42 resultados para Modelos de separação de efeitos
Resumo:
Ethanol withdrawn individuals present a wealth of signs and symptoms, some of them related with anxiety. To better understand brain areas involved in anxiety caused by ethanol abstinence, preclinical studies have been employing models of ethanol consumption followed by withdrawal in rodents submitted to behavioral tests of anxiety, such as the elevated plus-maze. The aim of this study was to investigate if short- or long-term ethanol withdrawal could alter both anxiety-related behaviors in the elevated plus-maze (EPM) and open field tests and the number of serotonin immunorreactive cels in the dorsal raphe nucleus, a midbrain area associated with anxiety. Female Wistar rats (90 days old) were submitted to increasing concentrations of ethanol (2% for 3 days, 4% for 3 days and 6% for 15 days) as the only source of liquid diet and the control group received water ad libitum. Both groups received food ad libitum. In the behavioral experiments, on 21st day of consumption, ethanol was substituted by water (withdrawal) and 72 h or 21 days after withdrawal animals were submitted to the EPM, where it was evaluated the percentage of time and entries in the open arms and the entries in the enclosed arms during 5 minutes. Twenty and four hours after testing in the EPM, animals were submitted to the open field test for 15 minutes, where the distance traveled by the animals was observed along this period. During the first 5 minutes, the distance traveled, entries and time spent in the center of the test were analyzed. In the immunohistochemistry study, animals were submitted to 21 days of consumption of ethanol followed or not by 72 hours and 21 days of withdrawal previously perfusion, brain tissue preparation and quantification of serotonin dyed cells in the dorsal and caudal portions in the dorsal raphe nucleus. Behavioral data showed that both short- and long-term ethanol withdrawals reduced the open arms exploration in the EPM. In the open field test there were no locomotor activity changes during the total 15 minutes; however, longterm ethanol withdrawal reduced the exploration in the center of the open field during the first 5 minutes. In the immunohistochemistry step, there were no differences, when short- and long-term withdrawn groups were compared with control group; nevertheless, the chronic consumption of ethanol decreased the number of serotonergic immunorreactive cells in the dorsal part of dorsal raphe nucleus. Taken together, results here obtained suggest that both short- and long-term ethanol withdrawals promoted an anxiogenic-like effect that was not related with changes in the serotonin immunorreactivity in the dorsal and caudal parts of the dorsal raphe nucleus.
Resumo:
Camu-camu (Myrciaria dubia H.B.K. (McVaugh)) is a native Amazon fruit, recognized worldwide as one of the main natural sources of ascorbic acid. Due to its great acidity, this fruit is generally consumed after processing into juice or as ingredient in food preparations. As a co-product of the camu-camu processing, a significant amount of agroindustrial residue is generated. Despite the studies showing the bioactive value and biological potential of the fruit, few studies have approached the possible processing techniques, transformation and preservation of camu-camu fruits and its agroindustrial pomace. Therefore, the present work has the objective of evaluating two different drying processes applied to camu-camu pomace (peel and seeds with residual pulp), freeze drying and hot air drying, in order to obtain a functional fruit product. This thesis was divided into three stages: the first one shows the studies related to the freeze drying and hot air drying, where we demonstrated the impact of the selected drying techniques on the bioactive components of camu-camu, taking the fresh pomace as the control group. Among the investigated conditions, the groups obtained at 50C and 4 m/s (SC50) and 80C and 6 m/s (SC80) were selected as for further studies, based on their ascorbic acid final content and Folin-Ciocalteau reducing capacity. In addition to SC50 and SC80, the fresh pomace (RF) and freeze dried (RL) samples were also evaluated in these further stages of the research. Overall, the results show higher bioactive concentration in the RF samples, followed by RL, SC50 and SC80. On the second step of the research, the antioxidant, antimicrobial and antienzymatic activities were evaluated and the same tendency was observed. It was also reported, for the first time in the literature, the presence of syringic acid in dried camu-camu pomace. In the third and final stage of the research, it was investigated the effect of dried camu-camu on aging and neuroprotective disorders, using the in vivo model C.elegans. It was observed that camu-camu extracts were able to modulate important signaling genes relevant to thermal and oxidative stresses (p < 0.05). The polar acid, polar basic and polar neutral fractions obtained from the low molecular extracts of SC50 were able to extend the lifespan of wild type N2 C. elegans in 20% and 13% (p < 0.001). Results also showed that the paralysis induced by the 1-42 amyloid was significantly (p < 0.0001) retarded in CL4176 worms. Similarly, the camu-camu extracts attenuated the dopaminergic induction associated to Parkinsons disease. Finally, a global analysis of the data presented here reveal that the camu-camu pomace, a co-product obtained from the industrial processing of a native Brazilian fruit, is a relevant natural source of health relevant compounds. This thesis, shows for the first time, the multifunctionality of camu-camu pomace, a natural resource still underexploited for scientific, commercial and technological purposes.
Resumo:
In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
Resumo:
In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.
Resumo:
Snakebites are a serious public health problem in tropical and subtropical countries and Bothrops genus is responsible for the accidents in Brazil and throughout Latin America (90% of cases). The local effects (pain, edema, hemorrhage and myonecrosis) and systemic (cardiovascular alterations, shock and blood clotting disorders) caused by the venom of Bothrops are due to the numerous protein and non-protein components, which are part of the constitution of the poison. The only form of therapy is scientifically validated antivenom serum therapy which, however, is not effective with respect to local effects produced, risk of immunological reactions, high cost and difficult access in some regions. Thus, the search for new alternatives to serum therapy becomes important, and in this context, many medicinal plants have been highlighted by the popular use as antiophidic. Among these plants, we can mention the species Jatropha mollissima (Euphorbiaceae) which has popular use in traditional medicine as antiophidic, anti-inflammatory, antimicrobial and antipyretic. Therefore, this study aims to evaluate the neutralizing potential of local effects induced by the venom of Bothrops erythromelas and Bothrops jararaca with the aqueous extract of the leaves of J. mollissima. The leaf extracts were prepared by decoction, fractionated (by liquid-liquid partition) and characterized by thin layer chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Antiophidic activity of the extract was evaluated in model of paw edema, peritonitis, bleeding and myotoxicity induced by venoms of B. jararaca and B. erythromelas. In all models, the extract was evaluated by intraperitoneal route at the doses of 50, 100 and 200 mg/kg, administered 30 minutes prior to injection of the venom (pretreatment protocol). Stains suggestive of the presence of flavonoids: apigenin, luteolin, orientin, isoorientin, vitexin and vitexin-2-O-rhamnoside were detected in the extract by co-CCD. By means of HPLC were identified isoorientin, orientin, vitexin and isovitexin. All tested doses of J. mollissima extract reduced the paw edema induced by the venom with intensity similar to dexamethasone. The aqueous extract of J. mollissima leaves on all evaluated doses, inhibited cell migration induced by B. jararaca and B. erythromelas promoting inhibition of recruitment of mononuclear cells and the polymorphonuclear cells. Local bleeding induced by B. jararaca venom was significantly inhibited by the extract. Both venoms were inhibited by the extract in myotoxic activity. These results indicate that the aqueous extract of J. mollissima leaves have snakebite potential, particularly with respect to local effects, which may justify the use of this plant in traditional medicine and complementary therapy as anti-venom serum.
Resumo:
Snakebites are a serious public health problem in tropical and subtropical countries and Bothrops genus is responsible for the accidents in Brazil and throughout Latin America (90% of cases). The local effects (pain, edema, hemorrhage and myonecrosis) and systemic (cardiovascular alterations, shock and blood clotting disorders) caused by the venom of Bothrops are due to the numerous protein and non-protein components, which are part of the constitution of the poison. The only form of therapy is scientifically validated antivenom serum therapy which, however, is not effective with respect to local effects produced, risk of immunological reactions, high cost and difficult access in some regions. Thus, the search for new alternatives to serum therapy becomes important, and in this context, many medicinal plants have been highlighted by the popular use as antiophidic. Among these plants, we can mention the species Jatropha mollissima (Euphorbiaceae) which has popular use in traditional medicine as antiophidic, anti-inflammatory, antimicrobial and antipyretic. Therefore, this study aims to evaluate the neutralizing potential of local effects induced by the venom of Bothrops erythromelas and Bothrops jararaca with the aqueous extract of the leaves of J. mollissima. The leaf extracts were prepared by decoction, fractionated (by liquid-liquid partition) and characterized by thin layer chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Antiophidic activity of the extract was evaluated in model of paw edema, peritonitis, bleeding and myotoxicity induced by venoms of B. jararaca and B. erythromelas. In all models, the extract was evaluated by intraperitoneal route at the doses of 50, 100 and 200 mg/kg, administered 30 minutes prior to injection of the venom (pretreatment protocol). Stains suggestive of the presence of flavonoids: apigenin, luteolin, orientin, isoorientin, vitexin and vitexin-2-O-rhamnoside were detected in the extract by co-CCD. By means of HPLC were identified isoorientin, orientin, vitexin and isovitexin. All tested doses of J. mollissima extract reduced the paw edema induced by the venom with intensity similar to dexamethasone. The aqueous extract of J. mollissima leaves on all evaluated doses, inhibited cell migration induced by B. jararaca and B. erythromelas promoting inhibition of recruitment of mononuclear cells and the polymorphonuclear cells. Local bleeding induced by B. jararaca venom was significantly inhibited by the extract. Both venoms were inhibited by the extract in myotoxic activity. These results indicate that the aqueous extract of J. mollissima leaves have snakebite potential, particularly with respect to local effects, which may justify the use of this plant in traditional medicine and complementary therapy as anti-venom serum.
Resumo:
A significant observational effort has been directed to investigate the nature of the so-called dark energy. In this dissertation we derive constraints on dark energy models using three different observable: measurements of the Hubble rate H(z) (compiled by Meng et al. in 2015.); distance modulus of 580 Supernovae Type Ia (Union catalog Compilation 2.1, 2011); and the observations of baryon acoustic oscilations (BAO) and the cosmic microwave background (CMB) by using the so-called CMB/BAO of six peaks of BAO (a peak determined through the Survey 6dFGS data, two through the SDSS and three through WiggleZ). The statistical analysis used was the method of the 2 minimum (marginalized or minimized over h whenever possible) to link the cosmological parameter: m, and 0. These tests were applied in two parameterization of the parameter of the equation of state of dark energy, p = (here, p is the pressure and is the component of energy density). In one, is considered constant and less than -1/3, known as XCDM model; in the other the parameter of state equantion varies with the redshift, where we the call model GS. This last model is based on arguments that arise from the theory of cosmological inflation. For comparison it was also made the analysis of model CDM. Comparison of cosmological models with different observations lead to different optimal settings. Thus, to classify the observational viability of different theoretical models we use two criteria information, the Bayesian information criterion (BIC) and the Akaike information criteria (AIC). The Fisher matrix tool was incorporated into our testing to provide us with the uncertainty of the parameters of each theoretical model. We found that the complementarity of tests is necessary inorder we do not have degenerate parametric spaces. Making the minimization process we found (68%), for the Model XCDM the best fit parameters are m = 0.28 0, 012 and X = 1.01 0, 052. While for Model GS the best settings are m = 0.28 0, 011 and 0 = 0.00 0, 059. Performing a marginalization we found (68%), for the Model XCDM the best fit parameters are m = 0.28 0, 012 and X = 1.01 0, 052. While for Model GS the best settings are M = 0.28 0, 011 and 0 = 0.00 0, 059.
Resumo:
A significant observational effort has been directed to investigate the nature of the so-called dark energy. In this dissertation we derive constraints on dark energy models using three different observable: measurements of the Hubble rate H(z) (compiled by Meng et al. in 2015.); distance modulus of 580 Supernovae Type Ia (Union catalog Compilation 2.1, 2011); and the observations of baryon acoustic oscilations (BAO) and the cosmic microwave background (CMB) by using the so-called CMB/BAO of six peaks of BAO (a peak determined through the Survey 6dFGS data, two through the SDSS and three through WiggleZ). The statistical analysis used was the method of the 2 minimum (marginalized or minimized over h whenever possible) to link the cosmological parameter: m, and 0. These tests were applied in two parameterization of the parameter of the equation of state of dark energy, p = (here, p is the pressure and is the component of energy density). In one, is considered constant and less than -1/3, known as XCDM model; in the other the parameter of state equantion varies with the redshift, where we the call model GS. This last model is based on arguments that arise from the theory of cosmological inflation. For comparison it was also made the analysis of model CDM. Comparison of cosmological models with different observations lead to different optimal settings. Thus, to classify the observational viability of different theoretical models we use two criteria information, the Bayesian information criterion (BIC) and the Akaike information criteria (AIC). The Fisher matrix tool was incorporated into our testing to provide us with the uncertainty of the parameters of each theoretical model. We found that the complementarity of tests is necessary inorder we do not have degenerate parametric spaces. Making the minimization process we found (68%), for the Model XCDM the best fit parameters are m = 0.28 0, 012 and X = 1.01 0, 052. While for Model GS the best settings are m = 0.28 0, 011 and 0 = 0.00 0, 059. Performing a marginalization we found (68%), for the Model XCDM the best fit parameters are m = 0.28 0, 012 and X = 1.01 0, 052. While for Model GS the best settings are M = 0.28 0, 011 and 0 = 0.00 0, 059.
Resumo:
ALVES, Janana da Silva. Anlise comparativa e teste emprico da validade dos modelos CAPM tradicional e condicional: o caso das aes da Petrobrs. Revista Cincias Administrativas, Fotaleza, v. 13, n. 1, p.147-157, ago. 2007.
Resumo:
With the disorganized decentralization occurred in Brazil after the 1988 Constitution, municipalities have risen to the level of federal entities. This phenomenon became known as "municipalism" also brought some negative effects such as low capacity financial, economic and political of these entities. In the face of this reality , the municipalities sought in models of collaborative features to address public policy issues ultrarregionais, one of these models are the Public Consortia. Characterized as the organization of all federal entities that aim to solve public policy implementation alone that they could not, or spend great resources for such. This reality of the municipalities have an aggravating factor when looking at the situation in Metropolitan Regions (MRs). This is because the RMs has a historical process of formation that does not encourage cooperation, since that were created top-down during the military regime. Furthermore, the metropolitan municipalities have significant power asymmetries, localist vision, rigidity earmarked revenues, different scenarios conurbation, difficulty standardization of concepts and others that contribute to the vision of low cooperation of these metropolitan areas. Thus, the problem of this work is in the presence of collaborative arrangements, such as the Public Consortia in metropolitan areas, which are seen as areas of low cooperation. To elucidate this research was used for analysis the cases of CONDIAM/PB and Consrcio Grande Recife/PE, because they are apparently antagonistic, but with some points of similarity. The cases has as foundation the Theory of Common Resources, which provides the possibility of collective action through the initiative of individuals. This theory has as its methodology for analyzing the picture IAD Framework, which proposes its analysis based on three axes: external variables, the arena of action and results. The nature of the method of this research was classified as exploratory and descriptive. For the stage of date analysis, was used the method of document analysis and content, Further than of separation of the cases according to theur especificities. At the end of the study, noted that the CONDIAM/PB was a strategy of municipal government of Joao Pessoa to attract funds from the Federal Government for the purpose of to build a landfill, and over the years the ideology of cooperation was left aside, the prevailing view localist municipalities. In the case of Consrcio Grande Recife/PE, members act with some degree of cooperation, especially the collaborative aspect of the region, however, still prevails with greater strength the power of the state of Pernambuco in the decisions and paths of the consortium. Thus, was conclude that the Public Consortia analyzed are an experience of collaborative arrangement, from the initiative of members, as the theory of common resources says, but has not actually signed as a practice of collective action to overcome the dilemmas faced by metropolitan areas
Resumo:
Seeds from legumes including the Glycine max are known to be a rich source of protease inhibitors. The soybean Kunitz trypsin inhibitor (SKTI) has been well characterised and has been found to exhibit many biological activities. However its effects on inflammatory diseases have not been studied to date. In this study, SKTI was purified from a commercial soy fraction, enriched with this inhibitor, using anion exchange chromatography Resource Q column. The purified protein was able to inhibit human neutrophil elastase (HNE) and bovine trypsin. . Purified SKTI inhibited HNE with an IC50 value of 8 g (0.3 nM). At this concentration SKTI showed neither cytotoxic nor haemolytic effects on human blood cell populations. SKTI showed no deleterious effects on organs, blood cells or the hepatic enzymes alanine amine transferase (ALT) and aspartate amino transferase (AST) in mice model of acute systemic toxicity. Human neutrophils incubated with SKTI released less HNE than control neutrophils when stimulated with PAF or fMLP (83.1% and 70% respectively). These results showed that SKTI affected both pathways of elastase release by PAF and fMLP stimuli, suggesting that SKTI is an antagonist of PAF/fMLP receptors. In an in vivo mouse model of acute lung injury, induced by LPS from E. coli, SKTI significantly suppressed the inflammatory effects caused by elastase in a dose dependent manner. Histological sections stained by hematoxylin/eosin confirmed this reduction in inflammation process. These results showed that SKTI could be used as a potential pharmacological agent for the therapy of many inflammatory diseases
Resumo:
The addition of active silica potentially improves the quality of concrete due to its high reactivity and pore refinement effect. The reactivity of silica is likely related to its charge density. Variations in surface charge alter the reactivity of the material consequently affecting the properties of concrete. The present study aimed at investigating variations in the charge density of silica as a function of acid treatments using nitric or phosphoric acid and different pH values (2.0, 4.0 and 6.0). Effects on concrete properties including slump, mechanical strength, permeability and chloride corrosion were evaluated. To that end, a statistical analysis was carried out and empirical models that correlate studied parameters (pH, acid and cement) with concrete properties were established. The quality of the models was tested by variance analysis. The results revealed that the addition of silica was efficiency in improving the properties of concrete, especially the electrochemical parameters. The addition of silica treated using nitric acid at pH = 4.0 displayed the best cement performance including highest strength, reduced permeability and lowest corrosion current
