Navegando por Assunto "Etanol"

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Acesso aberto (Open Access)
Acidente vascular encefálico isquêmico na exposição crônica ao etanol: estudo pré-clínico da comorbidade e da resposta a minociclina
(Universidade Federal do Pará, 2015-02-27) FONTES JÚNIOR, Enéas de Andrade; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101; CRESPO LÓPEZ, Maria Elena; http://lattes.cnpq.br/9900144256348265
Stroke is the second largest cause of death in the world and the leading in Brazil, with 87% of strokes due to ischemic processes. Chronic ethanol consumption, usually beginning in adolescence, is recognized as an independent risk factor for increased morbidity and mortality by stroke. Although cases combining the two diseases are relatively common, there is no data in animals or clinical models demonstrating the quality or mechanisms of interaction between the two morbidities, nor its impact on therapeutic intervention. Considering the recent studies proposing minocycline as a new therapeutic tool for the treatment of stroke, this study aimed to investigate the interaction between the Chronic Alcoholic Intoxication (CAI) started in adolescence and the stroke in motor cortex of adult rats, and the effects of treatment with minocycline on this interaction, using behavioral, cellular and molecular parameters. Female Wistar rats (35 days-old) were chronically exposed to ethanol (6.5 g/kg/day, 22.5% w/v) or water for 55 days. One day after the end of the CAI focal ischemia was induced in motor cortex with the endothelin-1 (ET-1), followed by seven-day treatment with minocycline or saline. After this period, the animals were assayed with open field and rota rod tests. Immediately, animals were sacrificed and cortex was dissected for evaluation of nitrite and lipid peroxidation levels. In all groups, some animals were perfused and the motor cortex subjected to histological analysis to assess the damage, and immunohistochemical labeling to neuronal death (anti-NeuN), microglial/macrophage (anti-ED1) and astrocytes (anti-GFAP) activation. The ethanol intoxication from puberty to adulthood potentiated the damage caused by stroke, causing major losses in capacity to start and running movements as well as the strength and motor coordination compared to ischemic animals pretreated with water. These manifestations were accompanied by increased neuronal loss, reduced ED-1+ and GFAP+ cells and higher levels of nitrite and lipid peroxidation. Treatment with minocycline was effective in preventing/reverse motor deficits and tissue damage induced by focal ischemia, also inhibiting the increase in oxidative stress markers. The CAI either alone with succeeded by focal ischemia, harmed the outcome of treatment with minocycline. Our results indicate that heavy alcohol intoxication during adolescence exacerbates the motor deficit and tissue damage in animals subjected to focal ischemia. This process appears to be associated with microglia/astroglial activation, but mainly with oxidative stress. It also shows that the previous history of CAI started adolescence interferes significantly in the treatment of cerebral ischemia with minocycline.
Acesso aberto (Open Access)
Alterações no comportamento motor e na bioquímica oxidativa de ratas intoxicadas agudamente com etanol no período inicial da adolescência
(Universidade Federal do Pará, 2015-01-30) CERASI JUNIOR, Antonio José; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
Ethanol (EtOH) is one of the most commonly psychoactive substances consumed by young people, usually occurring in episodes of binge consumption, which is an intense form of drinking followed by a period of abstinence. In Brazil, the rates of alcohol abuse by female adolescents have increased in the past few years. This population is more sensitive to the neurotoxic effects of this substance since the complete development of structures such as the cerebellum occurs in this stage of life. Acute and chronic consumption of ethanol and its catabolism are associated with motor behavior alterations so as the generation of reactive oxygen species (ROS) and other metabolites. The purpose of this study was to investigate the effects of EtOH exposure following an acute binge pattern in female rats on their early adolescence (n = 20, n = 10 animals per group) received distilled water or EtOH (3 g / kg / day, 20 w / v) by gavage, for 3 consecutive days. Seven and a half hours after the last day of administration, the behavioral tests of spontaneous locomotor activity and rotarod were performed. Subsequently, the animals were sacrificed for cerebellum removal and the oxidative biochemical tests in cerebellar tissue were carried out. Behavioral tests showed that acute binge in rats on early adolescence did not alter spontaneous locomotor activity, but elicited alterations in motor learning. Oxidative biochemical results showed a high activity of catalase, which demonstrates that there was an offset of the body to reverse the ROS production in the cerebellum of adolescent rats acutely exposed to EtOH followed by a withdrawal period (binge).
Acesso aberto (Open Access)
Atividade neuroprotetora do treinamento físico moderado contra os danos morfofuncionais cerebelares causados pelo consumo de etanol de forma intensa e episódica (Binge drinking) em ratos
(Universidade Federal do Pará, 2019-09) VIEIRA, Kátia Lamarão; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468; https://orcid.org/0000-0003-1486-4013
Ethanol (EtOH) is a psychotropic drug, central nervous system (CNS) depressant, but widely encouraged and consumed by Brazilian society, as well as in much of the world, reflecting on a public health problem. In recent decades, teenagers have been practicing a very common practice, which is binge drinking. The harmful consumption of EtOH promotes, besides biopsychosocial alteration, the homeostatic imbalance that causes neurodegeneration and loss of function with motor disorders. In contrast, the practice of moderate physical training (MPT) has been recommended for the maintenance of physical and mental health, as well as prevention or minimization of the development of some diseases due to motor activity inducing plastic and dynamic changes in the CNS, in order to favor the neurogenesis, synaptogenesis and angiogenesis, besides contributing to the synaptic modulation. In view of the benefits of MPT, it was investigated the neuroprotective effects on motor, tissue and biochemical parameters in the cerebellum of rats exposed to binge-pattern EtOH from adolescence to adulthood. Forty male Wistar rats with 30 days old were used and divided into four groups, the control being sedentary animals and treated with distilled H2O; the trained, composed of animals exercised and treated with distilled H2O; EtOH, formed by sedentary animals and treated with doses of 3 g/kg/day EtOH, 20% (w/v); and Trained + EtOH, with exercised animals and treated with doses of 3 g/kg/day EtOH, 20% (w/v). The MPT protocol was performed on a rodent treadmill for 5 days for 4 weeks and binge-pattern EtOH doses were administered by intragastric gavage in the same weeks as the MPT. After this period, the animals were submitted to open field and beam walking behavioral tests. Then, they were euthanized for cerebellum collection, evaluating immunohistochemistry from the levels of trolox equivalent antioxidant capacity (TEAC), reduced glutathione (GSH), nitrite and lipid peroxidation (LPO); as well as Purkinje cell morphology (PC), the fraction of anti-synaptophysine (SYP) and anti-myelin basic protein (MBP) immunolabeled area. According to the result, EtOH caused severe oxidative stress and motor damage, but the execution of the MPT performed promoted neuroprotective effects in the rat cerebellum, among them, the modulation of oxidative biochemistry by the restoration of GSH levels. decreased LPO levels and increased TEAC, as well as preventing neuronal loss, synaptic vesicle damage (SYP) and myelin components (MBP). Therefore, MPT can be considered as a significant therapeutic strategy for the acquisition of redox homeostasis, avoiding oxidative biochemistry imbalance, as well as tissue and functional damage in the cerebellum of rats treated by binge pattern EtOH.
Acesso aberto (Open Access)
Avaliação das alterações cerebelares decorrentes da exposição ao etanol da adolescência à fase adulta
(Universidade Federal do Pará, 2014-05-07) CUNHA, Polyane Alencar; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
Alcohol abuse has reached massive proportions, associated with a number of adverse consequences, becoming one of the most widespread phenomena of recent decades and therefore alcohol, alcoholic disease agent of a public health problem. Young people are under physiological and social transition, with the curiosity, the pressure of the social group, the family model, propaganda and lack of public policies, the main risk factors which lead to early alcohol consumption. The teenager once is maturing presents its central nervous system (CNS) vulnerable to aggression caused by the consumption of this drug. It is known that alcohol promotes a series of motor change the point of view of clinical and physiological concurrently. These amendments are consequential action of alcohol sore CNS, specifically on the Cerebellum, and by chronic use of the drug suffer (like other organs of the CNS) some changes. The aim of this study was to evaluate the cerebellar changes resulting from exposure to ethanol from adolescence to adulthood in rats, on the morphometric patterns observed in the organ, tissue response and investigation of oxidative balance the body against the injury caused by toxic. Mice received from the 35th day of postnatal life (puberty period) by gavage at a dose of EtOH 6.5g/kg/day for 90 days (adulthood). To view the injury caused to the fabric was made morphometric biochemical research and analysis through oxidative stress. The results show that cerebellar mass is not changed, but there is a reduction in organ size and an increase in the density of the cell population in the molecular and granular layers, however a decrease in neuronal cells, with all the changes occurred were not morphohistologics accompanied by alterations in the biochemical oxidation.
Acesso aberto (Open Access)
Avaliação do efeito neuroprotetor da cafeína em ratas intoxicadas por etanol no padrão binge
(Universidade Federal do Pará, 2019-05-03) BARROS, Mayara Arouck; FERNANDES, Luanna de Melo Pereira; http://lattes.cnpq.br/0156144290849777; https://orcid.org/0000-0001-7004-0719; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
Ethyl alcohol is a substance consumed since the dawn of mankind, extending to the present day. In this context, adolescents are attracting attention because consumption in this group is constantly rising, especially in the Binge Drinking pattern. This model of consumption leads to functional impairments, such as symptoms associated with anxiety and depression. For this reason, has been sought bioactive compound to prevent such damages, among them we can highlight the caffeine, substance widely consumed in the world. In view of this, this paper aims to investigate the neuroprotective effect of caffeine in self administration on the damages caused by EtOH intoxication in the binge pattern, aiming at an alternative to minimize the neurotoxic damages promoted by alcohol with the simple habit of drinking coffee. For this, Wistar rats, females, age 35 days (n = 40) were used. At treatment, animals received caffeine repeatedly from the 35th to the 72nd postnatal day (PND). Caffeine was administered as a 0.3g / L caffeinated solution in self-administration in the active period, starting 14 days before the first day of ethanol intoxication and persisting during the 4 weeks of BD. For ethanol intoxication in the binge pattern, it was administered by gavage at a dose of 3 g / kg / day (20 w / v) for three consecutive days weekly in the animals from the 49th to the 72nd PND. For behavioral tests, the animals were exposed to Open Field, Elevated-plus-maze, Splash and Forced swimming test. In relation to the anxious type behavior, the Caffeine + EtOH Group showed a significant increase in the distance and time traveled in the central area in the Open Field Test when compared to the EtOH group. In the LCE Test, the EtOH group showed reduction in %EBA and %TBA when compared to the control group. However, the caffeine group showed reversion when increasing both parameters when compared to the EtOH group. In the depressive-type behavior, the EtOH-intoxicated group presented reduction of the grooming time and increased immobility time, in the Splash and Forced Swim tests, respectively. The EtOH + Caffeine group was able to increase grooming time in the first test and reduce immobility time in the second. Thus, we can conclude that chronic consumption of caffeine promoted neuroprotection by reversing symptoms similar to anxiety and depression
Acesso aberto (Open Access)
Avaliação do processo de produção de etanol pela fermentação do caldo de mandiocaba (Manihot esculenta Crantz)
(Universidade Federal do Pará, 2013-02-28) SOUZA, Leiliane do Socorro Sodré de; FRANÇA, Luiz Ferreira de; http://lattes.cnpq.br/6545345391702172
The physico-chemical characteristics identified at sweet cassava root, was: moistures (%), fiber (%), protein (%), ash (%), total lipids (%), reducing sugars and total reducing sugars (%); the sap extract from sweet cassava root was characterized by pH, soluble solids (%), glucose and titratable acidity. This study used the yeast Saccharomyces cerevisiae PE-2. Was realized 15 tests that followed the conditions determined by the experimental design of Box- Behnken, with 3 independent variables: temperature (oC) (X1), pH (X2) and concentration of inoculum (g/L) (X3). The statistical analysis was performed with p>0,05. Through the analysis of variance (ANOVA) was proposed a second order polynomial model to the alcohol content (ºGl), and by analysis of response surfaces it was determined the optimum condition to the fermentation of sap extract from sweet cassava root without addition of nutrients, on original substrate concentration of it (6,46 g/L): 28ºC (temperature), 4,88 (pH) and 10 g/L (inoculum concentration). Under these conditions a test was conducted, which aimed to raise the curves of cell growth (yeast), CO2 production, consumption of sugars and ethanol production, to better understand the process of fermentation broth of sweet cassava. Through the cellular growth curve was determined the duration of the exponential phase, using the method of linear regression; this step in this study occurred at different time intervals. The value found to μm was 0,05 h-1.
Acesso aberto (Open Access)
Caracterização dos efeitos comportamentais, teciduais e bioquímicos da administração intermitente e episódica de EtOH em ratas da adolescência à fase adulta
(Universidade Federal do Pará, 2016-10-18) FERNANDES, Luanna de Melo Pereira; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
The consumption of ethanol (EtOH) is enhanced particularly in adolescent female pubic. The EtOH intake and intermittent episodic own consumption rate around 3 times per week. The toxic effects of this kind of consumption is especially dangerous over the continuous consumption of EtOH followed due to the high dietary intakes of abstinence, causing major changes in the central nervous system (CNS) maturing in a short time consumption. Considering the epidemiological relevance and the harmful effects of EtOH on the oxidative balance, hormone production and neurotrophin CNS maturing, the aim of this study was to investigate the behavioural, tissue and biochemical responses derived from intermittent and episodic consumption of EtOH in rats in phase from adolescence to adulthood. Wistar female adolescents (n = 80) received by gavage, distilled water or EtOH (3 g/kg/day) for 3 consecutive days per week. The animals were assessed seven and a half hours after the last administration day 1, 4 and 8 weeks of episodes of binge drinking (37, 58 and 86 DPN, respectively), besides, a period of 14 days of abstinence was added after BD 8 (100 DPN) to evaluate the ability to reverse the CNS damage generated on it. The battery of behavioural tests consisted of spontaneous locomotor activity, object recognition, elevated plus maze, test pole, walking beam and rotarod. The animals were sacrificed and blood samples collected for evaluation of corticosterone levels of malondialdehyde, catalase activity, the activity of superoxide dismutase and glutathione content. Therefore, the hippocampus was dissected to quantify the immunocontent BDNF. The administration of EtOH reached average peak blood concentration of 197.4 mg / dL and the period of 7.5 hours after the last administration EtOH in acute binge blood concentration was 0.7 mg / dL. Thus, the animals underwent behavioural tests post-consumer EtOH, not under the drug effect. Consumption of EtOH in binge did not affect weight gain of adolescent animals into adulthood, however, reduced the exploratory locomotor activity, impaired motor coordination, balance and motor learning associated with bradykinesia, as well as loss in the mnemonic process and increased anxiety-like behaviour. These losses were accompanied by hormonal elevation of corticosterone, reduced hippocampal BDNF levels and systemic imbalance in the oxidative balance. Thus, it was possible to identify that the damage found on the similar behaviour to anxiety, short-term memory, bradykinesia and spontaneous locomotor activity appeared from EtOH post-consumption for three consecutive days, however, they showed no recovery or worsening of damage after repeated episodes. In contrast, there was recovery of short-term memory in object recognition task associated with the return of normal levels of BDNF in adulthood. Moreover, it showed worsening in motor learning in young adult phase followed by gradual and partial recovery after prolonged period of drug withdrawal, yet the loss of motor coordination and balance remained in adulthood.
Acesso aberto (Open Access)
Cinética de secagem do camarão-da-amazônia (macrobrachium amazonicum) por refractance window
(Universidade Federal do Pará, 2023-10-19) ROSA, Matheus Yury de Oliveira; RODRIGUES, Antonio Manoel da Cruz; http://lattes.cnpq.br/7524720020580309
In the Amazon region, freshwater prawns are distributed throughout the hydrographic subbasins. Macrobrachium amazonicum, popularly known as the Amazon Prawn, is the species with the highest production in the region and has the greatest potential for fishing and aquaculture. Its capture and commercialization are one of the main and sometimes the only source of income for several families, especially those living along the riversides, due to the final destination of this production, with distribution in ports in Pará and Amapá. Although prawns are known for their high nutritional value, this characteristic can be affected when this food does not undergo a suitable preservation method to extend its shelf life. Given the importance of this food, it is necessary to explore new technologies, such as the use of ethanol in food pretreatment - which has the ability to dissolve cell membranes, alter the sample structure to be dehydrated, improve moisture transfer, and reduce drying time when combined with Refractance Window (RW) drying, a method that is known in literature as a technological innovation, in view of its advantages, which are: it retains bioactive compounds; it preserves quality and increases the product's shelf life; it has energy efficiency; it involves lower operating costs; and it is environmentally viable. The objective of this dissertation was to evaluate the performance of the RW drying method associated with ethanol pretreatment assisted by mechanical agitation and ultrasound in the dehydration process of an animal-based matrix (Amazon Prawn – Macrobrachium amazonicum). Simultaneously, mass transfer parameters and thermodynamic properties controlling the drying process were determined. The samples (peeled abdomen) were pretreated with 100% ethanol (1:18) under mechanical agitation (PTAG) and ultrasound (PTUS) for 10 minutes, in addition to the sample without pre-treatment (SPT). Then, the samples subjected to the drying process in RW at temperatures of 50, 70, and 90ºC. The parameters of the mathematical models by Dincer & Dost, Crank, and Motta Lima and Massarani were estimated using Origin Software 2023. The analyses were done in duplicate using analysis of variance (ANOVA) and the Tukey test at 5% probability. Additionally, the quality of fit for the experimental drying kinetics (CS) data was estimated by the coefficient of variation (R²) and the chi-squared (X²). After obtaining the data, the moisture determination indicated that at a temperature of 90ºC, the PTAG (12.93 ± 0.16%) and PTUS (11.86 ± 1.59%) samples had the lowest final moisture content. Through ANOVA, the results show that the ASPT and PTUS samples presented a significant difference, while the PTAG sample did not present a significant difference (p<0.05) between the temperatures. Regarding the mathematical modeling of CS, the Motta Lima and Massarani model showed the best fit to the experimental data, with R² ≥ 0.98 and reduced X² values for all temperatures. Thermodynamic properties were calculated based on data obtained by the Dincer & Dost model, such as activation energy (Ea) with a range between 42.97 - 30.37 kJ/mol; positive enthalpy (ΔH) values, indicating the need for heat energy for the drying process to occur; and negative entropy (ΔS) values, indicating that the process occurred without a significant increase in disorder in the system. Based on the results, it was evident that the combination of pretreatment with ethanol assisted by AG and US, coupled with RW drying, significantly reduced the time required for drying the Amazon Prawn.
Acesso aberto (Open Access)
Efeitos da exposição crônica ao etanol da adolescência à fase adulta em ratos sobre o processo mnemônico e na densidade celular no hipocampo
(Universidade Federal do Pará, 2012-11-30) OLIVEIRA, Maria Cristina Souza Pereira; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
The central nervous system is vulnerable to the action of several substances including these are psychoactive substances such as ethyl alcohol or ethanol, which is consumed by mankind for a long time and is associated with a range of medical social problems. Therefore, the objective of this study was to investigate the neurobehavioral alterations and tissue from exposure to ethanol from adolescence to adulthood on the hippocampus. For this, 30 Wistar rats were evaluated distributed into control and ethanol, which upon reaching 35 days of age (adolescence) received by gavage ethanol at a dose of 6.5 g/Kg/day for 90 days (adulthood ). After this period, the animals were subjected to behavioral tests of open field, social recognition and avoidance for evaluation and subsequently perfused tissue through histological processing by violet cresila. Were collected and processed sections of 50 μm, the samples were subjected to staining violet cresila. The results demonstrate a deficit in the parameters measured in the behavioral assays such as impairment in natural ambulation of the animal, the percentage of the number of quarters and time in the central core area which suggests anxiogenic-like behavior, increase in exploratory activity surveying related to animal. Observed impairment in the development of mnemonic processes with reduced memory retention of short and long term as well as in social recognition. Regarding the treatment histologically observed decrease in cell density in CA1 and CA3 regions of the hippocampus. These results indicate that chronic exposure to ethanol from adolescence to adulthood disrupts behavioral aspects related to the limbic system, the hippocampus where it entered.
Acesso aberto (Open Access)
Efeitos no comportamento motor após intoxicação subcrônica de metilmercúrio na presença de etanol (padrão binge) em ratas adolescentes à fase adulta
(Universidade Federal do Pará, 2015-11-06) OLIVEIRA, Aline do Nascimento de; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
Exposure to methylmercury through the contaminated seafood diet, concomitant abusive alcohol intake, in binge pattern, is quite common in gold mining communities of gold extraction, especially in the Amazon. The association between these two neurotoxicantes is also evident among adolescent women and creates the need to understand its effects on the central nervous system, especially in motor coordination, balance and spontaneous locomotion, because the studies are advanced only for the effects of exposure in isolation. Therefore this study aims to evaluate the effects on motor behavior resulting of subchronic exposure to methylmercury in the presence of alcohol, in binge pattern, in adolescents female rats until early adulthood (37-72 postnatal day), through behavioral motors tests, like Open Field, Pole Test, Rotarod and Beam Walking Test. The testing occurred 24 hours after the last intoxication of rats, which received methylmercury (0.04 mg / kg / day) for 35 days, concomitant with alcohol (3g / kg / day), 3 intermittent days, 1 time per week (binge), totaling 5 binges. The results showed a decrease in spontaneous locomotion in Open Field test through the parameters of the total distance traveled and number of rearing. In the Pole test was increased fall time, evidencing the bradykinesia. In the Rotarod there was a decrease in latency in the first three exhibitions, as well as Beam Walking Test was increased latency and number of slips, especially in thinner beams, showing that subchronic exposure to methylmercury in the presence of alcohol, in the binge, in adolescent female rats was able to produce behavioral damages related to coordinating motor, balance and spontaneous locomotor activity.
Acesso aberto (Open Access)
Estudo da hidrólise enzimática do caroço de açaí (euterpe oleraceae mart) para a produção de etanol
(Universidade Federal do Pará, 2016-08-31) CORDEIRO, Márcio de Andrade; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065; ALMEIDA, Ossalin; http://lattes.cnpq.br/7040173036131516; https://orcid.org/0000-0003-3895-0952
The use of Acai seed (Euterpe oleracea Mart), for energy purposes has been little studied, therefore we sought in this work to study the production of second generation ethanol from enzymatic hydrolysis of core açai in natura and treated with solvent two temperature conditions (60 to 70 °C). The enzyme β-glucosidase used in this study as technical specifications (Table 5). The Açai core samples, passed through washing, drying at ambient temperature, in an oven with air circulation at 105 ± 5 °C until constant weight, grinding and solvent treatment. The moisture content and the yield on a wet basis of acai core "in natura" was 39.59 and 60.41%. Morphological analysis by scanning electron microscopy (SEM), allowed to analyze the structure and the presence of chemical elements (C, O, Si and Al) in the core and fiber. The -ethanoic acid extract of acai seed showed satisfactory capacity (82%) to scavenge free radicals (antioxidant activity), against free radical DPPH. As a result of the enzymatic hydrolysis process, the core acai without treatment (CANT60) proved to be a promising lignocellulosic biomass to obtain second generation ethanol, it contains a high cellulose content (40.29%), besides presenting good income in the release of glucose (13.687 g L-1) after enzymatic hydrolysis. The average ash content for CANT and CAT were 0.15 and 0.13%. Treatment with acai core of the solvent in the conversion of cellulose into glucose, the yield was below 25%, in both temperature conditions (60 to 70 °C), it was not able to disrupt the plant wall biomass in particular cellulose, hemicellulose and lignin, making fermentable sugars available on the enzymatic hydrolysis process, because of possible inhibitors generated during the treatment. By analyzing the experimental data, we can say that the best condition of enzymatic hydrolysis of acai core was CANT60 and glucose obtained by enzymatic hydrolysis of acai seed was well assimilated by the yeast Saccharomyces cerevisiae for ethanol production.
Acesso aberto (Open Access)
Estudo de eletrocatalisadores de PtRu, PtRuRh e PtRuPd obtidos por modificação no Método Borohidreto de Sódio para eletro-oxidação de metanol e etanol
(Universidade Federal do Pará, 2016-01-25) ANDRADE, Flávio Vargas; SOUZA, José Pio Iúdice de; http://lattes.cnpq.br/1448978342555218
PtRu, PtRuRh and PtRuPd electrocatalysts supported on carbon has been widely studied for electro-oxidation of methanol and ethanol. Among different possibilities of preparing these electrocatalysts is the method of reducing with sodium borohydride. For the catalytic activity is optimized, it is necessary that the electrocatalyst is distributed evenly. One possibility is the use of complex precursor salts, including those with amine linker. In this work, we tried to assess the effect of adding an ammonium hydroxide solution (NH4OH) the solution of precursors. The electrocatalysts were characterized physically by Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX) and X-ray diffraction (XRD). For the electrochemical characterization, the techniques of chronoamperometry and cyclic voltammetry were used. The results of EDX showed that the compositions of the electrocatalysts were very close to the nominal composition. The crystallite size and the lattice parameter obtained by XRD showed changes with the change of the method. The TEM results show a homogeneous distribution more particle on electrocatalysts preparations with the addition of NH4OH solution 4 mol L-1 although this is not be determinant in electrocatalytic activity. Nos electrochemical testicles, as chains were for standard electro-oxidation of CO and load monolayer for the mass activity and compared this way. The cyclic voltammetry and chronoamperometry results showed different activities paragraph an electro-oxidation of methanol and ethanol. The results of DEMS electrocatalysts trimetallic of PtRuRh and PtRuPd showed different amounts of products and volatile. This way possible and establish an activity order these electrocatalysts.
Acesso aberto (Open Access)
Estudo de misturas de enzimas (complexo celulásico, complexo enzimático, xilanase, β-glucanase e xilanase, β-glucosidase e Glucoamilase) na bioconversão do bagaço da cana-de-açúcar em etanol
(Universidade Federal do Pará, 2015) MOREIRA, Rosiane Fernandes; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
This work, it was proposed to evaluate mixtures of commercial enzymes by supplier Novozymes A / S. The enzymes used in this work were: celulase complex, xylanase, β-glucosidase, enzymático complex, xylanase and β-glucanase and glucoamylase in the glucose production from sugarcane bagasse subjected to treatment with alkali hydroxide solution sodium at room temperature, 70 ° C, 90 ° C and 120 ° C. The BCA yield on a dry basis after treatment with NaOH solution 6 (w / v) were 30.64% ± 1.395 (PACTA), 44.00% ± 1.787 (PAC70), 65.91% ± 1.096 (PAC90), and 95.25% ± 1.461 (CAP 120), respectively. The ash content for the BCA were 2.05% ± 0.027 (PACTA), 0.62% ± 0.013 (PAC70), 0.48% ± 0.007 (PAC90) and 0.18% ± 0.008 (PAC120). The lignin contents were 20.67 ± 0.603 (PACTA), 13.03 ± 0.711 (PAC70), 6.05 ± 0.196 (PAC90) and 5.49 ± 0.151 (PAC120). The results suggest that the conversion rates of cellulosic waste into glucose are strongly dependent on temperature in the alkaline pulping process. The kinetic parameters obtained in kinetic adjustments enzymatic hydrolysis of the BCA for PACTA, PAC70, PAC90 and PAC120 were: Vmax (g/h) equal to 7.20; 5.12; 4.54 and 0.87 respectively; Km (g) equal to 3.6; 2.56; 2.27 and 2.56 respectively; Kcat (h) equal to 1.44; 1.02; 0.91 and 0.17 respectively; Km/Vmax equal to 0.5 for all samples and Kcat/Km of 0.4 for all samples.
Acesso aberto (Open Access)
Influência do método de preparação de eletrocatalisadores PtRu/C sobre a atividade catalítica frente à reação de oxidação de etanol em meio ácido
(2013) GOMES, Walber dos Santos; SILVA, Uriel Lean Valente; SOUZA, José Pio Iúdice de
In this work the influence of variations in the borohydrate reduction method on the properties of PtRu/C electrocatalysts was investigated. The electrocatalysts were prepared using 1:1 ; 2:1; 5:1; 50:1 and 250:1 molar ratios of NaBH4 to metals. The reduction was also performed by dripping or by fast addition of the solution. The results showed that PtRu nanoparticles obtained by fast addition had the smallest crystallite sizes. It was also noted that the catalytic activity increased as the borohydrate:metal molar ratio increased. The PtRu/C electrocatalyst (50:1) obtained by fast addition presented the best catalytic activity for ethanol electro-oxidation.
Acesso aberto (Open Access)
Investigação dos efeitos da cafeína e SCH58261 sobre as alterações comportamentais e no estresse oxidativo, e papel dos receptores A2A na potenciação de longo prazo após intoxicação por etanol em padrão binge em ratos fêmeas da adolescência a fase adulta
(Universidade Federal do Pará, 2022-11) PINHEIRO, Bruno Gonçalves; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
Introduction: Binge consumption of ethanol is an intermittent and episodic pattern of ingestion involved in several brain disorders that affect adolescents, considered more susceptible to damage that persists into adulthood. In the deleterious effects of ethanol, an important intoxication mechanism is the overproduction of adenosine, which causes hyperexcitability in its receptors, generating behavioral changes and oxidative stress. These receptors are antagonized by caffeine, a bioactive compound that can modulate the deleterious overactivation of ethanol. Objective: The aim of this study was to investigate the effects of caffeine administration on behavioral changes related to locomotion, anxiety, cognition and oxidative balance induced by ethanol in the binge drinking pattern during adolescence. In addition, it aims to assess the contribution of A2A receptors in the observed changes, including long-term potentiation (LTP). Material and Methods: Female Wistar rats (35 days old; n = 102) were allocated into six groups: control (distilled water, v.o), ethanol (3 g/kg/day; 3 days on-4 days off, v.o) , caffeine (10 mg/kg/day, v.o), caffeine + ethanol, A2A antagonist SCH58261 (0.1 mg/kg/day, intraperitoneal - i,p) and ethanol + SCH58261. The animals were submitted to open field behavioral tests, object recognition and elevated plus maze. The oxidative biochemistry parameters of trolox equivalent antioxidant capacity (TEAC), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) in the pre- frontal and hippocampus. LTP recordings in the medial prefrontal cortex (mPFC), ventral (vHip) and dorsal (dHIP) portions of the hippocampus of the control, ethanol, ethanol + SCH58261 and SCH58261 groups were evaluated through electrophysiology. Results: Caffeine prevented ethanol-induced behavioral impairments, including by blocking A2A receptors. In addition, it attenuated the oxidative stress induced by binge drinking by alternative A2A receptor pathways. Blockade of A2A receptors increased LTP levels in mPFC and vHIP, however decreased in dHIP. Conclusion: Caffeine showed neuroprotection in behavioral changes and oxidative stress induced by the binge drinking model in adolescent rats. In addition, blockade of A2A receptors mitigated the observed behavioral changes, with improvement of LTP levels in the prefrontal cortex and hippocampus, which suggests the contribution of this pathway to neuroprotection in deficits induced by ethanol exposure during adolescence.
Acesso aberto (Open Access)
Investigação dos prejuízos motores decorrentes da exposição crônica ao etanol, em ratas intoxicadas da adolescência à fase adulta
(Universidade Federal do Pará, 2013-09-19) SILVA, Fernando Bezerra Romualdo da; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
According to the World Health Organization, ethanol is the most widely used psychoactive drug in the world, occupying a prominent place by now be considered a public health problem worldwide. His heavy drinking among adolescents is on the rise, from 15 years and young adults A wide variety of research related to its damaging many organs and body systems effects, as well as damage and degeneration of the central nervous system structures, and the cerebellum one of its main targets is the affinity of the substance for cellular structures is the ability to generate a cascade of deleterious processes . The aim of this study was to evaluate behavioral changes associated with the cerebellum in rats chronically intoxicated with ethanol adolescence to adulthood. Female at 35 days of postnatal life received during 55 days, ethanol by gavage. After this period of intoxication, the animals underwent a battery of tests to assess motor deficits. Behavioral tests consisted Open Field, Pole Test, Walking Beam and Rotarod. The results showed that animals exposed to ethanol displayed motor deficits in all behavioral tests. Although several mechanisms are associated with cerebellar degeneration, further studies should be conducted to investigate the true effect of this drug and their correlation wiser the results obtained in this research.
Acesso aberto (Open Access)
Minociclina atenua os prejuízos motores em ratos submetidos à isquemia focal no córtex motor e expostos cronicamente ao etanol da adolescência à fase adulta
(Universidade Federal do Pará, 2012-08-30) OLIVEIRA, Gedeão Batista de; MAIA, Cristiane do Socorro Ferraz; http://lattes.cnpq.br/4835820645258101
According to World Health Organization, alcohol consumption in the world has become a public health problem. In this context, Brazil is at 63th position in the world in per capita alcohol consumption for people aged 15 or older. In addition to its socio-economic effects, ethanol is an important risk factor in the occurrence of cerebral ischemia. Exacerbated consumption of this drug contributes to the poor prognosis, as well as possible treatment for health problems related to stroke. The objective of this study was to evaluate neuromotor changes after blocking micróglial activation with minocycline in rats subjected to focal ischemia in the motor cortex, when treated chronically with ethanol from adolescence to adulthood. Rats were given for 55 days by gavage ethanol (6.5 g/kg/dia, 22.5 w/v). At the end of 55 days the animals were microinjected with the vasoconstrictor peptide endothelin-1 (40 pmol) for induction of focal ischemic lesion. The ischemic animals were treated with minocycline receiving two daily doses of 50 mg/kg in the first two days, and five daily applications of single 25mg/kg, intraperitoneally, by the seventh day post-ischemic induction. Behavioral tests consisted of open field, inclined plane and rota-rod. The results showed that the animals were exposed to ethanol showed motor deficits in all behavioral tests. However, treatment with minocycline was able to reverse them, enabling better performance on all tests. The results suggest that minocycline was able to reverse damage caused by motors stroke, even in the presence of ethanol. The exact mechanism involved in this process need to be investigated in future research.
Acesso aberto (Open Access)
Redução do volume hipocampal, perda neuronal e alterações gliais em ratos expostos cronicamente ao etanol da adolescência à fase adulta
(Universidade Federal do Pará, 2013-03-04) OLIVEIRA, Ana Carolina Alves de; LIMA, Rafael Rodrigues; http://lattes.cnpq.br/3512648574555468; LEAL, Walace Gomes; http://lattes.cnpq.br/2085871005197072
O consumo de etanol (EtOH) é considerado um problema de saúde pública do Brasil e no mundo, sendo alvo de pesquisas epidemiológicas e de seus efeitos no organismo durante as várias etapas do desenvolvimento humano. Neste contexto, torna-se necessário o entendimento dos efeitos do EtOH no Sistema Nervoso Central, mais especificamente sobre a formação hipocampal, pois embora seja conhecida como uma estrutura particularmente sensível aos seus efeitos deletérios do EtOH, os mecanismos subjacentes aos efeitos de exposição crônica são pouco estabelecidos. O presente estudo objetiva verificar quais as repercussões da exposição crônica ao EtOH em ratos, desde a adolescência até a idade adulta, sobre os padrões morfométricos e morfologia hipocampal. Ratos Wistar, fêmeas, receberam EtOH por gavagem (6,5 g/kg/dia, 22,5% V/v), do 35º ao 90º dia pós-natal, sendo comparado com grupo controle, o qual recebeu apenas água destilada. Foi realizada análise morfométrica e estereológica, bem como histoquímica e imunoistoquímica. Para a marcação imunoistoquímica, utilizou-se os anticorpos Anti-NeuN, Anti-GFAP e Anti-Iba1. Verificou-se perda neuronal significativa em CA1 e hilo, com CA3, apresentando diminuição não significante no número de células Neu-N+. Também foi encontra redução significativa da população microglial em todas as áreas investigadas, com ativação destas células. Houve redução no número de astrócitos em animais expostos ao EtOH em todas as áreas, embora não de forma significativa em CA1. Análise estereológica evidenciou redução de volume na formação hipocampal de ratos expostos ao EtOH em relação ao grupo controle. Desta forma, conclui-se que animais expostos cronicamente ao EtOH, sofrem redução volumétrica e perdas neuronal e glial na formação hipocampal.
Acesso aberto (Open Access)
Teoria do funcional de densidade aplicada a reatividade química de combustíveis e biocombustíveis na fase gasosa: gasolina, etanol e gasolina-etanol
(Universidade Federal do Pará, 2015-03-10) GOMES NETO, Abel Ferreira; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
We performed a theoretical study using the Density Functional Theory, with the B3LYP functional and the basis set 6-311 ++ g (d,p) to calculate thermodynamic properties of the following fuels and biofuels: gasoline, ethanol and gasoline-ethanol mixture, all in gas phase. The simulations were performed using the Gaussian 09W and Hyperchem 7.5 softwares and allowed obtaining fuel properties, witch, were calculated from the weighted average for the properties to each of its major components, considering the mass fractions of components of two kinds of gasoline, a Standard kind and other commercial Regular. The simulations were performed at various temperatures in the range 0.5K - 1500K and under pressure of 1 atm, using continuous polarizable model to simulate solvated systems with each component. Conformational search, optimization and frequency calculations (Raman and Infrared) were simulated were performed, where, was possible obtain physical quantities associated with the chemical reactivity and the calorific value of the fuel during injection phase in combustion chamber. It was also possible to prove and quantify some relevant characteristics of the fuels, such as, The high antiknock potential of ethanol when it is compared to the gasoline, as well as the influence caused for the ethanol when blended with gasoline. These comparisons were made from the study of thermodynamic potentials (internal energy, enthalpy and Gibbs free energy) obtained during the simulations. In addition to these properties, were calculated the rate-change of Gibbs free energy in relation to temperature, specific heat at constant pressure and entropy of major components. This methodology has been reproduced using the PM3 and PM6 semi-empirical computational methods with the purpose of comparing its accuracy and computational cost to the study fuels, to results obtained from the B3LYP functional. We found that semi-empirical methods can generate results with a good precision for calculations of thermodynamic properties of major components, as such as, functional B3LYP showed, but with a computational cost far lower enabling this work presents itself as a methodology quite effective for the thermodynamic characterization of fuels and biofuels in the gas phase, when they are injected into the combustion chamber.