Quantitative analysis of potentially toxic metals in alginates for dental use

Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closed-system microwave oven. Aqua regia (4mL concentrated HCI:HNO3, 3:1 v/v) and hydrofluoric acid (2mL concentrated HF) were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them.

Contar con todos: caja de herramientas para la inclusión de pueblos indígenas y afrodescendientes en los censos de población y vivienda

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Serological survey of Toxoplasma gondii in captive Neotropical felids from Southern Brazil

Toxoplasma gondii is the causative intracellular protozoan of toxoplasmosis in human being and animals. Members of the Felidae family are considered the single definitive host for the infection; both wild and domestic cats are able to excrete oocysts in the environment. Wild cats maintained in captivity may serve as source of infection for other clinically susceptible animals in the same environment. The aim of this study was to determine the frequency of T. gondii IgG antibodies in 57 neotropical felids (1 Leopardus geoffroyi; 3 Puma yagouaroundi; 17 Leopardus wiedii; 22 Leopardus tigrinus; and 14 Leopardus pardalis) kept at the Bela Vista Biological Sanctuary, Itaipu Binacional, Southern Brazil, by the modified agglutination test (MAT) using titer 16 as cut-off point. Seropositivity was observed in 38/57 (66.67%; 95% CI 53.66-77.51%) samples, with higher frequency in ocelots (71.43%). Wild-caught felids were three times more likely to be infected when compared to zoo-born animals (P≤ 0.05) and age of wild-caught animals (P= 0.6892; 95% CI. = 0.7528-1.66) was not significant as a risk factor for the infection, the same occurring with zoo-born animals (P= 0.05; 95% CI. = 0.6267-24.052). These results suggest that, despite efforts to control T. gondii infection in zoo facilities, such as individual pens, hygiene monitoring, veterinary care and pre-frozen meat offered as food, non-domestic felids kept in captivity, particularly the wild-caught specimens, may be invariably exposed to infection due to other environmental sources. © 2010 Elsevier B.V.

Relevancia y pertinencia de la información sociodemográfica para políticas y programas: el caso Guatemala

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Comercio intraindustrial entre las economías de Asia y el Pacífico y la Alianza del Pacífico, 2007-2011

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Gestión urbana: recuperación del centro de San Salvador, El Salvador: Proyecto Calle Arce

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Un marco de análisis para el fomento de las políticas de desarrollo productivo con enfoque de género

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Sector financiero y empleo femenino. El caso uruguayo

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Identidades y sentido de pertenencia y sus tensiones contemporáneas para la cohesión social: ¿del derrotero a las raíces y

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Nicaragua: ¿país de emigrantes?

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Evasión fiscal en México

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Ponencia de las actividades de información sobre población en la Secretaría de Planificación y Presupuesto (SPP) de la República de Nicaragua

Contiene las actividades sobre población de la Secretaría a traves de su Centro de Documentación, que en conjunto con el Instituto Nacional de Estadística y Censos desarrolló el Sistema Integrado de Información y Documentación en Población (SIDOP). Analiza la informacion sobre población utilizada y generada por las unidades de información bibliográfica y procesamiento de datos de la Institución. Presenta sugerencias sobre cooperación inter-institucional y regional.

O teatro experimental do negro -: estudo da personagem negra em duas peças encenadas (1947-1951)

Pós-graduação em Artes - IA

Leituras urbanas: torre de antena de rádio e televisão da TV Cultura e o bairro do Sumaré

Pós-graduação em Artes - IA

Nicaragua: características de la migración internacional; trabajo final

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