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Liberación de iones metálicos en el medio bucal por fenómenos de corrosión de aleaciones. (Velazco de Maldonado, Gladys y Weinhold, Elkis) Resumen Algunas aleaciones presentan problemas de corrosión mediante los cuales se liberan los iones metálicos que las componen al medio bucal. A pesar de esto no existe en Venezuela control riguroso o regulación de los metales usados particularmente en ortodoncia. Se han escrito varios artículos sobre una serie de alteraciones que oscilan desde alergias hasta necrosis tisulares, causadas por la presencia de elementos metálicos. Cuando se refiere a ciencias de la salud, es de hacer notar la cantidad de metales que introducimos al organismo humano y que pudiesen desatar problemas de hipersensibilidad en los pacientes. Abstract The corrosive process on some alloys used in odontology, can release metallic ion into the bucal media. In Venezuela there are not regulations about the particular use of metals in orthodontia. Many authors are write several articles about allergic and tissular necrosis alteration by presence of metallic elements. In medical science are big uses of metals into the organism and may be caused hypersensitivity problems in people. weinhold@ula.ve gvelazco@ula.ve Nivel monográfico

Asociaciones clínicas de hipersensibilidad tipo IV en un paciente sometido a tratamiento protésico. (Velazco de Maldonado, Gladys; Weinhold, Elkis y Alfonso, Reina) Resumen El propósito fundamental de este reporte radica en la importancia de reconocer las posibles implicaciones clínicas, relacionadas con la sensibilización a la que puede esta sujeto un paciente portador de una prótesis en odontología. Los estudios realizados en pacientes hipersensibles permiten diagnosticar, a un paciente portador de una prótesis parcial removible y coronas combinadas con una reacción de hipersensibilidad retardada mediada por células. Al analizar el caso y posterior a la realización de pruebas clínicas, microbiológicas, gravimetricas y químicas se detecto que, la paciente portadora de dichas estructuras padecía alteraciones por reacciones de hipersensibilidad tipo IV. Cabe destacar el hecho de la importancia de que el clínico evaluador y protesista conozca a fondo los problemas que puede acarrear dicha patología. Reporte del caso. Clinical associations of hypersensitivity type IV in a patient submissive treatment protésico. (Velazco de Maldonado, Gladys; Weinhold, Elkis y Alfonso, Reina) Abstract The fundamental intention of this report is in the importance of recognizing the possible clinical implications, related to the sensibilización to which a carrying patient of a prótesis in odontolgy can this subject. The studies made in hypersensible patients allow to diagnose, to a carrying patient of a removible partial prótesis and crowns combined with a reaction of hypersensitivity slowed down half-full by cells. When analyzing the later case and to the accomplishment of clinical, microbiological, gravimetricas and chemical tests I detect that, the carrying patient of these structures suffered alterations by reactions of hypersensitivity type IV. It is possible to emphasize the fact of the importance that the clinical evaluador and protesista knows the problems thorough that can carry this pathology. Report of the case. gvelazco@ula.ve weinhold@ula.ve reinaalf@ula.ve Nivel monográfico

Optimum phase-behavior formulation of surfactant/oil/water systems for the determination of chromium in heavy crude oil and in bitumen-in-water emulsion. (Burguera, José L.; Ávila G., Rita M.; Pascu de Burguera, Marcela; Antón, Raquel E.; Salager, Jean Louis; Bracho P., Carlos L.; Burguera Pascu, Margarita; Burguera Pascu, Constantin R.; Brunetto, Rosario; Gallignani, Maximo A.; Petit de P., Yaneira) Abstract An "oil in water" formulation was optimized to determine chromium in heavy crude oil (HCO) and bitumen-in-water emulsion (Orimulsion-400®) samples by transversally heated electrothermal atomic absorption spectrometry (TH-ET AAS) using Zeeman effect background correction. The optimum proportion of the oil-water mixture ratio was 7:3 v/v (70 ml of oil as the internal phase) with a non-ionic surfactant concentration (lntan-l00) in the emulsion of 0.2% w/w. Chromium was determined in different crude oil samples after dilution of the emulsions 1:9 v/v with a 0.2°/, w/w solution of surfactant in order to further reduce the viscosity from 100 to 1.6 cP and at the same time to bring the concentration of chromium within the working range of the ET AAS technique. The calibration graph was linear from 1.7 to 100 gg Cr 1- t. The sensitivity was of 0.0069 s 1 µg- ', the characteristic mass (mo) was of 5.7 pg per 0.0044 s and the detection limit (36) was of 0.52 pg 1-'. The relative standard deviation of the method, evaluated by replicate analyses of three crude oil samples varied in all cases between 1.5 and 2.6%. Recovery studies were performed on four Venezuelan crude oils, and the average chromium recovery values varied between 95.9-104.8, 90.6-107.6, 95.6-104.0 and 98.8-103.9% for the Cerro Negro, Crudo Hamaca and Boscan crude oils and for the Orimulsion®-400, respectively. The results obtained in this work for the Cerro Negro, Crudo Hamaca and Boscan crude oils and for the Orimulsion('~-400 following the proposed procedure were of 0.448±0.008, 0.338±0.004 0.524±0.021 and 0.174±0.008 mg Cr 1-t, respectively, which were in good agreement with the values obtained by a tedious recommended standard procedure (respectively: 0.470±0.05, 0.335±0.080, 0.570±0.021 and 0.173±0.009 mg Cr 1-t). CC) 2003 Elsevier B.V. All rights reserved. Artículo publicado en: Talanta 61 (2003) 353-361 burguera@ula.ve pascu@ula.ve ritaavila@ucla.edu.ve salager@ula.ve bracho@ula.ve rantons@cantv.net ypetit@ula.ve Nivel monográfico

Resumen temporalmente no disponible. La presente obra no cuenta con resumen provisto por el autor. Fil: Finkelstein, Sara Claudia. Universidad de Buenos Aires. Facultad de Filosofía y Letras.

Artículo publicado en: Saber, Universidad de Oriente, Venezuela. Vol. 18. Nº 2: 220-226. (2006) Venezuela vive un momento histórico caracterizado por cambios de tipo social, económico y tecnológico; haciendo este último necesario que los entornos educativos evolucionen y se actualicen adaptándose a este nuevo modelo de sociedad, llamado Sociedad de la Información. Dentro de este contexto de cambios, el docente necesita ser eficiente en el uso y aprovechamiento de las nuevas tecnologías de la información y la comunicación (NTIC) como herramienta de trabajo y crecimiento académico. En este sentido, el objetivo de ésta investigación de campo fue determinar el uso de computadores personales y la Internet en los docentes de Inglés en los Institutos de educación pública del municipio Candelaria durante el año escolar 2004-2005. Los datos se recolectaron a través de un cuestionario estructurado con 14 itemes dicotómicos validado por expertos en investigación. Los resultados mostraron que los docentes hacen uso muy limitado de las NTIC, orientado básicamente a registros de notas en computador personal y destacando el uso de correo electrónico como razón principal de su conexión a Internet. De igual forma, se encontró que la mayoría de los docentes desconoce direcciones electrónicas relacionadas con su quehacer profesional docente. Se concluyó que existe la necesidad de promover el uso de la tecnología (computador personal e Internet) y se presentan ideas factibles para favorecer el uso de las NTIC por parte de los profesores. Venezuela is experiencing social, economic, and technological changes of historical significance that are making it necessary to adapt the educational environment to the new societal model known as Information Society. Teachers today must be efficient in the use and application of the new technologies of information and communication (NTIC) as working and academic development tools. This research aimed at assessing the use of computers and the Interned by public school English teachers in the Candelaria municipality during the school year 2004-2005. Data were collected by use of a questionnaire comprising 14 dichotomic items validated by research experts. The results revealed that teachers make limited use of NTIC. Computers are mainly used for recording grades, and emailing stands out as the principal objective of Internet access. Most teachers do not avail themselves of the advantages of links and addresses pertaining to their professional teaching endeavors. There is an imperative need to promote the use of NTIC by high school teachers of English. 220-226 bexi@ula.ve

Artículo publicado en: Information Resources Management Association, IRMA. http://www.irma-international.org/proceeding-paper/methodology-educational-software-evaluation-ese/32962/ The pace to which the new technologies are being included in the educational context demand from teachers to develop skills to use technology and to evaluate educational software. Hence, the use given to technology for educational purposes will greatly depend on teachers’ knowledge and management of it. Our objective is to propose a methodology for educational software evaluation (ESE) that includes four criteria (technical, didactic, functional and economical) as well as seven techniques for ESE. Finally, a complete model of the integration of those aspects in six steps to follow in any evaluation process is presented. This methodology can be defined as a whole, simple, qualitative approach, suitable for the evaluation of software of any subject and easy to use even by inexperienced teachers. The authors do not expect this methodology to be a unique formula for ESE but to offer a guideline for teachers to perform the task. It will be the teacher’s decision to adapt this model to his group’s needs, pedagogical approach and goals. 939-941 bexi@ula.ve norelkys@ula.ve, norelkyse@yahoo.com