46 research outputs found

    Influence of different restraint protocols for the electrocardiogram values of feline night monkeys (Aotus azarae infulatus

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    Universidade do Estado do Pará. Centro de Ciências Biológicas e da Saúde. Laboratório de Cirurgia Experimental. Belém, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Centro Nacional de Primatas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Centro Nacional de Primatas. Ananindeua, PA, Brasil.Universidade Federal Rural da Amazônia. Instituto de Saúde e Produção Animal. Belém, PA, Brasil.Universidade do Estado do Pará. Centro de Ciências Biológicas e da Saúde. Laboratório de Cirurgia Experimental. Belém, PA, Brasil.Macacos-da-noite são muito susceptíveis ao estresse e por isso a contenção química ou física deve ser cuidadosamente avaliada antes de qualquer procedimento. Protocolos anestésicos podem alterar alguns parâmetros fisiológicos, sendo o eletrocardiograma (ECG) um exame muito utilizado para avaliação do ritmo e da frequência cardíaca. O objetivo deste estudo foi avaliar a influência de quatro diferentes protocolos de contenção sobre o ECG realizado em Aotus azarae infulatus. Para isso foram utilizados 10 animais, machos, adultos, submetidos à contenção com a associação tiletamina/zolazepam (TZ), isoflurano (ISO), associação cetamina e midazolam (CET) e contenção física (CF). Não foram observadas diferenças nos parâmetros de ondas e complexos obtidos no ECG em todos os grupos testados, no entanto, durante a avaliação do traçado os animais do grupo CF apresentaram uma quantidade maior de alterações. Concluiu-se que os protocolos de contenção utilizados não alteraram os valores do ECG e que não foi possível considerar o grupo CF como controle devido causar mais alterações do que todos os protocolos testados

    Electrodialytic recovery of rare earth elements from coal ashes

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    Fundação para a Ciência e a Tecnologia, I.P., Portugal, UIDB/04085/2020 (Research unit CENSE “Center for Environmental and Sustainability Research”). Fundação para a Ciência e a Tecnologia is also acknowledged for N. Couto Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/04210/2017).Rare earth elements (REE) are critical raw materials crucial for modern technologies and used in a variety of industries. There is a need of investment in REE recovery from secondary sources. The present work was designed to assess the potential of the electrodialytic process to recover REE from coal ash. The content of REE was evaluated in bituminous and anthracite ash. Anthracite presented higher REE concentration (447 ppm vs. 138 ppm) and a triple concentration of critical REE compared with bituminous ash. Anthracite ash was treated aiming to test the REE recover potential, including differences between light REE (LREE) and heavy REE (HREE) fractions as well as the specific recovery of REE with high criticality. A two-compartment electrodialytic cell was tested with the matrix placed in the anode compartment and a cation-exchange membrane separating the compartments. Experiments lasted a maximum of 7 days applying different current intensities and pH adjustment in the catholyte (≈ 2). Three main steps are observed in the removal process 1) REE solubilization - from the solid to the liquid phase (anolyte); 2) REE mobilization - movement from the anolyte towards the cathode end; 3) REE removal - presence in the catholyte. The extent of each step observed for the REE depends on their individual position in the periodic table with HREE removal being more regulated by step 1 and LREE by step 2. At the best tested conditions (50 mA, 3 days, pH adjustment), more than 70% of REE were extracted from the ash with the catholyte enclosing up to ≈ 50% of LREE and HREE. Combining the high criticality of neodymium with its high concentration in anthracite coal ash (65 ppm), the electrodialytic treatment is highly recommended to concentrate this REE in the catholyte. The results demonstrated the proof-of-concept for electro-assisted extraction of REE from anthracite coal ash, opening perspectives to a selective recovery of these elements from secondary sources.authorsversionpublishe

    Gerenciamento de resíduos químicos como uma proposta didática na disciplina de físico-química aplicada à biotecnologia

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    O gerenciamento e o reaproveitamento de resíduos químicos é uma atividade de grande importância para a formação acadêmica do graduando na área de ciências. Tendo em vista essa preocupação, no laboratório de Físico-Química/Química Analítica do Instituto de Saúde e Biotecnologia foram desenvolvidas algumas ações pelos acadêmicos do curso de Bacharelado em Biotecnologia durante as aulas experimentais da disciplina de Físico-Química. O resultado desse trabalho gerou o presente relato de experiência que tem como objetivo promover entre os acadêmicos o desenvolvimento da conscientização ambiental através do gerenciamento de resíduos químicos. No primeiro momento foi feito a triagem dos reagentes e dos resíduos químicos e o levantamento da carga horária semestral de aulas no referido laboratório, visando o desenvolvimento de metodologias para o tratamento, descarte e reaproveitamento adequado em aulas práticas. Foram analisadas dezoito soluções ociosas. Dessas soluções, foram aferidos pH, volume e verificado a toxicidade. Os resultados das substâncias avaliadas apontaram que 20% da substâncias são tóxicas, 27% são oxidantes, 5% são cancerígenas, 24% corrosivas e 24% irritantes, sendo o volume total 5,541 L. Além disso, o levantamento da carga horária semestral apontou 90 horas para o semestre par e 120 horas para o semestre ímpar distribuídas nas disciplinas de Química Analítica e Físico-Química. A partir desses resultados foi proposto requisitar bombonas para armazenar os descartes de maneira correta e um formulário de prática experimental conforme os princípios da química verde, visando mitigar o descarte incorreto e com a finalidade de reutilização ou doação de reagentes ociosos. Ainda que o projeto esteja em fase de aperfeiçoamento, a experiência dos acadêmicos com os procedimentos deste trabalho piloto no Instituto de Saúde e Biotecnologia promoveram o desenvolvimento da conscientização do controle de resíduos químicos, a consolidação da utilização de técnicas analíticas e maior conhecimento sobre as regras de segurança do laboratório por parte dos discentes da disciplina de Físico-Química aplicada à Biotecnologia

    Haptoglobin gene subtypes in three Brazilian population groups of different ethnicities

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    Haptoglobin is a plasma hemoglobin-binding protein that limits iron loss during normal erythrocyte turnover and hemolysis, thereby preventing oxidative damage mediated by iron excess in the circulation. Haptoglobin polymorphism in humans, characterized by the Hp*1 and Hp*2 alleles, results in distinct phenotypes known as Hp1-1, Hp2-1 and Hp2-2, whose frequencies vary according to the ethnic origin of the population. The Hp*1 allele has two subtypes, Hp*1F and Hp*1S, that also vary in their frequencies among populations worldwide. In this work, we examined the distribution frequencies of haptoglobin subtypes in three Brazilian population groups of different ethnicities. The haptoglobin genotypes of Kayabi Amerindians (n = 56), Kalunga Afro-descendants (n = 70) and an urban population (n = 132) were determined by allele-specific PCR. The Hp*1F allele frequency was highest in Kalunga (29.3%) and lowest in Kayabi (2.6%). The Hp*1F/Hp*1S allele frequency ratios were 0.6, 1.0 and 0.26 for the Kayabi, Kalunga and urban populations, respectively. This variation was attributable largely to the Hp*1F allele. However, despite the large variation in Hp*1F frequencies, results of FST (0.0291) indicated slight genetic differentiation among subpopulations of the general Brazilian population studied here. This is the first Brazilian report of variations in the Hp *1F and Hp*1S frequencies among non-Amerindian Brazilians

    In Vitro and In Vivo Investigation of the Efficacy of Arylimidamide DB1831 and Its Mesylated Salt Form - DB1965 - against Trypanosoma cruzi Infection

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    Chagas disease is caused by infection with the intracellular protozoan parasite Trypanosoma cruzi. At present, nifurtimox and benznidazole, both compounds developed empirically over four decades ago, represent the chemotherapeutic arsenal for treating this highly neglected disease. However, both drugs present variable efficacy depending on the geographical area and the occurrence of natural resistance, and are poorly effective against the later chronic stage. As a part of a search for new therapeutic opportunities to treat chagasic patients, pre-clinical studies were performed to characterize the activity of a novel arylimidamide (AIA - DB1831 (hydrochloride salt) and DB1965 (mesylate salt)) against T.cruzi. These AIAs displayed a high trypanocidal effect in vitro against both relevant forms in mammalian hosts, exhibiting a high selectivity index and a very high efficacy (IC50 value/48 h of 5–40 nM) against intracellular parasites. DB1965 shows high activity in vivo in acute experimental models (mouse) of T.cruzi, showing a similar effect to benznidazole (Bz) when compared under a scheme of 10 daily consecutive doses with 12.5 mg/kg. Although no parasitological cure was observed after treating with 20 daily consecutive doses, a combined dosage of DB1965 (5 mg/kg) with Bz (50 mg/kg) resulted in parasitaemia clearance and 100% animal survival. In summary, our present data confirmed that aryimidamides represent promising new chemical entities against T.cruzi in therapeutic schemes using the AIA alone or in combination with other drugs, like benznidazole

    Combined Treatment of Heterocyclic Analogues and Benznidazole upon Trypanosoma cruzi In Vivo

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    Chagas disease caused by Trypanosoma cruzi is an important cause of mortality and morbidity in Latin America but no vaccines or safe chemotherapeutic agents are available. Combined therapy is envisioned as an ideal approach since it may enhance efficacy by acting upon different cellular targets, may reduce toxicity and minimize the risk of drug resistance. Therefore, we investigated the activity of benznidazole (Bz) in combination with the diamidine prodrug DB289 and in combination with the arylimidamide DB766 upon T. cruzi infection in vivo. The oral treatment of T.cruzi-infected mice with DB289 and Benznidazole (Bz) alone reduced the number of circulating parasites compared with untreated mice by about 70% and 90%, respectively. However, the combination of these two compounds decreased the parasitemia by 99% and protected against animal mortality by 100%, but without providing a parasitological cure. When Bz (p.o) was combined with DB766 (via ip route), at least a 99.5% decrease in parasitemia levels was observed. DB766+Bz also provided 100% protection against mice mortality while Bz alone provided about 87% protection. This combined therapy also reduced the tissular lesions induced by T. cruzi infection: Bz alone reduced GPT and CK plasma levels by about 12% and 78% compared to untreated mice group, the combination of Bz with DB766 resulted in a reduction of GPT and CK plasma levels of 56% and 91%. Cure assessment through hemocultive and PCR approaches showed that Bz did not provide a parasitological cure, however, DB766 alone or associated with Bz cured ≥13% of surviving animals

    The global abundance of tree palms

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    Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

    Pervasive gaps in Amazonian ecological research

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    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
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