982 resultados para TISSUE TRACE-ELEMENTS
Resumo:
Este trabalho teve como objetivo avaliar o desempenho produtivo e a qualidade dos ovos de codornas japonesas em postura, em função da redução e da substituição parcial ou total de microminerais (manganês, zinco, ferro, cobre, iodo e selênio) orgânicos em substituição ao micromineral inorgânico. Foram conduzidos dois experimentos no setor de avicultura do Instituto Federal do Espírito Santo, com duração de 84 dias, distribuídos em quatro períodos de 21 dias. Em cada experimento, foram utilizadas 480 codornas japonesas fêmeas, com 79 dias de idade. As aves foram distribuídas em delineamento inteiramente ao acaso em 6 tratamentos, 10 repetições e 8 aves por unidade experimental. Foi utilizada uma mesma ração basal em ambos experimentos, variando apenas os níveis e a fonte dos microminerais utilizados. No primeiro experimento foi adicionado à essa ração cinco diferentes níveis de microminerais orgânicos 25; 50; 75; 100 e 125% da recomendação do complexo mineral orgânico e um nível com microminerais inorgânicos (100% da recomendação) sendo utilizado 1 kg/ton de ração. No segundo experimento, foram adicionados quatro diferentes níveis de mistura de microminerais orgânicos e inorgânicos (20% orgânico + 80% inorgânico, 40% orgânico + 60% inorgânico, 60% orgânico + 40% inorgânico e 80% orgânico + 20% inorgânico), um inorgânico (100%) e um orgânico (100%) na ração. As características avaliadas foram consumo de ração, taxa de postura, peso médio do ovo, massa dos ovos, conversão alimentar por massa do ovo e por dúzia de ovos, peso relativo e absoluto da gema, do albúmen e da casca, além da unidade Haugh. Os parâmetros avaliados não foram afetados de forma significativa pelas diferentes relações de uso de minerais orgânicos e inorgânicos. Observou-se que é possível reduzir para 25% da recomendação de microminerais, quando utiliza-se microminerais orgânicos e que, é possível a substituição em até 100% dos microminerais inorgânicos por orgânicos sem efeito sobre desempenho o produtivo e a qualidade de ovos de codornas japonesas.
Resumo:
An atmospheric aerosol study was performed in 2008 inside an urban road tunnel, in Lisbon, Portugal. Using a high volume impactor, the aerosol was collected into four size fractions (PM0.5, PM0.5-1, PM1-2.5 and PM2.5-10) and analysed for particle mass (PM), organic and elemental carbon (OC and EC), polycyclic aromatic hydrocarbons (PAH), soluble inorganic ions and elemental composition. Three main groups of compounds were discriminated in the tunnel aerosol: carbonaceous, soil component and vehicle mechanical wear. Measurements indicate that Cu can be a good tracer for wear emissions of road traffic. Cu levels correlate strongly with Fe, Mn, Sn and Cr, showing a highly linear constant ratio in all size ranges, suggesting a unique origin through sizes. Ratios of Cu with other elements can be used to source apportion the trace elements present in urban atmospheres, mainly on what concerns coarse aerosol particles. (C) 2013 Elsevier Ltd. All rights reserved.
Resumo:
A realização desta tese tinha como principal objectivo determinar a concentração de cobre, cobalto e molibdénio em alimentos seleccionados. Foram determinadas as concentrações de cobre, cobalto e molibdénio em feijões vermelho, feijões castanho, feijões branco, dois tipos de amêndoas, dois tipos de nozes e amendoins. Todos estes alimentos foram comprados e analisados na República Checa. Para a análise destes alimentos foi usado o método analítico Espectrometria de Massa Acoplada a Plasma Indutivo (ICP-MS). Antes de efectuar a análise foi necessário fazer um tratamento prévio que consistia na digestão do alimento no microondas, utilizando-se uma massa de 1 grama de alimento, 5 ml de HNO3 e 2 ml de H2O2. O alimento que tem maior concentração de cobre é as nozes fornecida pela empresa Fit Line (8,7 ± 0,6 μg/g) e o que tem a menor concentração de cobre são os amendoins (3,2 ± 0,2 μg/g). Em relação ao cobalto o alimento que tem a maior concentração de cobalto é feijão do tipo castanho (0,106 ± 0,005 μg/g) e o que apresenta a menor concentração é as amêndoas do tipo 2 (0,019 ± 0,003 μg/g). Para o molibdénio o alimento que apresenta uma maior concentração é o feijão do tipo branco (5,3 ± 0,6 μg/g) e o que tem a menor concentração é as nozes do tipo 2 (0,10 ± 0,01 μg/g).
Resumo:
Chromium copper arsenate(CCA)was used for the protection of wood building material suntil the restriction by EPA in2002. During a short period of time 14–24h,a comparative nephrotoxicity study was performed regarding the effects of CCA and its compounds per se. Histopathological and histochemical features were correlated with the concentration of the total arsenic and chromium in mice kidney. Animals were subcutaneously injected with CCA(7.2mg/kg arsenic and 10.2mg/kg chromium per body weight), CrO3 (10.2 mg/kg),As2O5 (7.2 mg/kg)andNaCl(0.9%) per se. The histopathological examination of the renal sections evidenced acute tubular necrosis in the groups of animals exposed to CCA(in both periods of time). Although the same contents of pentavalent arsenic and hexavalent chromium were injected in treated animals with CCA and with the prepared solutions of As2O5 and CrO3, the arsenic concentration on kidneys of CCA-exposed animals was much higher than those in animals exposed to As2O5 (32- and28-fold higher at 14 and 24h,respectively). However,the elimination of chromium seems to occur similarly in the kidneys of animals treated with CCA and CrO3 per se. Interactions among the components of CCA result in a marked decrease of the ability of kidney to eliminate simultaneously both analytes.The nephrotoxicity of CCA was higher than its components per se, evidencing a possible synergetic effect.
Resumo:
The chemical and mineralogical charactetistics of the intrusive and extrusive rocks of this igneous complex are presented. The suggest affinities between these rocks. The major and the trace elements lead us to conclude that these rocks were originated in a common magmatic chamber by fractional crystallization.
Resumo:
The chemical and mineralogical characteristics of the intrusive and extrusive rocks of this igneous complex are presented. The suggest affinities between these rocks. The major and the trace elements lead us to conclude that these rocks were originated in a common magmatic chamber by fractional crystallization.
Resumo:
Coal contains trace elements and naturally occurring radionuclides such as 40K, 232Th, 238U. When coal is burned, minerals, including most of the radionuclides, do not burn and concentrate in the ash several times in comparison with their content in coal. Usually, a small fraction of the fly ash produced (2-5%) is released into the atmosphere. The activities released depend on many factors (concentration in coal, ash content and inorganic matter of the coal, combustion temperature, ratio between bottom and fly ash, filtering system). Therefore, marked differences should be expected between the by-products produced and the amount of activity discharged (per unit of energy produced) from different coal-fired power plants. In fact, the effects of these releases on the environment due to ground deposition have been received some attention but the results from these studies are not unanimous and cannot be understood as a generic conclusion for all coal-fired power plants. In this study, the dispersion modelling of natural radionuclides was carried out to assess the impact of continuous atmospheric releases from a selected coal plant. The natural radioactivity of the coal and the fly ash were measured and the dispersion was modelled by a Gaussian plume estimating the activity concentration at different heights up to a distance of 20 km in several wind directions. External and internal doses (inhalation and ingestion) and the resulting risk were calculated for the population living within 20 km from the coal plant. In average, the effective dose is lower than the ICRP’s limit and the risk is lower than the U.S. EPA’s limit. Therefore, in this situation, the considered exposure does not pose any risk. However, when considering the dispersion in the prevailing wind direction, these values are significant due to an increase of 232Th and 226Ra concentrations in 75% and 44%, respectively.
Resumo:
SUMMARY The role of trace elements in dengue virulence is not yet known. The present study assessed the serum levels of two micronutrients, copper and iron, in cases of dengue fever. The study involved 96 patients of whom 48 had either severe or non-severe forms of dengue (with and without warning signs), and the remaining 48 were patients with other febrile illnesses (OFI), used as controls. Serum levels of copper and iron were evaluated at admission and by the time of defervescence using commercially available kits. At admission, no difference in the level of serum copper was observed between cases and controls. In the group of dengue cases, the copper level was found to be significantly decreased in severe and non-severe cases with warning signs, compared to non-severe cases without warning signs. In contrast, by the time of defervescence the copper level was found to be increased in all dengue cases compared to OFI controls, but no difference was observed among dengue cases. Unlike OFI controls, dengue cases showed an increasing pattern of copper levels from admission until defervescence. On the other hand, no such significant differences were observed in the serum level of iron in the clinical groups, except for a decreased iron level found in severe cases, compared to non-severe dengue without warning signs. The results show that copper is associated with dengue severity and this finding emphasizes the need to investigate the involvement of trace elements in disease severity so as to improve the prognosis of dengue.
Vitaminas, Minerais e Oligoelementos por Via Entérica no Recém-Nascido. Revisão do Consenso Nacional
Resumo:
Na presente atualização da recomendação sobre vitaminas, minerais e oligoelementos por via entérica no recém-nascido, é dada especial relevância às necessidades destes micronutrientes do recém-nascido de termo e pré-termo, suprimentos fornecidos pelo leite materno, leite humano fortificado, fórmulas lácteas para recém-nascido de termo e pré-termo comercializadas em Portugal e suplementos recomendados por rotina no recém-nascido de termo e pré-termo.
Resumo:
The present PhD thesis develops the cell functional enviromics (CFE) method to investigate the relationship between environment and cellular physiology. CFE may be defined as the envirome-wide cellular function reconstruction through the collection and systems-level analysis of dynamic envirome data. Throughout the thesis, CFE is illustrated by two main applications to cultures of a constitutive P. pastoris X33 strain expressing a scFv antibody fragment. The first application addresses the challenge of culture media development. A dataset was built from 26 shake flask experiments, with variations in trace elements concentrations and basal medium dilution based on the standard BSM+PTM1. Protein yield showed high sensitivity to culture medium variations, while biomass was essentially determined by BSM dilution. High scFv yield was associated with high overall metabolic fluxes through central carbon pathways concomitantly with a relative shift of carbon flux from biosynthetic towards energy-generating pathways. CFE identified three cellular functions (growth, energy generation and by-product formation) that together described 98.8% of the variance in observed fluxes. Analyses of how medium factors relate to identified cellular functions showed iron and manganese at concentrations close to PTM1 inhibit overall metabolic activity. The second application addresses bioreactor operation. Pilot 50 L fed-batch cultivations, followed by 1H-NMR exometabolite profiling, allowed the acquisition of data for 21 environmental factors over time. CFE identified five major metabolic pathway groups that are frequently activated by the environment. The resulting functional enviromics map may serve as template for future optimization of media composition and feeding strategies for Pichia pastoris. The present PhD thesis is a step forward towards establishing the foundations of CFE that is still at its infancy. The methods developed herein are a contribution for changing the culture media and process development paradigm towards a holistic and systematic discipline in the future.
Resumo:
This paper carried out a chemical investigation of archaeological ceramic artifacts found in archaeological sites with Black Earth (ABE) in the Lower Amazon Region at Cachoeira-Porteira, State of Pará, Brazil. The ceramic artifacts, mostly of daily use, belong to Konduri culture (from 900 to 400 years BP). They are constituted of SiO2, Al2O3, Fe2O3, Na2O and P2O5; SiO2 and Al2O3 together add up to 80 % and indicate influence of acid rocks, transformed into clay minerals basically kaolinite. The relative high contents of P2O5 (2.37 % in average) come out as (Al,Fe)-phosphate, an uncommon fact in primitive red ceramics, but found in some roman and egyptian archaeological sites. The contents of the trace elements are similar or below the Earth's crust average. This chemical composition (except P2O5) detaches saprolite material derived acid igneous rocks or sedimentary ones as the main raw material of the ceramics. The contents of K, Na and Ca represent the feldspars and rock fragments possibly introduced into saprolitic groundmass, indicated by mineralogical studies. The presence of cauixi and cariapé as well as quartz sand was confirmed by optical microscope, SEM analyses and by the high silica contents of ceramic fragments. Phosphorus was possibly incorporated into groundmass during cooking of foods, and ABE soil profile formation developed on yellow Latosols. The raw materials and its tempers (cauixi, or cariapé, feldspar, crushed rocks, old ceramic artifacts and quartz fragments) are found close to the sites and therefore and certainly came from them.
Resumo:
Samples of volcanic rocks from Alboran Island, the Alboran Sea floor and from the Gourougou volcanic centre in northern Morocco have been analyzed for major and trace elements and Sr-Nd isotopes to test current theories on the tectonic geodynamic evolution of the Alboran Sea. The Alboran Island samples are low-K tholeiitic basaltic andesites whose depleted contents of HFS elements (similar to0.5xN-MORB), especially Nb (similar to0.2xN-MORB), show marked geochemical parallels with volcanics from immature intra-oceanic arcs and back-arc basins. Several of the submarine samples have similar compositions, one showing low-Ca boninite affinity. Nd-143/Nd-144 ratios fall in the same range as many island-arc and back-arc basin samples, whereas Sr-87/Sr-86 ratios (on leached samples) are somewhat more radiogenic. Our data point to active subduction taking place beneath the Alboran region in Miocene times, and imply the presence of an associated back-arc spreading centre. Our sea floor suite includes a few more evolved dacite and rhyolite samples with (Sr-87/Sr-86)(0) up to 0.717 that probably represent varying degrees of crustal melting. The shoshonite and high-K basaltic andesite lavas from Gourougou have comparable normalized incompatible-element enrichment diagrams and Ce/Y ratios to shoshonitic volcanics from oceanic island arcs, though they have less pronounced Nb deficits. They are much less LIL- and LREE-enriched than continental arc analogues and post-collisional shoshonites from Tibet. The magmas probably originated by melting in subcontinental lithospheric mantle that had experienced negligible subduction input. Sr-Nd isotope compositions point to significant crustal contamination which appears to account for the small Nb anomalies. The unmistakable supra-subduction zone (SSZ) signature shown by our Alboran basalts and basaltic andesite samples refutes geodynamic models that attribute all Neogene volcanism in the Alboran domain to decompression melting of upwelling asthenosphere arising from convective thinning of over-thickened lithosphere. Our data support recent models in which subsidence is caused by westward rollback of an eastward-dipping subduction zone beneath the westemmost Mediterranean. Moreover, severance of the lithosphere at the edges of the rolling-back slab provides opportunities for locally melting lithospheric mantle, providing a possible explanation for the shoshonitic volcanism seen in northern Morocco and more sporadically in SE Spain. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
Several quartz crystals from three different Alpine vein localities and of known petrologic setting and evolution have been examined for possible elemental sector zoning in order to help to constrain the mechanisms of such trace element incorporation. Using different in situ techniques (EMPA, LA-ICPMS, SIMS, FTIR-spectroscopy), it was established that Al and Li concentrations can exceed several hundreds of ppma for distinct growth zones within crystals formed at temperatures of about 300 degrees C or less and that also display patterns of cyclic growth when examined with cathodoluminescence. In contrast, crystals formed at temperatures closer to 400 degrees C and without visible cyclic growth have low concentrations of Al and Li as well as other trace elements. Al and Li contents are correlated along profiles measured within the crystals and in general their proportion does not change along the profiles. No relationships were found between Al, Na, and K, and germanium has a qualitative relationship with Al. FTIR spectra also show OH(-) absorption bands within the quartz, with higher amplitudes in zones rich in Al and Li. Sector zoning is present. It is most pronounced between prismatic and rhombohedral faces of the same growth zone, but also between the rhombohedral faces of r and z, which contain different amounts of trace elements. The sector zoning is also expressed by changes in the Li/Al ratio, with higher ratios in 17 compared to r faces. It is concluded that the incorporation of trace elements into hydrothermal quartz from Alpine veins is influenced by growth mechanisms and surface-structures of the growing quartz crystals, the influence of which may change as a function of temperature, pH, as well as the chemical composition of the fluid.
Resumo:
The Mississippi Valley-type zinc and lead deposits at Topla (250,150 metric tons (t) of ore grading 1.0 wt % Zn and 3.3 wt % Pb) and Mezica (19 million metric tons (Mt) of ore grading 5.3 wt % Pb and 2.7 wt % Zn) occur within the Middle to Upper Triassic platform carbonate rocks of the northern Karavanke/Drau Range geotectonic units of the Eastern Alps, Slovenia. The ore and host rocks of these deposits have been investigated by a combination of inorganic and organic geochemical methods to determine major, trace, and rare earth element (REE) concentrations, hydrocarbon distribution, and stable isotope ratios of carbonates, kerogen, extractable organic matter, and individual hydrocarbons. These data combined with sedimentological evidence provide insight into the paleoenvironmental conditions at the site of ore formation. The carbonate isotope composition, the REE patterns, and the distribution of hydrocarbon biomarkers (normal alkanes and steranes) suggest a marine depositional environment. At Topla, a relatively high concentration of redox sensitive trace elements (V, Mo, U) in the host dolostones and REE patterns parallel to that of the North American shale composite suggest that sediments were deposited in a reducing environment. Anoxic conditions enhanced the preservation of organic matter and resulted in relatively higher total organic carbon contents (up to 0.4 wt %). The isotopic composition of the kerogen (delta C-13(kerogon) = -29.4 to -25.0 parts per thousand, delta N-15(kerogen) = -.13.6 to 6.8 parts per thousand) suggests that marine algae and/or bacteria were the main source of organic carbon with a very minor contribution from detrital continental plants and a varying degree of alteration. Extractable organic matter from Topla ore is generally depleted in C-13 compared to the associated kerogen, which is consistent with an indigenous source of the bitumens. The mineralization correlates with delta N-15(kerogen) values around 0 per mil, C-13 depleted kerogen, C-13 enriched n-heptadecane, and relatively high concentrations of bacteria] hydrocarbon biomarkers, indicating a high cyanobacterial biomass at the site of ore formation. Abundant dissimilatory sulfate-reducing bacteria, feeding on the cyanobacterial remains, led to accumulation of biogenic H2S in the pore water of the sediments. This biogenic H2S was mainly incorporated into sedimentary organic matter and diagenetic pyrite. Higher bacterial activity at the ore site also is indicated by specific concentration ratios of hydrocarbons, which are roughly correlated with total Pb plus Zn contents. This correlation is consistent with mixing of hydrothermal metal-rich, fluids and local bacteriogenic sulfide sulfur. The new geochemical data provide supporting evidence that Topla is a low-temperature Mississippi Valley-type deposit formed in an anoxic supratidal saline to hypersaline environment. A laminated cyanobacterial mat, with abundant sulfate-reducing bacteria was the main site of sulfate reduction.