stroke and inflammatory disorders. The aim of this paper is to review the clinical signs that aid in the location of the cerebellar lesion and discuss the possible causes of this syndrome in dogs and cats.