Resumo Introdução O Ministério da Saúde (MS) é responsável pela vigilância da qualidade da água de consumo humano. A confiabilidade nos resultados do monitoramento de parâmetros analíticos minimiza riscos à saúde pública. Objetivo Retratar aspectos funcionais, a aplicação de ferramentas da qualidade e a aderência dos laboratórios públicos que atuam no monitoramento da água de consumo humano aos requisitos da norma ABNT NBR ISO/IEC 17025. Método A pesquisa foi realizada com 30 laboratórios públicos de todas as regiões do país, respondendo a um questionário elaborado com 49 perguntas sobre a formação e capacidade dos profissionais, garantia da validade dos resultados e sobre a determinação de parâmetros da qualidade da água. Resultados Dos 161 profissionais, 46% possuem mais de 10 anos de experiência e 65% têm formação superior. Capacitações específicas foram requeridas por todos. A validação dos métodos analíticos não foi realizada por 59%. Materiais de referência certificados são acessados por 41% e apenas 18% têm facilidade em adquiri-los. A participação em ensaios de proficiência foi reportada por 68% dos laboratórios, mas com poucos parâmetros avaliados e dificuldades em contratar provedores. Conclusão Evidenciou-se a necessidade de ações para fortalecimento da metrologia em laboratórios públicos que atuam na vigilância da qualidade da água.

Abstract Background The Ministry of Health (MS) is responsible for drinking water quality surveillance. Reliability in the results of monitoring analytical parameters minimizes public health risks. Objective To present functionals aspects and the application of quality tools by public laboratories that work to monitor the quality of drinking water. Method A survey was conducted with 30 public laboratories from all regions of the country, answering a questionnaire elaborated with 49 questions about the training and capacity of professionals, guaranteeing the validity of the results and about the determination of basic parameters of water quality. Results Of the 161 professionals, 46% have more than 10 years of experience and 65% have higher education. Specific training was required by everyone. The validation of the analytical methods was not performed by 59%. Reference materials are accessed by 41% and only 18% can acquire them easily. Participation in proficiency tests was reported by 68% of the laboratories, but with few parameters evaluated and difficulties in hiring providers. Conclusion The need for actions to strengthen metrology in public laboratories that work in water quality surveillance was highlighted.

Introduction: Globally, depression rates are high among men who have sex with men (MSM). Multiple factors may interact synergistically to increase this risk. This analysis assessed the prevalence of symptoms of depression among MSM in Brazil and synergistic effects of several factors. Methods: Cross-sectional study conducted in 12 cities using respondent-driven sampling. Sociodemographic and behavioral characteristics were collected. The PHQ-9 was used to screen for depression. Having moderate-severe depressive symptoms was compared to none-mild using logistic regression. The syndemic factor was a composite of hazardous alcohol use, sexual violence, and discrimination due to sexual orientation. Those with one to three of these factors were compared to those with none. Results: The weighted prevalence of moderate-severe depressive symptoms was 24.9% (95%CI = 21.8-28.8) and 16.2%, 22.9%, 46.0% and 51.0% when none, one, two, or three syndemic factors were present, respectively, indicating a dose-response effect. Perception of HIV risk, high level of HIV knowledge, known HIV infection, and health self-rated as poor or very poor were also associated with depressive symptoms. Conclusion: The prevalence of moderate-severe depressive symptoms among MSM in Brazil is high, and selected factors act synergistically in increasing their prevalence. Public health policies should consider holistic depression prevention and treatment interventions for this population.

Abstract The aim of this study was to obtain ionic quantification in periradicular medium after diffusion tests of the solution used inside root canals during the electrochemical dissolution of endodontic file fragments and the NiTi-containing dissolution product via an apical foramen. Thirty single-rooted extracted human teeth had root canals prepared and were attached to Eppendorf tubes filled with sterile saline. The samples were divided into 3 groups (n = 10) according to the solution used inside the root canal during the diffusion tests: Group 1: [NaF 12 g/L + NaCl 1 g/L]; Group 2: [NaF 12 g/L + NaCl 1 g/L + NiTi 0.50 g/L]; Group 3: [NaF 6 g/L + NaCl 0.5 g/L + NiTi 0.25 g/L]. The sample in each Eppendorf tube was then analyzed to assay the ionic quantification in periradicular medium. The groups were compared in relation to ionic quantifications (Kruskal-Wallis and Dunn’s tests, p ≤ 0.05). Group 2 showed significantly higher F-, Ni and Ti quantities than groups 1 and 3 (p < 0.05). Group 3 showed significantly higher Ti and Ni quantities than group 1, where no measurable quantities of Ti and Ni were observed (p < 0.05). The conclusions were that a 50% dilution of the NiTi-containing dissolution product resulted in significantly lower F-, Ni and Ti quantities compared to the undiluted product. The quantifications observed here suggest that irrigation is recommendable during the electrochemical dissolution process to reduce the resultant ion concentrations in both the root canal and the periradicular medium.

Resumen: El objetivo de este trabajo fue evaluar el potencial de un juego de senderos centrado en la piracema de especies nativas, migratorias y en peligro de extinción del río Pomba, en la Mesorregión Noroeste Fluminense. El trabajo se desarrolló en una clase de 7° grado de la escuela primaria en una escuela municipal de Santo Antônio de Pádua/ RJ. El juego consistió en un recorrido de 50 casas, cinco peones representando la especie de pez, un dado, un manual de reglas y 12 cartas. El objetivo del juego era llegar al nacimiento del río. Los peones caminaron según el número dibujado por el dado. Algunas casas en el sendero correspondían a hechos que representaron obstáculos o ayudas que tuvieron los peces durante la piracema. El juego fue ganado por ese peón que llegó primero a la fuente del río. Después de usar el juego, fue evaluado por 15 alumnos del 7º año de primaria. Los estudiantes respondieron un cuestionario con preguntas abiertas y cerradas. Las preguntas cerradas se evaluaron cuantitativamente y las preguntas abiertas se evaluaron mediante análisis de contenido y nube de palabras. La evaluación del juego por parte de los estudiantes permitió concluir que el juego cumplía su rol de recurso didáctico lúdico al tiempo que fomentaba la diversión y el aprendizaje. De las respuestas de los estudiantes al cuestionario, se puede concluir que fueron sensibilizados sobre los temas abordados en el juego, como la migración de peces reproductivos, la contaminación y la prohibición de la pesca durante la veda.

Abstract: The objective of this work was to evaluate the potential of a trail game focusing on the piracema of the native, migratory and endangered species of the Pomba River, in the Northwest Fluminense Mesoregion. The work was developed in a 7th year elementary school class of a municipal school in Santo Antônio de Padua/RJ. The game consisted of a trail of 50 houses, five pawns representing the species of fish, a board dice, a rule manual and 12 cards. The objective of the game was to reach the source of the river. The pawns walked according to the number drawn by the board dice. Some houses on the trail corresponded to events that represented obstacles or help that the fish had during the piracema. The game was won by that pawn who reached the source of the river first. After using the game, it was evaluated by 15 students from the 7th year of elementary school. The students answered a questionnaire with open and closed questions. The closed questions were evaluated quantitatively, and the open questions were evaluated by content analysis and word cloud. The students' evaluation of the game allowed us to conclude that the game fulfilled its role as a ludic didactic resource while promoting fun and learning. From the students' responses to the questionnaire, it can be concluded that they were sensitized to the issues addressed in the game, such as reproductive fish migration, pollution and fishing prohibition during the closed season.

Resumo: O objetivo desse trabalho foi avaliar o potencial de um jogo de trilha enfocando a piracema das espécies nativas, migradoras e ameaçadas de extinção do rio Pomba, na Mesorregião Noroeste Fluminense. O trabalho foi desenvolvido em uma turma de 7º ano do ensino fundamental de uma escola municipal de Santo Antônio de Pádua/ RJ. O jogo foi constituído por uma trilha de 50 casas, cinco peões representando as espécies de peixes, um dado, um manual de regras e 12 cartas. O objetivo do jogo era chegar à nascente do rio. Os peões andavam de acordo com o número sorteado pelo dado. Algumas casas da trilha correspondiam a eventos que representavam obstáculos ou auxílios que os peixes tinham durante a piracema. Vencia o jogo aquele peão que chegasse primeiro à nascente do rio. Após a utilização do jogo, ele foi avaliado por 15 alunos do 7º ano do ensino fundamental. Os alunos responderam a um questionário com perguntas fechadas e abertas. As questões fechadas foram avaliadas quantitativamente e as questões abertas foram avaliadas por análise de conteúdos e nuvem de palavras. A avaliação do jogo feita pelos alunos permitiu concluir que o jogo cumpriu seu papel de recurso didático lúdico promovendo simultaneamente a diversão e a aprendizagem. A partir das respostas dos alunos ao questionário pode-se concluir que eles foram sensibilizados com as questões abordadas no jogo, tais como migração reprodutiva dos peixes, poluição e proibição da pesca durante o período de defeso.

RESUMO Os resíduos agroindustriais são materiais alternativos de baixo custo e possuem um grande potencial como adsorvente de poluentes. Partindo desse princípio, o presente estudo avaliou o potencial da fibra do sisal como adsorvente de corante têxtil. Antes de proceder com os ensaios de adsorção, foram realizados estudos de cinética de secagem da fibra do sisal nas temperaturas de 60 °C e 80 °C. Na ocasião, o menor tempo do equilíbrio de secagem foi alcançado em 180 min na temperatura de 80°C. Com o intuito de alcançar melhores resultados, os dados de secagem foram ajustados aos modelos de Page, Henderson e Pabis, Newton O’Callaghan, Logarítmico e Midilli. Os resultados mostraram que o modelo de Midilli mostrou-se o mais adequado para o processo em ambas as temperaturas. Quanto aos ensaios de adsorção, eles foram realizados em banho finito em que, se utilizou 25 ml da solução com corante, 0,25 g da fibra do sisal e agitação de 120 rpm. No estudo da adsorção, aplicou-se um planejamento fatorial 2³ para avaliar a influência da concentração do corante, da temperatura de secagem e do tempo de contato no processo de adsorção. Os resultados das análises estatística do planejamento fatorial 2³, mostraram que todas as variáveis de controle estudadas influenciam o processo de adsorção. Os maiores valores das variáveis q (mg.g-1) e Remoção (%) foram 3,23 mg.g-1 e 64,52 % respectivamente. Partindo dos efeitos significativos, foi possível conceber modelos empíricos para as variáveis dependentes, já que, todas apresentaram significância estatística para um nível de confiança de 95 %. Os coeficientes de determinação para os modelos empíricos foram, 99,64 % e 96,44 % respectivamente. Diante dos resultados obtidos, as fibras do sisal se mostraram como um excelente adsorvente alternativo, para o tratamento de águas residuárias, contendo corante têxtil.

ABSTRACT Agroindustrial waste is a low cost alternative material and has great potential as a pollutant adsorbent. Based on this principle, the present study evaluated the potential of sisal fiber as a textile dye adsorbent. Prior to the adsorption tests, drying kinetics studies of the sisal fiber were performed at temperatures of 60 ° C and 80 °C. At the time, the shortest drying balance time was reached in 180 min at 80 °C. In order to achieve better results, the drying data were adjusted to Page, Henderson and Pabis, Newton O’Callaghan, Logarithmic and Midilli models. The results showed that the Midilli model was the most suitable for the process at both temperatures. As for the adsorption tests, they were performed in a finite bath in which 25 ml of the dye solution, 0.25 g of sisal fiber and agitation of 120 rpm were used. In the adsorption study, a 2³ factorial design was applied to evaluate the influence of dye concentration, drying temperature and contact time on the adsorption process. The results of the statistical analysis of the 2³ factorial design showed that all control variables studied influence the adsorption process. The highest values of the variables q (mg.g-1) and Removal (%) were 3.23 mg.g-1 and 64.52 % respectively. From the significant effects, it was possible to conceive empirical models for the dependent variables, since all presented statistical significance for a confidence level of 95 %. The determination coefficients for the empirical models were 99.64 % and 96.44 % respectively. In view of the results obtained, the sisal fibers proved to be an excellent alternative adsorbent, for the treatment of wastewater, containing textile dye.

Resumo O texto pretende descrever a mudança de perspectiva no ambiente de tutela dos direitos no Brasil ocorrida nos últimos anos, a partir da incorporação e fortalecimento de métodos consensuais de solução de conflitos. Sobretudo após a entrada em vigor do Código de Processo Civil de 2015 e da Lei 13.140/2015, denominada Lei de Mediação. Confere especial atenção à mediação de conflitos, haja vista a expectativa de que poderá proporcionar resolução efetiva para controvérsias por meio do restabelecimento do diálogo entre as partes envolvidas. A pesquisa combina revisão bibliográfica com percepções empíricas e propõe reflexões sobre dificuldades e obstáculos à efetivação dessas inovações legislativas.

Abstract The text aims to reflect on the changes in the environment of rights protection in Brazil, occurred in recent years, based on the incorporation and strengthening of consensual methods of conflicts resolution, especially after Federal Laws 13.105/2015 e 13.140/2015. Discussions will be focused on conflicts mediation, because of the expectation that it will be able to provide effective resolution to disputes, given the possibility of reestablishing dialogue between the parties involved. The research combines bibliographic review and empirical perceptions. It proposes reflections about some difficulties that were observed in some Brazilian procedural practices.

Resumo A trombose venosa superficial (TVS), também denominada de tromboflebite superficial, caracteriza-se pela formação de trombos dentro de veias superficiais, com suboclusão ou oclusão da luz e reação inflamatória no seu trajeto, sendo mais comum nos membros inferiores. Afeta de 3 a 11% da população geral. O diagnóstico costuma ser clinicamente fácil, mas sua extensão e possíveis complicações tromboembólicas precisam de exames subsidiários para confirmação. A TVS pode estar associada a trombose venosa profunda em 6 a 40% dos casos, a embolia pulmonar assintomática (EP) em 20 a 33%, e a EP sintomática em 2 a 13%. Apesar de sua morbidade e das suas complicações, ainda não existem diretrizes brasileiras para a TVS. Nesta diretriz, foram analisadas as principais dúvidas quanto à definição, terminologia e etiologia da TVS, com recomendações para seu diagnóstico e tratamento.

Abstract Superficial venous thrombosis (SVT) or superficial thrombophlebitis is characterized by thrombi within superficial veins, with partial involvement or occlusion of the lumen and inflammatory reaction along the course of the vein. Clinical diagnosis tends to be straightforward, but supplementary tests and examinations are needed to confirm thrombosis extension and possible thromboembolic complications. SVT can be associated with deep venous thrombosis in 6 to 40% of cases, with asymptomatic pulmonary embolism (PE) in 20 to 33%, and with symptomatic PE in 2 to 13%. Despite the morbidity and complications, there are currently no Brazilian guidelines for SVT. These guidelines cover the most important issues related to SVT definition, terminology, and etiology, and set out recommendations for diagnosis and treatment.

Abstract: The production of selenium and selenomethionine certified reference material in yeast (Saccharomyces cerevisiae) and certification studies for its homogeneity, stability and characterization, have been accomplished before in our laboratory. Based on such results and experience of our laboratory in Metrology and according to literature, we discuss here the advantages and limitations of the calibration by “single point” as an alternative method to the classical calibration curve. The method traceability to the SI is checked in order to secure a robust determination. As the model analyte the mass fraction of the Se species selenomethionine is measured and compared in yeast samples. Results showed that a good agreement was obtained by both methods (the reference one of the calibration curve and “single point calibration”). This simple approach can be used for routine control of selenomethionine in commercial supplements of yeast samples, but the work carried out demonstrated its potential for the general routine quantitative analysis of the possible and important selenium species in other Se-enriched supplements commercialised in Latin America (i.e. mushrooms, garlic etc).

Resumen: La producción de material de referencia certificado de selenio y selenometionina en levadura (Saccharomyces cerevisiae) y los correspondientes estudios de certificación de homogeneidad, estabilidad y caracterización, se han llevado a cabo con anterioridad en nuestro laboratorio. Basándonos en los resultados y la experiencia de nuestro laboratorio en Metrología y según la bibliografía, discutimos aquí las ventajas y limitaciones de la calibración de “un punto” como un método alternativo a la curva de calibración clásica. Se verificó la trazabilidad del método al SI para asegurar una determinación robusta. Como analito modelo, se determina la especie de selenio, seleniometionina, presente en muestras de levadura. Los resultados obtenidos por ambos métodos (curva de calibración y la calibración de “un punto”) muestran una buena concordancia. Esta aproximación simple demostró su utilidad para el control rutinario de selenometionina en suplementos comerciales de levadura y su potencial para el análisis cuantitativo rutinario general de las otras importantes especies de selenio de interés en otros suplementos enriquecidos en Se comercializados en Latinoamérica (es decir, champiñones, ajo, etc.)

RESUMO Objetivo: conhecer o perfil epidemiológico dos pacientes submetidos à cirurgia do carcinoma bem diferenciado da tireoide no Hospital Universitário Cassiano Antônio Moraes da Universidade Federal do Espírito Santo, assim como os resultados oncológicos e as principais complicações pós-operatórias. Métodos: estudo transversal e retrospectivo de pacientes portadores de carcinoma bem diferenciado da tireoide operados no período de janeiro de 2008 a dezembro de 2015. Resultados: no período do estudo, dos 353 pacientes submetidos a tratamento cirúrgico da glândula tireoide, 95 eram portadores de CBDT. O carcinoma papilífero da tireoide foi o mais frequente (91,57%). A tireoidectomia total não associada a esvaziamento cervical foi o procedimento cirúrgico mais frequente (65,26%). As complicações pós-operatórias ocorreram em 6,31% dos pacientes, sendo o hematoma a mais frequente. O tempo médio de seguimento foi de 36,9 meses. A recidiva ocorreu em quatro pacientes (4,21%), sendo locorregional em todos os casos. Os fatores prognósticos analisados, como sexo, idade, tamanho do tumor, acometimento linfonodal, estadiamento, tipo de cirurgia, histologia e iodoterapia complementar não demonstraram significância estatística. Conclusão: o carcinoma papilífero da tireoide foi a neoplasia maligna mais frequente, acometendo o sexo feminino na faixa etária dos 49 anos mais frequentemente. A recidiva locorregional ocorreu em quatro pacientes. O hematoma foi a complicação mais frequente.

ABSTRACT Objective: to know the epidemiological profile of patients undergoing surgery for well-differentiated thyroid carcinoma at the Cassiano Antônio Moraes University Hospital of the Federal University of Espírito Santo, as well as the oncological results and the main postoperative complications. Methods: we conducted a cross-sectional, retrospective study of patients with well-differentiated thyroid carcinoma (WDTC) operated from January 2008 to December 2015. Results: During the study period, 95 of the 353 patients undergoing surgical treatment of the thyroid gland had WDTC. Papillary carcinoma was the most frequent (91.57%). Total thyroidectomy not associated with cervical emptying was the most frequent surgical procedure (65.26%). Postoperative complications occurred in 6.31% of patients, hematoma being the most frequent. The mean follow-up time was 36.9 months. Relapse occurred in four patients (4.21%), being locoregional in all cases. The prognostic factors analyzed, such as gender, age, tumor size, lymph node involvement, staging, type of surgery, histology and complementary iodine therapy did not show statistical significance. Conclusion: papillary carcinoma was the most common thyroid malignant neoplasm, affecting women in the 49-year-old age group more frequently. Loco-regional recurrence occurred in four patients. Hematoma was the most frequent complication.

An assessment of mercury (Hg) concentrations and nitrogen stable isotope (δ15N) was conducted in the food chain of the Atlantic spotted dolphin (Stenella frontalis), including phytoplankton, zooplankton, planktivorous fish and its major prey (predatory fish and a single species of cephalopod), that compose a tropical trophic chain of the Brazilian southeastern coast. Tissue concentrations of Hg in a voracious predator fish, the largehead hairtail (Trichiurus lepturus), one of the dolphin's prey, were 9.8 times lower than median concentrations found in dolphin tissues. δ15N values in predatory fish were found to be lower to those of its predator the spotted dolphin. Isotopic data suggested significant differences for δ15N along the trophic chain, with the top predator (dolphin) exhibiting heavier value, followed by the voracious predator fish and the benthonic carnivorous fish, the whitemouth croaker (Micropogonias furnieri). Phytoplankton displayed the lightest δ15N, followed by zooplankton and the planktophagous fish, the lebranche mullet (Mugil liza). This fish species and the cephalopod showed the lowest median Hg concentration. All links of the entire trophic chain presented trophic transfer of Hg with a biomagnification factor higher than 1. A significant relationship was found between the log Hg concentration and trophic level (TL) of all evaluated species, with a positive slope (β= 0.87). The calculated trophic magnification factor (TMF= 7.44) indicates that Hg concentration increased per TL, and also that the entire coastal food chain from the South Atlantic Ocean presented a biomagnification power of Hg within a range previously reported for tropical coastal ecosystems.

Se realizó una evaluación de las concentraciones del mercurio (Hg) y del isótopo estable de nitrógeno (δ15N) en la cadena trófica del Delfín Moteado del Atlántico (Stenella frontalis), incluyendo fitoplancton, zooplancton, peces planctívoros y sus principales presas (peces depredadores y una sola especie de cefalópodo), componentes de una cadena trófica tropical de la costa sureste de Brasil. Una de las presas del delfín, un pez depredador voraz, el pez sable (Trichiurus lepturus), presentó una concentración mediana del Hg 9,8 veces inferior que la del delfín. El valor de δ15N es más bajo que al de su depredador. Los datos del isótopo han sugerido que ha habido diferencias significativas para el δ15N a lo largo de la cadena trófica, en la que en el mayor depredador (delfín) se ha mostrado más pesado, seguido por el pez depredador y el pez bentófago, la corvina (Micropogonias furnieri). Se ha observado que el fitoplancton presentó el δ15N más liviano, seguido por el zooplancton y el pez planctófago, el lebranche (Mugil liza). Este pez y el cefalópodo han mostrado la mediana más baja de Hg. Se han encontrado transferencias mayores que 1 en todos los vínculos de la cadena evaluada. Se ha obtenido una relación significativamente positiva entre la concentración del Hg (en logaritmo) y el nivel trófico (TL), incluyendo todas las especies investigadas, presentando una pendiente positiva (β= 0,87). El factor de magnificación trófica (FMT= 7,44) indica que la concentración del Hg ha aumentado per TL, y también que toda la cadena trófica costera presentó un poder de biomagnificación de Hg dentro de un rango previamente reportado para ecosistemas costeros tropicales.

The extraction of nutrients from the soil by plants depends on soil fertility, plant management and plant production. The objec-tive of this study was to evaluate the effect of the application of sources and doses of nitrogen on macronutrient extraction by Panicum maximum cv. Mombaga. The experiment was conducted from 1 October 2011 to 14 April 2012 in the Federal Institute of Espirito Santo, Santa Teresa Campus. The experimental design was a randomised block design with three repetitions in a 3 X 6 factorial scheme, with three nitrogen fertilisers (urea, ammonium sulphate and calcium nitrate) and six nitrogen doses (0, 120, 240, 360, 480 and 600 kg ha-1). The established nitrogen doses were divided equally and applied every 28 days after the mombaga grass was cut, resulting in a total of seven applications during the 196-day experimental period. It was observed than nutrient extraction depends on forage plant production and was highest with the higher doses of nitrogen because of the greater dry matter production. The application of high doses of nitrogen in the form of calcium nitrate caused a reduced absorption of magnesium. Nitrogen fertilisation in pastures should be accompanied by the management of other nutrients to avoid nutritional imbalances or the depletion of soil fertility.

Fast curing biocompatible adhesives are a promising alternative to the metallic devices used for immobilization of fractures of small bone fragments as well as for some maxillofacial surgical procedures. They may serve as supports during the curing process, and present some advantages with respect to conventional fixation methods by plates and screws, such as their ease of application and the biodegradability of the material. The objective of the present study is to analyze the literature about bone adhesives based on cyanoacrylates, presenting the characteristics of these biomaterials, as well as their advantages and disadvantages for the fixation of small bone fragments in maxillofacial surgery and orthopedics. Study of the bioactivity, degradability, in vitro cytotoxicity, in vivo implantation and adhesiveness of the materials evaluated reveal their biocompatibility and their capacity to bind bone tissue.

Los adhesivos biocompatibles de curado rápido son una alternativa promisoria para sustituir los dispositivos metálicos empleados en la inmovilización de fracturas de pequeños fragmentos óseos y en algunos procedimientos de cirugía máxilo-facial. Ellos tienen la capacidad de servir de soporte en el proceso de curación, aportan ventajas respecto a los métodos convencionales de fijación mediante placas y tornillos, tales como: su facilidad de aplicación y la biodegradabilidad del material. El objetivo del presente trabajo es analizar la literatura relacionada con los adhesivos óseos basados en cianoacrilatos, exponiendo las características de estos biomateriales, sus ventajas y desventajas para la fijación de pequeños fragmentos óseos en cirugía máxilo facial y ortopedia. Los estudios realizados de bioactividad, degradabilidad, citotoxicidad in vitro, implantación in vivo y adhesividad han demostrado que los materiales evaluados son biocompatibles y capaces de unir el tejido óseo.

ABSTRACT Barium (Ba) is a trace element which occurs predominantly as barite mineral (BaSO4) in the marine environment. Previous work suggests that barite concentrations are related to the organic carbon flux and marine biological debris in the water column suggesting a direct or indirect involvement in the marine biological cycling. In addition, barite has a high preservation rate (~30%) in sediments and it is less affected by early diagenesis than other proxies for productivity such as carbonates (~10%) and organic carbon (~1%), for example. Therefore, Ba is considered an excellent proxy for ocean (paleo)productivity. However, correlating barite to productivity involves some caveats. Specifically, the post-depositional formation of barite in oxic sediments can lead to Ba release into porewaters under anoxic conditions, which can form barite again under oxic conditions. This diagenetic formation is not correlated to export production as the seawater authigenic barite formed with decaying organic matter in the water column. Therefore, the main goal of this work is to briefly review the marine Ba cycle and highlight its importance for (paleo)productivity research.

Mercury distribution and fractionation were determined in sediments from the Paraíba do Sul River – RJ, Brazil. Total mercury concentration ranged from 1 to 158 ng g-1. Hg associated with the weakly bound fraction was dominant in the estuarine areas (main - 60% and secondary - 55%); followed by fluvial end member (48%) and mangrove (18%). These results reinforce the mercury availability to fluvial and estuarine areas and emphasize the key role played by mangroves as an efficient biogeochemical barrier. In conclusion, the continuous reduction of the mangrove ecosystem around the world can exacerbate the damage resulting from the mercury accumulation.