838 research outputs found

    Comparison of digital and conventional radiographic techniques

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    This study aimed to evaluate the correlation between conventional and digital radiographic methods in the measurement of periapical lesions in primary molars and compares the time used to obtain the radiographic images betweenboth methods. Material and methods: This crossover study included children between 4 to 8-year-old with periapical lesion in primary mandibular molars. Fifteen molars were randomly assigned firstly to receive conventional or digital periapical radiograph during the steps of endodontic treatment. The time to obtain the radiographic image was evaluated in seconds and compared by the Mann-Whitney test. The periapical lesions measurement (mm2) were performed by the Image J software and the degree of correlation of measurement between both techniques was evaluated by the Spearman correlation test. Data was analyzed using the GraphPad Prism software (α = 0.05). Results: A strong positive correlation between the measurement of lesions occurred on conventional methods in comparison with the measurement on digital methods (r2=0.778; p<0.0006); however, the time to obtain the radiographic images was shorter in the digital method (p<0.0001). Conclusion: The digital method had a shorter amount of time to obtain the images and strong correlation for the lesions measurement in comparison to the conventional method. Therefore, the digital radiograph method is preferable for use in children

    Purification of a lectin with antibacterial activity from Bothrops leucurus snake venom

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    A novel lectin was isolated from Bothrops leucurus snake venom using a combination of affinity and gel filtration chromatographies. the lectin (BIL) agglutinated glutaraldehyde-treated rabbit and human erythrocytes with preference for rabbit erythrocytes. Galactose, raffinose, lactose, fetal bovine serum and casein inhibited lectin-induced rabbit erythrocyte agglutination. BIL, with a molecular mass of 30 kDa and composed of two subunits of 15 kDa, showed dependence on calcium. BIL is an acidic protein with highest activity over the pH range of 4.0-7.0 and stable under heating to 70 degrees C. Fluorescence emission spectra showed tryptophan residues partially buried within the lectin structure. the percentages of secondary structure revealed by circular dichroism were 1% alpha-helix, 44% beta-sheet, 24% beta-turn and 31% unordered. BIL showed effective antibacterial activity against Gram-positive bacteria Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis with minimal inhibitory concentrations of 31.25, 62.25 and 125 mu g/mL, respectively. in conclusion, B. leucurus snake venom contains a galactoside-binding lectin with antibacterial activity. (C) 2011 Elsevier Inc. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Fed Pernambuco, Dept Bioquim, BR-50670420 Recife, PE, BrazilUniv Fed Bahia, Dept Zool, BR-40170210 Salvador, BA, BrazilUniversidade Federal de São Paulo, Dept Bioquim, BR-04044020 São Paulo, BrazilUniv Fed Pernambuco, Dept Zool, BR-50670420 Recife, PE, BrazilUniv Estadual Oeste Parana, Ctr Engn & Ciencias Exatas, BR-85903000 Toledo, Parana, BrazilUniversidade Federal de São Paulo, Dept Bioquim, BR-04044020 São Paulo, BrazilWeb of Scienc

    Leucemia Linfoblástica Aguda (LLA) na população pediátrica: marcadores moleculares e implicações terapêuticas

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    A Leucemia Linfoblástica Aguda (LLA) é uma forma comum de câncer pediátrico, representando cerca de 80% dos casos de leucemia em crianças. A patologia é caracterizada pela proliferação descontrolada de células-tronco hematopoéticas na medula óssea, e avanços recentes na pesquisa genômica têm proporcionado uma compreensão mais profunda da complexidade molecular subjacente à doença. O presente estudo tem como objetivo oferecer uma visão abrangente dos principais marcadores moleculares e implicações terapêuticas associadas à LLA na população pediátrica. Este estudo, baseado em uma revisão sistemática da literatura científica, abrange o período de 2013 a 2023, utilizando as bases de dados PubMed (Medline), Cochrane Library e Scientific Electronic Library Online (SciELO). Marcadores moleculares preponderantes, como rearranjos cromossômicos específicos (t(12;21), t(1;19), t(9;22)), mutações genéticas distintivas (ETV6-RUNX1, E2A-PBX1, TP53) e amplificação do gene BCR-ABL1, têm sido objeto de estudo aprofundado. Esses marcadores desempenham um papel crucial na estratificação de risco e prognóstico, permitindo uma abordagem mais personalizada no tratamento da LLA em crianças. As implicações terapêuticas derivadas desses marcadores são vastas, destacando a promissora era das terapias direcionadas. Terapias específicas para mutações, como aquelas direcionadas à mutação BCR-ABL1, e inovações em imunoterapia estão moldando o cenário do tratamento da LLA, proporcionando resultados mais eficazes e menos tóxicos. Os resultados destacam a eficácia das terapias direcionadas e a necessidade contínua de pesquisa para otimizar a intervenção terapêutica, melhorar a qualidade de vida dos pacientes pediátricos afetados pela LLA e explorar novas facetas do tratamento. Em conclusão, este artigo fornece uma análise aprofundada dos marcadores moleculares e terapias associadas à LLA na população pediátrica, destacando avanços significativos e delineando áreas para investigação futura

    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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    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    Long-term thermal sensitivity of Earth’s tropical forests

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    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

    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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