Estudo da resistência mecânica e análise térmica da resina epóxi

Também conhecida como poliepóxidio, a Resina Epóxi é um tipo de Resina plástica que quando misturada a um catalisador inicia seu processo de cura. É um polímero termorrígido, que diferentemente dos polímeros termoplásticos, não pode ser reprocessada com calor, sendo maleável apenas no momento de sua fabricação. O fato de não poderem ser remodelados se deve pelo motivo de que suas macromoléculas formam uma estrutura chamada reticulado, que nada mais é do que uma rede de ligações tridimensionais que se ligam em todas as direções do espaço. Assim como os demais polímeros deste grupo a Resina Epóxi é infusível e insolúvel em solventes orgânicoscomuns. Ao final de sua polimerização tem granderesistência, não sendo sensível ao calor excessivo, água e ácidos. Este material é muito utilizado como cola para outros polímeros, compósitos, cerâmicos e até metais, mas têm as mais diversas aplicações na construção civil, na indústria, artesanato e na confecção de peças elétricas e eletrônicas. Neste trabalho foram confeccionados corpos de prova para avaliação de algumas propriedades da Resina Epóxi, que apresenta valores médios de dureza de 62,98SD, e 26MPa de tensão máxima de flexão

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

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

Angioplasty and stenting for below the knee ulcers in diabetic patients: protocol for a systematic review

Abstract Background The worldwide incidence and prevalence of diabetes mellitus (DM) are increasing. DM has a high social and economic burden due to its complications and associated disorders. Peripheral arterial disease (PAD) is closely related to DM. More than 85% of patients with DM will develop PAD in their lifetime, and between 10 and 25% of patients with DM will have a foot ulcer. In such cases, it is important to determine for each patient whether it is necessary and feasible to revascularise the affected limb as well as the optimal technique. Percutaneous transluminal angioplasty (PTA) is designed to restore blood flow through the vessel lumen by various devices including balloons, drug-coated balloons, bare stents, drug-eluting stents and endovascular atherectomes. This systematic review aims to evaluate the effects of PTA in the treatment of lower limb arterial ulcers in diabetic patients. Methods We will search randomised controlled trials (RCTs) and quasi-RCTs in the following databases (e.g., MEDLINE via PubMed, EMBASE, Lilacs, Cochrane Central Register of Controlled Trials, Ibecs, CINAHL, AMED, World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov, and OpenGrey). Our search strategy will use the following free-text terms and controlled vocabulary (e.g., Emtree, MeSH) for ‘foot ulcer’, ‘leg ulcer’, ‘diabetic foot’, ‘Peripheral Arterial Disease’, ‘Diabetes Complications’, ‘Peripheral Vascular Diseases’, ‘critical limb ischemia’, ‘below the knee ulcer’, ‘angioplasty’, ‘stents’, ‘stenting’, and ‘endovascular procedures’. There will be no limits on date or language of publication. Two authors will, independently, select studies and assess the data from them. Risks of bias (RoB) of included studies will be evaluated using the Cochrane’s RoB tool. If possible, we will perform and report structured summaries of the included studies and meta-analyses. Results are not available as this is a protocol for a systematic review, and we are currently in the phase of building a sensitive search strategy. Discussion While there are several available endovascular techniques for revascularisation, it is unclear which technique has better outcomes for ulcers below the knee in diabetic patients. A systematic review is required to validate and demonstrate these techniques and their outcomes to allow an evidence-based clinical decision. Systematic review registration PROSPERO CRD4201706517

Comentários a uma sentença anunciada : o processo Lula

“Comentários a uma sentença: o Caso Lula” é talvez o mais importante documento jurídico publicado no Brasil em décadas. A presente coletânea de artigos nasceu de um movimento espontâneo e bastante significativo de juristas brasileiros e estrangeiros que examinaram cuidadosamente a sentença proferida no âmbito do processo que tramitou na 13ª Vara Federal de Curitiba, no caso que ficou conhecido na mídia como o do “tríplex do Guarujá”. <br>De la presentación de Geraldo Prad

Comentarios a una sentencia anunciada : el proceso Lula

El centenar de textos que conforman este libro -escritos por un movimiento de prestigiosos/as juristas y abogados- desgranan el procedimiento al que fue sometido Lula. En la opinión de las y los autores de los artículos las normas no fueron observadas, y su inobservancia llevó a que se dictaminase una decisión injusta. Frases del estilo "Voy a tomar una decisión revolucionaria, dejando de lado la ley, porque por la ley no se puede condenarlo de ninguna manera”, dichas en los juicios por las más altas autoridades judiciales militares y civiles, hoy son conocidas gracias a quienes se abocaron al trabajo de escuchar los audios de aquellas sesiones, nutriendo las reflexiones que argumentan sobre el imperativo de la hora: restablecer el estado de derecho y absolver al presidente Lula Da Silva

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data