24 research outputs found
Glycerol Acetylation with Propionic Acid Using Iron and Cobalt Oxides in Al-MCM-41 Catalysts
In this work, Al-MCM-41 molecular sieves were synthesized, containing iron and/or cobalt oxides, impregnated by incipient wetness method, characterized and applied as catalysts in the acetylation reaction of glycerol with propionic acid to produce green glyceryl propionate molecules of high commercial value. According to this, X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Fourier Transform Infra Red (FT-IR), adsorption/desorption N2 isotherms, textural analysis, and Scanning Electron Microscope (SEM) analysis were recorded to evaluate the main characteristics of materials. The presence of Lewis and Brønsted acidic sites and catalysts surface area were observed as important key points to functionalize acetylation reaction. Thus, time reaction, temperature, and glycerol / propionic acid ratio varied to improve the most suitable reaction conditions and behaviors. As a result, glycerol conversion was above 96%, followed by 68% of selectivity to glyceryl monopropionate as well as the formation of glyceryl di- and tri- propionate and a small amount of ethylene glycol dipropionate as an undesired product. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Building a Portuguese Coalition for Biodiversity Genomics
The diverse physiography of the Portuguese land and marine territory, spanning from continental Europe to the Atlantic archipelagos, has made it an important repository of biodiversity throughout the Pleistocene glacial cycles, leading to a remarkable diversity of species and ecosystems. This rich biodiversity is under threat from anthropogenic drivers, such as climate change, invasive species, land use changes, overexploitation or pathogen (re)emergence. The inventory, characterization and study of biodiversity at inter- and intra-specific levels using genomics is crucial to promote its preservation and recovery by informing biodiversity conservation policies, management measures and research. The participation of researchers from Portuguese institutions in the European Reference Genome Atlas (ERGA) initiative, and its pilot effort to generate reference genomes for European biodiversity, has reinforced the establishment of Biogenome Portugal. This nascent institutional network will connect the national community of researchers in genomics. Here, we describe the Portuguese contribution to ERGA’s pilot effort, which will generate high-quality reference genomes of six species from Portugal that are endemic, iconic and/or endangered, and include plants, insects and vertebrates (fish, birds and mammals) from mainland Portugal or the Azores islands. In addition, we outline the objectives of Biogenome Portugal, which aims to (i) promote scientific collaboration, (ii) contribute to advanced training, (iii) stimulate the participation of institutions and researchers based in Portugal in international biodiversity genomics initiatives, and (iv) contribute to the transfer of knowledge to stakeholders and engaging the public to preserve biodiversity. This initiative will strengthen biodiversity genomics research in Portugal and fuel the genomic inventory of Portuguese eukaryotic species. Such efforts will be critical to the conservation of the country’s rich biodiversity and will contribute to ERGA’s goal of generating reference genomes for European species.info:eu-repo/semantics/publishedVersio
Transtorno bipolar em crianças: análise de relato de caso 2018-2023
O transtorno bipolar em crianças é uma realidade clínica que demanda atenção especializada. A compreensão dos sintomas, fatores de risco, prevalência e desafios diagnósticos é fundamental para proporcionar intervenções precoces e adequadas, visando melhorar a qualidade de vida desses jovens e reduzir o impacto a longo prazo dessa condição psiquiátrica. Trata-se de um estudo cujo objetivo foi objetivo revisar relatos de caso publicados entre 2018 e 2023 sobre transtorno bipolar em crianças, identificando o estado da arte desses estudos. Para isso, se realizou uma revisão sistemática de literatura utilizando as bases de dados Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Scientific Electronic Library Online (SCIELO). Com a análise e interpretação qualitativa dos resultados, a principal conclusão deste estudo é que o transtorno bipolar na infância é uma condição complexa, manifestando-se com comportamentos consistentes com o Transtorno de Conduta e sendo influenciado por fatores ambientais, familiares e genéticos. O tratamento eficaz requer uma abordagem multidisciplinar, integrando intervenções farmacológicas e não farmacológicas, personalizadas conforme as necessidades individuais. A supervisão familiar é crucial para a adesão ao tratamento, mas reconhece-se a necessidade contínua de pesquisa para aprimorar as estratégias terapêuticas diante da diversidade de casos
Pervasive gaps in Amazonian ecological research
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
Accuracy of mucocutaneous leishmaniasis diagnosis using polymerase chain reaction: systematic literature review and meta-analysis
Pervasive gaps in Amazonian ecological research
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
Study of embryonic zeolites as basic catalysts in Knoevenagel condensation
The accessibility to the catalytic sites is one of the main objectives involving the development of heterogeneous catalysts. In this context, several researches seek the reduction of crystal diameters or the creation of mesopores in zeolites. The present work presents a new way of increasing the accessibility to the sites through the synthesis of embryonic zeolites. This method consists of obtaining structures that have a short range order, which improves mass transfer and leads to better catalytic results, especially in the processing of larger molecules. For this, the study of formation of FAU, LTA and SOD structures was carried out, associated with the catalytic evaluation of Knoevenagel condensation between benzaldehyde and ethyl cyanoacetate. The synthesis of the microporous sieves was performed under various times at 60 °C and all materials obtained (with and without crystallinity) were evaluated as catalysts. The highest conversions of the condensation reagents were always achieved by the zeolite embryos, regardless of the structure that originated. This higher activity is related to the secondary units of construction of the zeolite structure, as observed by Raman spectroscopy, these units are formed during the induction period. While the zeolite structure is in formation all the catalytic sites are accessible to the reactants, as the crystallization process is initiated, some of the sites become inaccessible and consequently a reduction in catalytic activity is due. By means of the CO2 TPD technique, zeolites with high crystallinity have a higher number of sites compared to their homologues containing only the embryos, but the catalytic activity does not reflect this trend. That is, as verified by N2 physisorption, embryonic zeolites have no micro- or mesoporosity and hence bulky molecules of reagents have access to all sites. The presence of aluminum with tetrahedral coordination in all embryonic zeolites was evidenced by NMR technique. The zeolite embryos that gave rise to the LTA structure prove to be the most active catalyst of their FAU and SOD homologues. This higher activity is related to the fact that this catalyst has a higher content of aluminum in its network, that is, a larger number of basic sites. When performing XPS measurements and calculating activity by site (TOF0), it was found that the catalytic activity of the zeolite embryos is mainly dependent on the number of sites.Não recebi financiamentoA acessibilidade aos sítios catalíticos é um dos principais objetivos envolvendo o desenvolvimento de catalisadores heterogêneos. Neste contexto, diversas pesquisas buscam a redução do diâmetro dos cristais ou a criação de mesoporos em zeólitas. O presente trabalho apresenta uma nova forma de aumentar a acessibilidade aos sítios através da síntese de embriões de zeólitas. Este método consiste em obter estruturas que possuam uma organização de curto alcance, a qual melhora a transferência de massa e leva a melhores resultados catalíticos, especialmente no processamento de moléculas mais volumosas. Para tal, realizou-se o estudo de formação das estruturas FAU, LTA e SOD associado a avaliação catalítica na condensação de Knoevenagel entre o benzaldeído e o cianoacetato de etila. A síntese das peneiras microporosas foi realizada sob diversos tempos na temperatura de 60ºC e todos os materiais obtidos (com e sem cristalinidade), foram avaliados como catalisadores. As maiores conversões dos reagentes da condensação foram sempre alcançadas pelos embriões das zeólitas, independente da estrutura que foi originada. Essa maior atividade está relacionada às unidades secundárias de construção da estrutura zeolítica, como observado pela espectroscopia Raman essas unidades são formadas durante o período de indução. Enquanto a estrutura zeolítica se encontra em formação todos os sítios catalíticos estão acessíveis aos reagentes, à medida que o processo de cristalização é iniciado, parte dos sítios se tornam inacessíveis e, consequente, uma redução na atividade catalítica é decorrente. Por meio da técnica de TPD de CO2, verificou-se que as zeólitas com alta cristalinidade possuem uma maior quantidade de sítios em relação aos seus homólogos contendo apenas os embriões, porém, a atividade catalítica não reflete essa tendência. Ou seja, como verificado pela fisissorção de N2, os embriões das zeólitas não possuem micro- e nem mesoporosidade, logo, as moléculas volumosas dos reagentes têm acesso a todos sítios. Através técnica de RMN 27Al evidenciou-se apenas a presença de alumínio com coordenação tetraédrica em todas as zeólitas embrionárias. Os embriões da zeólita que originaram a estrutura LTA demonstram ser o catalisador mais ativo que seus homólogos da FAU e SOD. Essa maior atividade está relacionada com o fato desse catalisador possuir um maior teor de alumínio em sua rede, ou seja, uma maior quantidade de sítios básicos. Ao realizar as medidas de XPS e calcular a atividade por sítio (TOF0), verificou-se que a atividade catalítica apresentada dos embriões das zeólitas é principalmente dependente da quantidade de sítios
Review of experimental models: sinusitis in rabbits
INTRODUCTION: In order to better understand the pathophysiology of rhinosinusitis, several attempts have been made to create the disease in an animal model. Among the studied rodents each has its advantages and disadvantages. Rabbits are considered more appropriate for studies that require surgical manipulation or invasive procedures. OBJECTIVES: To evaluate the most viable experimental model of rhinosinusitis in rabbits to be adopted in future studies. METHODS: An electronic search for studies with experimental models of rhinosinusitis in rabbits published in English and Portuguese between July of 1967 and January of 2013 was conducted in Medline, Pub Med, Cochrane, and CAPES databases, using the keywords "sinusitis", "rabbits", and "polyps". RESULTS: A total of 256 studies were retrieved, but in accordance with the inclusion and exclusion criteria, only ten studies were selected. Many different methods of response assessment were used in these studies. CONCLUSION: To date, there is no ideal experimental model for induction of acute or chronic rhinosinusitis in rabbits, but the rhinogenic model appears to be the most viable option for the continuity of studies of the disease