Testing extractants for Cu, Fe, Mn, and Zn in tropical soils treated with sewage sludge for 13 consecutive years

In this paper, we report on a field experiment being carried out in a Typic Eutrorthox. The experiment was initiated in the 1997-98 agricultural season as a randomized block design with four treatments (0, 5, 10, and 20 t ha -1) of sewage sludge and five replicates. Compound soil samples were obtained from 20 subsamples collected at depths of 0-0.1 and 0.1-0.2 m. Cu, Fe, Mn, and Zn concentrations were extracted with DTPA pH 7.3; 0.1 mol L -1 HCl, Mehlich-I, Mehlich-III, and 0.01 mol L-1 CaCl 2. Metal concentrations were determined via atomic absorption spectrometry. Diagnostic leaves and the whole above-ground portion of plants were collected to determine Cu, Fe, Mn, and Zn concentrations extracted by nitric-perchloric digestion and later determined via atomic absorption spectrometry. Sewage sludge application caused increases in the concentrations of soil Cu, Fe, and Mn in samples taken from the 0-0.1 m depth evaluated by the extractants Mehlich-I, Mehlich-III, 0.01 mol L-1 HCl and DTPA pH 7.3. None of the extractants provided efficient estimates of changes in Mn concentrations. The acid extractants extracted more Cu, Fe, Mn, and Zn than the saline and chelating solutions. The highest concentrations of Cu, Fe, and Zn were obtained with Mehlich-III, while the highest concentrations of Mn were obtained with HCl. We did not observe a correlation between the extractants and the concentrations of elements in the diagnostic leaves nor in the tissues of the whole maize plant (Zea mays L.). © 2013 Springer Science+Business Media Dordrecht.

Role of Ca, Fe, Cu and Zn in breast cancer: Study by X-ray fluorescence techniques and immunohistochemical analysis

In recent years, several studies have shown that concentrations of trace elements are altered in neoplastic breast tissues. However, the microenvironment and metabolic changes caused by tumors are complex and still not completely understood. Under this aspect, the combination of different techniques to investigate the role of trace elements in promoting and/or maintaining a tumor is interesting once the combination of information obtained by analytical techniques and immunohistochemical assays, associated with clinicopathological data, may allow a better metabolic understanding of trace elements in breast cancer. In this work, the role of the trace elements Ca, Fe, Cu and Zn in neoplastic breast tissues was investigated by X-ray fluorescence (XRF) techniques and immunohistochemical assays. We determined concentrations of Ca, Fe, Cu and Zn in normal and neoplastic breast tissues using energy dispersive XRF, and these values were used to set the positive or negative expression of elements in normal and neoplastic tissues. These expressions were correlated with the spatial distributions of trace elements (evaluated by micro-XRF) and with immunoexpression of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs and vascular endothelial growth factor. The results revealed that the expression of the trace elements Fe, Cu and vascular endothelial growth factor are related, indicating that higher levels of these elements can be associated with the angiogenic process in breast cancer. Also, associations between Ca, Zn and MMPs expression have been observed, possibly because of the fact that both metals are present in these proteins. © 2013 John Wiley & Sons, Ltd.

Acute toxicity and environmental risk of teflubenzuron to Daphnia magna, Poecilia reticulata and Lemna minor in the absence and presence of sediment

This study aimed to estimate the acute toxicity of teflubenzuron (1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea) (TFB) for Daphnia magna, Lemna minor and Poecilia reticulata, in the absence and presence of sediment; evaluate the effect of sediment on the TFB bioavailability; and to classify this insecticide according to its environmental poisoning risk for agricultural and aquaculture uses. The tests of TFB acute toxicity were conducted in static system in a completely randomized design with increasing TFB concentrations, and a control group. The TFB has been classified according to the estimated values of EC50 and LC50 by its acute toxicity and environmental risk. The sediment significantly reduced toxicity and bioavailability of TFB in water column. Therefore, the insecticide can be classified as being highly toxic to Daphnia magna, which means the agricultural and aquacultural uses of TFB pose a high risk of environmental toxicity to non-target organisms. However, it was practically non-toxic to L. minor and P. reticulata. © 2013 Copyright Taylor and Francis Group, LLC.

Simple procedure for nutrient analysis of coffee plant with energy dispersive X-ray fluorescence spectrometry (EDXRF)

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

On the electrochemical behavior of Cu-16%Zn-6.5%Al alloy containing the β'-phase (martensite) in borate buffer

In this work, the electrochemical behavior of Cu-16(wt.%)Zn-6.5(wt.%)Al alloy containing the β'-phase (martensite) was studied in borate buffer solution (pH 8.4) by means of open-circuit potential (EOC), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The alloy EOC was -0.29 V vs. Hg/HgO/OH-, similar to that of pure copper in this medium, indicating that the processes which occur on the alloy surface are mainly governed by copper. EIS response was related to the dielectric and transmission properties of the complex oxide layer. The CVs showed peaks concerning the redox reactions for copper and zinc. These peaks were assigned to the formation and reduction of copper and zinc species. Furthermore, they showed that the copper oxidation was suppressed by the presence of zinc and aluminum in the alloy composition. The copper and zinc oxidation to form complex oxide layers and the reduction of the different metallic oxides generated in the anodic potential scan suggest that a solid state reaction could determine the metallic oxide formation. © 2013 Elsevier Ltd. All rights reserved.

Toxicity of hydramethylnon to the leaf-cutting ant Atta sexdens rubropilosa forel (hymenoptera: Formicidae)

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

Anthropogenic influences on Cd, Cr,Cu, Ni, Pb and Zn concentrations in soils and sediments in a watershed with sugar cane crops at São Paulo State, Brazil

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

PLA and Montmorilonite Nanocomposites: Properties, Biodegradation and Potential Toxicity

The concern related to solid waste increases efforts to develop products based on biodegradable materials. At present, PLA has one of the highest potentials among biopolyesters, particularly for packaging. However, its application is limited in some fields. In order to optimize PLA properties, organo-modified montmorilonites have been extensively used to obtain nanocomposites. Although PLA nanocomposites studies are widely reported in the literature, there is still few information about the influence of organoclays on de biodegradation process, which is a relevant information, since one of the main purposals related to the final disposal of biopolymers as PLA is composting. Besides, in the last years some research has been conducted in order to evaluate the potential toxicity of montmorilonite, unmodified or organo-modified. Since the use of montmorilonite is expanding in different applications, human exposure and risk assessment are important issues to be investigated. In this context, this review intends to compile available information related to common organoclays used for PLA nanocomposites, its properties, biodegradation analysis and potential toxicity evaluation of nanocomposites, focused on montmorilonite as filler. Two issues of relevance were pointed out. The first is food safety and quality, and the second consideration is the environmental effect. © 2013 Springer Science+Business Media New York.

In vivo analgesic activity, toxicity and phytochemical screening of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine

Ethnopharmacological relevance: Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity. Materials and methods: ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated. Results: ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400 mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD 50>400 μg/mL). The extract exhibited free radical scavenging activity as evidenced by IC 50 values (15.9 μg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins. Conclusions: The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant. © 2013 Elsevier B.V. All rights reserved.

Ecotoxicological assessment of sediments from an urban marine protected area (Xixová-Japuí State Park, SP, Brazil)

This study aimed to evaluate the environmental quality of the marine portion of Xixová-Japuí State Park (XJSP), an urban marine protected area, which is influenced by multiple contamination sources, by using ecotoxicological and geochemical analyses. Sediments were predominantly sandy, with low CaCO3 and organic matter contents, and presented contamination by metals (Cd,Cu,Zn). Acute toxicity was detected in three tested samples, and copepod exposed to sediments from four stations exhibited lower fecundities, despite the absence of significant effects. Contamination and toxicity seemed to be associated, suggesting that the environment is degraded and presents risks to the biota. Whole sediment TIE indicated ammonia as a main responsible for toxicity, suggesting sewage is a main contributor to sediment degradation. As external contamination sources seem to be negatively influencing the sediment quality, the park conservation objectives are not being fully reached, demanding actions to mitigate impacts. © 2013 Elsevier Ltd.

Ferritas 'MG IND. 1' - 'delta'ZN''delta''FE' IND. 2'O IND. 4' obtidas por síntese de reação de combustão: caracterização estrutural e nanoestrutural

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

Estudo eletroquímico de uma liga de Cu-Zn-Al, monofásico de fase'beta' poli e monocristalina com orientação (100)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geologia e mineralogia de pegmatito mineralizado em estanho e metais associados (Nb, Ta, Zn, Cu, Pb), Mina Bom Futuro, Rondônia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analiticidade e efeito gráfico da dilatação em funções octoniônicos quaseconformes do tipo F(Z)=Zn

Pós-graduação em Matemática - IBILCE

Mn, Zn e Se associados a moléculas orgânicas na alimentação de galinhas poedeiras no segundo ciclo de produção

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)