Aplicação de sistemas microemulsionados ácidos em acidificação de poços

Stimulation operations have with main objective restore or improve the productivity or injectivity rate in wells. Acidizing is one of the most important operations of well stimulation, consist in inject acid solutions in the formation under fracture formation pressure. Acidizing have like main purpose remove near wellbore damage, caused by drilling or workover operations, can be use in sandstones and in carbonate formations. A critical step in acidizing operation is the control of acid-formation reaction. The high kinetic rate of this reaction, promotes the consumed of the acid in region near well, causing that the acid treatment not achive the desired distance. In this way, the damage zone can not be bypassed. The main objective of this work was obtain stable systems resistant to the different conditions found in field application, evaluate the kinetic of calcite dissolution in microemulsion systems and simulate the injection of this systems by performing experiments in plugs. The systems were obtained from two non ionic surfactants, Unitol L90 and Renex 110, with sec-butanol and n-butanol like cosurfactants. The oily component of the microemlsion was xilene and kerosene. The acqueous component was a solution of HCl 15-26,1%. The results shown that the microemulsion systems obtained were stable to temperature until 100ºC, high calcium concentrations, salinity until 35000 ppm and HCl concentrations until 25%. The time for calcite dissolution in microemulsion media was 14 times slower than in aqueous HCl 15%. The simulation in plugs showed that microemulsion systems promote a distributed flux and promoted longer channels. The permeability enhancement was between 177 - 890%. The results showed that the microemulsion systems obtained have potential to be applied in matrix acidizing

Sistema supervisório para poços de petróleo baseados no método de elevação artificial Plunger Lift

The several existing methods for oil artificial lifting and the variety of automation equipment for these methods many times lead the supervisory systems to be dedicated to a unique method and/or to a unique manufacturer. To avoid this problem, it has been developed the supervisory system named SISAL, conceived to supervise wells with different lifting methods and different automation equipments. The SISAL system is working in several Brazilian states but, nowadays, it is only supervising rod pump-based wells. The objective of this work is the development of a supervision module to the plunger lift artificial lift method. The module will have the same characteristics of working with automation hardware of many manufacturers. The module will be integrated to the SISAL system, incorporating the capacity to supervise the plunger lift artificial lift method.

Análise da modelagem experimental da perda de injetividade

Injectivity decline, which can be caused by particle retention, generally occurs during water injection or reinjection in oil fields. Several mechanisms, including straining, are responsible for particle retention and pore blocking causing formation damage and injectivity decline. Predicting formation damage and injectivity decline is essential in waterflooding projects. The Classic Model (CM), which incorporates filtration coefficients and formation damage functions, has been widely used to predict injectivity decline. However, various authors have reported significant discrepancies between Classical Model and experimental results, motivating the development of deep bed filtration models considering multiple particle retention mechanisms (Santos & Barros, 2010; SBM). In this dissertation, inverse problem solution was studied and a software for experimental data treatment was developed. Finally, experimental data were fitted using both the CM and SBM. The results showed that, depending on the formation damage function, the predictions for injectivity decline using CM and SBM models can be significantly different

Estudo da formulação de pré-misturas secas para a cimentação de poços em terra

An economical solution for cementing oil wells is the use of pre-prepared dry mixtures containing cement and additives. The mixtures may be formulated, prepared and transported to the well where is added water to be pumped.Using this method, becomes dispensable to prepare the cement mixes containing additives in the cementing operation, reducing the possibility of error. In this way, the aim of this work is to study formulations of cement slurries containing solid additives for primary cementing of oil wells onshore for typical depths of 400, 800 and 1,200 meters. The formulations are comprised of Special Class Portland cement, mineral additions and solids chemical additives.The formulated mixtures have density of 1.67 g / cm ³ (14.0 lb / gal). Their optimization were made through the analysis of the rheological parameters, fluid loss results, free water, thickening time, stability test and mechanical properties.The results showed that mixtures are in conformity the specifications for cementing oil wells onshore studied depths

Efeitos do potencial probiótico Enterococcus faecium 32 e de sua associação com o extrato da alga marinha Caulerpa mexicana no tratamento de colite experimental murina

Ulcerative colitis comprising an inflammatory bowel disease, whose most severe consequence is the development of intestinal neoplasia. The drugs currently used to treat the disease trigger a variety of serious adverse effects and are not effective in many cases. Recent studies demonstrated the effectiveness of natural products for the treatment of inflammatory processes. Seaweed extracts and their purified products have shown protective effects in models of inflammation and the association of traditional therapies with probiotics has significantly improved the clinical symptoms of ulcerative colitis. Therefore, the aims of this study include evaluating the potential effects of the use of probiotic strain Enterococcus faecium 32 (Ef32), the methanolic extract of the green seaweed Caulerpa mexicana (M.E.) and their concomitant administration in a murine model of colitis induced by dextran sodium sulfate (DSS). Accordingly, C57BL /6 mice were pretreated orally with Ef32 (109 CFU/ml) for seven days. In the seven days following, the colitis was induced by administration of 3% DSS (w/v) diluted in the animals drinking water. During this period, animals were treated daily with Ef32 and the M.E. (2.0 mg/kg) every other day by intravenous route. The development of colitis was monitored by the disease activity index (DAI), which takes into account the loss of body weight, consistency and presence of blood in stools. After euthanasia, the colon was removed, its length measured and tissue samples were destined for histological analysis and culture for cytokine quantification. The levels of cytokines in the culture supernatant of the colon were measured by ELISA. The treatments with the probiotic Ef32 or the M.E. alone or the combination of these two substances provoked significant improvement as to weight loss and DAI, and prevented the shortening of the colon in response to DSS. The isolated treatments triggered a slight improvement in intestinal mucosal tissue damage. However, their combination was able to completely repair the injury triggered by DSS. The association was also able to reduce the levels of all the cytokines analyzed (IFN-γ, IL-4, IL-6, IL-12, IL-17A and TNF-α). On the other hand, the treatment with Ef32 did not interfere with the levels of TNF-α, whereas treatment with M.E. did not alter the levels of IL-6. Moreover, the treatment with Ef32 not interferes in TNF-α levels, whereas treatment with M.E. did not alter the levels of IL-6. Therefore, the potential probiotic Ef32 and M.E. and especially when these samples were associated proved promising alternatives in the treatment of ulcerative colitis as demonstrated in an experimental model because of its beneficial effects on morphological and clinical parameters, and by reducing the production of proinflammatory cytokines of Th1, Th2 and Th17

Avaliação de parâmetros de estresse oxidativo em plantas de cana-de-açúcar tratadas com peróxico de hidrogênio

The genus Saccharum belongs to Poaceae family. Sugarcane has become important monocultures in Brazil due to their products: ethanol and sugar. The production may change between different regions from Brazil. This difference is related to soil, climatic conditions and temperature that promotes oxidative stress that may induce an early flowering. The aim of this work was to identify the effects of oxidative stress. In order to analyse this, sugarcane plants were submitted to oxidative stress using hydrogen peroxide. After this treatment, the oxidative stress were analyzed Then, the plant responses were analyzed under different approaches, using morphophysiological, biochemical and molecular tools. Thus, sugarcane plants were grown under controlled conditions and until two months they were subjected first to a hydroponics condition for 24 hours in order to acclimation. After this period, these plants were submitted to oxidative stresse using 0 mM, 10 mM, 20 mM and 30 mM hydrogen peroxide during 8 hours. The histomorphometric analysis allowed us to verify that both root and leaf tissues had a structural changes as it was observed by the increased in cell volume, lignin accumulation in cell walls. Besides, this observation suggested that there was a change in redox balance. Also, it was analyzed the activity of the SOD, CAT and APX enzymes. It was observed an increase in the SOD activity in roots and it was also observed a lipid peroxidation in leaves and roots. Then, in order to identify proteins that were differently expressed in this conditions it was used the proteomic tool either by bidimensional gel or by direct sequencing using the Q-TOF EZI. The results obtained with this approach identified more than 3.000 proteins with the score ranging from 100-5000 ions. Some of the proteins identified were: light Harvesting; oxygenevolving; Thioredoxin; Ftsh-like protein Pftf precusor; Luminal-binding protein; 2 cys peroxiredoxin e Lipoxygenase. All these proteins are involved in oxidative stress response, photsynthetic pathways, and some were classified hypothetical proteins and/or unknown (30% of total). Thus, our data allows us to propose that this treatment induced an oxidative stress and the plant in response changed its physiological process, it made changes in tissue, changed the redox response in order to survival to this new condition

Simulação em uso dos pisos de madeira de Eucalyptus sp e Corymbia maculata

A caracterização anatômica, física, mecânica e química da madeira fornece informações importantes para sua melhor utilização. Contudo, para que madeiras se tornem boa opção para o mercado de pisos, adicionalmente é necessária a realização de ensaios que simulem suas reais condições em serviço. Esses ensaios simulam o pisoteio executado pelos sapatos de salto com pequenas áreas de pressão, o arraste e a queda de objetos, a resistência à abrasão da superfície e o atrito oferecido durante o deslocamento de pessoas que caminham sobre ele. Grande dificuldade da seleção de novas madeiras para pisos está na ausência de valores de referência físico-mecânicos. O presente trabalho visou a caracterizar as madeiras de Eucalyptus clöeziana F. Muell, de Eucalyptus microcorys F. Muell e de Corymbia maculata Hook, para as propriedades de densidade básica, retratibilidade, aplicação de carga rolante, de atrito estático e dinâmico, endentação causada por cargas aplicadas em pequenas áreas, impacto da esfera de aço cadente e resistência à abrasão. Foi observado que as madeiras estudadas podem ser utilizadas para a confecção de pisos, de acordo com seus resultados obtidos e por meio de comparações com resultados de literatura.

Avaliação de diferentes formas de preservação e desenvolvimento in situ de folículos ovarianos pré-antrais caprinos

This study evaluated the effect of indole-3-acetic acid (IAA) in the activation of goats preantral follicles (FOPA). Were used four pairs of ovaries of adult mixed breed goats. Each ovarian pair was divided into 23 fragments. One fragment was fixed for histology and other fragment was using to follicular isolation procedure. The remaining fragments were cultured in 1.0 ml of Minimum Essential Medium (MEM) or MEM supplemented with IAA at concentrations of 10, 40, 100, 500 or 1000 ng/mL. The in vitro culture was performed at 39°C in incubator with 5% CO2 for 1, 3 and 5 days. After in vitro culture was evaluated histological integrity and viability of FOPA. The addition of 100 ng/ml of IAA to MEM showed a significant increase in follicles transition in the third day of in vitro culture, characterizing follicular activation. Moreover, this concentration was obtained maintaining the histological integrity of PAF by the fifth day of in vitro culture. The viability test confirmed the results of histology. Thus, we conclude that IAA can promote the activation of goats FOPA

Adesão, proliferação e genotoxicidade celular de celulose bacteriana modificada por plasma

Bacterial cellulose (BC) has a wide range of potential applications, namely as temporary substitute skin in the treatment of skin wounds, such as burns, ulcers and grafts. Surface properties determine the functional response of cells, an important factor for the successful development of biomaterials. This work evaluates the influence of bacterial cellulose surface treatment by plasma (BCP) on the cellular behavior and its genotoxicity potential. The modified surface was produced by plasma discharge in N2 and O2 atmosphere, and the roughness produced by ion bombardment characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cell adhesion, viability and proliferation on BCP were analysed using crystal violet staining and the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium (MTT) method. Genotoxicity was evaluated using the comet and cytokinesis block micronucleus assay. The results show that the plasma treatment changed surface roughness, producing an ideal cell attachment, evidenced by more elongated cell morphology and improved proliferation. The excellent biocompatibility of BCP was confirmed by genotoxicity tests, which showed no significant DNA damage. The BCP has therefore great potential as a new artificial implant

Influência do ácido α-lipóico na adaptação antioxidante ao exercício físico em ratas wistar hígidas e ovariectomizadas

Introdução: Os hormônios estrogênicos possuem importante papel na defesa contra as espécies reativas do oxigênio, fato que se evidencia na maior incidência de doenças cardiovasculares e neurodegenerativas após a menopausa. O exercício físico melhora as defesas antioxidantes, contudo em altas cargas e em baixas concentrações de estrógeno possui efeito aditivo ao dano oxidativo. O ácido α-lipóico possui uma ampla gama de ação antioxidante e poderia contribuir para diminuição do dano nestas condições. Objetivo: O objetivo deste estudo é caracterizar a ação do ácido α-lipóico sobre a adaptação antioxidante e funções reprodutivas de ratas submetidas a natação moderada. Material e métodos: Os animais foram submetidos a natação diária (1 hora) e sacrificados após 30, 60 e 90 dias. Os animais foram divididos em controles sedentários e exercitados; suplementados (ácido α-lipóico 100mg/Kg/dia) sedentários e exercitados e animais ovariectomizados e suplementados com ácido lipóico. Avaliou-se diariamente o ciclo estral e os seguintes marcadores de estresse oxidativos foram mensurados em fígado e sangue: atividade enzimática da SOD, GPx e CAT, além do SRAT e GSH. Resultados: O protocolo de exercício aumentou a duração do ciclo estral no grupo controle exercitado, sobretudo na fase diestral. Neste mesmo grupo, houve diminuição da lipoperoxidação com melhora da atividade antioxidante da SOD e GPx. O grupo exercitado e suplementado não apresentou alteração na duração do ciclo estral e manteve os benefícios sobre o sistema antioxidante antes observado nos animais exercitados. A suplementação antioxidante juntamente com a natação em períodos superiores a 30 dias, diminuiu o processo de adaptação antioxidante quando comparado aos animais somente exercitados. Nos animais ovariectomizados, o exercício e a suplementação com ácido lipóico não promoveu adaptação antioxidante ao contrário dos demais grupos. Conclusão: O aumento na duração do ciclo estral e a melhora nos marcadores de estresse oxidativo seriam uma resposta adaptativa frente ao exercício moderado. O ácido lipóico impediu a alteração no ciclo induzida pelo exercício, mas preservou a melhoria no sistema antioxidante. A depleção estrogênica provocada pela ovariectomia eleva o potencial de dano oxidativo gerado pelo exercício. A ação antioxidante do LA na presença de estrógeno diminuiu excessivamente o dano oxidativo, comprometendo a adaptação antioxidante a natação. Nos animais ovariectomizados, contudo, o AL promoveu adaptação antioxidante ao exercício

Risco de doença cardiovascular em mulheres com história de distúrbio hipertensivo da gravidez

OBJECTIVE: Preeclampsia is a disease that can lead to a high maternal and infant morbidity. Worldwide, the incidence of this disease is highly variable and there is no data on this disorder in the Brazilian population. This study aimed at determining incidence and risk factors in the hypertensive disorders during pregnancy in a neighborhood of Natal, in addition to observing the evolution of these disorders one year and five years after delivery. METHODS: Prospective cohort study to assess the outcome of pregnancies of 242 women who became pregnant between 2004-2007 in the neighborhood of Bom Pastor in the city of Natal, state of RN, Brazil. Five years after delivery, there was an active search of thirty-nine (39) women who became pregnant and had a hypertensive disorder during pregnancy and/or pré-eclâmpsia, out of the total of 242 participants in the initial study. We administered a structured questionnaire to obtain basic information about the current clinical situation of patients and occurrences of subsequent pregnancy and presence of hypertensive disorders during pregnancy. We also searched for information on the use of hypotensive drugs and contraceptives. The following characteristics were checked and recorded: a) current weight, b) blood pressure c) body mass index - BMI, and we collected biological samples (blood and urine) for measurement of biochemical parameters and evaluation of microalbuminúria. Finally, we monitored the ambulatory blood pressure (ABP), which uses the method of automatic measurement of heart rate, systolic and diastolic blood pressure and an average of the two for the period of 24 hours. RESULTS: Out of 218 women who completed the study, the incidence of hypertensive disorders was of 16.9% (37 out of 218), while the incidence of preeclampsia was 13.8% (30 of 218). Women with preeclampsia had a BMI (body mass index) averaged of 25.3 (± 4.8) while this ratio in normotensive women was of 23.5 (± 3.7), p = 0.02. The risk of preeclampsia rises with age (OR 1084 p = 0.0034) and with a family history of hypertension (OR 2.6 p = 0.01). The follow-up one year after delivery revealed that 50% of women with hypertensive disorders in pregnancy remained hypertensive. High BMI was also observed after 5 years of delivery. CONCLUSIONS: an elevated BMI, age above 35 years and excessive weight gain during pregnancy were associated with hypertension in the long term in patients with prior preeclampsia. History of preeclampsia increases the risk of chronic hypertension

Avaliação da prevalência de Síndrome Metabólica, Microalbuminúria e Risco Cardiovascular em mulheres com Síndrome dos Ovários Policísticos

Avaliar fatores de risco cardiovascular em mulheres brasileiras com síndrome dos ovários policísticos (SOP), através da utilização de múltiplos parâmetros, incluindo a determinação da prevalência de síndrome metabólica e seus componentes e pesquisa de microalbuminúria como marcador de um possível dano renal precoce nessas pacientes. Métodos: Foram avaliadas 102 mulheres de 20-34 anos de idade, com diagnóstico de SOP pelo Consenso de Rotterdam, tendo sido analisados parâmetros clínicos, antropométricos, bioquímicos e hormonais. Para diagnóstico de síndrome metabólica, foram adotados critérios do National Cholesterol Education Program s Adult Treatment Panel III (NCEP-ATP III). Para avaliação da microalbuminúria foi utilizada a relação albumina/creatinina (A/C), calculada a partir dos níveis de albumina e creatinina em amostra isolada de urina. Foram realizados testes estatísticos para avaliar associações e correlações entre variáveis, bem como comparação de médias ou medianas, adotando-se nível de significância de 5%. Resultados: A prevalência de síndrome metabólica foi de 28,4% (29 em 102 pacientes), estando associada ao aumento do índice de massa corporal (IMC). Quanto à análise da prevalência dos componentes individuais da síndrome metabólica, evidenciou-se: HDL-colesterol < 50 mg/dl em 69,6%, circunferência da cintura ≥ 88 cm em 57,9%, triglicerídeos ≥150 mg/dl em 31,7%, pressão arterial ≥130/85 mmHg em 18,6% e glicemia de jejum ≥110 mg/dl em 2,9%. Quando definida pelos limites convencionais para a relação A/C (3,5 35 mg/mmol), a microalbuminúria esteve presente em apenas três pacientes (3,3%). Entretanto, considerando diferentes limites de corte estabelecidos em recentes estudos que demonstraram aumento do risco cardiovascular associado a níveis muito baixos da relação A/C, a prevalência em mulheres com SOP foi alta, variando de 17,7 a 43,3% (para valores ≥ 0,58 e ≥ 0,37 mg/mmol, respectivamente). Mulheres com intolerância à glucose apresentaram nível significativamente mais elevado da relação A/C, quando comparadas às mulheres com normoglicemia. Os valores de microalbuminúria não apresentaram correlação significativa com IMC, níveis pressóricos, índices de sensibilidade insulínica ou perfil lipídico. Conclusões: Os dados evidenciam uma alta prevalência de síndrome metabólica e seus componentes individuais em mulheres brasileiras com SOP. Além do mais, observou-se elevado percentual de mulheres com níveis de excreção urinária de albumina em faixas significativamente associadas com aumento do risco para eventos cardiovasculares. Em conjunto, esses dados alertam para a necessidade da abordagem interdisciplinar e multidisciplinar das pacientes com SOP, visando à instituição de medidas voltadas para a prevenção primária cardiovascular

Perfil de imunoglobulinas e correlação de autoanticorpos com a ocorrência de diversas formas clínicas em pacientes chagásicos crônicos

Introdução: O dano miocárdico na doença de Chagas resulta tanto da ação parasitária quanto da resposta imune do hospedeiro humano. O mimetismo molecular entre proteínas do Trypanosoma cruzi e vários antígenos do hospedeiro tem sido amplamente descrito gerando células T CD8+ e anticorpos autorreativos. Entretanto, a geração dos autoanticorpos e seu papel na imunopatogenia da doença de Chagas ainda não têm sido elucidados, o que nos levou, neste trabalho, a avaliar a produção de imunoglobulina G total (IgGt) e seus isotipos anti-T. cruzi, proteínas cardíacas e sua possível associação com as diferentes formas clínicas da doença de Chagas. Métodos: A produção de IgGt e isotipos foi mensurada pelo método de ELISA no soro de pacientes com as formas clínicas indeterminada (IND, n=72), cardíaca (CARD, n=47) e digestiva/cardio-digestiva (DIG/CARD-DIG, n=12) da doença de Chagas, usando como antígenos as formas epimastigota e tripomastigota do T. cruzi e proteínas cardíacas humana (miosina e troponina T). As amostras de indivíduos não infectados saudáveis (CONT, n= 30) e pacientes com cardiomiopatia isquêmica (ISCH, n=15) foram usadas como controle. Os títulos de autoanticorpos foram correlacionados com parâmetros da função cardíaca obtidos por exames eletrocardiográficos, radiográficos e ecocardiográficos. Resultados: Neste estudo foram incluídos 131 indivíduos sem diferença significativa relativa à idade ou sexo. Destes, 55% foram classificados como IND, 35,9% CARD e 9,1% DIG/CARD-DIG. Os títulos de IgGt foram mais elevados em pacientes com as formas clínicas IND, CARD e DIG/CARD-DIG do que em indivíduos CONT e ISCH usando os antígenos as formas tripomastigotas e epimastigotas do T. cruzi e, proteínas cardíacas humanas. Os pacientes com formas clínicas CARD e DIG/CARD-DIG mostraram a produção mais elevada de IgG total dirigida contra antígenos de tripomastigota e epimastigota do que os IND. Os grupos de pacientes IND e CARD apresentaram uma similar produção de IgG total específica direcionada à miosina e troponina T, e mais elevada do que em indivíduos CONT e ISCH. Há uma correlação negativa entre a produção de anticorpos anti-proteínas cardíacas com a fração de ejeção do ventrículo esquerdo (FEVE) em pacientes chagásicos crônicos. Os pacientes foram agrupados em baixo e alto produtores de autoanticorpos e comparados com a fração de ejeção demonstrando que em pacientes alto produtores de anti-troponina T (p=0.042) e miosina (p=0.013) a FEVE foi mais baixa do que os baixo produtores. A maioria dos pacientes chagásicos produz simultaneamente autoanticorpos direcionados à ambas proteínas cardíacas (r=0.9508, p=0.0001). Conclusões: Estes resultados indicam que os autoanticorpos anti- troponina T e miosina cardíaca parecem induzir redução FEVE e deve ser associado com o desenvolvimento de cardiomiopatia chagásica

Concentrações de hormônio na carcaça de tilápias-do-nilo e maturação precoce após reversão sexual

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo do efeito dos metabólitos do benzeno e tolueno sobre as mitocôndris cerebrais e hepáticas de ratos

Aim: The aim of this work was to investigate the hypothesis that catechol and 3MC inhibit FADH2-linked basal respiration in mitochondria isolated from rat liver and brain homogenates. Moreover, catechol ability to induce DNA damage in rat brain cells through the comet assay (alkaline single-cell gel electrophoresis assay) was also observed. Methods: Two different catechols were evaluated: pirocatechol (derived from benzene) and 3-methylcatechol (derived from toluene); rat liver and brain homogenates were incubated with 1mM catechol at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate for a period of 12 minutes. In additional experiments, rat brain cells were treated with 1, 5 and 10mM pirocatechol for up to 20 minutes at 37º C, and submitted to electrophoresis. Results: Catechols (pirocatechol and 3methylcatechol) induced a time-dependent partial inhibition of FADH2-linked basal mitochondrial respiration. Indeed, pirocatechol was able to produce a dosedependent DNA oxidative damage in rat brain cells by 2 and 4 injury levels. These results suggest that reactive oxygen species generated by the oxidation of catechols, induced an impairment on mitochondrial respiration and a DNA damage, which might be related to their citotoxicity. Conclusion: Catechols produced an inhibition of basal respiration associated to FADH2 in isolated liver and brain mitochondria; 3-methylcatechol, at the same concentration, produced similar toxicity in the mitochondrial model. Indeed, pirocatechol induced a DNA damage in rat brain cells, mainly observed in comets formation and consequent DNA degradation