19 research outputs found

    Environmental impact monitoring of a minero-chemical complex in Catalão urban area of PTS, PM10 and PM2.5 by EDX characterization

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    Depending on its nature, particulate matter has very different size, composition and morphology. By the combination of these criteria it is possible to distinguish the emitting sources (primary or secondary). The shape and the dimension of the particles have also a direct interaction with the risk assessment for human health. The minero-chemical complex consists of phosphate fertilizer manufacturing, rock phosphate and niobium mining open pits and it is located northeast of the urban area of the city. Environmental issues associated with it include the following: fugitive emissions which are primarily associated with operational leaks from tubing, valves, connections, flanges, packings, open ended lines, floating roof storage tank and pump seals, gas conveyance systems, compressor seals, pressure relief valves, tanks or open its/containments, and loading and unloading operations of products. Furthermore the area of study is characterized by a predominantly northeast winds direction. The monitoring was performed weekly particulates samples were collected in two seasonal episodes at one representative places in the urban area of Catalao (a Brazilian city located in Goias state) in the period from August to November of 2014. Suspended particles were sampled on pure fiberglass filters by using a High Volume air sampler and were analyzed via an energy dispersive X-ray microanalysis system (EDX). The airborne particulate matter was characterized from a physico-chemical point of view to supply information on the particle composition and the compounds carried on their surfaces. The microanalysis enables identification of several groups of particles such as: soot, Si-rich, metal-rich and biological particules. These results may help in controlling and preventing fugitive emissions in atmospheric air.Depending on its nature, particulate matter has very different size, composition and morphology. By the combination of these criteria it is possible to distinguish the emitting sources (primary or secondary). The shape and the dimension of the particles h4319091914CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSsem informaçãosem informaçãoFinancial support and scholarships from the Brazilian funding agencies CNPq, FAPEG and Environment Office City of Catalão, City Council Environmental Protection of Catalão and Public Ministry of Goiás State are gratefully acknowledged

    Prevalence of antibodies against Chlamydophila spp. in herds with bovine abortion of Paraná state, Brazil

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    Chlamydophila abortus é o agente etiológico do aborto epizoótico bovino, cujas manifestações clínicas mais freqüentes são aborto, nascimento de bezerros prematuros e de animais fracos, natimorto e repetição de cio em intervalos irregulares. O objetivo deste trabalho foi estimar a prevalência de anticorpos anti-Chlamydophila spp. em fêmeas bovinas de propriedades rurais com histórico de aborto, selecionadas dentro do delineamento amostral do Plano Nacional de Controle e Erradicação da Brucelose e Tuberculose no estado do Paraná. Foram testadas pela prova de fixação de complemento 3.102 amostras de soro de fêmeas bovinas (idade > 24 meses), provenientes de 373 propriedades. Ao total, 44 (1,42%) animais foram positivos com títulos > 32. A prevalência de focos foi de 8,82% (6,15%-12,17%). Animais confinados ou semi-confinados (OR=3.339, P=0.004), propriedade com menos de 35 matrizes (OR=3.339, P=0.017), presença de produtos do aborto na pastagem (OR=2.372, P=0.037) e aluguel de pasto (OR=3.398, P=0.006) foram considerados fatores de risco para Chlamydophila spp. A infecção por Chlamydophila spp. acometeu um número pequeno de animais, oriundos de propriedades com histórico de aborto. A importância deste agente como causa de aborto em bovinos no estado do Paraná, se existir, é muito pequena.Chlamydophila abortus is a recognized cause of bovine epizootic abortion. Abortion, premature birth and weak lamb/calf, stillbirth and repeat breeding in irregular intervals are the most frequent disease manifestations. The complement fixation test is the recommended by the World Organization of Animal Health (OIE) for Chlamydophila spp. serologic diagnosis. The aim of this study was estimate the prevalence of antibodies against Chlamydophila spp. in cattle herds with abortion, selected inside the sampling design of National Program of Control and Erradication of Brucellosis in Paraná state. Serum samples of 3,102 cows (age > 24 months) from 373 herds were analyzed by complement fixation test. Totally, 44 (1.42%) animal were positive with titers > 32. The seroprevalence of Chlamydophila spp. in the herds was 8.82% (6.15%-12.17%). Four variables were associated with seroprevalence for Chlamydophila spp. in the final model of logistic regression: confined or semi-confined breeding (OR=3.339, P=0.004), farms with less than 35 cows (OR=3.339, P=0.017), abortion in the pasture (OR=2.372, P=0.037) and pasture rent (OR=3.398, P=0.006) were risk factors for Chlamydophila spp. This bacterium infected a small number of cattle from herds with abortion in Paraná state. Chlamydophila spp impact as abortion cause is reduced in this state

    Arachnids of medical importance in Brazil: main active compounds present in scorpion and spider venoms and tick saliva

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    Solid state NMR characterization of NaNbO3 and LiNbO3 nanoparticles obtained by microwave-assisted combustion

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    Nanoparticles of LiNbO3 and NaNbO3 were obtained for the first time by microwave-assisted combustion. Preliminary experiments reveal that the synthetic conditions influence their microstructure and optoelectronic features. Therefore, there is a need for performing the structural characterization of these materials, obtained by this new route. In the case of NaNbO3, there are two polimorphs which are stable at room temperature, space groups P21ma and Pbma. Powder x-Ray diffraction experiments were not capable to identify the crystalline phases present in the nanoparticles. Therefore, we have performed a detailed structural characterization of the nanoparticles by 1D and 2D solid state 23Na and 93Nb Nuclear Magnetic Resonance (NMR) techniques. 23Na results reveal the presence of both phases, Pbma and P21ma, for samples prepared using NaNO3 precursor in a 1:1 Na:Nb ratio or NaCl in excess. On the other hand, the P21ma polymorph could be isolated in the synthesis using NaCl salt in 1:1 Na:Nb ratio. On the other hand, LiNbO3 nanoparticles display the usual rhombohedral structure R3c. 7Li MAS NMR results reveal the presence of two types of Li species, with distinct dynamics. Highly mobile Li+ ions are found at the surface of the nanoparticles, while bulk Li+ show restricted movement. Finally, as a proof of principle, the photocatalytic activity of these niobates was tested for the degradation of methylene blue dye, a common organic-water contaminant

    Synthesis, theoretical calculation and anticancer activity of 4,6-diacetylresorcinol-dithiocarbazates and their Copper(II) complexes

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    The present work reports the synthesis and structural elucidation of two dithiocarbazate ligands derived from 4,6-diacetylresorcinol (H3L1) and (H3L2) and two Cu(II) complexes, [Cu(μ-HL1)]2 (1) and [Cu(μ-HL2)]2 (2). These compounds were studied by the Density Functional Theory with which it was possible to identify their lowest energy conformations. With the optimized configurations, the UV–vis, HOMO, LUMO and gap properties were determined and compared with the experimental data. Energy calculations for the compounds were useful to determine binding sites and predicting the reactivity of the compounds. The experiment ESI (+) - MS/MS revealed dinuclear structures of the complexes. The set of spectroscopic analysis agreed with the proposed theoretical structures. The antitumor activity and selectivity of free dithiocarbazates and their Cu(II) complexes were evaluated against MCF-7, PBMC and healthy cells. In all tests, a higher activity of the complexes over free ligands was observed, which agrees with the predicted theory

    Structural Design, Anticancer Evaluation, and Molecular Docking of Newly Synthesized Ni(II) Complexes with <i>ONS</i>-Donor Dithiocarbazate Ligands

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    The current article reports the investigation of three new Ni(II) complexes with ONS-donor dithiocarbazate ligands: [Ni(L1)PPh3] (1), [Ni(L2)PPh3] (2), and [Ni(L2)Py] (3). Single-crystal X-ray analyses revealed mononuclear complexes with a distorted square planar geometry and the metal centers coordinated with a doubly deprotonated dithiocarbazate ligand and coligand pyridine or triphenylphosphine. The non-covalent interactions were investigated by the Hirshfeld surface and the results revealed that the strongest interactions were π⋅⋅⋅π stacking interactions and non-classical hydrogen bonds C–H···H and C–H···N. Physicochemical and spectroscopic methods indicate the same structures in the solid state and solution. The toxicity effects of the free ligands and Ni(II) complexes were tested on the human breast cancer cell line MCF-7 and non-malignant breast epithelial cell line MCF-10A. The half-maximal inhibitory concentration (IC50) values, indicating that the compounds were potent in inhibiting cell growth, were obtained for both cell lines at three distinct time points. While inhibitory effects were evident in both malignant and non-malignant cells, all three complexes demonstrated lower IC50 values for malignant breast cell lines than their non-malignant counterparts, suggesting a stronger impact on cancerous cell lines. Furthermore, molecular docking studies were performed showing the complex (2) as a promising candidate for further therapeutic exploration
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