Hydroxyapatite aerogels with piezoelectric particles for bone regeneration

Several materials have been researched to replace the damaged tissues or assist in the regeneration pro-cesses of the bone. New strategies for designing advanced functional biomimetic structures are contin-uously being reviewed and optimized. Advances not only on the chemical composition of the implants but also on their physical surface play an important role in enhancing the functionality of implants. This dissertation focuses on the production of Hydroxyapatite (HAp) aerogels and aerogel composites of HAp with Barium Titanate (BaTiO3) particles for bone tissue regeneration. The aerogels are com-posed of HAp nanowires (NWs) produced through solvothermal synthesis and later freeze dried. All the commercially bought particles, 280nm, 2μm and 3μm, proved to contain BaTiO3 in its tetragonal phase when characterized by an XRD, FTIR and Raman analysis. A thermal analysis (DSC and TGA) of the particles allowed to observe a shift in the phase of BaTiO3, for the 280nm particles, around its Curie temperature, 130.6℃. The product of the solvothermal reaction at a temperature of 180℃ for 18hours was verified to be car-bonated Hydroxyapatite through a XRD and FTIR analysis. The aerogels with and without particles were observed with SEM, proving the existence of Hap wires, heterogeneous sized pores, as well as a good distribution of the BaTiO3 particles. The BaTiO3 particles proved to be non-cytotoxic while the fabricated aerogels with and without particles were considered cytotoxic, however, the higher surface of the aerogels and easy dissolution may have altered the results. In the assays of bioactivity assays, in SEM/EDS, difficulties were found when trying to differentiate between the apatite structures and the surface of the HAp wires. However, a quantitative EDS analysis shows that there is a possibly a cycle of CaP deposition followed by dissolution occurring.Diversos materiais têm sido investigados de modo a substituir tecidos danificados ou auxiliar nos pro-cessos regenerativos do osso. Novas estratégias de modo a produzir estruturas biomiméticas funcionais avançadas são continuamente revisadas e otimizadas. Avanços não apenas na composição química dos implantes, mas também na sua superfície física, desempenham um papel importante em melhorar a funcionalidade dos implantes. Esta dissertação dedica-se à produção de aerogéis de hidroxiapatite (HAp) e compostos de aerogel de HAp com partículas de Titanato de Bário (BaTiO3) para regeneração do tecido ósseo. Os aerogéis são compostos por nanofios (NWs) de HAp produzidos por meio de síntese solvotérmica e posteriormente liofilizados. Todas as partículas comerciais, 280nm, 2μm e 3μm, demonstraram a existência de BaTiO3 em fase tetragonal quando caracterizadas por uma análise de DRX, FTIR e Raman. Uma análise térmica (DSC e TGA) das partículas permitiu observar uma mudança na fase do BaTiO3 em torno de sua temperatura de Curie, 130.6 ℃, para as partículas de 280nm. O produto da reação solvotérmica a uma temperatura de 180℃ por 18 horas demonstrou ser hidroxia-patite carbonatada através de uma análise de DRX e FTIR. Os aerogéis com e sem partículas foram observados no SEM, comprovando a existência de fios de Hap, poros de tamanhos heterogêneos, bem como uma boa distribuição das partículas de BaTiO3. As partículas de BaTiO3 mostraram-se não citotóxicas enquanto os aerogéis fabricados com e sem par-tículas foram considerados citotóxicos, no entanto, a elevada área superficial dos aerogéis e fácil disso-lução podem ter alterado os resultados. Nos ensaios de bioatividade, encontrou-se dificuldade em diferenciar, no SEM/EDS, entre estruturas definidas de apatites e a superfície dos fios de HAp. No entanto, a análise quantitativa de EDS mostra que possivelmente existe um ciclo de deposição de CaP seguido de dissolução

Sistemas agroflorestais na recuperação de áreas degradadas / Agroforestry systems in the recovery of degraded areas

Esse artigo buscou realizar um estudo de referencial teórico para apresentar as contribuições da implantação de sistemas agroflorestais na recuperação de áreas degradadas e a importância no contexto local das comunidades, na resolução de problemas sociais e ambientais. A recuperação de áreas degradadas é uma estratégia importante adotada como caminho para a sustentabilidade dos ecossistemas, que poderá contribuir positivamente não só na agenda social e econômica das comunidades, como também promovendo a subsistência da humanidade. Dito isso, abordaremos os mecanismos da degradação ambiental, os conceitos de sistema agroflorestal, as modalidades praticadas em conformidade com as realidades locais das comunidades alvo, a intervenção da proposta, listaremos indicativos das espécies e posicionamento adequado para a formação dos sistemas, as formas de realização de diagóstico rápido e participativo, a forma de elaboração do arranjo ou desenho de SAF. Como resultados foi possível concluir que a recuperação de áreas degradadas requer profundo conhecimento local do lugar a ser intervisto, compreensão da cultura, dos dizeres e fazeres locais, e entendimento de que a efetividade só é alcançada quando a recuperação e o uso responsável ocupa um lugar de privilégio e importância na vida da comunidade de forma orgânica. Foi possível inferir que os SAFs proporcionam aumento da biodiversidade, regulação de ciclo hidrológico, controle erosivo, do assoreamento e ciclagem de nutrientes.

Critical analysis of legislation on degraded areas in Brazil / Análise crítica da legislação sobre áreas degradadas no Brasil

This study survey and analyze the evolution of the main normative instruments for environmental protection in Brazil. The research showed that the environmental protection models in Brazil developed as ecological awareness and control over environmental issues became relevant points. In this sense, environmental degradation, especially of soils, is a concern that has always been under discussion in Brazil. As can be seen, over the years, the Brazilian legislation has sought mechanisms to improve the formulation of more efficient normative instruments

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

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

Revisão sistematizada da literatura e opinião de peritos

Objective: The 3E (Evidence, Expertise, Exchange) Initiative is a multinational effort of rheumatologists aimed at developing evidence-based recommendations addressing specific questions relevant to clinical practice. The objective of the Portuguese contribution for the 3E Initiative was to develop evidence-based recommendations on how to investigate, follow-up and treat undifferentiated peripheral inflammatory arthritis (UPIA) adapted to local reality and develop additional recommendations considered relevant in the national context. Methods: An international scientific committee from 17 countries selected a set of questions concerning the diagnosis and monitoring of UPIA using a Delphi procedure. Evidence-based answers to each question were sought by a systematic literature search, performed in Medline, Embase, the Cochrane Library and ACR/EULAR 2007-2009 meeting abstracts. Relevant articles were reviewed for quality assessment, data extraction and synthesis. In a national meeting, a panel of 63 Portuguese rheumatologists used the evidence which was gathered to develop recommendations, and filled the gaps in the evidence with their expert opinion. Finally, national recommendations were formulated and agreement among the participants was assessed. Results: A total of 54754 references were identified, of which 267 were systematically reviewed. Thirteen national key recommendations about the investigation, follow-up and treatment of UPIA were formulated. One recommendation addressed differential diagnosis and investigations prior to the established operational diagnosis of UPIA, eight recommendations were related to the diagnostic and prognostic value of clinical and laboratory assessments in established UPIA (history and physical examination, acute phase reactants, serologies, autoantibodies, radiographs, magnetic resonance imaging and ultrasound, genetic markers and synovial biopsy), one recommendation highlighted predictors of persistence (chronicity), one addressed monitoring of clinical disease activity in UPIA, one aimed to find an useful method/score to predict a definitive diagnosis and the last one was related to treatment. Conclusion: Portuguese evidence-based recommendations for the management of UPIA in everyday practice were developed. Their dissemination and implementation in daily clinical practice should help to improve practice uniformity and optimize the management of UPIA patients.publishersversionpublishe