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Search Results: 1 - 10 of 418909 matches for " Robson José de Cássia Franco Afonso "
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Determination of PAHs in Surface Waters from the Doce and Piracicaba Rivers in Brazil  [PDF]
Aniel da Costa Lima, Fernanda Fernandes Heleno, Robson José de Cássia Franco Afonso, Mauricio Xavier Coutrim
Journal of Water Resource and Protection (JWARP) , 2015, DOI: 10.4236/jwarp.2015.75034
Abstract: Sixteen polycyclic aromatic hydrocarbons were determined in water samples from the Piracicaba River and the Doce River in the municipality of Ipatinga, Minas Gerais State, Brazil. The polycyclic aromatic hydrocarbons were extracted by solid-phase extraction and were analyzed by high-performance liquid chromatographic with diode-array detector. The limit of detection was as low as 1.3 ng·L-1. All polycyclic aromatic hydrocarbons were found above the limit of quantification in water from at least four of the eight sampling points. Benzo[a]pyrene and chrysene were found at concentrations up to 80% above the limit set by Brazilian and European environmental legislation (0.05 μg·L-1). The isomer ratios of the compounds indicated that crude oil and combustion processes were the main sources of the polycyclic aromatic hydrocarbons.
High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products  [PDF]
Frederico Jehár Oliveira Quint?o, Geraldo Célio Brand?o, Silvana de Queiroz Silva, Sérgio Francisco Aquino, Robson José de Cássia Franco Afonso
American Journal of Analytical Chemistry (AJAC) , 2017, DOI: 10.4236/ajac.2017.84020
Abstract: The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.
Caracteriza??o de contaminantes presentes em sistemas de tratamento de esgotos, por cromatografia líquida acoplada à espectrometria de massas tandem em alta resolu??o
Leite, Gustavo de Sousa;Afonso, Robson José de Cássia Franco;Aquino, Sérgio Francisco de;
Química Nova , 2010, DOI: 10.1590/S0100-40422010000300044
Abstract: this work shows results on the characterization, by liquid chromatography coupled to high resolution tandem mass spectrometry (lc-it-tof-ms) with electrospray ionization, of organic compounds present in raw and treated effluents from a combined sewage treatment systems (upflow anaerobic sludge blanket-trickling filter). the sewage samples were prepared by c18 solid phase extraction and the spectra obtained from the various extracts were submitted to principal component analysis to evaluate their pattern and identify the major deprotonated species. some target compounds were submitted to semiquantitative analysis, using phenolphtalein as internal standard. the results showed the anaerobic step had little impact on the removal of anionic surfactants (las), fatty acids, and some contaminantes such as bisphenol a and bezafibrate, whereas the aerobic post-treatment was very efficient in removing these organics.
Determina??o de carbamato de etila em aguardentes de cana por CG-EM
Labanca, Renata Adriana;Glória, Maria Beatriz Abreu;Afonso, Robson José de Cássia Franco;
Química Nova , 2008, DOI: 10.1590/S0100-40422008000700044
Abstract: a simple, specific and sensitive gc-ms procedure with ion m/z 62 was validated for the determination of ethyl carbamate (ec) in spirits. it exhibited linearity over the concentration of 30 to 600 μg/l with 30 μg/l limit of quantification. ec was detected in 70 of the 71 samples analyzed with levels from 33 to 2609 μg/l (mean level = 893 μg/l). 35% of the samples contained 500 to 1000 μg/l and 23% contained 150 to 500 and 1000 to 1500 μg/l. no significant correlation was found between ec and the levels of copper, ph and alcohol content of the samples.
Fast Determination of Benzodiazepines in Human Urine via Liquid-Liquid Extraction with Low Temperature Partitioning and LC-HRMS  [PDF]
Elisangela Jaqueline Magalh?es, Clésia Cristina Nascentes, Rodinei Augusti, Maria Eliana Lopes Ribeiro de Queiroz, Júlio César Cardoso da Silva, Robson José de Cássia Franco Afonso
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.32017
Abstract: A simple and high-throughput method to simultaneously determine selected benzodiazepines (i.e., diazepam, lorazepam, clonazepam, and bromazepam) in urine was developed and validated. The entire methodology consisted of the application of an innovative extraction/cleanup procedure, namely liquid-liquid extraction with low-temperature partitioning (LLE-LTP), and analysis by liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). The LLE-LTP procedure was optimized via factorial design and by evaluating crucial variables, specifically the freezing mode (either slow or fast), the urine/acetonitrile volume ratio, and the sample ionic strength. The benzodiazepines were quantified using matrix-matched calibration curves where the following parameters were assessed by validation protocol: in general, linearity range of 17 - 200 μg?L–1 (r > 0.9957); limits of detection lower than 5 μg?L–1; relative standard deviations (RSD) lower than 12.5%; and accuracy ranging from 72.3 to 117%. To test this procedure’s performance, the method was applied to determine the content of diazepam in actual urine samples. The validation results obtained for the method demonstrated that the present methodology could be potentially applied in proficient laboratories as a routine approach for determining benzodiazepines compounds content in urine.
Determina??o dos teores de cobre e grau alcoólico em aguardentes de cana produzidas no estado de Minas Gerais
Labanca, Renata Adriana;Glória, Maria Beatriz Abreu;Gouveia, Vitor José Pinto;Afonso, Robson José de Cássia Franco;
Química Nova , 2006, DOI: 10.1590/S0100-40422006000500036
Abstract: the objective of this work was to investigate if producers of sugar cane spirits in minas gerais, brazil, have improved the copper content of their products and also if they have adjusted to the new standards of identity for 'cacha?a' and 'aguardente'. seventy-one samples, obtained from may 2003 until march 2004, were analyzed. mean copper content was 2.30 mg/l, which indicates a significant reduction in levels. the mean alcohol content was 45.6 % v/v. all of the 'aguardente' but only 79% of the 'cacha?a' attended to the standard of identity for alcohol content for these products.
Determina o dos teores de cobre e grau alcoólico em aguardentes de cana produzidas no estado de Minas Gerais
Labanca Renata Adriana,Glória Maria Beatriz Abreu,Gouveia Vitor José Pinto,Afonso Robson José de Cássia Franco
Química Nova , 2006,
Abstract: The objective of this work was to investigate if producers of sugar cane spirits in Minas Gerais, Brazil, have improved the copper content of their products and also if they have adjusted to the new standards of identity for 'cacha a' and 'aguardente'. Seventy-one samples, obtained from May 2003 until March 2004, were analyzed. Mean copper content was 2.30 mg/L, which indicates a significant reduction in levels. The mean alcohol content was 45.6 % v/v. All of the 'aguardente' but only 79% of the 'cacha a' attended to the standard of identity for alcohol content for these products.
Influence of Harvest Season and Maturation of Different Sugarcane (Saccharum Spp.) Cultivars on the Chemical Composition of Alembic Brazilian Sugarcane Spirit  [PDF]
Oscar William Barbosa Fernandes, Débora Faria Silva, Ananda Lima Sanson, Mauricio Xavier Coutrim, Robson José de Cássia Franco Afonso, Paulo Eichler, Fernando Santos
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103266
Abstract:
Contrary to the ethanol industrial production, the quality and composition of sugar cane as raw material for the production of alembic cachaca have until now not been completely addressed. This work evaluated the influence of five different sugarcane cultivars and degree of maturation over the physicochemical composition of cachaca produced under strict controlled conditions. Three harvest seasons were used in order to obtain different stages of maturation. The sugarcane quality was assessed by the juice brix, sugarcane POL, reducing sugars, and purity. The cultivars quality did not differ within each harvest stage. However, significant quality differences were observed among sugarcane harvested in June and the other harvest months, particularly on reducing sugar content. This indicates different stages of sugarcane maturation. The 45 samples of cachaca produced from those sugarcanes were submitted to physicochemical and gas chromatography/mass spectrometry (GC/MS) qualitative analysis. The GC/MS composition pattern showed that the type of cultivar did not alter the composition of the cachaca at the same harvest stage. Otherwise, the production of acetic acid, ethyl lactate and n- butyl alcohol was higher in the first harvest (June) when compared to the others. The results from sugar cane quality and GC/MS when submitted to principal component analysis (PCA) showed consistently the separation between the groups of cachaca produced in the three seasons, indicating the influence of sugarcane ripening over the cachaca composition.
Intestinal Wall Atrophy and Increase of Sulphomucin Secretion in the Jejunal Epithelium of Rats Submitted to Severe Protein Malnutrition
Franco,Cássia Luiza de Marins; Sant'Ana,Débora de Mello Gon?ales; Araújo,Eduardo José de Almeida;
International Journal of Morphology , 2010, DOI: 10.4067/S0717-95022010000200026
Abstract: the effects of severe protein malnutrition on the morphometry of the intestinal wall in the jejunum of adult rats were evaluated in this study. six 90-day-old wistar rats (rattus norvegicus) were assigned into two groups: cg (control group, n = 3) and mg (malnourished group, n = 3). cg animals were fed a 26%-protein chow whereas controls were fed a 4%-protein chow. after 90 days, part of the jejunum was collected and subjected to routine histology. he-staining and histochemical techniques - periodic acid schiff (pas) and alcian blue (ab), ph 2.5/ph 1.0 - were used for the detection of glycoconjugates in 4μm -thick transverse cuts. morphometric analysis of the he-stained cuts revealed a decrease of the total thickness of the jejunal wall, mostly on the following layers: external muscle and mucosa - enterocyte height also decreased. cuts stained by using histochemical techniques for the detection of glycoconjugates revealed maintenance of goblet cells reactive to pas and ab ph 2.5, whereas the number of cells reactive to ab ph 1.0 increased. protein malnutrition was concluded to provoke severe atrophy of the jejunal wall and an increase of sulphomucin secretion within the intestinal epithelium.
Intestinal Wall Atrophy and Increase of Sulphomucin Secretion in the Jejunal Epithelium of Rats Submitted to Severe Protein Malnutrition Atrofia de la Pared Intestinal y Aumento de la Secreción de Sulfomucinas en el Epitélio Yeyunal de Ratas Sometidas a Intensa Desnutrición Protéica
Cássia Luiza de Marins Franco,Débora de Mello Gon?ales Sant'Ana,Eduardo José de Almeida Araújo
International Journal of Morphology , 2010,
Abstract: The effects of severe protein malnutrition on the morphometry of the intestinal wall in the jejunum of adult rats were evaluated in this study. Six 90-day-old Wistar rats (Rattus norvegicus) were assigned into two groups: CG (Control Group, n = 3) and MG (Malnourished Group, n = 3). CG animals were fed a 26%-protein chow whereas controls were fed a 4%-protein chow. After 90 days, part of the jejunum was collected and subjected to routine histology. HE-staining and histochemical techniques - Periodic Acid Schiff (PAS) and Alcian Blue (AB), pH 2.5/pH 1.0 - were used for the detection of glycoconjugates in 4μm -thick transverse cuts. Morphometric analysis of the HE-stained cuts revealed a decrease of the total thickness of the jejunal wall, mostly on the following layers: external muscle and mucosa - enterocyte height also decreased. Cuts stained by using histochemical techniques for the detection of glycoconjugates revealed maintenance of goblet cells reactive to PAS and AB pH 2.5, whereas the number of cells reactive to AB pH 1.0 increased. Protein malnutrition was concluded to provoke severe atrophy of the jejunal wall and an increase of sulphomucin secretion within the intestinal epithelium. Fueron evaluados los efectos de la desnutrición proteica severa sobre la morfometría de la pared intestinal del yeyuno de ratas adultas . Para esto, se utilizaron seis ratas (Rattus norvegicus) Wistar, con 90 días de edad, distribuidas en dos grupos: GC (grupo control, n=3) y el GD (grupo desnutrido, n=3). Los animales del GC recibieron ración con un contenido proteico de 26% y los del GD ración con 4% de proteínas. Después de 90 días de experimentación, parte del yeyuno fue retirado y sometido a un procesamiento histológico de rutina. Cortes transversales de 4 μm fueron te idos con HE y técnicas histoquímicas (Periodic Acid Schifff (PAS) y Alcian Blue (AB) pH 2,5 y pH 1,0.) para evidenciar glicoconjugados. El análisis morfométrico te idos con HE demostró reducción en el grosor total de la pared del yeyuno, especialmente de las túnicas muscular y mucosa, además se observó una disminución en la altura de los entericitos. Los cortes te idos con técnicas histoquímicas revelaron que el número de células caliciformes reactivas al PAS y al AB pH 2,5 se mantuvo; por otro lado, hubo un aumento en el número de células reactivas al AB pH 1,0. Se concluye que la desnutrición proteica severa provoca atrofia de la pared yeyunal y aumento de la secreción de sulfomucinas en el epitelio intestinal.
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