1,796 research outputs found

    BIOMASS AND NUTRIENTS REMOVAL IN PURE AND MIXED POPULATIONS OF Pinus sp. IN SOUTHWEST BAHIA - BRAZIL

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    The magnitude of export of nutrients with forest harvest depends on the adopted waste management and, above all, on the distribution of biomass and nutrients in the trees, which is conditioned by the genetic potential and the species composition of forest stand.  The objective of this study was to quantify the biomass and nutrients of the trees and evaluate the effect of the management of harvest residues on the removal of nutrients from pure and mixed plantations of Pinus sp.. The study areas are located in the Southwest region of Bahia State, Brazil. Twenty trees per species were selected and felled under both planting conditions. The biomass quantification was performed by the destructive method. Samples of the tree components were analyzed for N, P, K, Ca and Mg contents. The total biomass was 75 Mg ha-1 for pure planting, and 81 Mg ha-1 for mixed planting, with wood and bark as the most representative compartments. Removal of the wood with bark led to too much nutrient removal, reaching a further 50% of the total contained in the biomass. Mixed planting has been shown more prone to export P, K and Mg. For both plantations, 64% of the N, P, K, Ca and Mg are in other components of the aerial part of the tree, and not in the wood. The elements that represent the highest risk for maintaining productivity are Ca and Mg

    Polymerization depths of conventional and bulk fill composites photoactivated by different methods

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    The aim of this study was to evaluate the depth of cure of conventional (Filtek Z350 and Esthet-X HD) and bulk fill resins composites (Filtek bulk fill flow and SDR) using different photoactivation methods. Samples were made using five discshaped matrices (1 mm high and 8 mm central diameter) with interposed polyester strips. The samples were photoactivated using different methods [continuous high-irradiance light (LCA), continuous low-irradiance light (LCB), and soft-start (SS)], maintaining 24 J/cm² radiant exposure. After 24h, Knoop microhardness test was performed at 5 depths (surface, 1 mm, 2 mm, 3 mm and 4 mm). The Knoop microhardness were analyzed by ANOVA two-way and Tukey’s test (5%). Conventional resins presented the highest results up to 2 mm depth, except for Esthet-X photoactived by LCB, which showed significant lower Knoop hardness from 2 mm depth. Bulk fill resins photoactivated with LCA and SS had the highest results in 4 mm depth. The LCA and SS photoactivation methods produce suitable photoactivation in conventional composites up to 2 mm and bulk fill up to 4 mm depth and the bulk fill composites present higher polymerization depth than conventional composites.Keywords: Dental curing lights; hardness test; photoactivation; polymerization; resi

    Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Histopathological Evaluation

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    Introduction: This study evaluated the in vivo response of apical and periapical tissues of dogs' teeth with apical periodontitis after one-session endodontic treatment with and without antimicrobial photodynamic therapy (aPDT). Methods: Sixty root canals with experimentally induced apical periodontitis were instrumented and assigned to 4 groups receiving aPDT and root canal filling (RCF) or not: group aPDT+/RCF- (n = 20): aPDT (photosensitizer phenothiazine chloride at 10 mg/mL for 3 minutes and diode laser [2 = 660 nm, 60 mW/cm(2)] for 1 minute) and RCF in the same session; group aPDT+/RCF (n = 10); group aPDT /RCF+ (n = 20), and group aPDT /RCF (n = 10). Teeth were restored, and the animals were killed after 90 days. Sections from the maxillas and mandibles were stained with hematoxylin-eosin and Mallory trichrome and examined under light microscopy. Descriptive (ie, newly formed apical mineralized tissue, periapical inflammatory infiltrate, apical periodontal ligament thickness, and mineralized tissue resorption) and quantitative (ie, periapical lesion size and number of inflammatory cells) microscopic analysis was performed. Quantitative data were analyzed by the Kruskal-Wallis and Dunn tests (alpha =.05). Results: In the aPDT-treated groups, the periapical region was moderately/severely enlarged with no inflammatory cells, moderate neoangiogenesis and fibrogenesis, and the smallest periapical lesions. Conclusions: Although apical closure by mineralized tissue deposition was not achieved, the absence of inflammatory cells, moderate neoangiogenesis, and fibrogenesis in the periapical region in the groups treated with aPDT indicate that this can be a promising adjunct therapy to cleaning and shaping procedures in teeth with apical periodontitis undergoing one-session endodontic treatment. (J Endod 2012;38:360-366

    Tromboembolismo pulmonar: dos aspectos epidemiológicos ao tratamento / Pulmonary thromboembolism: from epidemiological aspects to treatment

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    Introdução: O tromboembolismo pulmonar se trata de uma doença relativamente comum, potencialmente fatal e que requer diagnóstico rápido e preciso. Apesar das inovações tecnológicas na medicina que permitiram avanços em seu tratamento, ele constitui um paradoxo para a área da saúde, uma vez que à medida que ocorre o progresso medicinal, maior é o número de situações que predispõem ao embolismo. Objetivo: Investigar, interpretar e revisar os achados sobre epidemiologia, fisiopatologia, métodos diagnósticos, profiláticos e de tratamento dessa doença. Metodologia: Utilizou-se a base Medical Literature Analysis and Retrieval System Online (MEDLINE/PubMed), sob os descritores Embolia pulmonar; Tratamento; Tromboembolia venosa, com a seleção de artigos de revisão e artigos originais, seguindo critérios de elegibilidade. Foram encontrados 5866 textos, com seleção inicial de 488, dos quais restaram 23 artigos elegíveis. Resultados: Os artigos, em sua maioria redigidos em língua inglesa, contemplavam também publicações de autores e periódicos de diferentes nacionalidades. A maioria dos artigos abrangiam os anos de 2017 (sete) e 2018 (cinco), e grande parte foi publicada nos últimos cinco anos. Considerações finais: Pelo fato de o tromboembolismo pulmonar possuir diferentes formas clínicas e, assim, manifestar sinais e sintomas inespecíficos e capazes de serem confundidos com outros diagnósticos possíveis, é fundamental a tomada de decisão rápida e eficiente sobre a suspeição e a abordagem clínica desse quadro

    Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial

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    Background Recent open-label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression. Methods To test the antidepressant effects of ayahuasca, we conducted a parallel-arm, double-blind randomized placebo-controlled trial in 29 patients with treatment-resistant depression. Patients received a single dose of either ayahuasca or placebo. We assessed changes in depression severity with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating scale at baseline, and at 1 (D1), 2 (D2), and 7 (D7) days after dosing. Results We observed significant antidepressant effects of ayahuasca when compared with placebo at all-time points. MADRS scores were significantly lower in the ayahuasca group compared with placebo at D1 and D2 (p = 0.04), and at D7 (p < 0.0001). Between-group effect sizes increased from D1 to D7 (D1: Cohen's d = 0.84; D2: Cohen's d = 0.84; D7: Cohen's d = 1.49). Response rates were high for both groups at D1 and D2, and significantly higher in the ayahuasca group at D7 (64% v. 27%; p = 0.04). Remission rate showed a trend toward significance at D7 (36% v. 7%, p = 0.054). Conclusions To our knowledge, this is the first controlled trial to test a psychedelic substance in treatment-resistant depression. Overall, this study brings new evidence supporting the safety and therapeutic value of ayahuasca, dosed within an appropriate setting, to help treat depression. This study is registered at http://clinicaltrials.gov (NCT02914769)

    Educomunicação, Transformação Social e Desenvolvimento Sustentável

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    Esta publicação apresenta os principais trabalhos dos GTs do II Congresso Internacional de Comunicação e Educação nos temas&nbsp;Transformação social, com os artigos que abordam principalmente Educomunicação e/ou Mídia-Educação, no contexto de políticas de diversidade, inclusão e equidade; e, em Desenvolvimento Sustentável&nbsp;os artigos que abordam os avanços da relação comunicação/educação no contexto da educação ambiental e desenvolvimento sustentável
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