8 resultados para 1G-GDGT-TEX86

em Universidade Federal do Rio Grande do Norte(UFRN)


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Sugarcane (Saccharum spp.) is a plant from Poaceae family that has an impressive ability to accumulate sucrose in the stalk, making it a significant component of the economy of many countries. About 100 countries produce sugarcane in an area of 22 million hectares worldwide. For this reason, many studies have been done using sugarcane as a plant model in order to improve production. A change in gravity may be one kind of abiotic stress, since it generates rapid responses after stimulation. In this work we decided to investigate the possible morphophysiological, biochemical and molecular changes resulting from microgravity. Here, we present the contributions of an experiment where sugarcane plants were submitted to microgravity flight using a vehicle VSB-30, a sounding rocket developed by Aeronautics and Space Institute teams, in cooperation with the German Space Agency. Sugarcane plants with 10 days older were submitted to a period of six minutes of microgravity using the VSB-30 rocket. The morphophysiological analyses of roots and leaves showed that plants submitted to the flight showed changes in the conduction tissues, irregular pattern of arrangement of vascular bundles and thickening of the cell walls, among other anatomical changes that indicate that the morphology of the plants was substantially influenced by gravitational stimulation, besides the accumulation of hydrogen peroxide, an important signaling molecule in stress conditions. We carried out RNA extraction and sequencing using Illumina platform. Plants subjected to microgravity also showed changes in enzyme activity. It was observed an increased in superoxide dismutase activity in leaves and a decreased in its activity in roots as well as for ascorbate peroxidase activity. Thus, it was concluded that the changes in gravity were perceived by plants, and that microgravity environment triggered changes associated with a reactive oxygen specie signaling process. This work has helped the understanding of how the gravity affects the structural organization of the plants, by comparing the anatomy of plants subjected to microgravity and plants grown in 1g gravity

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This project describes a methodology optimization that would allow for a more efficient microwave assisted digestion process for petroleum samples. With the possible chance to vary various factors at once to see if any one factor was significant enough in the answers, experimental planning was used. Microwave assisted digestion allows, through the application of potency, an increasing number of collisions between the HNO3 and H2O2 molecules, favoring sample opening for complex matrixes. For this, a 24 factorial experimental planning was used, varying potency, time and the volumes for HNO3 65% and H2O2 30%. To achieve the desired answers, several elements were monitored (C, Cu, Cr, Fe, Ni, Zn and V) through Inductively coupled plasma atomic emission spectroscopy (ICP-OES). With this initial study it was noticed that the HNO3 was not a significant factor for any of the statistical studies for any of the analytes and the other 3 factors and their interactions showed statistical significance. A Box Behnken experimental planning was used taking in consideration 3 factors: H2O2 volume, time (min) and Potency (W), Nitric Acid kept at 4mL for a mass of 0,1g of petroleum. The results were extremely satisfying showing higher efficiency in the digestion process and taking in a responsibility between the answers for each analyte and the carbon monitoring was achieved in the following conditions: 7mL of H2O2, 700 Watts of potency and a reaction time of 7 minutes with 4mL de HNO3 for a mass of 0,1g of petroleum. The optimized digestion process was applied to four different petroleum samples and the analytes determined by ICP-OES

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Solid substrate cultivation (SSC) has become an efficient alternative towards rational use of agro industrial wastes and production of value-added products, mainly in developing countries. This work presents the production and functional application results of phenolic extracts obtained by solid substrate cultivation of pineapple (Ananas comosus L.) and guava (Psidium guajava L.) residues associated to soy flour and bioprocessed by Rhizopus oligosporus fungus. Two experimental groups were tested: (1) 9g of fruit residue and 1g of soy flour (A9 or G9); (2) 5g of fruit residue and 5g of soy flour (A5 or G5). After SSC, 100ml of distilled water was added to each Erlenmeyer flask containing 10g of bioprocessed material in order to obtain the phenolic extracts. Samples were taken every two days for total phenolic concentration (TPC) and antioxidant capacity evaluation by DPPH test during 12-day cultivation. The 2-day and 10-d ay extracts were selected and concentrated by ebullition until 1/10 of original volume was reached. After that, both non-concentrated and concentrated extracts were evaluated for their antimicrobial activity against Staphylococcus aureus and Salmonella enterica and a-amylase inhibitory capacity. It was observed an inverse relationship between total phenolic concentration (TPC) and antioxidant capacity during the cultivation. Besides that, the concentrated pineapple samples after two days were able to inhibit both pathogens tested, especially S. aureus. Guava concentrated extracts after 2 days showed expressive inhibition against S. enterica, but negative results against S. aureus growth. When it comes to a-amylase inhibition, A9 extracts after 2 days, both concentrated or not, completely inhibited enzyme activity. Similar behavior was observed for G9 samples, but only for concentrated samples. It was shown that concentration by ebullition positively affected the enzymatic inhibition of G9 and A9 samples, but on the other side, decreased antiamylase activity of A5 and G5 samples

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Chondroitin sulfate (CS) is a naturally glycosaminoglycan found in the extracellular matrix of connective tissues and it may be extracted and purified those tissues. CS is involved in various biological functions, which may be related to the having structural variability, despite the simplicity of the linear chain structure from this molecule. Researches in biotechnology and pharmaceutical field with wastes from aquaculture has been developed in Brazil. In recent decades, tilapia (Oreochromis niloticus), native fish from Africa, has been one of the most cultivated species in various regions of the world, including Brazil. The tilapia farming is a cost-effective activity, however, it generates large amount of wastes that are discarded by producers. It is understood that waste from tilapia can be used in research as a source of molecules with important biotechnological applications, which also helps in reducing environmental impacts and promote the development of an ecofriendly activity. Thus, nile tilapia viscera were subjected to proteolysis, then the glycosaminoglycans were complexed with ion exchange resin (Lewatit), it was fractionated with increasing volumes of acetone and purified by ion exchange chromatography DEAE-Sephacel. Further, the fraction was analyzed by agarose gel electrophoresis and nuclear magnetic resonance (NMR). The electrophoretic profile of the compound together the analysis of 1H NMR spectra and the HSQC correlation allow to affirm that the compound corresponds to a molecule like chondroitin sulfate. MTT assay was used to assess cell viability in the presence of CS tilapia isolated and showed that the compound is not cytotoxic to normal cells such as cells from the mouse embryo fibroblast (3T3). Then, this compound was tested for the ability to reduce the influx of leukocytes in model of acute peritonitis (in vivo) induced by sodium thioglycolate. In this context, it was done total and differential leukocytes counting in the blood and peritoneal fluid collected respectively from vena cava and the peritoneal cavity of the animals subjected to the experiment. The chondroitin sulfate for the first time isolated from tilapia (CST ) was able to reduce the migration of leukocytes to the peritoneal cavity of inflamed mice until 80.4 per cent at a dose 10µg/kg. The results also show that there was a significant reduction (p<0.001) of the population of polymorphonuclear leukocytes from peritoneal cavity in the three tested doses (0.1µg/kg; 1µg/kg and 10µg/kg) when it was compared to the positive control (just thioglycolate). Therefore, since the CST structure and mechanism of action has been completely elucidated, this compound may have potential for therapeutic use in inflammatory diseases

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The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50°C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).

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The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50°C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).

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Sugarcane (Saccharum spp.) is a plant from Poaceae family that has an impressive ability to accumulate sucrose in the stalk, making it a significant component of the economy of many countries. About 100 countries produce sugarcane in an area of 22 million hectares worldwide. For this reason, many studies have been done using sugarcane as a plant model in order to improve production. A change in gravity may be one kind of abiotic stress, since it generates rapid responses after stimulation. In this work we decided to investigate the possible morphophysiological, biochemical and molecular changes resulting from microgravity. Here, we present the contributions of an experiment where sugarcane plants were submitted to microgravity flight using a vehicle VSB-30, a sounding rocket developed by Aeronautics and Space Institute teams, in cooperation with the German Space Agency. Sugarcane plants with 10 days older were submitted to a period of six minutes of microgravity using the VSB-30 rocket. The morphophysiological analyses of roots and leaves showed that plants submitted to the flight showed changes in the conduction tissues, irregular pattern of arrangement of vascular bundles and thickening of the cell walls, among other anatomical changes that indicate that the morphology of the plants was substantially influenced by gravitational stimulation, besides the accumulation of hydrogen peroxide, an important signaling molecule in stress conditions. We carried out RNA extraction and sequencing using Illumina platform. Plants subjected to microgravity also showed changes in enzyme activity. It was observed an increased in superoxide dismutase activity in leaves and a decreased in its activity in roots as well as for ascorbate peroxidase activity. Thus, it was concluded that the changes in gravity were perceived by plants, and that microgravity environment triggered changes associated with a reactive oxygen specie signaling process. This work has helped the understanding of how the gravity affects the structural organization of the plants, by comparing the anatomy of plants subjected to microgravity and plants grown in 1g gravity

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This project describes a methodology optimization that would allow for a more efficient microwave assisted digestion process for petroleum samples. With the possible chance to vary various factors at once to see if any one factor was significant enough in the answers, experimental planning was used. Microwave assisted digestion allows, through the application of potency, an increasing number of collisions between the HNO3 and H2O2 molecules, favoring sample opening for complex matrixes. For this, a 24 factorial experimental planning was used, varying potency, time and the volumes for HNO3 65% and H2O2 30%. To achieve the desired answers, several elements were monitored (C, Cu, Cr, Fe, Ni, Zn and V) through Inductively coupled plasma atomic emission spectroscopy (ICP-OES). With this initial study it was noticed that the HNO3 was not a significant factor for any of the statistical studies for any of the analytes and the other 3 factors and their interactions showed statistical significance. A Box Behnken experimental planning was used taking in consideration 3 factors: H2O2 volume, time (min) and Potency (W), Nitric Acid kept at 4mL for a mass of 0,1g of petroleum. The results were extremely satisfying showing higher efficiency in the digestion process and taking in a responsibility between the answers for each analyte and the carbon monitoring was achieved in the following conditions: 7mL of H2O2, 700 Watts of potency and a reaction time of 7 minutes with 4mL de HNO3 for a mass of 0,1g of petroleum. The optimized digestion process was applied to four different petroleum samples and the analytes determined by ICP-OES