Application of green zero-valent iron nanoparticles to the remediation of soils contaminated with ibuprofen

Zero-valent iron nanoparticles (nZVIs) are often used in environmental remediation. Their high surface area that is associated with their high reactivity makes them an excellent agent capable of transforming/degrading contaminants in soils and waters. Due to the recent development of green methods for the production of nZVIs, the use of this material became even more attractive. However, the knowledge of its capacity to degrade distinct types of contaminants is still scarce. The present work describes the study of the application of green nZVIs to the remediation of soils contaminated with a common anti-inflammatory drug, ibuprofen. The main objectives of this work were to produce nZVIs using extracts of grape marc, black tea and vine leaves, to verify the degradation of ibuprofen in aqueous solutions by the nZVIs, to study the remediation process of a sandy soil contaminated with ibuprofen using the nZVIs, and to compare the experiments with other common chemical oxidants. The produced nZVIs had nanometric sizes and were able to degrade ibuprofen (54 to 66% of the initial amount) in aqueous solutions. Similar remediation efficiencies were obtained in sandy soils. In this case the remediation could be enhanced (achieving degradation efficiencies above 95%) through the complementation of the process with a catalyzed nZVI Fenton-like reaction. These results indicate that this remediation technology represents a good alternative to traditional and more aggressive technologies.

Remediação de solos contaminados por compostos farmacêuticos

O recente surgimento de nanopartículas de ferro valente-zero (nFZV), um material com elevada capacidade de remediação de solos por via de reacções de oxidação/redução pode ser uma opção viável para a remoção de fármacos do solo. A sua aplicação já é uma realidade em alguns tipos de solos contaminados por compostos específicos e, com este trabalho, procura-se estudar a sua capacidade de remediação de solos contaminados por compostos farmacêuticos, recorrendo-se a uma tecnologia “verde” de síntese destas nanopartículas. Esta tecnologia é bastante recente, ainda não aplicada no campo de trabalho, que se baseia no uso de folhas de certas árvores para produzir extratos naturais que reduzem o ferro (III) a ferro zero valente, formando nFZV. Desta forma procedeu-se, à escala laboratorial, ao estudo da eficiência das nFZV na degradação de um fármaco – paracetamol – e comparou-se com a eficiência demonstrada por oxidantes, muito utilizados hoje em dia em casos de remediação in situ como o permanganato de potássio, o peróxido de hidrogénio, o persulfato de sódio e o reagente de Fenton. O estudo foi efectuado em dois meios diferentes: solução aquosa e solo arenoso. De forma muito sucinta, o estudo baseou-se na introdução dos oxidantes/nFZV em soluções/solos contaminados com paracetamol e consequente monitorização do processo de remediação através de cromatografia líquida de alta eficiência. Nos ensaios com soluções aquosas contaminadas com paracetamol, o permanganato de potássio e o reagente de Fenton revelaram capacidade para degradar o paracetamol, atingindo mesmo um grau de degradação de 100%. O persulfato de sódio também demonstrou uma capacidade de degradação do paracetamol, chegando a atingir 99% de degradação, mas apenas recorrendo ao uso de um volume de oxidante elevado quando comparado com os outros dois oxidantes já referidos. Por outro lado, o peróxido de hidrogénio não demonstrou qualquer capacidade de degradação do paracetamol, pelo que o seu uso não passou desta fase. Verificou-se também que o uso de ferro granulado para o tratamento de água contaminada com paracetamol revelou resultados diferentes dos observados no uso de nFZV, obtendo-se eficiências de 87%. Existiram dificuldades analíticas na quantificação do paracetamol, especificamente relacionadas com o uso do extracto de folhas de amoreira, cuja composição continha substâncias que causaram dificuldades acentuadas na análise dos cromatogramas. Por fim, um pequeno teste de combinação do reagente de Fenton com os fenómenos de biodegradação resultantes dos microrganismos presentes em folhas do extracto de chá preto demonstrou que este pode ser uma área que pode e deve ser mais estudada. Desta forma, a utilização das nFZV para o tratamento de água contaminada com paracetamol não permitiu a retirada de conclusões seguras sobre a capacidade que as nFZV produzidas com extractos de folhas de amoreira e de chá preto têm de degradação do paracetamol. Nos testes de remediação de solos contaminados os resultados demonstraram que, mais uma vez, tanto o permanganato de potássio como o reagente de Fenton se revelam como os melhores oxidantes para a degradação do paracetamol, obtendo-se a degradação total do paracetamol. Por outro lado, voltou a ser necessário uma elevada quantidade de persulfato de sódio quando comparada com os dois anteriores, para que ocorra a degradação desta mesma quantidade de paracetamol, demonstrando mais uma vez que, apesar de não ideal, o persulfato demonstra capacidade de degradação do paracetamol.

What to drink with cheese fondue

Comment on: Heinrich H, Goetze O, Menne D, Iten PX, Fruehauf H, Vavricka SR, Schwizer W, Fried M, Fox M. Effect on gastric function and symptoms of drinking wine, black tea, or schnapps with a Swiss cheese fondue: randomised controlled crossover trial. BMJ. 2010 Dec 14;341:c6731. doi: 10.1136/bmj.c6731. PMID 21156747

Choice of outcome measures in postprandial trials

Comment on: Heinrich H, Goetze O, Menne D, Iten PX, Fruehauf H, Vavricka SR, Schwizer W, Fried M, Fox M. Effect on gastric function and symptoms of drinking wine, black tea, or schnapps with a Swiss cheese fondue: randomised controlled crossover trial. BMJ. 2010 Dec 14;341:c6731. doi: 10.1136/bmj.c6731. PMID 21156747.

A novel method for fast enrichment and monitoring of hexavalent and trivalent chromium at the ppt level with modified silica MCM-41 and its determination by inductively coupled plasma optical emission spectrometry

Chromium(III) at the ng L-1 level was extracted using partially silylated MCM-41 modified by a tetraazamacrocyclic compound (TAMC) and determined by inductively coupled plasma optical emision spectrometry (ICP OES). The extraction time and efficiency, pH and flow rate, type and minimum amount of stripping acid, and break- through volume were investigated. The method's enrichment factor and detection limit are 300 and 45.5 pg mL-1, respectively. The maximum capacity of the 10 mg of modified silylated MCM-41 was found to be 400.5±4.7 µg for Cr(III). The method was applied to the determination of Cr(III) and Cr(VI) in the wastewater of the chromium electroplating industry and in environmental and biological samples (black tea, hot and black pepper).

Astringent Food Compounds and Their Interactions with Taste Properties

Astringency is traditionally thought to be induced by plant tannins in foods. Because of this current research concerning the mechanism of astringency is focused on tannin‐protein interactions and thus on precipitation, which may be perceived by mechanoreceptors. However, astringency is elicited by a wide range of different phenolic compounds, as well as, some non‐phenolic compounds in various foods. Many ellagitannins or smaller compounds that contribute to astringent properties do not interact with salivary proteins and may be directly perceived through some receptors. Generally, the higher degree of polymerization of proanthocyanidins can be associated with more intense astringency. However, the astringent properties of smaller phenolic compounds may not be directly predicted from the structure of a compound, although glycosylation has a significant role. The astringency of organic acids may be directly linked to the perception of sourness, and this increases along with decreasing pH. Astringency can be divided into different sub‐qualities, including even other qualities than traditional mouth‐drying, puckering or roughing sensations. Astringency is often accompanied by bitter or sour or both taste properties. The different sub‐qualities can be influenced by different astringent compounds. In general, the glycolysation of the phenolic compound results in more velvety and smooth mouthdrying astringency. Flavonol glycosides and other flavonoid compounds and ellagitannins contribute to this velvety mouthdrying astringency. Additionally, they often lack the bitter properties. Proanthocyanidins and phenolic acids elicit more puckering and roughing astringency with some additional bitter properties. Quercetin 3‐O‐rutinoside, along with other quercetin glycosides, is among the key astringent compounds in black tea and red currants. In foods, there are always various other additional attributes that are perceived at the same with astringency. Astringent compounds themselves may have other sensory characteristics, such as bitter or sour properties, or they may enhance or suppress other sensory properties. Components contributing to these other properties, such as sugars, may also have similar effects on astringent sensations. Food components eliciting sweetness or fattiness or some polymeric polysaccharides can be used to mask astringent subqualities. Astringency can generally be referred to as a negative contributor to the liking of various foods. On the other hand, perceptions of astringent properties can vary among individuals. Many genetic factors that influence perceptions of taste properties, such as variations in perceiving a bitter taste or variations in saliva, may also effect the perception of astringency. Individuals who are more sensitive to different sensations may notice the differences between astringent properties more clearly. This may not have effects on the overall perception of astringency. However, in many cases, the liking of astringent foods may need to be learned by repetitive exposure. Astringency is often among the key sensory properties forming the unique overall flavour of certain foods, and therefore it also influences whether or not a food is liked. In many cases, astringency may be an important sub‐property suppressed by other more abundant sensory properties, but it may still have a significant contribution to the overall flavour and thus consumer preferences. The results of the practical work of this thesis show that the astringent phenolic compounds are mostly located in the skin fractions of black currants, crowberries and bilberries (publications I–III). The skin fractions themselves are rather tasteless. However, the astringent phenolic compounds can be efficiently removed from these skin fractions by consecutive ethanol extractions. Berries contain a wide range of different flavonol glycosides, hydroxycinnamic acid derivatives and anthocyanins and some of them strongly contribute to the different astringent and bitterness properties. Sweetness and sourness are located in the juice fractions along with the majority of sugars and fruit acids. The sweet and sour properties of the juice may be used to mask the astringent and bitterness properties of the extracts. Enzymatic treatments increase the astringent properties and fermented flavour of the black currant juice and decrease sweetness and freshness due to the effects on chemical compositions (IV). Sourness and sweetness are positive contributors to the liking of crowberry and bilberry fractions, whereas bitterness is more negative (V). Some astringent properties in berries are clearly negative factors, whereas some may be more positive. The liking of berries is strongly influenced by various consumer background factors, such as motives and health concerns. The liking of berries and berry fractions may also be affected by genetic factors, such as variations in the gene hTAS2R38, which codes bitter taste receptors (V).

Antioxidant activities of kombucha prepared from three different substrates and changes in content of probiotics during storage

Kombucha is a health-promoting fermented beverage worldwide. The present study compared the free-radical scavenging abilities and total reducing power (TRP) of kombucha prepared from low-cost green tea (LGTK), black tea (BTK), and tea powder (TPK). LGTK had the highest scavenging abilities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radicals, while BTK showed the highest TRP. Changes in content of probiotics in LGTK were investigated during storage as well. The number of acetic acid bacteria decreased moderately up to 10 days of storage. The number of lactic acid bacteria (LAB) decreased significantly, and their survival rate was only 0.98% at the 8th day of storage.

Estimated dietary intakes and sources of flavanols in the German population (German National Nutrition Survey II)

Background/Objectives Data from intervention studies suggest a beneficial effect of flavanols on vascular health. However, insufficient data on their intake have delayed the assessment of their health benefits. The aim of this study was to estimate intake of flavanols and their main sources among people living in Germany. Subjects/Methods Data from diet history interviews of the German National Nutrition Survey II for 15,371 people across Germany aged 14–80 years were analyzed. The FLAVIOLA Flavanol Food Composition Database was compiled using the latest US Department of Agriculture and Phenol-Explorer Databases and expanded to include recipes and retention factors. Results Mean intake of total flavanols, flavan-3-ol monomers, proanthocyanidins (PA), and theaflavins in Germany was 386, 120, 196, and 70 mg/day, respectively. Women had higher intakes of total flavanols (399 mg/day) than men (372 mg/day) in all age groups, with the exception of the elderly. Similar results were observed for monomers (108 mg/day for men, 131 mg/day for women) and PA (190 mg/day; 203 mg/day), although intake of theaflavins was higher in men (74 mg/day; 66 mg/day). There was an age gradient with an increase in total flavanols, monomers, and theaflavins across the age groups. The major contributor of total flavanols in all subjects was pome fruits (27 %) followed by black tea (25 %). Conclusions This study demonstrated age- and sex-related variations in the intake and sources of dietary flavanols in Germany. The current analysis will provide a valuable tool in clarifying and confirming the potential health benefits of flavanols.

A Nonstaining and Tasteless Hydrophobic Salt of Chlorhexidine

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resíduos da agroindústria de chá preto como substrato para produção de mudas de hortaliças

O objetivo do trabalho foi determinar o efeito do resíduo do chá preto como substrato na produção de mudas de alface, tomate e pepino. Para tal, foram conduzidos testes de germinação e ensaios de crescimento empregando, respectivamente, extrato aquoso e diferentes tipos de resíduo. Nos testes de germinação, sementes de alface, tomate e pepino foram colocadas em bandejas sobre papel de filtro umedecido com água ou extrato aquoso na concentração de 1, 5 e 10%. Nos ensaios de crescimento, sementes das mesmas espécies foram colocadas em bandejas contendo: 1. vermiculita; 2. resíduo decomposto mais vermiculita; 3. resíduo decomposto e 4. resíduo bruto lavado mais vermiculita. O resíduo decomposto foi obtido após processo de decomposição do resíduo bruto e o resíduo bruto lavado foi obtido a partir da lavagem do resíduo bruto em água. Nos testes de germinação e ensaios de crescimento, foi adotado o delineamento experimental inteiramente casualizado com quatro tratamentos e quatro repetições com 30 sementes cada. Os resultados indicaram que o extrato aquoso inibiu a germinação das sementes e o crescimento das plântulas de alface, tomate e penino. O uso do resíduo bruto lavado mais vermiculita reduziu a emergência das plântulas. O resíduo decomposto e o resíduo decomposto mais vermiculita estimularam a emergência e o crescimento das plântulas. O processo de decomposição tornou viável a utilização do resíduo da indústria de chá preto como substrato para produção de mudas de hortaliças.

Chá: aspectos relacionados à qualidade e perspectivas

O chá preto é uma das bebidas mais consumidas no mundo. Essa bebida é feita a partir da infusão de folhas processadas de Camellia sinensis, que é cultivada em mais de 30 países, tendo grande importância socioeconômica. Estudos sugerem que o chá tem efeito protetor contra diversos tipos de câncer e doenças cardiovasculares devido à presença de polifenóis denominados catequinas, que são oxidadas enzimaticamente durante o processamento das folhas, gerando uma mistura constituída principalmente de teaflavinas, teasinensinas e tearubiginas. A produção mundial de chá tem aumentado mais do que o consumo, provocando redução do preço que, juntamente com o aumento no custo de produção, implica a necessidade de alta produtividade e qualidade. Apesar disso, ainda não foram estabelecidos critérios precisos e eficientes para predizer a qualidade do chá a partir das folhas, bem como quais práticas agronômicas contribuem para o aumento da qualidade. No Brasil, a cultura do chá se concentra no Vale do Ribeira, em São Paulo (SP), sendo quase toda produção exportada. Apesar de o produto brasileiro não ser de alta qualidade, tem conseguido bons preços no mercado internacional. A produção brasileira, a área de produção e o número de indústrias de chá vêm diminuindo ao longo dos últimos anos, o que demonstra a necessidade de investimentos.

Eficácia de protocolo de clareamento dental de consultório em função do tempo de contato e uso de fotocatalização

Pós-graduação em Ciências Odontológicas - FOAR

Clareamento dental com perôxido de hidrogênio contendo nano partículas de óxido de titânio como semicondutor: efeito de concentrações, tempos e formas de ativação

Pós-graduação em Ciências Odontológicas - FOAR

Análise in vitro da estabilidade de cor e rugosidade superficial de braquetes ortodônticos cerâmicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da escovação dentária no manchamento de braquetes estéticos cerâmicos

Objective: this study aimed to analyze the in vitro effect of brushing on the color stability of ceramic brackets immersed in dye solutions. Materials and Methods: seven ceramic brackets of four commercial brands were tested: two monocrystalline and two polycrystalline. The parameters of color were obtained by spectrophotometer before and after 21 days of immersion of the brackets in coffee, red wine, Coca-Cola, black tea and artificial saliva. Another group of brackets of each brand were also immersed in the same solutions and for an equal time to the previous group, but with intervals of daily brushing performed by a toothbrushing machine (Mavtec). The data were evaluated by analysis of variance, multiple comparison tests for means and Student's t-test. Results: the mean color change of the brackets without brushing ranged from 0.46 to 7.61, while in the group with brushing these means ranged from 0.36 to 2.50. The staining still remained noticeable (change of color greater than 3.7) for all brackets when immersed in black tea. Conclusion: daily brushing helped significantly in the color stability of ceramic brackets, maintaining the color change to levels considered not visible to the human eye, except for the solution of black tea in which the staining remained relevant.