New voltammetry-based analytical method for indirect determination of procymidone in brazilian apples

Procymidone, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to apple crops. In this work, we propose a reliable and sensitive method to determine procymidone in Brazilian apples. The method involves differential pulse (DPV) and square-wave voltammetry (SWV) techniques on a glassy carbon electrode. In a supporting electrolyte solution of 0.5 mol L−1 NaOH, procymidone undergoes an irreversible one-electron oxidation at +1.42 V by cyclic voltammetric vs. Ag|AgCl, KCl 3 M reference electrode. The proposed DPV and SWV methods have a good linear response in the 8.00–20.0 mg L−1 range, with limits of detection (LOD) of 0.678 and 0.228 mg L−1, respectively, in the absence of the matrix. We obtained improved LOD (0.097 mg L−1) in the presence of apple matrix and the supporting electrolyte solution. We used three commercial apple samples to evaluate recovery, and we achieved recovery percentages ranging from 94.6 to 110 % for procymidone determinations. We also tested the proposed voltammetric method for reproducibility, repeatability, and potential interferents, and the results were satisfactory for electroanalytical purposes.

Desenvolvimento de método limpo para a determinação de uréia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A prática do assistente social na Escola Municipal Adolfo Bezerra de Menezes: uma experiência do município de Uberaba/MG

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Compartimentação morfoestrutural da região do Triângulo Mineiro (MG): aplicado a exploração de recursos hídricos subterrâneos

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

Avaliação geoambiental em áreas de cerrado no triângulo mineiro para implantação de pequenos reservatórios superficiais de água: aplicação na folha de Tupaciguara, MG (1:100.000)

Pós-graduação em Geociências e Meio Ambiente - IGCE

A fabricação do urbano: civilidade, modernidade e progresso em Uberabinha-MG (1888-1929)

Pós-graduação em História - FCHS

A dinâmica do patrimônio cultural e o Museu da Inconfidência em Outro Preto (MG)

Pós-graduação em História - FCHS

Legislação e geotecnologias na definição das áreas de preservação permanente e das reservas legais: aplicação à bacia do Córrego das Posses, município de Extrema - MG

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção do espaço e gestão hídrica na Bacia do Rio Paraibuna (MG-RJ): uma análise crítica

Pós-graduação em Geografia - FCT

Application of carbon composite adsorbents prepared from coffee waste and clay for the removal of reactive dyes from aqueous solutions

A novel carbon composite was prepared from a mixture of coffee waste and clay with inorganic:organic ratio of 1.3 (CC-1.3). The mixture was pyrolysed at 700 °C. Considering the application of this adsorbent for removal of anionic dyes, the CC-1.3 was treated with a 6 mol L^-1 HCl for 24 h to obtain ACC-1.3. Fourier transform infrared (FTIR), N₂ adsorption/desorption curves, scanning electron microscope (SEM) and powder X-ray diffractometry (XRD) were used for characterisation of CC-1.3 and ACC-1.3 carbon adsorbents. The adsorbents were effectively utilised for removal of reactive blue 19 (RB-19) and reactive violet 5 (RV-5) textile dyes from aqueous solutions. The maximum amounts of RB-19 dye adsorbed at 25 °C are 63.59 (CC-1.3) and 110.6 mg g^-1 (ACC-1.3), and 54.34 (CC-1.3) and 94.32 mg g^-1 (ACC-1.3) for RV-5 dye. Four simulated dye-house effluents were used to test the application of the adsorbents for treatment of effluents.

Alternativas ao modelo hegemônico da agricultura: o caso da associação de produtores rurais dos Garcias no município de Bom Repouso (MG)

Pós-graduação em Ciências Sociais - FCLAR

Effects of propofol in lipid-based emulsion and in microemulsion on the incidence of endothelial lesion in rabbits

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

Comparison of initial loading doses of 5 mg and 10 mg for warfarin therapy

CONTEXTO:A melhor dose para o início do tratamento anticoagulante com varfarina vem sendo debatida nos últimos dez anos. Em nosso meio, não observamos nenhum estudo comparativo quanto a estas características.OBJETIVO:Comparar segurança e eficácia de dois esquemas de dosagem inicial de varfarina para tratamento anticoagulante.MÉTODOS:Foram estudados prospectivamente 110 pacientes de ambos os sexos, consecutivos, com indicação de anticoagulação por tromboembolismo venoso ou arterial. Durante os três primeiros dias de tratamento, estes pacientes receberam doses adequadas de heparina (RT - razão dos tempos - alvo entre 1,5 e 2,5) e 5 mg de varfarina, cuja dose foi reajustada a partir do quarto dia pelo Razão Normatizada Internacional - RNI (alvo entre 2 e 3). Esse grupo foi comparado com série histórica de 110 pacientes que receberam 10 mg nos dois primeiros dias, 5 mg a partir do terceiro dia, com ajuste posterior de dose baseado no RNI. Os desfechos foram: recorrência do tromboembolismo, sangramentos e tempo para alcançar níveis terapêuticos.RESULTADOS:A eficácia, a segurança e o tempo de internação foram similares entre os grupos. O grupo que recebeu 10 mg atingiu níveis terapêuticos mais precocemente (média de 4,5 dias × 5,8 dias), sendo as doses na alta menores e os níveis terapêuticos mais adequados na primeira visita de retorno.CONCLUSÃO:O esquema de dosagem de 10 mg proporcionou menor tempo para alcançar nível terapêutico, com menores doses de varfarina na alta e RNI mais adequado no retorno.

Espécies de Meloidogyne Goeldi em cafeeiro no município de Araguari-MG

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Comparison of Physicochemical Surface Conditioning Methods for Adhesion of bis-GMA Resin Cement to Particulate Filler Composite and Surface Characterization

This study compared the effect of physicochemical surface conditioning methods on the adhesion of bis-GMA-based resin cement to particulate filler composite (PFC) used for indirect dental restorations. PFC blocks (N (block)=54, n (block)=9 per group) were polymerized and randomly subjected to one of the following surface conditioning methods: a) No conditioning (Control-C), b) Hydrofluoric acid (HF)etching for 60s (AE60), c) HF for 90s (AE90), d) HF for 120s (AE120), e) HF for 180s (AE180), and f) air-abrasion with 30 mu m silica-coated alumina particles (AB). The conditioned surfaces were silanized with an MPS silane, and an adhesive resin was applied. Resin composite blocks were bonded to PFC using resin cement and photo-polymerized. PFC-cement-resin composite blocks were cut under coolant water to obtain bar specimens (1mmx0.8mm). Microtensile bond strength test (mu TBS)was performed in a universal testing machine (1mm/min). After debonding, failure modes were classified using stereomicroscopy. Surface characterization was performed on a set of separate specimen surfaces using Scanning Electron Microscopy (SEM), X-Ray Dispersive Spectroscopy (XDS), X-Ray Photoelectron Spectroscopy (XPS), and Fourier Transform-Raman Spectroscopy (FT-RS). Mean mu TBS (MPa) of C (35.6 +/- 4.9) was significantly lower than those of other groups (40.2 +/- 5.6-47.4 +/- 6.1) (p<0.05). The highest mu TBS was obtained in Group AB (47.4 +/- 6.1). Prolonged duration of HF etching increased the results (AE180: 41.9 +/- 7), but was not significantly different than that of AB (p>0.05). Failure types were predominantly cohesive in PFC (34 out of 54) followed by cohesive failure in the cement (16 out of 54). Degree of conversion (DC) of the PFC was 63 +/- 10%. SEM analysis showed increased irregularities on PFC surfaces with the increased etching time. Chemical surface analyses with XPS and FT-RS indicated 11-70% silane on the PFC surfaces that contributed to improved bond strength compared to Group C that presented 5% silane, which seemed to be a threshold. Group AB displayed 83% SiO2 and 17% silane on the surfaces.