14 research outputs found

    Processo de reciclagem química de PET em meio alcalino: efeito da concentração do íon hidróxido, da cor do PET e do tempo de reação

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    Este trabalho investigou o processo de hidrólise química de poli(tereftalato de etileno) (PET) em meioalcalino; especificamente de garrafas incolores e coloridas pós-uso. A reciclagem química de embalagensPET pós-uso ainda é muito pouco explorada no Brasil, não sendo tão diferente do que está sendo praticadoem outros países. Dentre variáveis possíveis de investigação, aquelas estudadas neste trabalho foram aconcentração de hidróxido de sódio (NaOH) e a cor do PET. A reação de despolimerização do PET pós-usofoi realizada na concentração de 1,0, 3,0, 5,0, 7,5 e 10,0 mol L-1 de NaOH, sendo que em 7,5 mol L-1 foiaquela que mostrou os melhores resultados, relativamente à extensão da reação e à pureza do monômerorecuperado, o ácido tereftálico (TPA). A reação também foi feita para PET de cores diferentes, naconcentração de 7,5 mol L-1 de NaOH, cujos resultados mostraram um menor desempenho quandocomparados com aqueles obtidos para o PET não colorido. Esse resultado sugere ser devido à presença decorantes, que pela estrutura química dos mesmos, competem pelo ataque nucleofílico do íon hidroxila (OH-),durante a reação de hidrólise do PET. As análises por Espectrofotometria no Infravermelho (FTIR), Difraçãode Raios X (DRX) e Termogravimétrica (TGA/DTG) confirmaram que os produtos de reação resultaram emTPA, uma vez que os espectros foram coincidentes com aqueles do TPA comercial. O crescente consumo deembalagens PET e o descarte ambiental aleatório precisam de soluções rápidas; os resultados do presentetrabalho são importantes e corroboram com o avanço da pesquisa para a reutilização de matéria prima.Palavras-chave: PET, hidrólise, reciclagem química

    Utilização do monitor de eventos externo (web-loop) na identificação de sintomas associados a arritmias cardíacas em uma população geral

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    ObjectiveTo correlate arrhythmic symptoms with the presence of significant arrhythmias through the external event monitoring (web-loop). MethodBetween January and December 2011, the web-loop was connected to 112 patients (46% of them were women, mean age 52±21 years old). Specific arrhythmic symptoms were defined as palpitations, pre-syncope and syncope observed during the monitoring. Supraventricular tachycardia, atrial flutter or fibrillation, ventricular tachycardia, pauses greater than 2 seconds or advanced atrioventricular block were classified as significant arrhythmia. The association between symptoms and significant arrhythmias were analyzed. ResultThe web-loop recorded arrhythmic symptoms in 74 (66%) patients. Of these, in only 14 (19%) patients the association between symptoms and significant cardiac arrhythmia was detected. Moreover, significant arrhythmia was found in 11 (9.8%) asymptomatic patients. There was no association between presence of major symptoms and significant cardiac arrhythmia (OR=0.57, CI95%: 0.21-1.57; p=0.23). ConclusionWe found no association between major symptoms and significant cardiac arrhythmia in patients submitted to event recorder monitoring. Event loop recorder was useful to elucidate cases of palpitations and syncope in symptomatic patients.ObjetivoCorrelacionar sintomas arrítmicos com a presença de arritmias significativas por meio do monitor de eventos externo (web-loop). MétodoEntre janeiro e dezembro de 2011, o web-loop foi instalado em 112 pacientes (46% mulheres, 52±21 anos). Sintomas específicos foram definidos como palpitação, pré-síncope e síncope, presentes durante a monitorização. Arritmia significativa foi definida como taquicardia paroxística supraventricular, flutter e fibrilação atrial, taquicardia ventricular, pausas superiores a 2 segundos ou bloqueio atrioventricular avançado. A associação entre presença de sintomas e arritmias significativas foi avaliada. ResultadoO monitor de eventos registrou sintomas específicos em 74 (66%) pacientes, entretanto a associação entre sintomas específicos e arritmia significativa foi observada em apenas 14 (19%) deles. Em 11 pacientes (9,8%), foi detectada arritmia significativa na ausência de sintomas. Não houve associação entre a presença de sintomas e a detecção de arritmia significativa (OR=0,57, IC95%: 0,21-1,57; p=0,23). ConclusãoEm pacientes monitorizados pelo web-loop, não houve associação entre a presença de sintomas específicos e a detecção de arritmias significativas. O monitor de eventos pode ter importância na elucidação de sintomas de palpitações e síncope dos pacientes.Hospital Israelita Albert EinsteinUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

    Attenuation of motor deficits by hydroethanolic extract of Poincianella pyramidalis in a Parkinson's disease model

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    The present study aimed to evaluate the possible neuroprotective effect of the hydroethanolic extract of Poincianella pyramidalis (EFIPp) (Tul.) L. P. Queiroz (Fabaceae), an endemic plant found in Northeastern Brazil, commonly used in folk medicine, on the motor deficits induced by repeated treatment with reserpine (RES) in rats. Adult male Wistar rats received 10 s.c. injections of 0.1 mg/kg RES or vehicle (VR), every 48 h, and daily i.p. injections daily of HEPp (25 mg/kg) or vehicle (VE). Throughout treatment, catalepsy behavior and oral movements were scored. After behavioral tests, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in the prefrontal cortex, hippocampus and striatum. RES treatment induced a progressive increase of catalepsy time in the treated group compared to control groups starting at day 15. RES also increased the number of vacuous chewing movements, tongue protrusions and duration of facial twitching. Treatment with HEPp attenuated the motor deficit in the catalepsy test and delayed the onset of oral movements induced by RES. No significant changes were observed in the antioxidant assay. Taken together, these results show a beneficial effect of HEPp on motor deficits induced by reserpine, suggesting a neuroprotective effect in a rat model of PD.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundação de Apoio a Pesquisa e a Inovação Tecnologica do Estado de Sergipe (FAPITEC)Pro-reitoria de Pesquisa da Universidade Federal de Sergipe (POSGRAP/UFS)Univ Fed Sergipe, Dept Physiol, Sao Cristovao, SE, BrazilUniv Massachusetts, Neurosci & Behav Program, Amherst, MA 01003 USAMinist Educ, CAPES Fdn, BR-70040020 Brasilia, DF, BrazilUniv Fed Sao Paulo, Dept Biosci, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Pharmacol, Sao Paulo, SP, BrazilUniv Fed Sergipe, Dept Biosci, Itabaiana, SE, BrazilUniv Fed Sao Paulo, Dept Biosci, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Pharmacol, Sao Paulo, SP, BrazilWeb of Scienc

    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

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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 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

    Efeito do cimento Portland modificado e MTA na viabilidade de fibroblastos e produção de ciocinas

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    Objetivo: o objetivo desse estudo foi investigar os efeitos da nova formulação do Cimento Portland (CPM) comparando-o ao MTA Angelus na viabilidade celular e liberação de IL-1b e IL-6 em fibroblastos de rato. Métodos: tubos de polietileno preenchidos com os materiais estudados foram colocados em placas de cultura celular de 24 poços com fibroblastos de rato. Tubos vazios foram utilizados como controle. Após 24 horas, ensaio MTT foi utilizado para avaliar a viabilidade celular. Para o ensaio de citocinas, fibroblastos de ratos foram incubados em placas de fundo plano de 24 poços com discos dos materiais no fundo, ou sem material, como controle. Após 24 horas, o meio de cultura foi coletado para a avaliação das citocinas pelo ELISA. Resultados: o CPM e MTA Angelus não inibiram a viabilidade celular. Ambos os materiais induziram liberação de IL-6 e IL-1b e a quantidade foi estatisticamente significativa se comparada ao grupo controle. Conclusão: ambos os materiais não foram citotóxicos em cultura de fibroblastos e induziram a liberação de IL-6 e IL-1b

    Depressant effect of geraniol on the central nervous system of rats: Behavior and ECoG power spectra

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    Geraniol is a monoterpene alcohol that is derived from the essential oils of aromatic plants, with anti-inflammatory, antimicrobial, antioxidant and neuroprotective properties. This study characterized the effect of geraniol on behavior and brainwave patterns in rats. Male rats were submitted to administration of geraniol (25, 50 and 100 mg/kg). The hole board (HB) and open field (OF) tests were performed to evaluate anxiety and motor behavior, respectively. In addition, barbiturate-induced sleeping time (BIST) was used to analyze sedative effect. Finally, electrocorticogram (ECoG) recordings were used to characterize brain-wave patterns. The results showed that geraniol treatment in rats decreased the distance traveled, rearing numbers and lead to increase in immobility time in HB and OF tests. In BIST test, geraniol treatment increased sleep duration but not sleep latency in the animals. Furthermore, geraniol-treated animals demonstrated an increase in the percentage of delta waves in the total spectrum power. Taken together, our results suggested that geraniol exerted a depressant effect on the central nervous system of rats. Keywords: Sedation, Monoterpene, Brain waves, Hypnose, Natural produc
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