Dos caminhos de água aos caminhos de ferro: a construção da hegemonia de Natal através das vias de transporte (1820-1920)

At a time of changes on the territory during the 19th century, the political and socioeconomic elites of the province and later State of Rio Grande do Norte evolved a discourse in order to justify the permanence of Natal as a city holding a status of capital. In this work we analyze the means employed by the ruling classes to impose their wish to raise Natal to an outstanding position among the existing cities by intervening on the territory during a period of one hundred years (1820-1920). During that time, which was characterized by changing commercial flows and technological development, the elites interventions were essentially directed to the implementation of modes of transportation, especially the railway. We try to understand the reinforcement of Natal as a capital city not only in political and administrative terms, but mainly in a commercial and symbolic manner, through the discourse and interventions undertaken by the local administrative elites, who stimulated the creation of a set of relations on the territory that also imprinted visible marks in the capital s urban fabric. These interventions were based upon the establishment of an infrastructure for exporting the State s production, firstly through and despite the Potengi River, and later on by the construction of railways. Although the project of Natal s hegemony had been outlined before the establishment of the railway network, in both cases the ultimate objective was to reinforce and develop the capital city as a commercial urban center to the detriment of other cities

O papel modulatório do ferro sobre a resposta imune na Leishmaniose Visceral

Iron is an essential element for many cellular functions, including the immune response against intracellular pathogens. In this study, we aimed evaluate the effect of iron on IRP2, IFN-γ, TNF-α, IL-6, IL-10, MIG and IP10 expression in PBMC and assess the effect of the spleen parasite load on the expression of these genes in the spleen of L. infantum naturally infected dogs. Blood sample from 7 DTH+ donor was collected and PBMC was obtained. The cells were cultivated in absence (iron chelator desferroximane, DFO 10 μM supplemented media) or in presence of iron (hemin 6 mM) for 1 h, followed by stimulation with Leishmania infatum antigen for 4 h. 44 dog spleen samples were obtained and parasite load in this organ was determinate by qPCR. Gene expression was analyzed by qPCR and cytokine production quantified by flow cytometry. In antigen stimulated cells, genes involved in immune response are significantly more expressed in presence of iron. T CD4+ and TCD8+ lymphocytes produces IFN-γ, TNF-α and IL-10 possibly in iron dependent pathway. Monocytes antigen stimulated reduced TNF-α, IL-6 and IL-10 production in presence of iron. We found spleen of infected dogs IRP2 expression increases according to parasite load in that organ, while an inverse profile was found for IFN-γ, TNF-α e IL-10 expression. These results suggest that T lymphocytes depends on iron to produce IFN-γ, TNF-α and IL-10, while iron seems to inhibit cytokine production in monocytes. So, we propose an immunoregulatory mechanism carried out by iron during L. infantum infection in humans and dogs

Resposta de Chromobacterium Violaceum cultivada em alta concentração de ferro

The Chromobacterium violaceum is a β-proteobacterium Gram-negative widely found in tropical and subtropical regions, whose genome was sequenced in 2003 showing great metabolic versatility and biotechnological and pharmaceutical potential. Given the large number of ORFs related to iron metabolism described in the genome of C. violaceum, the importance of this metal for various biological processes and due to lack of data about the consequences of excess of iron in free-living organisms, it is important to study the response mechanism of this bacterium in a culture filled with iron. Previous work showed that C. violaceum is resistant to high concentrations of this metal, but has not yet been described the mechanism which is used to this survival. Thus, to elucidate the response of C. violaceum cultured in high concentrations of iron and expecting to obtain candidate genes for use in bioremediation processes, this study used a shotgun proteomics approach and systems biology to assess the response of C. violaceum grown in the presence and absence of 9 mM of iron. The analysis identified 531 proteins, being 71 exclusively expressed by the bacteria grown in the presence of the metal and 100 just in the control condition. The increase in expression of proteins related to the TCA cycle possibly represents a metabolic reprogramming of the bacteria caused by high concentration of iron in the medium. Moreover, we observed an increase in the activity assay of superoxide dismutase and catalase as well as in Total Antioxidant Activity assay, suggesting that the metal is inducing oxidative stress in C. violaceum that increases the levels of violacein and antioxidant enzymes to better adapt to the emerging conditions. Are also part of the adaptive response changes in expression of proteins related to transport, including iron, as well as an increased expression of proteins related to chemotaxis response, which would lead the bacteria to change the direction of its movement away from the metal. Systems Biology results, also suggest a metabolic reprogramming with mechanisms coordinated by bottleneck proteins involved in transcription (GreA), energy metabolism (Rpe and TpiA) and methylation (AhcY)

Síntese e impregnação de peneiras moleculares Fe MCM-41 derivada de sílica da casca do arroz

The mesoporous molecular sieves of the MCM-41 and FeMCM-41 type are considered promissory as support for metals used as catalysts in oil-based materials refine processes and as adsorbents for environmental protection proposes. In this work MCM-41 and FeMCM41 were synthesized using rice husk ash - RHA as alternative to the conventional silica source. Hydrothermal synthesis was the method chosen to prepare the materials. Pre-defined synthesis parameters were 100°C for 168 hours, later the precursor was calcinated at 550°C for 2 hours under nitrogen and air flow. The sieves containing different proportions of iron were produced by two routes: introduction of iron salt direct synthesis; and a modification post synthesis consisting in iron salt 1 % and 5% impregnation in the material followed by thermal decomposition. The molecular sieves were characterized by X ray diffraction XRD, Fourier transform infrared spectroscopy FT-IR, X ray fluorescence spectroscopy XFR, scanning electronic microscopy SEM, specific surface area using the BET method, Termogravimetry TG. The kinetic model of Flynn Wall was used with the aim of determining the apparent activation energy of the surfactant remove (CTMABr) in the MCM- 41 porous. The analysis made possible the morphology characterization, identifying the presence of hexagonal structure typical for mesoporous materials, as well as observation of the MCM41 and iron of characteristic bands.

Estudo da adição do resíduo proveniente da extração de minério de ferro em argilas do Rio Grande do Norte

The mining industry is responsible for the generation of waste from their natural process of extraction. The mining impacts in urban areas are of special importance due to the high urban occupation, which are exacerbated due to the proximity of the mined areas and populated areas. Some solutions to wastedisposal have the potential to significantly reduce the environmental risks and liabilities, but represent higher costs in the stages of deployment and operation. The addition of mining waste as raw material in the development of commercial products reduces the environmental impacts, transforming the waste into a positive element in the generation of employment and income. This thesis studies the incorporation of waste iron ore in two clays, one from the ceramic industry of the City of Natal and the other from the ceramic industry of the Seridó Region, both in the State of Rio Grande do Norte, Brazil. Percentages of iron ore waste of 5%, 10% , 15%, 20%, 25% and 30% were used in the tested ceramic matrix. The two clays and the iron ore waste used as part of this investigation were characterized by X-ray diffraction tests, X-ray fluorescence tests, differential thermal analysis, thermogravimetric analysis and dilatometric analysis. The samples were sintered under temperatures of 850 °C, 950 °C and 1050°C at a heating rate of 5 °C/min with isotherms of two hours. The following tests were performed with the samples: linear shrinkage, water absorption, apparent porosity, apparent density, mass loss in fire and bending resistance in order to obtain their physical and mechanical properties. An amount of 5% of waste iron ore in the matrix clay at a temperature of 850 0C resulted in na increase of about 65% in the tensile strength of the clay samples from the Natal ceramic industry. A linear shrinkage of only 0.12% was observed for the samples, which indicates that the physical properties of the final product were not influenced by the addition of the waste

Estudo do efeito da adição da escória de aciaria no processamento e propriedades finais de telhas cerâmicas

This research presents an overview of the addition steelwork dust of ceramic shingles in order to contribute to the utilization use of such residue. The ceramic industry perspective in the Brazilian State of Piauí is quite promising. Unlike other productive sectors, the ceramic industry uses basically natural raw materials. Its final products are, in short, the result of transforming clay compounds. These raw materials are composed primarily of aluminum oxide, silicon, iron, sodium, magnesium, end calcium, among others. It was verified that steelwork dust is composed primarily of these same oxides, so that its incorporation in to structural ceramics is a very reasonable idea. Both clay and steelwork powder were characterized by AG, XRF, XRD, TGA and DTA. In addition, steelwork dust samples containing (0%, 5%, 10%, 15%, 20% and 25%) were extruded and burned at 800°C, 850°C, 900°C and 950°C. Then t echnological tests of linear shrinkage, water uptake, apparent porosity, apparent density and flexural strengthwere carried at. The results showed the possibility of using steelwork powder in ceramic shingles until 15% significant improvement in physical and mechanical properties. This behavior shows the possibility of burning at temperatures lower than 850ºC, thus promoting a product final cost reduction

Impregnação de metais em xisto retortado para uso como adsorventes

Concern with the environment has lead to an increase in the research for new adsorption techniques, low cost adsorvent materials and with high availability. Many works search the development of higher selectivity modified adsorvents. The Brazil has the second world reserve of oiled shale, because of it, the use of that reject is of great interest. This study has the goal of characterize and analyze the retorted shale, reject of the pirobetuminous shale pyrolysis, and the retorted shale modified through the humid impregnation method, wich the precursors were the metals nitrates ( Cobalt, Nickel and Copper), to the usage has adsorvent materials. The samples were characterized chemically, textually and structurally by the X ray fluorescence (XRF), BET, X ray diffraction (XRD) and scanning electronic microscopy (SEM) techniques. The impregnated samples showed a reduction in the superficial area and in the pore volume when compared with the retorted shale. Besides that, diffractions referred to the impregnated metals where observed in the XRD analysis, wich were the same metals detected in the XRF and SEM analysis. The materials showed homogeneity in it s composition. The results shows that the materials presents adequate adsorption characteristics