850 resultados para MULTIMODAL ELUTION
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This paper seeks to show which impacts there are of the combined use of different modal for the coffee’s outflow. Nowadays is used, almost exclusively, the roadway to transport. How-ever, for this product with low added value, the types of transports best suited, in the litera-ture, are the railway and waterway. For this, is describe the development and spread of coffee throughout Brazil. Subsequently, is calculate the current cost of transporting two producing regions (Minas Gerais and Rondônia), using for that information about the freight, the social cost, and the level of losses along the way. After that is projected costs if utilizes the multi-modal model, when considering the same cost parameters used for the current model. Here-after, an analysis is made of the obtained cost, speed, consistency, capacity, availability and frequency of each transport model. Therefore, note that the multi-modal system is more ef-ficient and economical than current, based on transport by road
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Indiscriminate and inappropriate use of pesticides in agriculture has been pointed out for increasing health problems and environmental damage. Considering that water resources are the principal destiny of those compounds after application, the present study presents optimization and validation of two simple and effi cient analytical methods for pesticides quantifi cation in both surface and groundwater. Were selected the pesticides more commonly used at Dourados (MS - Brazil), region with intense agricultural activity. Pesticides were preconcentrated by solid-phase extraction using C18 (500 mg) cartridges and then divided in two groups for elution and quantifi cation: 2.4-D and 2.4-DCP were eluted with methanol and quantifi ed by high performance liquid chromatography with ultra-violet detector (HPLC-UV) while atrazine, DIA, DEA, trifl uralin and methyl parathion were eluted with ethylacetate (1:1, v/v) and quantifi ed by gas chromatography with thermionic specifi c detector (GC-TSD). The methods showed satisfactory accuracy (76-107%) and precision (<12%) for the substances analyzed at the fortifi ed levels selected for the study, except for DIA (<51%). Study of pesticide stability also presented good results: C18 cartridges could be stored for at least for 21 days at -20ºC with no signs of the compounds degradability. Both methods limits of quantifi cation of the pesticides (0.22 - 0.48 μg L-1) are in accordance to the levels currently established by the Brazilian national legislation for pesticides in water. Although only the pesticide 2.4-D has been detected in two distinct collection points in the study period of time, this work warns for the requirement of systematical analysis of pesticides presence in water destined to human consume, principally in areas of intense agriculture activity. Such monitoring can provide subsidies for public environmental policies.
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Pós-graduação em Anestesiologia - FMB
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Pós-graduação em Química - IQ
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O carcinoma espinocelular é uma das quatro neoplasias malignas que mais acomete gatos, principalmente os de pele clara e que residem em países tropicais onde a incidência de raios solares é intensa. O tratamento cirúrgico é o mais indicado, mas nem sempre é possível de ser realizado seja pelo estágio avançado do tumor, pela sua localização ou por opção do proprietário que não quer ver seu animal mutilado. O objetivo desta revisão sistemática foi verificar a eficácia da quimioterapia com ou sem associações terapêuticas para o tratamento do carcinoma espinocelular superficial, multicêntrico e de cabeça e pescoço em gatos. Os melhores resultados para o tratamento do carcinoma espinocelular superficial foram observados com a aplicação intralesional do quimioterápico associado à radioterapia ou à eletroterapia, para o tipo multicêntrico faltam trabalhos sobre o assunto e o único encontrado não apresentou resultados satisfatórios. No caso do carcinoma espinocelular de cabeça e pescoço que alberga o pior prognóstico, a terapia multimodal com associação de quimioterapia, radioterapia e excisão cirúrgica demonstrou ser eficiente. Mais estudos sobre o assunto devem ser realizados utilizando um número maior de animais e com um tempo de seguimento mais longo
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Relevance feedback approaches have been established as an important tool for interactive search, enabling users to express their needs. However, in view of the growth of multimedia collections available, the user efforts required by these methods tend to increase as well, demanding approaches for reducing the need of user interactions. In this context, this paper proposes a semi-supervised learning algorithm for relevance feedback to be used in image retrieval tasks. The proposed semi-supervised algorithm aims at using both supervised and unsupervised approaches simultaneously. While a supervised step is performed using the information collected from the user feedback, an unsupervised step exploits the intrinsic dataset structure, which is represented in terms of ranked lists of images. Several experiments were conducted for different image retrieval tasks involving shape, color, and texture descriptors and different datasets. The proposed approach was also evaluated on multimodal retrieval tasks, considering visual and textual descriptors. Experimental results demonstrate the effectiveness of the proposed approach.
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Polyphenol oxidase (PPO, EC 1.14.18.1) extracted from sweet potato root [Ipomoea batatas (L.) Lam.] was purified 189-fold by precipitation with ammonium sulfate and elution from columns of Sephadex G-25, DEAE-cellulose, and Sephadex G-100. Polyacrylamide gel electrophoresis of the purified preparation revealed that PPO was highly purified by the procedure adopted. The purified enzyme had an estimated molecular weight of 96 000 and Km values of 26, 8, 5, and 96 mM for 4-methylcatechol, chlorogenic acid, caffeic acid, and catechol, respectively. The optimum pH varies from about 4.0 to 6.5, depending on the substrate. PPO activity was inhibited by p-coumaric and cinnamic acids, sodium metabisulfite, dithioerythritol, ascorbic acid, L-lysine, D-phenylalanine, L-methionine, glycine, L-isoleucine, and L-glutamine. Heat inactivation between 60 and 80 °C was biphasic. Sucrose, (NH4)2SO4, NaCl, and KCl appeared to be protective agents of sweet potato PPO against thermal denaturation. © 1992 American Chemical Society.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The prodrug hydroximethylnitrofurazone (NFOH) presents antichagasic activity with greatly reduced toxicity compared to its drug matrix nitrofurazone (NF). Besides these new characteristics, the prodrug was more active against the parasite T. cruzi amastigotes. These advantages make the prodrug a possible therapeutic alternative for the treatment of both acute and the chronic phase of Chagas disease. However, the knowledge of pharmacokinetic profile is crucial to evaluate the feasibility of a new drug. In this study, our objective was to evaluate the in vivo formation of NF from the NFOH single administration and to evaluate its pharmacokinetic profile and compared it to NF administration. A bioanalytical method to determine the NF and NFOH by LCMS/MS was developed and validated to perform these investigations. Male albino rabbits (n=15) received NF intravenously and orally in doses of 6.35 and 63.5 mg / kg respectively, and NFOH, 80.5 mg / kg orally. The serial blood samples were processed and analyzed by mass spectrometry. The system operated in positive and negative modes for the analites determination, under elution of the mobile phase 50:50 water: methanol. The administration of NFOH allowed the calculation of pharmacokinetic parameters for the prodrug, and the NF obtained from NFOH administration. Using the pharmacokinetic profile obtained from the NF i.v. administration, the oral bioavailability of NF from the administered prodrug was obtained (60.1%) and, as a key parameter in a prodrug administration, should be considered in future studies. The i.v. and oral administrations of NF differ in the constant of elimination (0.04 vs 0.002) and elimination half-life (17.32 min vs 276.09 min) due to the low solubility of the drug that hinders the formation of molecular dispersions in the digestory tract. Still, there was observed no statistical differences were observed between the pharmacokinetic parameters of orally administered NF and NF obtained from NFOH. The calculated area under the curve (AUC 0-∞) showed that the exposure to the parental drug was fairly the same (844.79 vs 566.44) for NF and NF obtained from the prodrug administration. The tendency to higher NF's mean residence time (MRT) as observed in the prodrug administration (956.1 min vs 496.3 min) guarantees longer time for the action of the drug and it allows the expansion of the administration intervals. These findings, added with the beneficial characteristics of the prodrug encourage new efficacy tests towards the clinical use of NFOH.
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A montmorillonite from Wyoming-USA was used to prepare an organo-clay complex, named 2-thiazoline-2-thiol-hexadecyltrimethylammonium-clay (TZT-HDTA-clay), for the purpose of the selective adsorption of the heavy metals ions and possible use as a chemically modified carbon paste electrode (CMCPE). Adsorption isotherms of Hg 2+, Pb 2+, Cd 2+, Cu 2+, and Zn 2+ from aqueous solutions as a function of the pH were studied at 298 K. Conditions for quantitative retention and elution were established for each metal by batch and column methods. The organo-clay complex was very selective to Hg(II) in aqueous solution in which other metals and ions were also present. The accumulation voltammetry of Hg(II) was studied at a carbon paste electrode chemically modified with this material. The mercury response was evaluated with respect to the pH, electrode composition, preconcentration time, mercury concentration, cleaning solution, possible interferences and other variables. A carbon paste electrode modified by TZT-HDTA-clay showed two peaks: one cathodic peak at about 0.0 V and an anodic peak at 0.25 V, scanning the potential from -0.2 to 0.8 V (0.05 M KNO 3 vs. Ag/AgCl). The anodic peak at 0.25 V presents excellent selectivity for Hg(II) ions in the presence of foreign ions. The detection limit was estimated as 0.1 μg L -1. The precision of determination was satisfactory for the respective concentration level. 2005 © The Japan Society for Analytical Chemistry.