26 research outputs found

    Sedimentological, petrographic, and geochemical characterization of Ediacaran platform carbonates (Tamengo Formation, Corumbá Group)

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    Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Programa de Pós-Graduação em Geologia, 2019.A Formação Tamengo aflora na parte sul da Faixa Paraguai e apresenta um registro geológico contínuo do Neoproterozóico Superior no Brasil, com seus sedimentos carbonáticos e siliciclásticos sendo os remanescentes de um período marcado por muitas mudanças ambientais. Embora suas particularidades paleontológicas, estruturais e estratigráficas tenham sido amplamente estudadas, ainda existe uma deficiência na caracterização sedimentológica. Este estudo apresenta novas seções estratigráficas detalhadas, análise de fácies e dados isotópicos de carbono de duas seções da Formação Tamengo (Corcal e Laginha), com o objetivo de aprimorar a compreensão do ambiente deposicional da Rampa Ediacarana de Corumbá. A unidade compreende principalmente calcários escuros com intercalações de marga e lamito, além de um registro fóssil notável, incluindo os taxa Cloudina lucianoi (Beurlen & Sommer, 1957) e Corumbella werneri (Hahn et al., 1982), marcadores do Ediacarano. Os resultados de δ 13CPDB na Laginha revelam um sinal complexo, com valores altamente variáveis, inclusive negativos, não observados nas seções vizinhas. Esse registro pode ser influenciado por processos primários e diagenéticos. No entanto, a seção Corcal apresenta um sinal primário, estável, e correlativo a outras seções de renome no Ediacarano superior. A análise de fácies na seção Corcal revelou um contexto de rampa, com mergulho suave, e influenciada por flutuações no nível do mar, além de estruturas típicas de ambientes influenciados pela maré, que indicam um ambiente mais raso do que o descrito anteriormente. Por outro lado, a seção Laginha apresenta uma associação de fácies diversa, marcada por contribuição terrígena, sugerindo um cenário com uma topografia mais acidentada, provavelmente controlada pela tectônica extensional. Os resultados sugerem que a Formação Tamengo oi depositada em contexto de graben, com uma topografia complexa.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Fundação de Apoio à Pesquisa do Distrito Federal (FAP/DF).The Tamengo Formation crops out in the southern portion of the Paraguay Belt and presents continuous geological record of the late Neoproterozoic in Brazil, with its carbonate and siliciclastic sediments being the remnants of a period marked by many environmental changes. Even though its paleontological, structural and stratigraphic features had been broadly studied, there is still a deficiency on sedimentological characterization. This study presents new detailed stratigraphic sections, facies analysis, and carbon isotopic data from two sections of the Tamengo Formation (Corcal and Laginha), aiming to enhance the understanding of the Corumbá Ediacaran Ramp palaeodepositional environment. The unit comprises mainly dark limestones with marl and mudstone intercalations, in addition to a remarkable fossil record, including the Ediacaran marker taxa Cloudina lucianoi (Beurlen & Sommer, 1957) and Corumbella werneri (Hahn et al., 1982). The δ13CPDB results in Laginha reveal a complex signal, with highly variable values, including negative ones, not observed in neighbour sections. This record might be influenced both by primary and diagenetic processes. Nevertheless, the Corcal section bears a primary signal, steady and correlative to other renowned upper Ediacaran reference sections. The facies analysis in the Corcal section revealed a gently dipping ramp setting with sea level fluctuations, as well as peritidal to inner ramp structures, which indicate an environment shallower than previously outlined. On the other hand, the Laginha section displays a diverse facies association, marked by terrigenous contributions, suggesting a setting with a steeper topography, probably controlled by extensional tectonics. The results suggest that the Tamengo Formation deposited in graben type setting, with a complex topography

    New facies model and carbon isotope stratigraphy for an ediacaran carbonate platform from South America (Tamengo Formation—Corumbá Group, SW Brazil)

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    The Ediacaran is a period characterized by the diversification of early animals and extensive neritic carbonate deposits. These deposits are still not well understood in terms of facies and carbon isotope composition (δ13C). In this study we focus on the Tamengo Formation, in southwestern Brazil, which constitutes one of the most continuous and well-preserved sedimentary record of the late Ediacaran in South America. We present new detailed lithofacies and stable isotopes data from two representative sections (Corcal and Laginha) and revise the paleoenvironmental and stratigraphic interpretation of the Tamengo Formation. The Corcal section consists of neritic deposits including shallow-water limestone beds, alternated with shale and subordinate marl beds. These facies yield specimens of the Ediacaran fossils Cloudina lucianoi and Corumbella werneri. On the other hand, the Laginha section shows more heterogeneous facies, such as impure carbonates, breccias, marls, and subordinate mudstone beds, as well as no evidence of Corumbella werneri. The stable carbon isotope record is also different between the two sections, despite belonging to the same unit. The Corcal section displays higher and more homogeneous δ13C values, consistent with those of Ediacaran successions worldwide. The Laginha section, instead, displays more variable δ13C values, which suggest the influence of local and post depositional processes. The difference between the two sections was attributed to the different distance from the shore. We propose that the difference is due to topographic variations of the continental platform, which, at the Laginha site, was steeper and controlled by extensional faults. Therefore, the Corcal section is a better reference for the Tamengo Formation, whereas the Laginha is more particular and influenced by local factors. Besides, the lithofacies associations of the Tamengo Formation are like those of the Doushantuo and Dengying formatios, in South China, with no significant biogenic carbonate buildups, and different from those of other important Ediacaran units, such as the Nama Group in Nmibia and the Buah Formation in Oman. Our work highlights the complexity and heterogeneity of Ediacaran carbonate platforms and of their carbon isotopic composition. In addition, we characterize the Corcal section as a possible reference for the Ediacaran in South America

    Transtorno Opositor Desafiador: Impactos no desenvolvimento infantil

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    Introduction: Oppositional Defiant Disorder, also known as Oppositional Defiant Disorder (ODD), is a psychiatric condition characterized by defiant behaviors towards authority figures, often present since childhood. Objective: The objective of this study is to analyze the impacts on child development of children affected by ODD. Methodology: An observational approach was used, reviewing 11 scientific documents published between 2020 and 2024, selected from PubMed and SciELO. The documents were analyzed independently by two reviewers. The results were synthesized and organized for a detailed analysis of the impacts of ODD on child development. Results and Discussion: ODD has significant ramifications on child development, affecting academic performance, social relationships and presenting short- and long-term risks. Manifestations such as irritability and defiance of rules can harm school performance and make social interactions difficult, leading to family conflicts and disciplinary punishments. In the long term, ODD is associated with a greater risk of developing other mental disorders and legal problems, affecting professional life. Final Considerations: The study highlights the complexity of ODD and the need for appropriate interventions. Early and personalized management strategies are essential, as is continued research to develop innovative therapies. The engagement of the scientific community and health professionals is crucial to address the challenges associated with ODD and improve the quality of life of affected children.Introdução: O Transtorno Opositivo Desafiador, também conhecido como Transtorno Opositivo-Desafiador (TOD), é uma condição psiquiátrica caracterizada por comportamentos desafiadores em relação a figuras de autoridade, frequentemente presente desde a infância. Objetivo: O objetivo deste estudo é analisar os impactos no desenvolvimento infantil de crianças afetadas por TOD. Metodologia: Utilizou-se uma abordagem observacional, revisando 11 documentos científicos publicados entre 2020 e 2024, selecionados na PubMed e SciELO. Os documentos foram analisados independentemente por dois revisores. Os resultados foram sintetizados e organizados para uma análise detalhada dos impactos do TOD no desenvolvimento infantil. Resultados e Discussão: O TOD tem ramificações significativas no desenvolvimento infantil, afetando o desempenho acadêmico, as relações sociais e apresentando riscos a curto e longo prazo. Manifestações como irritabilidade e desafio às regras podem prejudicar o rendimento escolar e dificultar as interações sociais, levando a conflitos familiares e punições disciplinares. A longo prazo, o TOD está associado a um maior risco de desenvolver outros transtornos mentais e problemas legais, afetando a vida profissional. Conclusão: O estudo destaca a complexidade do TOD e a necessidade de intervenções adequadas. Estratégias de manejo precoce e personalizado são essenciais, assim como a pesquisa contínua para o desenvolvimento de terapias inovadoras. O engajamento da comunidade científica e profissionais de saúde é crucial para enfrentar os desafios associados ao TOD e melhorar a qualidade de vida das crianças afetada

    AVANÇOS NO DIAGNÓSTICO PRECOCE DA ENDOMETRIOSE: MÉTODOS E DESAFIOS

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    This article aims to provide an in-depth look at recent advances and persistent challenges in early detection of endometriosis, with the aim of significantly improving the quality of life for people affected by this complex condition. To select the articles, the Scielo and Pubmed databases were used, with the search terms “Endometriosis”, “Early diagnosis”, “Diagnostic techniques and procedures”, combined by the Boolean operator “AND”. The results indicate that new early diagnostic techniques, such as contrast-enhanced MRI, 3D anorectal ultrasound and the integration of biomarkers, demonstrate great potential to improve both the accuracy and speed of identifying endometriosis.Este artículo pretende ofrecer una mirada en profundidad a los avances recientes y los desafíos persistentes en la detección temprana de la endometriosis, con el objetivo de mejorar significativamente la calidad de vida de las personas afectadas por esta compleja condición. Para la selección de los artículos se utilizaron las bases de datos Scielo y Pubmed, con los términos de búsqueda “Endometriosis”, “Diagnóstico temprano”, “Técnicas y procedimientos de diagnóstico”, combinados por el operador booleano “AND”. Los resultados indican que las nuevas técnicas de diagnóstico temprano, como la resonancia magnética con contraste, la ecografía anorrectal 3D y la integración de biomarcadores, demuestran un gran potencial para mejorar tanto la precisión como la velocidad de identificación de la endometriosis.Este artigo visa apresentar uma visão detalhada sobre os avanços recentes e os desafios persistentes na detecção precoce da endometriose, com o objetivo de melhorar significativamente a qualidade de vida das pessoas afetadas por essa condição complexa. Para a seleção dos artigos, foram utilizadas as bases de dados Scielo e Pubmed, com os termos de busca “Endometriose”, “Diagnóstico precoce”, “Técnicas de diagnóstico e procedimentos”, combinados pelo operador booleano “AND”. Os resultados indicam que as novas técnicas de diagnóstico precoce, como a ressonância magnética com contraste, a ultrassonografia anorretal 3D e a integração de biomarcadores, demonstram um grande potencial para aprimorar tanto a precisão quanto a agilidade na identificação da endometriose

    GERENCIANDO A DOR DA HÉRNIA DE DISCO: EXPLORANDO AS OPÇÕES CIRÚRGICAS

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    Introduction: A herniated disc (HD) occurs when the intervertebral disc, the structure between the vertebrae of the spine, ruptures or dislocates, pressing on nearby nerves and causing pain. This can result in symptoms such as back pain, depending on the location of the hernia. Relevance: As this is a topic of pain associated with nerve compressions, the study reaffirms the importance of intervention therapies to resolve this latent comorbidity, as well as its more in-depth discussion. Problematic: HD sometimes presents a significant challenge to be considered a chronic condition. Even after treatments and interventions, some patients may continue to deal with persistent symptoms for the long term. Objective: Understand how to treat disc pain caused by HD, especially low back pain, and analyze therapeutic options for pain management and surgical options in the literature. Methodology: Systematic review through the platforms: Latin American and Caribbean Literature in Health Sciences (LILACS), Scientific Electronic Library Online (SciELO), Virtual Health Library (VHL), to carry out the selection of health descriptors (DECs) controlled: “Intervertebral Disc Displacement”, “Surgical Intervention”, “Pain Treatment”. Results: Treatment can range from conservative measures to more invasive surgeries, such as surgeries to alleviate nervous symptoms. The stage of the disease depends on the severity of the hernia, response to treatment, and nerve involvement. Recovery can vary and some patients experience specific improvements while others may deal with residual symptoms. Conclusion: Effective management of HD often requires a combination of approaches to control pain and improve the patient's quality of life. Although surgery may be an option in severe cases or when conservative treatments do not sufficiently resolve the problem, it is crucial to consider other original interventions.Introdução: A hérnia de disco (HD) ocorre quando o disco intervertebral, uma estrutura entre as vértebras da coluna, se rompe ou se desloca, pressionando os nervos próximos e causando dor. Isso pode resultar em sintomas como dor nas costas, dependendo da localização da hérnia. Relevância: Por ser um tema de dor associada a compressões nervosas, o estudo reintegra a importância de terapias de intervenção para resolução desta comorbidade latente bem como sua discussão mais aprofundada. Problemática: A HD, por vezes, apresenta um desafio significativo por ser considerada uma condição crônica. Mesmo após tratamentos e intervenções, alguns pacientes podem continuar a lidar com sintomas persistentes a longo prazo. Objetivo: Entender como gerenciar a  dor da HD de disco, em especial a lombar e analisar na literatura as opções terapêuticas de realização do manejo da dor até as opções cirúrgicas. Metodologia: Revisão sistemática através das plataformas: Literatura Latino-americana e do Caribe em ciências da Saúde (LILACS), Scientific Eletronic Library Online (SciELO), Biblioteca Virtual em Saúde (BVS), para conduzir a seleção foram usados os descritores em saúde (DECs)controlados: “Deslocamento do Disco Intervertebral”, “Intervenção Cirúrgica”, “Manejo da Dor”. Resultados: O tratamento pode variar desde medidas conservadoras, até intervenções mais invasivas, como cirurgia para aliviar a compressão nervosa. O desfecho da doença depende da gravidade da hérnia, da resposta ao tratamento e do comprometimento dos nervos A recuperação pode variar, e alguns pacientes experimentam melhora considerável, enquanto outros podem lidar com sintomas residuais. Conclusão: A gestão eficaz da HD muitas vezes requer uma combinação de abordagens para controlar a dor e melhorar a qualidade de vida do paciente. Embora a cirurgia possa ser uma opção em casos graves ou quando os tratamentos conservadores não proporcionam alívio suficiente, é crucial reconhecer outras intervenções originais

    ANÁLISE COMPARATIVA DO USO DA ESTATINA E DO ÁCIDO NICOTÍNICO NO TRATAMENTO DA SÍNDROME METABÓLICA

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    Considering metabolic syndrome (MS) as a pathophysiological condition characterized by arterial hypertension, central obesity, insulin resistance, dyslipidemia, and hyperglycemia, this study aims to compare the use of statins and nicotinic acid in the treatment of MS. To this end, a comparative analysis based on relevant clinical and epidemiological studies was conducted. Thus, it is observed that statins significantly reduce LDL cholesterol by about 50% and decrease the risk of cardiovascular events by 25% to 35%, with an odds ratio (OR) of improvement between 0.70 and 0.80. Statins are widely available and accessible, especially in generic versions, and have a relatively manageable adverse effect profile. In contrast, nicotinic acid reduces LDL cholesterol by 15% to 25%, increases HDL cholesterol, and reduces triglycerides, but with less consistent efficacy in preventing cardiovascular events (OR ranging from 0.90 to 1.10) and significant side effects, such as skin flushing and hepatotoxicity. The cost and availability of nicotinic acid are more limited compared to statins. It is concluded that statins are the preferred choice for the treatment of MS due to their robust efficacy and accessibility, while nicotinic acid may be considered in specific cases, with caution due to its adverse effects.Considerando a síndrome metabólica (SM) como uma condição fisiopatológica caracterizada por hipertensão arterial, obesidade central, resistência à insulina, dislipidemia e hiperglicemia, este estudo objetiva comparar o uso de estatinas e ácido nicotínico no tratamento da SM. Para tanto, procede-se a uma análise comparativa baseada em estudos clínicos e epidemiológicos relevantes. Desse modo, observa-se que as estatinas reduzem significativamente o LDL-colesterol em cerca de 50% e diminuem o risco de eventos cardiovasculares em 25% a 35%, com odds ratio (OR) de melhora entre 0,70 e 0,80. As estatinas são amplamente disponíveis e acessíveis, especialmente nas versões genéricas, e apresentam um perfil de efeitos adversos relativamente manejável. Em contraste, o ácido nicotínico reduz o LDL-colesterol em 15% a 25%, aumenta o HDL-colesterol e reduz os triglicerídeos, mas com uma eficácia menos consistente na prevenção de eventos cardiovasculares (OR variando de 0,90 a 1,10) e efeitos colaterais significativos, como rubor cutâneo e hepatotoxicidade. O custo e a disponibilidade do ácido nicotínico são mais limitados em comparação às estatinas. Conclui-se que as estatinas são a escolha preferida para o tratamento da SM devido à sua eficácia robusta e acessibilidade, enquanto o ácido nicotínico pode ser considerado em casos específicos, com precaução devido aos seus efeitos adversos

    Avanços da cirurgia robótica no tratamento de doenças cardiovasculares

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    Várias cirurgias médicas já utilizaram a tecnologia robótica, tais como: cirurgias no estômago, bexiga, rins, próstata, cérebro e inclusive no coração, o qual proporciona-se a reparação de válvulas cardíacas e até mesmo cirurgias nas artérias. O principal objetivo do presente estudo é discutir por meio da literatura científica acerca dos avanços da cirurgia robótica no tratamento de doenças cardiovasculares. Trata-se de uma revisão sistemática da literatura, dos quais, utilizou-se as bases e biblioteca eletrônica Scielo e Periódico Capes, totalizando 5 artigos elegíveis. A cirurgia robótica tem sido um dos principais métodos utilizados em tratamentos cardiovasculares quando comparados com técnicas convencionais, sobretudo, no que diz respeito, a cirurgia de revascularização do miocárdio

    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

    Pervasive gaps in Amazonian ecological research

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    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
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