Trace analysis of environmental matrices by large-volume injection and liquid chromatography-mass spectrometry

The time-honored convention of concentrating aqueous samples by solid-phase extraction (SPE) is being challenged by the increasingly widespread use of large-volume injection (LVI) liquid chromatography–mass spectrometry (LC–MS) for the determination of traces of polar organic contaminants in environmental samples. Although different LVI approaches have been proposed over the last 40 years, the simplest and most popular way of performing LVI is known as single-column LVI (SC-LVI), in which a large-volume of an aqueous sample is directly injected into an analytical column. For the purposes of this critical review, LVI is defined as an injected sample volume that is ≥10% of the void volume of the analytical column. Compared with other techniques, SC-LVI is easier to set up, because it requires only small hardware modifications to existing autosamplers and, thus, it will be the main focus of this review. Although not new, SC-LVI is gaining acceptance and the approach is emerging as a technique that will render SPE nearly obsolete for many environmental applications.In this review, we discuss: the history and development of various forms of LVI; the critical factors that must be considered when creating and optimizing SC-LVI methods; and typical applications that demonstrate the range of environmental matrices to which LVI is applicable, for example drinking water, groundwater, and surface water including seawater and wastewater. Furthermore, we indicate direction and areas that must be addressed to fully delineate the limits of SC-LVI

A school-based oral health educational program: the experience of Maringa- PR, Brazil Programa educacional em saúde bucal baseado em escolas: a experiência de Maringá- PR, Brasil

The main purpose of this study was to evaluate the preliminary results of a school-based oral health educational strategy adopted in public primary schools from the city of Maringa, State of Parana, Brazil. The study sample was composed by 556 children and adolescents aged 6 to 17 years old, 124 schoolteachers and a group of 55 mothers. The educational approach was implemented for 18 months and consisted of reinforcements of interventions addressed to students and schoolteachers at school level and few activities targeted at the mothers, performed by means of home visits. Baseline and follow-up interviews focused on oral health care were undertaken for the entire study population. As a stimulus for the students to achieve proper oral hygiene habits, the simplified oral hygiene index was assessed at three different moments. A statistically significant improvement in their oral hygiene index (p<0.001) was recorded. The results achieved suggest an encouraging tendency towards the improvement in the levels of oral health care among the school-age youths studied. They also point out the need of intensifying the preparation of schoolteachers in oral health topics, as well the instructions to the mothers for their oral health care. Moreover, they highlight the importance of the continuous implementation of school-based programs to promote the oral health.<br>O principal propósito deste estudo foi avaliar os resultados preliminares de uma estratégia educacional baseada em escolas sobre saúde bucal adotada em escolas públicas de ensino fundamental da cidade de Maringá, estado do Paraná, Brasil. A amostra de estudo foi composta por 556 crianças e adolescentes entre 6 e 17 anos de idade, 124 professoras e um grupo de 55 mães. A abordagem educacional foi implementada por um período de 18 meses e consistiu de reforços das intervenções educativas dirigidas aos estudantes e professores a nível escolar e de poucas atividades tendo como alvo as mães, desenvolvidas através de visitas domiciliares. Entrevistas iniciais e de acompanhamento focando cuidados em saúde bucal foram realizadas com toda a população de estudo. Como um estímulo aos estudantes para assumirem hábitos apropriados de higiene bucal, o índice de higiene oral simplificado foi avaliado em três diferentes momentos. Uma melhora estatisticamente significante em seus índices de higiene oral (p< 0,001) foi registrada. Os resultados alcançados sugerem uma encorajadora tendência de melhoria nos níveis de cuidados em saúde bucal entre os jovens em idade escolar estudados. Eles, também, apontam para a necessidade de se intensificar o preparo das professoras em tópicos relacionados à saúde bucal, bem como a instrução das mães para os cuidados apropriados com a saúde bucal. Além disso, eles evidenciam a importância da contínua implementação de programas baseados em escolas para a promoção da saúde bucal

Iulii Obsequentis Prodigiorum liber ... / per Conradum Lycostenem... integritati suae retitutus. Polydori Vergilii... De Prodigiis libri III. Ioachimi Camerarii... De Ostentis libri II

Marca tip. a la port. - Capll. ornade