Elemental characterization of sparkling wine and cork stoppers

The variations of the elemental concentrations in sparkling white wine and respective cork stoppers throughout 18 months of storage time were determined with the PIXE (Particle-Induced X-ray Emission) technique. Three portions of the cork stoppers were analyzed: the top part (external layer), the inner part (bulk layer) and the bottom layer (which was in contact with the sparkling wine). Elements such as Na, Mg, Si, P, S, Cl, K, Ca, Mn, Fe, Zn and Rb were determined for both cork stoppers and sparkling wine samples. Similar concentrations of Si, P, S, Cl and Ca were found in the external and bottom layers of the corks. Distinct behaviors of the changes in the elemental concentrations as a function of the time were observed for cork stoppers and sparkling wines. The concentrations of Mg, S, K, Ca, Cu, Sr and Ba increased in the bottom layer of the cork as a function of storage time. On the other hand, concentrations of Al, Si, Cl, Ti, Zn and Br proved to be invariant, while the concentrations of P and Fe showed a slight decrease. Concerning the sparkling wine, an increasing trend of elemental concentrations was observed for most elements throughout the storage time. A diffusion mechanism of elements in the cork and the role of the secondary fermentation in the bottle are discussed

The potentialities of ultrasound as an alternative to chemical etching for proton beam writing micropatterning

In this paper, we explore the potentialities of using ultrasound waves as a post-irradiation treatment after proton beam writing (PBW) patterning of PTFE. To that end, 2-mm-thick foils of PTFE were irradiated with 2.2 MeV protons with an average current of 50 pA. Straight line structures were patterned on the polymer with a 3.5 × 3.5 μm2 focused proton beam. Post-irradiation polymers were placed in a heat bath at 60 °C and immersed either in distilled water or in a 6 M solution of NaOH under the action of 40 kHz ultrasound waves for developing the patterned structures. The results indicate that distilled water submitted to ultrasound waves is very efficient for removing rough structures created by the proton irradiation and thus providing a good aspect ratio to the PBW microstructures. On the other hand, the use of 6 M NaOH instead of water did not improve the quality of the structures patterned with the proton beam. The results are discussed in terms of the parameters that characterize the interaction of ultrasound waves with the liquid media and the polymer

Variance of elemental concentrations of organic products : the case of Brazilian coffee

Elemental composition can be used to help determining the origin and quality of food and beverage. The present study aims to investigate the variation of the elemental composition of a Brazilian coffee brand across different production batches. To that end, 102 samples from 11 different batches of “Melitta Tradicional” roasted ground coffee were analyzed using the Particle-Induced X-ray Emission (PIXE) technique. The concentrations of Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu, Zn and Rb were determined. Differences in the elemental concentrations between at least two batches were observed for all investigated elements but Ti. For elements such as Cl, Ca, Cu and Rb the concentration varied over 50% between batches. The differences observed among batches indicate that the characterization of coffee by brand or origin is not a straightforward task

Gambling as a teaching aid in the introductory physics laboratory

Dice throwing is used to illustrate relevant concepts of the statistical theory of uncertainties, in particular the meaning of a limiting distribution, the standard deviation, and the standard deviation of the mean. It is an important part in a sequence of especially programmed laboratory activities, developed for freshmen, at the Institute of Physics of the University of S˜ao Paulo. It is shown how this activity is employed within a constructive teaching approach, which aims at a growing understanding of the measuring processes and of the fundamentals of correct statistical handling of experimental data

Elemental concentration of tomato paste and respective packages through particle-induced X-ray emission

The elemental concentrations of three brands of Brazilian tomato paste packed in cans and Tetra Pak® cardboard boxes were determined through the Particle-Induced X-ray Emission (PIXE) technique. The elements Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br and Rb were identified in the tomato pastes. The metallic cannisters are characterized primarily by the presence of Fe and Sn, while several elements including Al, Cl, Ti, Fe and Zn showed up in Tetra Pak® boxes. The elemental concentrations of tomato paste varied significantly among different brands and packages. The major elements present in tomato paste are Na, Cl and K with concentrations ranging from 1700 mg/kg up to 7500 mg/kg, while trace elements like Br and Rb had average concentrations around 2 mg/kg. Tomato paste from different brands and packages stored for long periods of time were evaluated as well. Canned tomato paste showed distinct rising and decreasing trends of Fe and Al concentrations as a function of the storage time respectively. Possible transfer mechanisms are discussed

Basal levels of inorganic elements, genetic damages, and hematological values in captive Falco peregrinus

It is essential to determine the basal pattern of different biomarkers for future evaluation of animal health and biomonitoring studies. Due to their great displacement capacity and to being at the top of their food chains, birds of prey are suitable for monitoring purposes. Furthermore, some birds of prey are adapted to using resources in urban places, providing information about this environment. Thus, this study determined the basal frequency of micronuclei and other nuclear alterations in peripheral blood erythrocytes of Falco peregrinus. Hematological and inorganic elements analysis were also performed. For this purpose, 13 individuals (7 females and 6 males) were sampled in private breeding grounds. Micronucleus, nuclear buds, nucleoplasmic bridges, notched nuclei, binucleated cells and nuclear tails were quantified. Inorganic elements detected included the macro-elements Ca, P, Mg, Na, Cl, S and K as well as the micro-elements Fe, Al and Zn. Our study found similar values compared to previous studies determining the reference ranges of hematologic parameters in falcons. The only different value was observed in the relative number of monocytes. Thus, this study is the first approach to obtaining reference values of cytogenetic damage in this species and could be useful for future comparisons in biomonitoring studies

Quantificação de elementos presentes na raiz e parte aérea de plantas de arroz submetidas a estresse por excesso de ferro

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From: Larry Roberts (enclosure)

Illegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed to provide early warning for public health. Furthermore, the elemental profile of the seized products can be useful in criminal investigations. For the first time an ion beam analysis (IBA) procedure to characterise authentic Viagra® tablets and sildenafil-based illegal products is described. Moreover, results are compared with the ones obtained by instrumental neutron activation analysis (INAA) on authentic Viagra® tablets in two reactors. IBA results showed that a combination of particle-induced X-ray emission (PIXE) and secondary ion mass spectrometry using primary ions with energies in the range of several MeV (MeV-SIMS) is a powerful tool to characterise different products in a straightforward manner, allowing discrimination between legal and illegal products. INAA allowed accurate elemental quantification and also showed a great potential for the future implementation of an inter- laboratory classification system

Presença de metais em erva-mate

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Papel da ferritina na tolerância de arroz ao excesso de ferro

Deficiência de ferro (Fe) ocorre freqüentemente em plantas, uma vez que este mineral é pouco disponível em condições aeróbicas. Plantas de arroz cultivadas sob alagamento, no entanto, estão sujeitas ao excesso de Fe, que pode ser extremamente tóxico. Alguns cultivares de arroz são resistentes a altas concentrações de ferro, mas os mecanismos fisiológicos responsáveis por essa resistência são pouco conhecidos. A ferritina é uma proteína de ampla distribuição e capaz de armazenar ferro, sendo considerada importante para a homeostase deste metal. Acúmulo de ferritina em condições de alta disponibilidade de ferro já foi descrito em algumas espécies vegetais. Entretanto, o papel da ferritina no mecanismo de tolerância de plantas de arroz ao excesso de ferro não é conhecido. Neste trabalho, expressamos ferritina de arroz em E. coli, produzimos um anticorpo policlonal anti-ferritina de arroz e este foi utilizado para avaliar o acúmulo de ferritina em dois cultivares de arroz (Oryza sativa) considerados suscetível (BR-IRGA 409) e tolerante (EPAGRI 108) ao excesso de ferro. O anticorpo foi capaz de reconhecer ferritina purificada de sementes de ervilha, assim como ferritina de folhas de arroz. Aumentos nos níveis de mRNA e proteína foram observados nos dois cultivares sob excesso de ferro, com maior acúmulo da proteína no cultivar EPAGRI 108. Quando submetidas a excesso do elemento, plantas deste mesmo cultivar atingiram concentrações de Fe mais baixas do que plantas do cultivar BR-IRGA409, principalmente nas partes aéreas. Sugere-se que o mecanismo de tolerância ao excesso de ferro no cultivar EPAGRI 108 inclui limitação da translocação de Fe e aumento do acúmulo de ferritina. Este é o primeiro trabalho que mostra maior acúmulo da proteína ferritina em um cultivar de Oryza sativa tolerante ao excesso de Fe, fornecendo evidência de um possível papel desta proteína nos mecanismos de tolerância a este metal.Plants ordinarily face iron (Fe) deficiency, since this mineral is poorly available in soils under aerobic conditions. Nonetheless, wetland and irrigated rice plants can be exposed to excess, highly toxic Fe. Ferritin is a ubiquitous Fe-storage protein, important for iron homeostasis. Increased ferritin accumulation resulting from higher Fe availability was shown in some plant species. However, the role of ferritin in tolerance mechanisms to Fe overload in rice is yet to be established. In this study, recombinant rice ferritin was expressed in Escherichia coli, producing an anti-rice ferritin polyclonal antibody which was used to evaluate ferritin accumulation in two rice (Oryza sativa L.) cultivars, either susceptible (BR-IRGA 409) or tolerant (EPAGRI 108) to Fe toxicity. Increased ferritin mRNA and protein levels resulting from excess Fe treatment were detected in both cultivars, with higher ferritin protein accumulation in EPAGRI 108 plants, which also reached lower shoot Fe concentrations when submitted to iron overload. The tolerance mechanism to excess Fe in EPAGRI 108 seems to include both restricted Fe translocation and increased ferritin accumulation. This is the first work that shows higher accumulation of the ferritin protein in an iron-excess tolerant Oryza sativa cultivar, providing evidence of a possible role of this protein in iron tolerance mechanisms