Funções e algumas de suas propriedades

In this TCC the deal with a underlying but essential topic of Mathematics, namely: Functions. Many students start their course in the University asking: Why do we need functions? With that in mind we try to antecipate to this question and we try to show that functions come up so naturally that a name was needed to express that association which exists between the elements of two sets. After this definition was established, we present and formalize some other concepts that functions might have, as: an interview of ascendence/descendence, 1-1, etc.

Extração, caracterização e prospecção de atividades farmacológicas de polissacarídeos sulfatados da macroalga verde Caulerpa prolifera

This study aimed to extract, characterize and conduct a prospective analysis of pharmacological activities of sulfated polysaccharides from green seaweed Caulerpa prolifera. Seven fractions (CP-0.3/CP-0.5/CP-0.7/CP-0.9/CP-1.1/CP-1.5/CP-2.0) were obtained from C. prolifera by alkaline proteolysis followed by sequential precipitation in acetone. The physicochemical analyzes indicated that C. prolifera synthesizes a homogalactan (CP-0.9) and different populations of sulfated heteropolysaccharides. In the analysis of anticoagulant activity, all fractions except CP-0.3, influenced the intrinsic coagulation pathway. All fractions showed antioxidant activity in six different assays being more pronounced in hydrogen peroxide scavenging assay, especially CP-0.3, CP-0.7 and CP-0.9 (which obtained 61% of hydrogen peroxide scavenging), in ferric chelation assay (especially CP-0.9 with 56% chelation) and cupric chelation assay (especially CP-2.0 with 78% chelation). With respect to immunomodulatory activity, the presence of CP-0.3, CP-0.7 and CP-0.9 showed an immunogenic potential, increasing the production of nitric oxide (NO) by 48, 142 and 163 times, respectively. Conversely, the NO synthesis fell 73% after the activation of macrophages by LPS, incubated concurrently with CP-2.0. The anti-adipogenic activity of the fractions was also evaluated and CP-1.5 was able to reduce the differentiation of pre-adipocytes (3T3-L1) into adipocytes by 60%, without affecting the cell viability. The fractions CP-0.3, CP-0.5 and CP-0.9 reduced the viability of the HeLa cells (human cervical adenocarcinoma) by 55% and CP-1.5 reduced the viability of the 786-0 cells (human renal adenocarcinoma) by 75%. Leishmanicidal activity and microbicide effect against Carbapenem-resistant Klebsiella pneumoniae (KPC) have not been identified. However, the viability of Staphylococcus epidermidis was reduced by 23.8% in the presence of CP -1.5. All fractions were able to change the formation of calcium oxalate crystals. CP-0.3, CP-0.5 and CP-1.1 only promoted the formation of COD type crystals with a very small size (1 μm). Confocal microscopy and zeta potential data of crystals formed in the presence of the samples showed that the polysaccharides present in the fractions must interact with calcium ions present throughout the crystal lattice, affecting the growth and morphology of crystals The results described herein indicate that the fractions rich in polysaccharides obtained from the green seaweed C. prolifera present a multi therapeutic potential, and subsequent purification steps, as well as research on the mechanisms of action by which these polymers act should be investigated.

Estudo fitoquímico de Waltheria ferruginea

The Waltheria genus belonging to the Sterculiaceae family, it is reported as a prolific source of flavonoids and quinolone alkaloids, substances of great interest due to several associated biological activities. This work describes a novel phytochemical study from Waltheria ferruginea, aiming to contribute to the chemical knowledge of this specie and the isolation of substances with biological potential. For the phytochemical study were used chromatography techniques on silica gel and molecular exclusion in Sephadex LH-20.The structural elucidation of the isolated compounds was performed through spectrometric techniques 1H and 13C NMR, including uni and bidimensional pulse sequences, and comparison with data from literature. Five substances were isolated, namely: the flavonids kaempferol-3-O-β-(6''-cumaroil)-glucopyranoside (F1) and kaempferol -3 -O- β - glucopyranoside (F2), both analyzes with pharmacological properties, the flavonol quercetin-3-O-β-glucopyranoside (F3 ) pure and in the epimeric mixture α (F3') and (F3), the terpenegeranyl - geranyl (G1) and the 12-hydroxi-octadecanoic acid, all no previous reported in the literature.

Influência do retardante de chamas nas propriedades mecânicas e flamabilidade em compósitos poliméricos de epóxi/fibra de curauá

Currently, there is a great search for materials derived from renewable sources. The vegetable fibers as reinforcement for polymer matrixes, has been used as an alternative to replace synthetic fibres, being biodegradable and of low cost. The present work aims to develop a composite material with epoxy resin reinforced with curauá fibre with the addition of alumina trihydrate (aluminum hydroxide, Al(OH)3) as a flame retardant, which was used in proportions of 10 %, 20% and 30% of the total volume of the composite. The curauá fibers have gone through a cleaning process with an alkaline bath of sodium hydroxide (NaOH ), parallelized by hand and cut carding according to the default length . They were molded composites with fibers 30cm. Composites were molded in a Lossy Mold with unidirectional fibres in the proportion of 20% of the total volume of the composite. The composites were prepared in the Chemical Processing Laboratory of the Textile Engineering Department at UFRN. To measure the performance of the material, tests for the resistance to traction and flexion were carried out. with samples that were later analyzed in the Electronic Microscopy Apparatus (SEM ). The composites showed good mechanical properties by the addition of flame retardant and in some cases, leaving the composite more vulnerable to breakage. These mechanical results were analyzed by chi-square statistical test at the 5% significance level to check for possible differences between the composite groups. Flammability testing was conducted based on the standard Underwriters Laboratory 94 and the material showed a satisfactory result taking their average burn rate (mm / min) decreasing with increasing addition of the flame retardant composite.

Síntese de ferritas de cobalto e níquel dopadas com zinco e caracterização de suas propriedades eletromagnéticas

This work shows that the synthesis by combustion is a prominent alternative to obtain ceramic powders of higher oxides, nanostructured and of high purity, as the ferrites of formulas Co(1-x)Zn(x)Fe2O4 e Ni(1-x)Zn(x)Fe2O4 with x ranging from 0.2 mols, in a range from 0.2 ≤ x ≥ 1.0 mol, that presents magnetic properties in coexistence of ferroelectric and ferrimagnetic states, which can be used in antennas of micro tapes and selective surfaces of low frequency in a range of miniaturized microwaves, without performance loss. The obtainment occurred through the combustion process, followed by appropriate physical processes and ordered to the utilization of the substrate sinterization process, it gave us a ceramic material, of high purity degree in a nanometric scale. The Vibrating Sample Magnetometer (VSM) analysis showed that those ferritic materials presents parameters, as materials hysteresis, that have own behavior of magnetic materials of good quality, in which the magnetization states can be suddenly changed with a relatively small variation of the field intensity, having large applications on the electronics field. The X-ray Diffraction (XRD) analysis of the ceramic powders synthesized at 900 °C, characterize its structural and geometrical properties, the crystallite size and the interplanar spacing. Other analysis were developed, as Scanning Electron Microscopy (SEM), X-ray Fluorescence (XRF), electric permittivity and the tangent loss, in high frequencies, through the equipment ZVB - 14 Vector Network Analyzer 10 MHz-14 GHz, of ROHDE & SCHWART.

Síntese, estrutura e propriedades de polímeros de coordenação à base de íons lantanídeos e ácidos benzenodicarboxílicos

Metal Organic Frameworks (MOFs) are hybrids materials, often crystalline, consisting of metal or metal clusters, connected by polytopic organic ligands repetitively, leading to structures, usually porous. In this work, MOFs based on lanthanide ions (La3+ and Gd3+) and dicarboxylate type of ligands (isophthalic and terephthalic acids), were synthesized by hydrothermal, solvothermal and hydro(solvo)thermal methods. The effects of the synthetic route as well as the type of heating, conventional or by microwave, on the structure and properties of MOFs were studied. The powder samples obtained were characterized by X-ray diffraction, infrared spectroscopy, thermal analysis and scanning electron microscopy. The results suggest that the addition of an organic or inorganic base is needed to promote the deprotonation of the ligand, since in the samples prepared by the hydrothermal method, without the use of a base, no formation of the metalorganic framework was observed. On the other hand, the presence of DMF as solvent or cosolvent, afforded the deprotonation of the ligand with the consequent formation of MOFs. At least two different crystalline structures were identified for the samples prepared with terephthalic acid. These samples are isostructural with those reported for phases Eu(1,3-BDC)DMF, Eu2(1,4-BDC)3 (DMF)2 and Tb(1,4-BDC)H2O. The presence of water in the reaction medium in the hydro(solvo)thermal method, provoked the growth of the structure different from that observed in the absence of water. This can be explained by the difference in the coordination mode of water and DMF to lanthanide ions. Although not identified by XRD, the samples prepared with isophthalic acid, also present metalorganic structures, which was confirmed by the presence of the characteristic displacement of the carbonyl group band in their infrared spectra, compared to the spectrum of the pure ligand. This shift was also observed in the samples prepared with terephthalic acid. Thermal analisys shows that the metal organic frameworks do not collapse occurs at a temperature below 430°C.The analysis of scanning electron microscopy suggests that the morphology of powders is highly dependent on the type of heating used, conventional or by microwave.

Efeito da força iônica nas propriedades de fluidos de perfuração aquosos à base de polímeros carboxilados e sulfatados

In the well drilling operations problems caused by contamination of the drilling fluid are common. The dissolution of ions from the geological formations affects the rheological and filtration properties of the fluids. These ions shield the charges of ionic polymers, leading to its precipitation. In this work was performed a detailed study on the stability of the properties of aqueous solutions and aqueous drilling fluids in the presence of sulphated and carboxylated polymers, using carboxymethylcellulose and kappa-carrageenan as polymer compounds carboxylated and sulfated model, respectively. The effects of ionic strength of the aqueous medium containing Na+, Mg2+ and Ca2+ on rheological properties of the polymer and drilling fluids solutions were evaluated by varying the concentration of salts, pH and temperature. It was observed that the fluids with κ-carrageenan suffered less influence against the contamination by the ions at pH 9 to 10, even at higher concentrations, but higher influence on pH> 11. The fluids containing carboxymethylcellulose were more sensitive to contamination, with rapid reduction in viscosity and significant increase of the filtrate volume, while the fluid based polymer sulfated kappa-carrageenan showed evidence of interaction with cations and preserve the rheological properties and improved stability the volume of filtrate.

Efeito da força iônica nas propriedades de fluidos de perfuração aquosos à base de polímeros carboxilados e sulfatados

In the well drilling operations problems caused by contamination of the drilling fluid are common. The dissolution of ions from the geological formations affects the rheological and filtration properties of the fluids. These ions shield the charges of ionic polymers, leading to its precipitation. In this work was performed a detailed study on the stability of the properties of aqueous solutions and aqueous drilling fluids in the presence of sulphated and carboxylated polymers, using carboxymethylcellulose and kappa-carrageenan as polymer compounds carboxylated and sulfated model, respectively. The effects of ionic strength of the aqueous medium containing Na+, Mg2+ and Ca2+ on rheological properties of the polymer and drilling fluids solutions were evaluated by varying the concentration of salts, pH and temperature. It was observed that the fluids with κ-carrageenan suffered less influence against the contamination by the ions at pH 9 to 10, even at higher concentrations, but higher influence on pH> 11. The fluids containing carboxymethylcellulose were more sensitive to contamination, with rapid reduction in viscosity and significant increase of the filtrate volume, while the fluid based polymer sulfated kappa-carrageenan showed evidence of interaction with cations and preserve the rheological properties and improved stability the volume of filtrate.

Ordenamento de cargas e propriedades magnéticas de ortoferritas de lantânio dopadas com estrôncio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ordenamento de cargas e propriedades magnéticas de ortoferritas de lantânio dopadas com estrôncio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da adição de WC e Co na sinterização e propriedades mecânicas da alumina

Composites based on alumina (Al2O3), tungsten carbide (WC) and cobalt (Co) exhibit specific properties such as low density, high oxidation resistance, high melting point and high chemical inertia. That composite shows to be a promising material for application in various fields of engineering. In this work, the mechanical properties of the composite (Al2O3 – WC – Co), particularly density and hardness, were evaluated according to the effects of the variables of powder processing parameters, green compact and sintered. Powder composites with the composition of 80 wt% Al2O3, 18 wt% WC and 2 wt% Co were processed by high energy ball milling in a planetary mill for 50 hours as well as mixed by manual mixing in a glass vessel with the same proportion. Samples were collected (2, 10, 20, 30, 40 and 50 hours) during the milling process. Then, the powders were compacted in a cylindrical die with 5 mm in diameter in a uniaxial press with pressures of 200 and 400 MPa. The sintering was in two stages: first, the solid phase sintering was performed at 1126 and 1300 °C for 1 hour with a heating rate of 10 °C/min in a resistive furnace under argon atmosphere for green samples compacted in 200 and 400 MPa; the second sintering was performed on dilatometer in solid phase at 1300 °C for green sample compacted in 200 MPa, another sintering also was performed on dilatometer, this time in liquid phase at 1550 °C for green samples compacted in 200 and 400 MPa, with the same parameters used in resistive furnace. The raw materials were characterized by X – ray diffraction (XRD), X – ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and laser particlemeter. The sintered samples were subjected to microhardness testing. The results showed that high energy milling achieved to the objectives regarding the particle size and the dispersion of composite phases. However, the hardness did not achieve to significant results, this is an indication that the composite has low fracture toughness.

Efeito da adição de WC e Co na sinterização e propriedades mecânicas da alumina

Composites based on alumina (Al2O3), tungsten carbide (WC) and cobalt (Co) exhibit specific properties such as low density, high oxidation resistance, high melting point and high chemical inertia. That composite shows to be a promising material for application in various fields of engineering. In this work, the mechanical properties of the composite (Al2O3 – WC – Co), particularly density and hardness, were evaluated according to the effects of the variables of powder processing parameters, green compact and sintered. Powder composites with the composition of 80 wt% Al2O3, 18 wt% WC and 2 wt% Co were processed by high energy ball milling in a planetary mill for 50 hours as well as mixed by manual mixing in a glass vessel with the same proportion. Samples were collected (2, 10, 20, 30, 40 and 50 hours) during the milling process. Then, the powders were compacted in a cylindrical die with 5 mm in diameter in a uniaxial press with pressures of 200 and 400 MPa. The sintering was in two stages: first, the solid phase sintering was performed at 1126 and 1300 °C for 1 hour with a heating rate of 10 °C/min in a resistive furnace under argon atmosphere for green samples compacted in 200 and 400 MPa; the second sintering was performed on dilatometer in solid phase at 1300 °C for green sample compacted in 200 MPa, another sintering also was performed on dilatometer, this time in liquid phase at 1550 °C for green samples compacted in 200 and 400 MPa, with the same parameters used in resistive furnace. The raw materials were characterized by X – ray diffraction (XRD), X – ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and laser particlemeter. The sintered samples were subjected to microhardness testing. The results showed that high energy milling achieved to the objectives regarding the particle size and the dispersion of composite phases. However, the hardness did not achieve to significant results, this is an indication that the composite has low fracture toughness.

Caracterização estrutural e atividades farmacológicas do alginato obtido da alga Dictyopteris delicatula (J.V. Lamouroux., 1809) e seu derivado sulfatado

Marine algae are rich sources of various structural compounds which recently has been increasingly studied as a new source of bioactive substances. The alginate, as come as fucans, are considered the main acidic polysaccharides found in brown seaweed. This molecule consists a linear natural polysaccharide, non-sulfated, and presents monosaccharides: acid β-D-mannuronic (M) and α-L-guluronic acid (G); in a vast amount compositions and threads. Alginate has been widely applied in food and pharmaceutical industries because of its ability to retain water, forming films and gels as well as thickening, stabilizing and form emulsions. In this work we aimed to extract, structurally characterize, compare and analyze the possible pharmacological activities of native alginate molecule obtained from brown seaweed Dyctiopteris delicatula (DYN), and its chemically sulfated derivative (DYS). The alginate structure and composition molecule can be proven through chemical dosing, that showed low protein contamination and high sugar level, existence and separation of M and G blocks in the descending paper chromatography, infrared spectroscopy and nuclear magnetic resonance. Molecule sulfation was proven with sulphate dosage, resulting in 28.56% sulphate in molecule; electrophoresis, verify metachromasia with toluidine blue; and infrared spectroscopy, that showed a characteristic band at 1221cm-1 corresponding a sulfate group vibration. For the pharmacological activities the tests was: antioxidant activity, changes in cell function (MTT test) and anticoagulant test. In the antioxidant activity we observed that DYN showed better results in the kidnapping of hydroxyl radicals and ferric chelation compared to DYS, this had the best result in the total antioxidant capacity. Both showed similar activity in reducing power and the kidnapping radicals DPPH. In MTT test DYN and DYS had not proliferative and cytotoxic activity in fibroblast cells (3T3) and showed antiproliferative and cytotoxic activity in cancer cell lines HeLa and B16 melanoma. In anticoagulant assay DYN showed good activity in the intrinsic pathway of blood coagulation, and a small activity in the extrinsic pathway, in the other hand DYS showed only a very small activity in the extrinsic pathway, but cannot come to be regarded as an anticoagulant agent. From these results it can be concluded that the alginate was extracted and sulfated, revealing a potential compound to be used in the pharmaceutical industry as an anticoagulant agent, antioxidant and antitumor and the sulfation has not been conclusively important to performance in the tested pharmacological activities

Avaliação das atividades farmacológicas de fucoidans obtidos do extrato bruto de fucoidan comercial de Fucus vesiculosus

Fucoidan is a term used to define heteropolysaccharides that are composed of less than 90% L-fucose. The exception to this rule is the homofucoidan obtained from the seaweed Fucus vesiculosus. This fucoidan can be purchased from SIGMA Co. and have been used in various research for evaluation of their pharmacological activities. However, it is not a pure molecule. In fact, it is a mix of several fucoidan molecules. In this work, were obtained, from acetone precipitation, and biochemically characterized, four fucoidan molecules from SIGMA-ALDRICH Co. fucoidan to evaluate their anticoagulant, antioxidant, antiadipogenic, immunomodulatory and antiurolithiatic activities. In anticoagulant activity, evaluated by aPTT assay, fucoidans F0.9, F1.1 and F2.0 increased eightfold the coagulation time, compared to the control, when a mass of 10 μg was used. To PT test, only fucoidan F0.9 was capable of increase the coagulation time, compared to control. In the total antioxidant capacity assay (TAC), the fucoidan F2.0 showed 400 ascorbic acid equivalents, while fucoidan F0.5, the lest effective, 38 equivalents. In respect to the effect on pre-adipocyte cell lines (3T3-L1) adipogenesis, was observed that fucoidan F1.1 and F2.0 reduced the adipogenesis and this effect was associated to the reduction in the expression of regulatoy proteins C/EBPα, C/EBPβ and PPARγ. On the other hand, fucoidans F0.5 and F0.9 induced increased expression of these regulatory proteins. Furthermore, fucoidan F2.0 induced hydrolysis of triglycerides present in the interior of adipocytes. The immunomodulatory effect was evaluated and observed that the presence of fucoidans F0.5 , F1.1 and F2.0 significantly reduced the production of nitric oxide by activated macrophages with LPS specially fucoidan F2.0 that in 100 μg/mL, reduced about 55% the effect caused by LPS. Relative to the effect upon the formation of calcium oxalate crystals, fucoidan F0.5 was more effective in reduce the aggregation of the crystals and this effect it was not significantly different regarding the effect caused by the crude. Besides, fucoidan F0.5 only promoted the formation of COD type crystals, while fucoidans F1.1 and F2.0 did not influence the formation of crystals compared with the control. The results described in this study indicate that the commercial crude fucoidan of Fucus vesiculosus it’s a mix of several fucoidan which, in turn, have different chemical compositions besides having different pharmacological activities. The use of these fucoidans it´s indicated according the pharmacological activity to be evaluated.

Avaliação das atividades farmacológicas de fucoidans obtidos do extrato bruto de fucoidan comercial de Fucus vesiculosus

Fucoidan is a term used to define heteropolysaccharides that are composed of less than 90% L-fucose. The exception to this rule is the homofucoidan obtained from the seaweed Fucus vesiculosus. This fucoidan can be purchased from SIGMA Co. and have been used in various research for evaluation of their pharmacological activities. However, it is not a pure molecule. In fact, it is a mix of several fucoidan molecules. In this work, were obtained, from acetone precipitation, and biochemically characterized, four fucoidan molecules from SIGMA-ALDRICH Co. fucoidan to evaluate their anticoagulant, antioxidant, antiadipogenic, immunomodulatory and antiurolithiatic activities. In anticoagulant activity, evaluated by aPTT assay, fucoidans F0.9, F1.1 and F2.0 increased eightfold the coagulation time, compared to the control, when a mass of 10 μg was used. To PT test, only fucoidan F0.9 was capable of increase the coagulation time, compared to control. In the total antioxidant capacity assay (TAC), the fucoidan F2.0 showed 400 ascorbic acid equivalents, while fucoidan F0.5, the lest effective, 38 equivalents. In respect to the effect on pre-adipocyte cell lines (3T3-L1) adipogenesis, was observed that fucoidan F1.1 and F2.0 reduced the adipogenesis and this effect was associated to the reduction in the expression of regulatoy proteins C/EBPα, C/EBPβ and PPARγ. On the other hand, fucoidans F0.5 and F0.9 induced increased expression of these regulatory proteins. Furthermore, fucoidan F2.0 induced hydrolysis of triglycerides present in the interior of adipocytes. The immunomodulatory effect was evaluated and observed that the presence of fucoidans F0.5 , F1.1 and F2.0 significantly reduced the production of nitric oxide by activated macrophages with LPS specially fucoidan F2.0 that in 100 μg/mL, reduced about 55% the effect caused by LPS. Relative to the effect upon the formation of calcium oxalate crystals, fucoidan F0.5 was more effective in reduce the aggregation of the crystals and this effect it was not significantly different regarding the effect caused by the crude. Besides, fucoidan F0.5 only promoted the formation of COD type crystals, while fucoidans F1.1 and F2.0 did not influence the formation of crystals compared with the control. The results described in this study indicate that the commercial crude fucoidan of Fucus vesiculosus it’s a mix of several fucoidan which, in turn, have different chemical compositions besides having different pharmacological activities. The use of these fucoidans it´s indicated according the pharmacological activity to be evaluated.