37 research outputs found

    A critical analysis of the sanitization strategies on root canal cleaning

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    Objective: To assess the efficacy of irrigant solutions used in endodontic treatment in terms of cleanliness, smear layer removal and tissue dissolving potency by means of a systematic review of longitudinal studies. Method: Articles were identified in electronic bibliographies accessible via MEDLINE. Searches were run on the PubMed Database (http://www.ncbi.nlm. nih.gov/PubMed) for articles published from 1966 to January 10, 2012, using combinations of the following keywords: (Endodontic or root canal) and (Smear layer or clean* or tissue dissolution or organic dissolution) and (irrigants or NaOCl or sodium hypochlorite or Milton Solution or Dakin solution or Labarraque solution or chlorinated soda or chlorine or chloride or hypoclean or hypochlor or niclor or Chlor-xtra or chlorhexidine or chx or cloreximid or peridex or periogard or EDTA or Acid or citric or acetic or peracetic or malic or vinegar or citrate or Hydrogen peroxide or H2O2 or Iodine or iodide or povidone or povidine or PVP or Ozone or ozonated or MTAD or Tetraclean or Endoptc or Rc prep or Morinda citrifolia or Aquatine or hydroxyethylcellulose or cat’s claw or propolis). Studies were assessed for inclusion and exclusion criteria by two independent examiners. Results: The search returned 817 articles. Four (04) studies met the preestablished inclusion criteria and not the exclusion criteria. Teeth were assessed histologically at points 1, 2 and 3 mm from the root apex. Sodium hypochlorite at 5.25% and 6% was the only irrigating solution for which there is scientific evidence of root wall cleaning activity. Conclusions: Addition of ultrasound improved the cleaning potency of irrigant solutions. Isthmus regions had the lowest percentages of area free from debris

    Uma coleção de história em um museu de ciências naturais: o Museu Paulista de Hermann von Ihering

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    Instalado em um edifício-Monumento, data de 1895 a inauguração do Museu Paulista. Seu primeiro diretor, o zoólogo Hermann Von Ihering (1895-1916), teve a tarefa de organizar suas vastas coleções, as quais possuíam objetos de diversos ramos do conhecimento, entre eles, a História. Este artigo tem a intenção de entender a dimensão, dinâmica e concepção desta coleção de História, que recebeu pouca atenção da Historiografia relativa ao tema.The Museu Paulista, installed in a landmark building, was inaugurated in 1895. Its first director, the zoologist Herman von Ihering (1895-1916) undertook the assignment of organizing its extensive collections, which comprehended objects pertaining to varied fields of knowledge, including that of History. The present article aims at understanding the dimension, the dynamics and the conception of this historical collection. Until now little attention has been bestowed upon this subject matter by the specialized historiography

    Antioxidant activity and acute toxicity of Neoglaziovia variegata (Bromeliaceae)

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    Antioxidant activities of Neoglaziovia variegata were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching and was compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The total phenolics content of the extracts was determined by the Folin-Ciocalteu method. Total flavonoid was also determined. The most significant total phenolic content was of 543.50 ± 9.38 mg of gallic acid equivalent/g for ethyl acetate extract (AcOEt), which presented the best antioxidant activity (IC50 5.08 ± 0.20 μg/ml) for DPPH scavenging. The acute toxicity of Nv-EtOH was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in mice. No mortality and no toxicity signs were observed, indicating low toxicity of the extract. Blood was removed after 14 days for laboratory analysis of hematological and biochemical parameters. Alterations of aspartate aminotransferase (AST) and creatinine were observed. The data obtained showed that the doses induced microscopic alterations in the liver and kidney. In conclusion, the Nv-EtOH can be considered of low toxicity.Keywords: Antioxidant activity, acute toxicity, Neoglaziovia variegata, Bromeliacea

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
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