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Search Results: 1 - 10 of 343316 matches for " Frederico Jehár Oliveira Quint?o "
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High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products  [PDF]
Frederico Jehár Oliveira Quinto, 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.
Altered responsiveness to extracellular ATP enhances acetaminophen hepatotoxicity
Sylvia S Amaral, André G Oliveira, Pedro E Marques, Jayane L Quinto, Daniele A Pires, Rodrigo R Resende, Bruna R Sousa, Juliana G Melga?o, Marcelo A Pinto, Remo C Russo, Ariane K Gomes, Lidia M Andrade, Rafael F Zanin, Rafaela Vaz Pereira, Cristina Bonorino, Frederico M Soriani, Cristiano Xavier Lima, Denise C Cara, Mauro M Teixeira, Maria F Leite, Gustavo B Menezes
Cell Communication and Signaling , 2013, DOI: 10.1186/1478-811x-11-10
Abstract: APAP overdose resulted in liver necrosis, massive neutrophil infiltration and large non-perfused areas, as well as remote lung inflammation. In the liver, these effects were significantly abrogated after ATP metabolism by apyrase or P2X receptors blockage, but none of the treatments prevented remote lung inflammation, suggesting a confined local contribution of purinergic signaling into liver environment. In vitro, APAP administration to primary mouse hepatocytes and also HepG2 cells caused cell death in a dose-dependent manner. Interestingly, exposure of HepG2 cells to APAP elicited significant release of ATP to the supernatant in levels that were high enough to promote direct cytotoxicity to healthy primary hepatocytes or HepG2 cells. In agreement to our in vivo results, apyrase treatment or blockage of P2 receptors reduced APAP cytotoxicity. Likewise, ATP exposure caused significant higher intracellular Ca2+ signal in APAP-treated primary hepatocytes, which was reproduced in HepG2 cells. Quantitative real time PCR showed that APAP-challenged HepG2 cells expressed higher levels of several purinergic receptors, which may explain the hypersensitivity to extracellular ATP. This phenotype was confirmed in humans analyzing liver biopsies from patients diagnosed with acute hepatic failure.We suggest that under pathological conditions, ATP may act not only an immune system activator, but also as a paracrine direct cytotoxic DAMP through the dysregulation of Ca2+ homeostasis.
Efeito da restri??o alimentar pré e pós-natal sobre o crescimento dos órg?os internos de cordeiros Santa Inês
Geraseev, L.C.;Perez, J.R.O.;Pedreira, B.C.;Quinto, F.A.;Oliveira, R.P.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2008, DOI: 10.1590/S0102-09352008000400027
Abstract: the effects of pre and postnatal nutritional restriction on allometric growth of thoracic and abdominal organs of santa inês lambs were evaluated. sixty-eight lambs were divided into three groups: lambs with prenatal nutritional restriction (prer), lambs with postnatal nutritional restriction (posr), and lambs without restriction (control). the lambs in each group were slaughted at birth, 10kg, 15kg, 25kg, 35kg, and 45kg of live weight. after slaughtering, heart, lungs, trachea and esophagus, liver, spleen, pancreas, rumen-reticulum, abomasum, omasum, and small and large intestines were individually weighted. at birth, prer affected the weights of heart, lungs, trachea and esophagus, abomasum, pancreas, and spleen, with means of 54g, 16g, 22g, 16g, 2g, and 5g, respectively. however, the organs of the prer lambs at 15kg of live weight showed the same weight of that organs of the others animals, indicating a compensatory growth. posr did not affect the weight of the organs of thoracic cavity;however, in abdomen cavity, rumen, small intestine, and liver were affected, with means of 385g, 488g, and 371g, respectively. the allometric study showed that rumen and omasum presented a positive heterogonic development; while abomasum presented a negative heterogonic development; and liver, small and large intestines showed an isogonic development. the pancreas of control and posr lambs presented an isogonic development, while pancreas of prer lambs showed a positive heterogonic delevopment. in this experiment, the alimentary restriction affected weigth, growth, and type of development of internal organs of santa inês lambs, evidencing the importance of the feeding for ewes at the last third of gestation as well as for the lambs during the growth phase.
Two Dimensional Honeycomb Materials: random fields, dissipation and fluctuations
T. Frederico,O. Oliveira,W. de Paula,M. S. Hussein,T. R. Cardoso
Physics , 2015,
Abstract: In this paper, we propose a method to describe the many-body problem of electrons in honeycomb materials via the introduction of random fields which are coupled to the electrons and have a Gaussian distribution. From a one-body approach to the problem, after integrating exactly the contribution of the random fields, one builds a non-hermitian and dissipative effective Hamiltonian with two-body interactions. Our approach introduces besides the usual average over the electron field a second average over the random fields. The interplay of two averages enables the definition of various types of Green's functions which allow the investigation of fluctuation-dissipation characteristics of the interactions that are a manifestation of the many-body problem. In the current work we study only the dissipative term, through the perturbative analysis of the dynamics associated the effective Hamiltonian generated by two different kinds of couplings. For the cases analysed, the eigenstates of the effective Hamiltonian are complex and, therefore, some of the states have a finite life time. Moreover, we also investigate, in the mean field approximation, the most general parity conserving coupling to the random fields and compute the width of charge carriers $\Gamma$ as a function of the Fermi energy $E_F$. The theoretical prediction for $\Gamma (E_F)$ is compared to the available experimental data for graphene. The good agreement between $\Gamma_{theo}$ and $\Gamma_{exp}$ suggests that description of the many-body problem associated to the electrons in honeycomb materials can indeed be done via the introduction of random fields.
Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols
Cazita, P.M.;Castilho, L.N.;Carvalho, M.D.T.;Sesso, A.C.;Oliveira, H.C.F.;Quinto, E.C.R.;
Brazilian Journal of Medical and Biological Research , 2010, DOI: 10.1590/S0100-879X2010007500136
Abstract: we determined the influence of fasting (fast) and feeding (fed) on cholesteryl ester (ce) flow between high-density lipoproteins (hdl) and plasma apob-lipoprotein and triacylglycerol (tg)-rich emulsions (em) prepared with tg-fatty acids (fas). tg-fas of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/ml as the source of ce transfer protein. the transfer of ce from hdl to fed was greater than to fast tg-rich acceptor lipoproteins, 18% and 14%, respectively. however, percent ce transfer from hdl to apob-containing lipoproteins was similar for fed and fast hdl. the ce transfer from hdl to em depended on the em tg-fa chain length. furthermore, the chain length of the monounsaturated tg-containing em showed a significant positive correlation of the ce transfer from hdl to em (r = 0.81, p < 0.0001) and a negative correlation from em to hdl (r = -041, p = 0.0088). regarding the degree of em tg-fas unsaturation, among ems containing c18, the ce transfer was lower from hdl to c18:2 compared to c18:1 and c18:3, 17.7%, 20.7%, and 20%, respectively. however, the ce transfer from ems to hdl was higher to c18:2 than to c18:1 and c18:3, 83.7%, 51.2%, and 46.3%, respectively. thus, the em fa composition was found to be the rate-limiting factor regulating the transfer of ce from hdl. consequently, the net transfer of ce between hdl and tg-rich particles depends on the specific arrangement of the tg acyl chains in the lipoprotein particle core.
Fishers' knowledge and seahorse conservation in Brazil
Ierecê ML Rosa, R?mulo RN Alves, Kallyne M Bonifácio, José S Mour?o, Frederico M Osório, Tacyana PR Oliveira, Mara C Nottingham
Journal of Ethnobiology and Ethnomedicine , 2005, DOI: 10.1186/1746-4269-1-12
Abstract: Over a decade ago, Ruddle [1] pointed out the great potential value of local knowledge as an information base for local management of marine environments and resources, especially in the tropics, where conventionally-used data were usually scarse to non-existent. A number of subsequent studies have documented and recognized the value of local knowledge to conservation and management of fisheries [2-12].A pragmatic view of the relevance of fishers knowledge to fisheries management has been expressed by Ames [8]: "fishermen and their subjective, anecdotal descriptions have a pivotal role to play in the development and function of sustainable fisheries (.......) fishermen are, in fact, the only available source of local, historical, place-based information". Nevertheless, lack of sound management practices have led to the collapse of particular types of fisheries in some parts of the world, and, as pointed out by Meewig et al. [13], interest in participatory approaches in resource management in part reflects the failure of top-down, centralized approaches to manage natural resources.Definitions of artisanal, subsistence fisheries have traditionally focused on the capture and trade of food fish. However, a growing number of examples of fish species being traded worldwide for purposes other than alimentary (e.g., as pets, remedies, souvenirs) has revealed the existence of an international and multi-faceted commerce, supported by a diffuse (and generally poorly quantified) harvesting of a number of species.Those forms of exploitation have received little attention when compared with the trade of animals for alimentary purposes [14]. In the marine realm, the scarcity of data has rendered the identification of key elements for conservation and management, and the assessment of impacts difficult.Seahorses (Hippocampus spp.) are among the few non-food marine fishes whose trade has been documented, initially in Asia [15], where the demand for those fishes was primarily for use
Influência de fatores socioecon?micos na contamina??o por agrotóxicos, Brasil
Oliveira-Silva,Jefferson José; Alves,Sérgio R; Meyer,Armando; Perez,Frederico; Sarcinelli,Paula de Novaes; Mattos,Rita de Cássia O da Costa; Moreira,Josino C;
Revista de Saúde Pública , 2001, DOI: 10.1590/S0034-89102001000200005
Abstract: objective: the indiscriminate use of pesticides has been contributing for the environmental quality degradation, as well as it increases the occupational exposures to these products, determining a serious public health problem in rural areas. the purpose of this study was to evaluate the exposures of rural workers of rio de janeiro state to anticholinesterasic pesticides, through the analyses of the acetylcholinesterase from red cells (ache) and plasmatic butyrilcholinesterase (bche) levels. social-economic factors, such as the educational level of these workers, can strongly influence this situation, reason why the impact of some social-economic indicators and practices of pesticides' use in the human contamination status for rural areas were also evaluated. methods: the evaluation of rural workers exposure to pesticides was performed to a random sample of 55 workers among the 300 inhabitants of the study area ? five communities of magé county, rj. the ache and bche activities were determined to these workers. the enzymatic activities were evaluated according to the ellman's method modified by oliveira-silva. social-economic and pesticides use data were collected by a structured interview. the possible role of social-economic and pesticide use indicators as determinants of the worker's contamination was estimated by multivariate statistic techniques, using the enzymatic activity as the dependent variable and the social-economics pesticides use indicators as independent variables. results and conclusions: the data showed distinct results concerning the incidence of excessive exposure, according to the enzymatic indicator used. in the studied sample, a result of 3.0 % was found for the bche values, and 41.8 %, according to ache. individuals with at least one positive enzymatic indicator result were considered as "intoxicated". when these data were compared to the social-economic and pesticides use factors, it was showed the importance of educational level in the prev
Fatores de risco para doen?as cr?nicas n?o-transmissíveis: inquérito domiciliar no Município de S?o Paulo, SP (Brasil). Metodologia e resultados preliminares
Rego,Ricardo A.; Berardo,Frederico A. N.; Rodrigues,Sérgio S.R.; Oliveira,Zélia M.A.; Oliveira,Marcia B.; Vasconcellos,Cidia; Aventurato,Lauro V.O.; Moncau,José E.C.; Ramos,Luiz R.;
Revista de Saúde Pública , 1990, DOI: 10.1590/S0034-89101990000400005
Abstract: the non-communicable chronic diseases are important causes of death in brazil, mainly in the great urban centres. there are various risk factors related to these diseases, whose remotion or attenuation would contribute to a fall in mortality. the methodology of the first comprehensive multicenter study into risk factors of non-communicable chronic diseases carried out in latin america is explained. in brazil, this study was carried out in the cities of s. paulo, sp and porto alegre, rs. preliminary results from the city of s. paulo as to the prevalence of arterial hypertension (22.3%), tabagism (37.9%), obesity (18.0%), alcoholism (7.7%) and sedentarism (69.3%) are presented. these results are compared with existing data from brazil and other countries, and the relationship between various risk factors and the mortality from cardiovascular diseases in s. paulo and some developed countries is discussed.
Levantamento do estado nutricional de plantas de coffea arabica L. pelo dris, na regi?o do Alto Paranaíba - Minas Gerais
Lana, Regina Maria Quinto;Oliveira, Sebasti?o Alberto de;Lana, ?ngela Maria Quinto;Faria, Marcos Vieira de;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000400014
Abstract: a striking characteristic of soils under savanna vegetation is the low natural fertility, as in soils in the upper paranaíba region - mg. this characteristic is aggravated by the use of low fertilizer quantities, which may cause nutritional imbalance in plants. the objective of this study was to evaluate the nutritional status of coffee plants in the upper paranaíba region - mg, using the integrated system for diagnose and recommendation (dris) to interpret leaf analyses and apply the fertilization response potential to the dris index and analyze the correlations and interactions between leaf nutrient concentrations and dris index. coffee leaf samples were collected in the initial fruit growth stage, removing two pairs of leaves from each plant in 20 random plants, in 59 commercial plantations of the region. nutrient levels were determined and interpreted by the dris. dris indicated that the yield-limiting nutrients were: p, fe, k = mn, and zn = b. the nutrients to which coffee plants tended to respond positively were: p, b, fe, k, and mn. the positives correlations between the dris index were: n(p, k and s), p(k, mg and s) and k(mg and s), and the negatives correlations: n(ca, b, fe, and zn), p(ca, b, fe, mn, and zn) and k(ca, b, fe, mn, and zn).
Linking Dynamical Gluon Mass to Chiral Symmetry Breaking via a QCD Low Energy Effective Field Theory
O. Oliveira,W. de Paula,T. Frederico
Physics , 2011,
Abstract: A low energy effective field theory model for QCD with a scalar color octet field is discussed. The model relates the gluon mass, the constituent quark masses and the quark condensate. The gluon mass comes about $\sqrt{N_c}\, \Lambda_{QCD}$ with the quark condensate being proportional to the gluon mass squared. The model suggests that the restoration of chiral symmetry and the deconfinement transition occur at the same temperature and that, near the transition, the critical exponent for the condensate is twice the gluon mass one. The model also favors the decoupling like solution for the gluon propagator.
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