oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 218 )

2018 ( 405 )

2017 ( 418 )

2016 ( 597 )

Custom range...

Search Results: 1 - 10 of 274135 matches for " Daniel R.;Lima-Neto "
All listed articles are free for downloading (OA Articles)
Page 1 /274135
Display every page Item
A rapid and sensitive method for dimethylsulphide analysis in Brazilian sugar cane sugar spirits and other distilled beverages
Cardoso, Daniel R.;Andrade Sobrinho, Luiz G.;Lima-Neto, Benedito S.;Franco, Douglas W.;
Journal of the Brazilian Chemical Society , 2004, DOI: 10.1590/S0103-50532004000200019
Abstract: a purge and trap concentrator coupled to gas chromatography was used to quantify dimethylsulphide in distilled beverages. a very good performance was obtained using a hp-ffap column and a mass selective detector operating in sim mode (m/z 62): detection limit 8 x 10-9 mol l-1; good repeatability and total time of analysis 25 minutes. the method has been applied for sixty samples of alcoholic beverages (cacha?as, tiquiras, grappas, whiskies, brandies, vodkas, rum and a tequila). the cacha?as exhibit the highest content of dimethylsulphide (median 3.16 x 10-4 mol l-1), followed by grappa (median 1.45 x 10-4 mol l-1). the presence of dimethylsulphide was not observed in the samples of rum.
Influência do material do destilador na composi??o química das aguardentes de cana: parte II
Cardoso, Daniel R.;Lima-Neto, Benedito S.;Franco, Douglas W.;Nascimento, Ronaldo F. do;
Química Nova , 2003, DOI: 10.1590/S0100-40422003000200004
Abstract: the quantitative chemical analysis of the brazilian sugar cane spirit distilled from glass column packaged with copper, stainless steel, aluminum sponge, or porcelain balls is described. the main chemical compounds determined by gas chromatography coupled with flame ionization (fid) and flame photometric (fpd) detectors and liquid chromatography coupled with diode array detector are aldehydes, ketones, carboxylic acids, alcohols, esters and dimethylsulfite (dms). the spirits produced either in columns filled with copper or aluminum pot still exhibits the lowest dms contents but the higher sulfate and methanol contents, whereas spirits produced in stainless steel or porcelain showed higher dms concentration and lower teors of sulfate ion and methanol. these observations are coherent with dms oxidation to sulfate, with methanol as by product, in the presence of either copper or aluminum.
Influência do material do destilador na composi o química das aguardentes de cana: parte II
Cardoso Daniel R.,Lima-Neto Benedito S.,Franco Douglas W.,Nascimento Ronaldo F. do
Química Nova , 2003,
Abstract: The quantitative chemical analysis of the Brazilian sugar cane spirit distilled from glass column packaged with copper, stainless steel, aluminum sponge, or porcelain balls is described. The main chemical compounds determined by gas chromatography coupled with flame ionization (FID) and flame photometric (FPD) detectors and liquid chromatography coupled with diode array detector are aldehydes, ketones, carboxylic acids, alcohols, esters and dimethylsulfite (DMS). The spirits produced either in columns filled with copper or aluminum pot still exhibits the lowest DMS contents but the higher sulfate and methanol contents, whereas spirits produced in stainless steel or porcelain showed higher DMS concentration and lower teors of sulfate ion and methanol. These observations are coherent with DMS oxidation to sulfate, with methanol as by product, in the presence of either copper or aluminum.
A rapid and sensitive method for dimethylsulphide analysis in Brazilian sugar cane sugar spirits and other distilled beverages
Cardoso Daniel R.,Andrade Sobrinho Luiz G.,Lima-Neto Benedito S.,Franco Douglas W.
Journal of the Brazilian Chemical Society , 2004,
Abstract: A purge and trap concentrator coupled to gas chromatography was used to quantify dimethylsulphide in distilled beverages. A very good performance was obtained using a HP-FFAP column and a mass selective detector operating in SIM mode (m/z 62): detection limit 8 x 10-9 mol L-1; good repeatability and total time of analysis 25 minutes. The method has been applied for sixty samples of alcoholic beverages (cacha as, tiquiras, grappas, whiskies, brandies, vodkas, rum and a tequila). The cacha as exhibit the highest content of dimethylsulphide (median 3.16 x 10-4 mol L-1), followed by grappa (median 1.45 x 10-4 mol L-1). The presence of dimethylsulphide was not observed in the samples of rum.
Tuning of photochemical and photophysical properties of [RuII(2,2'-bipyridine)2Lx] complexes using nonchromophoric ligand variations
Inglez, Simone D.;Lima, Francisco C. A.;Camilo, Mariana R.;Daniel, Juliana F. S.;Santos, Evania D. A.;Lima-Neto, Benedito S.;Carlos, Rose M.;
Journal of the Brazilian Chemical Society , 2010, DOI: 10.1590/S0103-50532010000100023
Abstract: mo calculations were carried out on a cis-[ru(bpy)2lx](pf6) 2 complex, where bpy is 2,2'-bipyridine and l is 3-aminopyridine (complex 1 with x = 2), with the gaussian 03 package using the dft method. the electronic structure and molecular properties of 1 were characterized in vacuum and in acetonitrile solution, and the results were compared to those obtained from the complex with l = 5,6-bis(3-amidopyridine)-7-oxanorbornene (complex 2 with x = 1). the electronic spectra of 1 and 2 were investigated by td-dft. experimental data from cyclic voltammetry, uv-visible spectroscopy, photochemical and photophysical experiments were compared to the theoretical data to discover the influence of l on the electronic transitions and to interpret the differences between the photochemical behaviors of these complexes.
Characterisation of electrodeposited and heat-treated Ni?Mo?P coatings
Melo, Régis L.;Casciano, Paulo N. S.;Correia, Adriana N.;Lima-Neto, Pedro de;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012000200020
Abstract: the electrodeposition, hardness and corrosion resistance properties of ni?mo?p coatings were investigated. characterisations of the electrodeposited coatings were carried out using scanning electron microscopy, x-ray diffraction and energy dispersive x-ray analysis techniques. corrosion tests were performed at room temperature in 10-1 mol dm-3 nacl solutions and by potentiodynamic linear polarisation. amorphous ni?mo?p coatings were successfully obtained by electrodeposition using direct current. the coating composition showed to be dependent on the bath composition, current density and bath temperature. both p and mo contents contribute for the hardness properties of the ni?mo?p coatings and the absence of cracks is a requirement to produce electrodeposited ni?mo?p coatings with good hardness properties. the hardness values increase with heat-treatment temperature due to the precipitation of ni, ni3p and nimo phases during the heat treatment. the corrosion resistance of the electrodeposited ni?mo?p amorphous coatings increases with p content in the layer. among the electrodeposited ni?mo?p amorphous coatings, ni78mo10p12 presented the best hardness and corrosion-resistance properties. the results showed that the addition of p is beneficial for the hardness and corrosion resistance properties of the ni?mo-based coatings.
Compostos nitrogenados em bebidas destiladas: cacha a e tiquira
POLASTRO Lisanias R.,BOSO Lisangela M.,ANDRADE-SOBRINHO Luiz G.,LIMA-NETO Benedito S.
Ciência e Tecnologia de Alimentos , 2001,
Abstract: Utilizando métodos colorimétricos foram investigadas as presen as de íon am nio, uréia e aminoácidos em 51 amostras de aguardente de cana-de-a úcar (cacha a) e em 9 amostras de aguardente de mandioca (tiquira). Foram semelhantes os teores médios de íon am nio determinados para as aguardentes-de-cana (0,013mmoles/L) e de mandioca (0,010mmoles/L). As tiquiras apresentaram teores médios de aminoácidos (0,290mmoles/L) e uréia (1,45mmoles/L) superiores aos da aguardente-de-cana: 0,093mmoles/L e 0,316mmoles/L, respectivamente.
Role of Selective Cyclo-Oxygenase-2 Inhibitor Celecoxib in Canine Osteosarcoma Cell Culture  [PDF]
Paulo R. O. Bersano, Maria T. S. Alves, Maria F. M. R. Gartner, Adriana Camargo Ferrasi, Jo?o F. Lima-Neto, Fernanda C. Landim, Stephane C. Vexenat, Carlos Eduardo Fonseca Alves, Glenda Nicioli da Silva, Noeme S. Rocha
Open Journal of Pathology (OJPathology) , 2013, DOI: 10.4236/ojpathology.2013.34027
Abstract:

Background: Experimental studies have shown that cyclo-oxygenase-2 (Cox2) is related to the development and progression of tumors, since this enzyme is induced and expressed by cells such as macrophages, osteoblasts, activated endothelial cells, and tumor cells. The activity in tumors includes proliferation, cell transformation, tumor growth, invasion and metastasis and may play an important role in carcinogenesis of the canine osteosarcoma, since it has high expression in tissue fragments. The combination of selective Cox2 inhibitors and other treatment modalities is the basis for a new anti-cancer therapy strategy. This in vitro study exposed primary cells of five different canine osteosarcoma cultures to selective Cox2 inhibitor at increasing concentrations and times. Results: For Cox2 negative cultures, despite the absence of differences, greater sensitivity of cells to treatment was observed. For Cox2 positive cultures, a higher number of necrotic cells were observed (P ≤ 0.05), when compared with negative cultures. For exposure times with Celecoxib doses, no difference (P > 0.05) was found between the three times analyzed for living, apoptotic and apoptotic/necrotic cells. There are similarities in the values of 24 h and 48 h, with slight reduction of living cells, increasing those undergoing apoptosis and apoptosis/necrosis. There was significance for necrosis (P ≤ 0.05). In 72 hours, a significant difference was observed between the other two previous values (P ≤ 0.05). It was found for the group of 100 μML-1, that there was a numerically greater signaling for apoptosis and lower (P = 0.08) for necrosis, and this point was the onset of the pharmacodynamic phenomenon, with drop in the values for living cells and increased number of necrotic cells, with a tendency (P = 0.08) for reducing the percentage of necrotic cells for the group of 100 μML-1 when compared to that of

Compostos nitrogenados em bebidas destiladas: cacha?a e tiquira
POLASTRO, Lisanias R.;BOSO, Lisangela M.;ANDRADE-SOBRINHO, Luiz G.;LIMA-NETO, Benedito S.;FRANCO, Douglas W.;
Ciência e Tecnologia de Alimentos , 2001, DOI: 10.1590/S0101-20612001000100017
Abstract: ammonium ion, urea and amino acids were quantified by using colorimetric methods in 51 samples of sugar cane spirit (cacha?a) and 9 samples of cassava spirit (tiquira). the average contents of ammonium ion for sugar cane (0.013mmoles/l) and cassava (0.010mmoles/l) spirits are similar. tiquiras present average contents of amino acids (0.290mmoles/l) and urea (1.45mmoles/l) higher than in sugar cane, which are 0.093mmoles/l and 0.316mmoles/l, respectively.
Constru??o de modelos para ilustra??o de estruturas moleculares em aulas de química
Lima, M. B.;Lima-Neto, P. De;
Química Nova , 1999, DOI: 10.1590/S0100-40421999000600021
Abstract: this paper describes the construction of a kit of molecular model for illustration of molecular structure in chemical class using cheap materials. the atoms were represented by plastic spheres and the bonds between the atoms were made from plastic straws which were cut in the required length using a scale of 1.6 cm corresponding to 100 pm. examples of adaptations made in this kit for didactical application are given.
Page 1 /274135
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.