Micropoluentes emergentes em águas de abastecimento público : estratégia analítica para priorização de mananciais e diagnóstico preliminar no DF

Tese (doutorado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Química, 2018.Este trabalho teve como objetivos desenvolver uma estratégia para priorização de mananciais, utilizados na produção de água para consumo humano e realizar um diagnóstico inicial quanto a presença de contaminantes em água para consumo humano do Distrito Federal. Na primeira etapa do trabalho empregou-se a cafeína, uma substância indicadora de atividade antrópica, como parâmetro para priorizar ambientes impactados por micropoluentes emergentes. Foi desenvolvido e validado método para quantificação de cafeína em água para consumo humano por LC-MS/MS. O método apresentou-se seletivo e linear (R2>0,99), os limites de detecção e quantificação foram de 0,12 e 0,33 ng L-1, respectivamente, e as recuperações utilizando cartucho SPE C18 foram, em média, de 91 ± 7%. Ensaios de preservação de amostras indicaram a possibilidade de envio de amostras a pH 2 e temperatura ambiente para análise em um laboratório central em até 3 dias. O método foi aplicado em cinco amostras de água para consumo humano no DF e as concentrações variaram de 10 ± 1 a 17,3 ± 0,8 ng L-1. Considerando que altas concentrações de cafeína podem indicar a presença de outros contaminantes, o método foi considerado satisfatório, sendo proposto um kit voltado à coleta de água para consumo humano de diferentes regiões do país. Na segunda parte do trabalho foi desenvolvido e validado método para quantificação de 35 analitos, incluindo fármacos, metabólitos, produtos de higiene pessoal, dentre outros. O método, baseado na quantificação por adição de padrão, mostrou-se preciso e exato para a maior parte dos analitos e foi aplicado em sete amostras de água para consumo humano do DF. Dos 35 analitos avaliados, 20 foram detectados em ao menos uma amostra enquanto que cafeína, DEET e bisfenol A (BPA) apresentaram frequência de detecção de 100%. As concentrações variaram entre 1,20 e 21,98 ng L-1, sendo o nível mais baixo encontrado para estrona (E1) e o nível mais alto para o DEET. Foi realizado uma avaliação de risco ambiental e para a saúde humana através do cálculo de quociente de risco (QR). 17α etinilestradiol (EE2), 17β-estradiol (E2) e E1, apresentaram QRamb superiores a 1,0, indicando risco. Estriol, BPA, atrazina e gemfibrozil apresentaram QRamb superiores a 0,1 indicando a necessidade de mais estudos. Para a saúde humana, EE2 e E2 apresentaram QRhum superiores a 1, indicando risco. Espera-se que os dados obtidos neste trabalho, possam servir de base para a realização de pesquisas futuras de abrangência nacional.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).The objective of this work was to develop a strategy for the prioritization of water sources used in the production of water for human consumption and to carry out an initial diagnosis of the presence of contaminants in drinking water in the Federal District. In the first stage of the work, caffeine, an indicator of anthropic activity, was used as a parameter to prioritize environments impacted by emerging micropollutants. A method was developed and validated for the quantification of caffeine in drinking water by LC-MS/MS. The method was selective and linear (R2> 0.99), the limits of detection and quantification were 0,12 and 0,33 ng L-1, respectively, and recoveries using C18 SPE cartridge were on an average of 91 ± 7%. Specimen preservation tests indicated the possibility of sending samples at pH 2 and at ambient temperature for analysis in a central laboratory within 3 days. This method was applied in five samples of drinking water in the FD and the concentrations ranged from 10 ± 1 to 17,3 ± 0,8 ng L-1. Considering that high concentrations of caffeine may indicate the presence of other contaminants, the method was considered satisfactory, therefore, a kit is being proposed for the collection of drinking water samples from different regions of the country. In the second part of the work, another method was developed and validated for the quantification of 35 analytes, including drugs, metabolites, personal care products, among others. This method, based on standard addition quantification, was accurate for most of the analytes and was applied to seven samples of drinking water from the FD. Of the 35 analyzed analytes, 20 were detected in at least one sample while caffeine, DEET and bisphenol A (BPA) have evidenced a detection frequency of 100%. Concentrations ranged from 1,20 to 21,98 ng L-1, the lowest level found for estrone (E1) and the highest level for DEET. An environmental and human health risk assessment was performed by calculating the risk quotient (RQ). 17α ethinylestradiol (EE2), 17β-estradiol (E2) and E1, had RQamb higher than 1,0, indicating risk. Estriol, BPA, atrazine and gemfibrozil presented RQamb higher than 0,1 indicating the need for further studies. For human health, EE2 and E2 presented QRhum greater than 1, indicating risk. It is hoped that the data obtained in this work could serve as a basis for conducting future surveys of national scope

Desenvolvimento de microssistemas de análise por injeção em fluxo à base de uretana-acrilato para determinações por quimiluminescência

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Química, 2013.Este trabalho descreve o desenvolvimento e avaliação de microssistemas de análise por injeção em fluxo à base de Uretana-Acrilato com célula de detecção por quimiluminescência integrada. A fotolitografia profunda no ultravioleta foi empregada para gravar os canais (largura de 500 μm e profundidade de 440 μm, aproximadamente) em fotoresiste de Uretana-Acrilato (UA), sendo a célula de detecção, em formato de serpentina ou caracol, desenvolvida com diâmetro de 1,0 cm, tamanho adequado ao tamanho dos detectores utilizados. Para a realização de medidas de quimiluminescência, foram utilizados dois fotodiodos (Centronic OSD50-E) e alternativamente foi utilizada uma mini fotomultiplicadora (Hamamatsu -H7468-03). O dispositivo microfluídico proposto suportou vazões de até 3,0 mL/min sem vazamentos e foi avaliado na determinação de peróxido de hidrogênio em soluções padrões, na determinação de hipoclorito em amostras comerciais de água sanitária e na determinação de nitrito em patês comerciais. Os sinais analíticos obtidos para a determinação de peróxido de hidrogênio utilizando detecção com fotodiodos demonstraram uma relação linear (R2=0,99987) para faixa de concentração entre 50 e 200 μmol/L e apresentou frequência analítica 110 injeções/h, enquanto que a determinação utilizando a fotomultiplicadora apresentou uma resposta linear (R2= 0,99999) na faixa de concentrações de 5 a 25 μmol/L e frequência analítica de 150 injeções/h. Para determinação de hipoclorito em amostras comerciais de água sanitária a curva analítica construída a partir dos dados obtidos com o microssistema com detecção por fotodiodos apresentou uma boa resposta linear (R2= 0,99848) na faixa de concentrações de 2 a 20 mg/L e frequência analítica de 80 injeções/h. Para a determinação de nitrito em patês comerciais foi utilizado um microssistema com detecção por fotomultiplicadora, em que os dados obtidos apresentaram uma resposta linear (R2= 0,99965) na faixa de concentração de 10 a 80 μg/L e frequência analítica de 60 injeções/h. Os resultados obtidos nas determinações de hipoclorito e nitrito foram comparados com os respectivos métodos de referência e não apresentaram diferenças significativas ao nível de 95% de confiança. Estes resultados demonstraram a viabilidade de se desenvolver microssistemas de análise por injeção em fluxo com célula de detecção por quimiluminescência integrada. _______________________________________________________________________________________ ABSTRACTThis work describes the development and evaluation of micro flow injection analysis systems based on Urethane – Acrylate photoresist with integrated chemiluminescence detection cell. The deep ultraviolet photolithography was employed to engrave the channels (width of 500 μm and depth of 440 μm, approximately) on plates of Urethane acrylate photoresist - ( UA ), and the detection cell (with serpentine or snail shapes) was developed with 1.0 cm diameter, an appropriate size for adaptation of the used detectors. To perform chemiluminescence measurements, two photodiodes (Centronic OSD50 -E) or, alternatively, a mini photomultiplier (Hamamatsu-H7468-03) were employed. The proposed microfluidic devices can operate with flow rates up to 3.0 ml/min, without leaks, and was evaluated in determining hydrogen peroxide in standard solutions, hypochlorite ions in commercial bleach samples and for the determination of nitrite in commercial pates. The signals obtained for the analytical determination of hydrogen peroxide using photodiodes as transducers demonstrated a linear relationship (R2= 0.99987) in the concentration range between 50 and 200 μmol/L and the analytical throughput of 110 injections/h. The results for the same determination using the photomultiplier showed a linear response (R2=0.99999 ) in the concentration range from 5 to 25 μmol/L and the injection rate of about 150/h. For determination of hypochlorite in commercial bleach samples to the analytical curves obtained with the detection by photodiodes showed a good linear response (R2=0.99848) in the concentration range of 2 - 20 mg/L with analytical frequency of 80 injections/h. The results were compared with the reference method and showed relative deviations of less than 5%. For the determination of nitrite in pates, using a photomultiplier to detect quenching of chemiluminescence, where the data obtained showed a linear response (R2 =0.99965) in the concentration range of 10-80 μg/L and analytical frequency of 60 injections/h. The results were compared with the reference method and no signicant difference was observed in 95% confidence level. These results demonstrated the feasibility of developing microsystems in UA with integrated chemiluminescence detection cells

Seasonal and spatial distribution of caffeine, atrazine, atenolol and DEET in surface and drinking waters from the Brazilian Federal District

Selected emerging contaminants in water samples from the Brazilian capital were investigated by liquid chromatography-mass spectrometry after solid-phase extraction. In Paranoá Lake, an urban reservoir that will be used to produce drinking water, caffeine was the most abundant contaminant found (average of 53 ng L-1), followed by atenolol (34 ng L-1), N, N -diethyl-meta -toluamide (DEET, 12 ng L-1) and atrazine (3.8 ng L-1). The role of wastewaters discharges could not be evidenced probably due to the water flow and circulation in the lake. However, higher concentrations were detected during the dry season suggesting the presence of point sources, except for atrazine. In source waters, concentrations were lower in comparison with Paranoá Lake waters. Environmental risk assessment shows the need for further surveys for atrazine. For drinking waters, only caffeine and atrazine were detected at average concentrations of 8.6 and 3.2 ng L-1, respectively. No risk for human health was observed

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

Neurostimulation Combined With Cognitive Intervention in Alzheimer’s Disease (NeuroAD): Study Protocol of Double-Blind, Randomized, Factorial Clinical Trial

Despite advances in the treatment of Alzheimer’s disease (AD), there is currently no prospect of a cure, and evidence shows that multifactorial interventions can benefit patients. A promising therapeutic alternative is the use of transcranial direct current stimulation (tDCS) simultaneously with cognitive intervention. The combination of these non-pharmacological techniques is apparently a safe and accessible approach. This study protocol aims to compare the efficacy of tDCS and cognitive intervention in a double-blind, randomized and factorial clinical trial. One hundred participants diagnosed with mild-stage AD will be randomized to receive both tDCS and cognitive intervention, tDCS, cognitive intervention, or placebo. The treatment will last 8 weeks, with a 12-month follow-up. The primary outcome will be the improvement of global cognitive functions, evaluated by the AD Assessment Scale, cognitive subscale (ADAS-Cog). The secondary outcomes will include measures of functional, affective, and behavioral components, as well as a neurophysiological marker (Brain-derived neurotrophic factor, BDNF). This study will enable us to assess, both in the short and long term, whether tDCS is more effective than the placebo and to examine the effects of combined therapy (tDCS and cognitive intervention) and isolated treatments (tDCS vs. cognitive intervention) on patients with AD.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02772185—May 5, 2016

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

Chemical and fatty acids composition of rump cap from young bulls fed protected or unprotected oils

Strategies to improve the nutritional aspects of beef, mainly the fatty acids composition, have become an important goal to the scientific community. The use of different oils sources could be an interesting device due its polyunsaturated fatty acids composition. The chemical and fatty acid composition of rump cap (Biceps femoris) from 35 Nellore young bulls finished at feedlot (96 days) were analyzed. These animals were fed a control diet with sugar cane and concentrate without oil or diets containing sugar cane and concentrate with different sources of oil (soybean or linseed), protected or not from ruminal degradation. A randomized block design was adopted with five treatments and seven replications. The means were compared using orthogonal contrasts at 0.05 significance level. Animals fed diets with oil showed higher levels (P&lt;0.05) of protein and lower levels (P&lt;0.05) of ash than control diet. Lower cholesterol (P&lt;0.05) levels resulted from linseed oil added treatment compared to soybean oil (37.70 and 43.80 mg/100 g, respectively); on the other hand, cholesterol levels increased (P&lt;0.05) for protected oils compared to non-protected (44.53 and 33.97 mg/100 g). Oil added diets resulted in higher (P&lt;0.05) linolenic acid levels. Linseed oil increased (P&lt;0.05) the levels of the fatty acids C14:1, C16:1 and C18:1 n9. Addition of linseed oil, whether protected or not, to the animal diets improves the fatty acid composition of the rump cap by increasing the amount of omega-3 fatty acids and improving the omega-6:omega-3 ratio.</span