Performance Evaluation of Active and Non-active Electrodes for Doxorubicin Electro-oxidation

Electrochemical remediation is an innovative technique that utilizes electro-oxidation reactions to degrade micropollutants such as doxorubicin (DOX) that is a drug widely used to treat many types of cancer,  and it is present in hospital effluents. The aim   of this work is to evaluate the efficiency of active and non-active electrodes in DOX degradation during electrochemical treatments. AuO-TiO2@graphite, a nanostructured electrode, and BDD, a commercial electrode, were used as active and non-active electrodes respectively. DOX treatments were realized at concentration of 1.25 mmol L-1 in medium with 10 mmol L-1 NaCl as support electrolyte. Studies were realized in 5 V of voltage source. Results: The treatment of DOX with BDD promoted 100% of DOX degradation in 20 min, while the same result was obtained for the AuO-TiO2@graphite in 40 min of treatment. Also, the modified electrode presented an energy expenditure of 1.12 kWh m-3 and the BDD achieved 0.462 kWh m-3. Thus, the active and non-active electrodes were efficient to promote DOX degradation, and the BDD, the non-active electrode demonstrated a better performance. Keywords: Eletro-Oxidadion, Modified Graphite Anodes, BDD, Doxorubicin, Micropollutant

Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection

The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 M (r = 0.99), showing detection limits of 0.4 M. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compound

Differential pulse voltammetric determination of albendazole and mebendazole in pharmaceutical formulations based on modified sonogel carbon paste electrodes with perovskite-type LaFeO3 nanoparticles.

Benzimidazoles, such as albendazole (AB) and mebendazole (MB), are common anthelmintic agents, widely used throughout the world to combat parasitic diseases. The electroanalytical sensing of AB and MB based on Perovskite-Type LaFeO3 nanoparticles modified sonogel carbon paste electrodes has been reported for the first time. Perovskite-type LaFeO3 nanoparticles were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD indicates the formation of monophase perovskite LaFeO3 and FT-IR spectrum shows a band at 570 cm-1 which is associated to the formation of lanthanum ferrite. Microscopy images show that the distribution in pore size and shape is not well defined. The particles sizes are found to be above 200 nm. It was found that sonogel carbon paste modified electrodes with Perovskite-type LaFeO3 nanoparticles exhibit higher catalytic activity and sensitivity toward the detection of AB and MB compared to the unmodified electrode. The limits of detection for albendazole and mebendazole were reported to be 0.3 μM and 0.6 μM respectively and the limits of quantification 0.8 μMand 1.7 μMrespectively. The electroanalytical protocol was successfully applied for the sensing of AB and MB in pharmaceutical formulations

Cardiomiopatia de Takotsubo: uma breve revisão sistemática: Takotsubo Cardiomiopathy: a brief systematic review

A cardiomiopatia de Takotsubo é uma nova cardiomiopatia que foi noticiada pela primeira vez em 2001. A doença é definida por disfunção reversível do ventrículo esquerdo e manifesta-se normalmente como uma síndrome coronária aguda. Este estudo teve como objetivo discutir as principais características da cardiomiopatia takotsubo. Para isso, foi desenvolvida uma revisão sistemática de literatura, recorrendo-se às bases de dados Scielo, Medline e Lilacs, selecionando-se estudos publicados nos últimos 5 anos. A partir da análise e interpretação dos dados das fontes foi possível concluir que a cardiomiopatia de takotsubo é desencadeada pelo estresse físico e é vista como uma complicação para outras doenças não cardíacas, se apresentando geralmente em mulheres pós-menopausa, acima dos 70 anos de idade. Manifesta-se com início súbito de dor torácica e dispneia, após um evento emocional estressante que precede o início dos sintomas. Com principais consequências, tem-se choque cardiogênico, obstrução da via de saída do ventrículo esquerdo, trombo da parede ventricular esquerda, arritmias ventriculares, ruptura da parede ventricular e paragem cardíaca, registrando-se alguns casos de morte súbita

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

Bio-electrochemical remediation of synthetic sex hormone 17-a- ethinylestradiol

Submitted by Marlene Santos ([email protected]) on 2016-06-08T18:45:11Z No. of bitstreams: 2 Dissertação - Luane Ferreira Garcia - 2016.pdf: 1247655 bytes, checksum: 7639a387a5a3d1f4157419202b05240e (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2016-06-09T11:35:52Z (GMT) No. of bitstreams: 2 Dissertação - Luane Ferreira Garcia - 2016.pdf: 1247655 bytes, checksum: 7639a387a5a3d1f4157419202b05240e (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5)Made available in DSpace on 2016-06-09T11:35:52Z (GMT). No. of bitstreams: 2 Dissertação - Luane Ferreira Garcia - 2016.pdf: 1247655 bytes, checksum: 7639a387a5a3d1f4157419202b05240e (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2016-03-28Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESHormones are released constantly in sewage, originated by of human/animal excreta, or waste of pharmaceutical industries, not treated satisfactorily. The eviction of these pollutants in water resources produces great environmental impact, as disruption in animals’ endocrine system. The 17α-ethinylestradiol (EE2) is the most popular synthetic estrogen, which is found in water and in considerable concentrations. Several strategies are being studied to remedy this pollutant. Enzymes as laccases, which have low specificity, are able to oxidize various pollutants, thus suggesting their potential in the treatment of effluents. Another alternative are the electrochemical processes as electro-oxidation and electrocoagulation. The aim of this study was to evaluate the removal efficiency of the EE2 for biological or/and electrochemical process. The crude extract containing the laccase from Pycnoporus sanguineus was immobilized in Ca/Cu-alginate-chitosan beads. For partial characterization were determined optimum pH and optimum temperature of enzyme activity, for free and immobilized enzyme. Biological remediation was performed in these conditions: shaking (100 rpm); temperature at 28°C (± 2); times of 4, 8 and 24 hours; EE2 solution buffered at pH 4 and 5, and EE2 solution without addition of buffer. For the electrochemical remediation: magnetic stirring; voltage of 2.5, 5 and 7.5 V; times of 10, 20 and 40 minutes; pHs 5 and 7. For bio-electrochemical remediation the best conditions were used. In the remediation assays of the EE2 with immobilized enzyme, the best result was obtained for the support Ca-alginate-chitosan with 89.81% (± 2.71) removal, in sodium acetate buffer pH 5.0 and 24 hours of treatment. Under the same conditions to the free enzyme, 91.81% (± 0.86) of removal was obtained. For electrochemical remediation with titanium electrode, 86.21% (± 9.30) was removed in pH 7 phosphate buffer and 40 minutes. For sequential bio-electrochemical remediation, EE2 concentrations were below the limit of detection of the chromatograph, with the removal by immobilized enzyme acting in unbuffered solution. It can be concluded that the two technologies are very effective for the removal of the EE2.Hormônios são lançados constantemente em esgotos, sejam oriundos de excretas humanas ou animais, sejam de resíduos provenientes das indústrias farmacêuticas, não tratados de forma eficaz. O despejo destes micropoluentes nos recursos hídricos produz grande impacto ambiental, como desregulação do sistema endócrino em animais. O 17α-etinilestradiol (EE2) é o mais popular estrogênio sintético, sendo encontrado nos recursos hídricos em concentrações consideráveis. Diversas estratégias estão sendo estudadas para remediação deste poluente. Enzimas como as lacases, que possuem baixa especificidade, são capazes de oxidar diversos poluentes, sugerindo assim seu potencial no tratamento de efluentes. Outra alternativa são os processos eletroquímicos, como a eletro-oxidação e eletrocoagulação. Sendo assim, o objetivo deste trabalho foi avaliar a eficiência de remoção do EE2 por processo biológico ou/e eletroquímico. O extrato bruto contendo a lacase de Pycnoporus sanguineus foi imobilizado em beads de quitosana-alginato-Ca/Cu. Para caracterização parcial da enzima livre e imobilizada foram determinados pH e temperatura ótima de atividade enzimática. A remediação biológica foi realizada nas condições: agitação (100 rpm); temperatura em 28°C (± 2); tempos de 4, 8 e 24 horas; solução de EE2 tamponada em pHs 4 e 5, e solução do hormônio sem adição de tampão. A remediação eletroquímica: agitação magnética; tensão de 2,5, 5 e 7,5 V; tempos de 10, 20 e 40 minutos; solução de EE2 tamponada em pHs 5 e 7. Para remediação bio-eletroquímica, de modo sequencial, foram utilizadas as condições mais adequadas para ambas as tecnologias. Nos ensaios de remediação do hormônio EE2 com a enzima imobilizada, o melhor resultado foi obtido para beads de quitosana-alginato-Ca com remoção de 89,81% (± 2,71) em tampão acetato de sódio pH 5 e 24 horas de tratamento. Nas mesmas condições, para a enzima livre foi obtido 91,81% (± 0,86) de remoção. Para remediação eletroquímica, com eletrodo de titânio foi removido 86,21% (± 9,30) do EE2, em tampão fosfato pH 7 e 40 minutos. Para a remediação bio-eletroquímica em modo sequencial, obteve-se remoção do EE2 em concentrações abaixo do limite de detecção do cromatógrafo, com a enzima imobilizada atuando em solução não tamponada. Conclui-se que as duas tecnologias são bastante eficientes para a remoção do EE2, podendo ser utilizadas separadamente ou em conjunto