957 resultados para 640300 First Stage Treatment of Ores and Minerals


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Background Peroxisome proliferator activated receptor gamma (PPARgamma) is a ligand-activated transcription factor known to be central to both adipose tissue development and insulin action. Growth of adipose tissue requires differentiation of preadipocytes with acquisition of specific cellular functions including insulin sensitivity, leptin secretion and the capacity to store triglyceride. Dietary fatty acids and members of the thiazolidinedione class of compounds have been reported to influence adipogenesis at the transcriptional level. Here, we compare the effects of a dietary fatty acid, linoleic acid, and a thiazolidinedione, rosiglitazone, on biochemical and functional aspects of human preadipocyte differentiation in vitro . Materials and methods Human omental and subcutaneous preadipocytes were subcultured 2-3 times and subsequently differentiated for 21 days in the presence of either linoleic acid or rosiglitazone. Differentiation was assessed using a number of biochemical and functional parameters. Results Omental and subcutaneous preadipocytes differentiated in the presence of linoleic acid showed marked cytoplasmic triacylglycerol accumulation however, no biochemical markers of differentiation (LPL expression, G3PDH gene expression and enzyme activity and leptin expression or secretion) were detected. In contrast, treatment of these cells with rosiglitazone induced full biochemical differentiation as judged by all markers assessed, despite comparatively little lipid accumulation. The rosiglitazone effects were subcutaneous depot-specific. Cells treated with linoleic acid showed decreased glucose uptake cf rosiglitazone-treated cells. A luciferase reporter assay demonstrated that rosiglitazone potently activates h-peroxisome proliferator activated receptor gamma while linoleic acid had no effect. Conclusions These studies demonstrate that (a) human preadipocytes have the potential to accumulate triacylglycerol irrespective of their stage of biochemical differentiation; (b) while omental preadipocytes are refractory to biochemical differentiation in vitro , they are able to accumulate triacylglycerol; and (c) rosiglitazone and linoleic acid may exert their effects via different biochemical pathways.

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Low temperatures impose restrictions on rice (Oryza sativa L.) production at high latitudes. This study is related to low temperature damage that can arise mid-season during the panicle development phase. The objective of this study was to determine whether low temperature experienced by the root, panicle, or foliage is responsible for increased spikelet sterility. In temperature-controlled glasshouse experiments, water depth, and water and air temperatures, were changed independently to investigate the effects of low temperature in the root, panicle, and foliage during microspore development on spikelet sterility. The total number of pollen and number of engorged pollen grains per anther, and the number of intercepted and germinated pollen grains per stigma, were measured. Spikelet sterility was then analysed in relation to the total number of pollen grains per spikelet and the efficiency with which these pollen grains became engorged, were intercepted by the stigma, germinated, and were involved in fertilisation. There was a significant combined effect of average minimum panicle and root temperatures on spikelet sterility that accounted for 86% of the variation in spikelet sterility. Total number of pollen grains per anther was reduced by low panicle temperature, but not by low root temperature. Whereas engorgement efficiency ( the percentage of pollen grains that were engorged) was determined by both root and panicle temperature, germination efficiency (the percentage of germinated pollen grains relative to the number of engorged pollen grains intercepted by the stigma) was determined only by root temperature. Interception efficiency (i.e. percentage of engorged pollen grains intercepted by the stigma), however, was not affected by either root or panicle temperature. Engorgement efficiency was the dominant factor explaining the variation in spikelet sterility. It is concluded that both panicle and root temperature affect spikelet sterility in rice when the plant encounters low temperatures during the microspore development stage.

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An adequate supply of nutrients is essential for obtaining high yields of coffee. The objective of this study was to evaluate the effect of N, K and the N:K ratio on vegetative and reproductive growth of coffee. For this purpose, coffee plants were grown in nutrient solution containing K in the concentrations of 1.08; 2.15; 3.23 and 5.38 mmol L-1 combined with a dose of 6 mmol L-1 N, resulting in the N:K ratios (w/w): 1:0.5; 1:1; 1:1.5 and 1:2.5. The control treatment consisted of the doses 3 and 1.61 mmol L-1 of N and K respectively, resulting in the N:K ratio (w/w) 1.0:1.5. The following variables were evaluated: height, stem diameter, number of nodes of the eighth plagiotrofic branch (index branch), pairs of plagiotrofic branches and number of nodes in the orthotropic branch every three weeks from the beginning of the experiment. Additionally, it was evaluated the chemical composition of processed beans and leaves between the flowering and the rapid expansion stage of the cherry beans, production of cherry beans per plant and classification of beans according to the size. N influenced mainly the characteristics of vegetative growth and K influenced mainly the reproductive growth evaluated by the production. The lowest production resulted in the highest percentages of beans retained on sieves with holes larger than 16/64", while the highest production promoted an increase in the percentage of beans retained on sieves with holes smaller than 16/64".

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Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

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The objective of this study was to evaluate the effect of the fungus Aspergillus niger strain CCT4355 in the release of nutrients contained in two types of rock powder (diabase and phonolite) by means of in vitro solubilization trials. The experimental design was completely randomized in a 5 x 4 factorial design with three replications. It was evaluated five treatments (phonolite dust + culture medium; phonolite dust + fungus + culture medium; diabase powder + culture medium; diabase powder + fungus + culture medium and fungus + culture medium) and four sampling dates (0, 10, 20 and 30 days). Rock dust (0.4% w/v) was added to 125 mL Erlenmeyer flasks containing 50 mL of liquid culture medium adapted to A. niger. The flasks were incubated at 30°C for 30 days, and analysis of pH (in water), titratable acidity, and concentrations of soluble potassium, calcium, magnesium, zinc, iron and manganese were made. The fungus A. niger was able to produce organic acids that solubilized ions. This result indicates its potential to alter minerals contained in rock dust, with the ability to interact in different ways with the nutrients. A significant increase in the amount of K was found in the treatment with phonolite dust in the presence of the fungus. The strain CCT4355 of A. niger can solubilize minerals contained in these rocks dust.

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Improving the treatment of obesity remains a critical challenge. Several health behaviour change models, often based on a social-cognitive framework, have been used to design weight management interventions (Baranowski et al., 2003). However, most interventions have only produced modest weight reductions (Wadden et al., 2002) and socialcognitive variables have shown limited power to predict weight outcomes (Palmeira et al., 2007). Other predictors, and possibl alte nati e e planatory models, are needed to better understand the mechanisms by which weight loss and other obesity treatment-outcomes are brought about (Baranowski, 2006). Self-esteem is one of these possible mechanisms, because is commonly reported to change during the treatment, although these changes are not necessarily associated with weight loss (Blaine et al., 2007; Maciejewski et al., 2005). This possibility should be more evident if the program integrates regular exercise, as it promotes improvements in subjective well-being (Biddle & Mutrie, 2001), with possible influences on long-term behavioral adherence (e.g. diet, exercise). Following the reciprocal effects model tenets (Marsh & Craven, 2006), we expect that the influences between changes in weight, selfesteem and exercise to be reciprocal and might present one of the mechanisms by which obesity treatments can be improved.

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Introduction/Aims: The purpose of the study is to evaluate the perception of the organization, the development and the evaluation of the initial stage in the internship of students, in order to improve these activities and to establish the adequate objectives in accordance with the changes concerning the concept of modern pharmacy. Materials and methods: An online survey was made using Google Docs ® -Create Form extension. All results were accumulated and computed using Microsoft Excel ®. The questionnaire consisted of 11 questions, structured on several levels: the objectives and how they can be achieved, internship organization, the internship training (effective participation in specific activities and integration in the pharmaceutical activity), the assessment, the profile of tutor / pharmacy. The questionnaire was completed by students from the Faculty of Pharmacy, University of Medicine and Pharmacy "Iuliu Haţieganu" Cluj Napoca, Romania. Results and discussions. The study was conducted on 308 students (60% of all students from the study years II-IV. 90% of the respondents had actually participated in the internship, whilst 10% only formally participated in this activity. The main responsibilities of the students were: storage and reception of pharmaceutical products (94%, respectively 79%) and working with the receipts (57%). Most of the students appreciate that they were integrated into the work in the pharmacy, this being due largely pharmacist tutor, who expressed interest and ability in mentoring activities. They appreciated that the role of tutor requires 3-5 years of professional experience. In terms of the internship objectives, these should aim at applying the knowledge gained until the graduation year, but also familiarization with activities which might turn into applications for the coming years. 43% of students believe that only 25% of the theoretical knowledge was useful during the internship. 90 % of the total questioned considered useful to develop a practice guideline adapted to the year of study. Conclusions. The professional training of the future pharmacist’s students depends largely on experience gained by students during the internship activity. Feed-back from the students’ shows that they are aware of the usefulness of the internship, but believe the objectives must be updated and a better correlation between work in pharmacy and theoretical knowledge has to be made. A first step is to develop a practical guide adapted to each year of study. The involvement of the tutor pharmacist is also essential to the success of this activity

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Mestrado em Radiações Aplicadas às Tecnologias da Saúde.

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The presented work was conducted within the Dissertation / Internship, branch of Environmental Protection Technology, associated to the Master thesis in Chemical Engineering by the Instituto Superior de Engenharia do Porto and it was developed in the Aquatest a.s, headquartered in Prague, in Czech Republic. The ore mining exploitation in the Czech Republic began in the thirteenth century, and has been extended until the twentieth century, being now evident the consequences of the intensive extraction which includes contamination of soil and sub-soil by high concentrations of heavy metals. The mountain region of Zlaté Hory was chosen for the implementation of the remediation project, which consisted in the construction of three cells (tanks), the first to raise the pH, the second for the sedimentation of the formed precipitates and a third to increase the process efficiency in order to reduce high concentrations of metals, with special emphasis on iron, manganese and sulfates. This project was initiated in 2005, being pioneer in this country and is still ongoing due to the complex chemical and biological phenomenon’s inherent to the system. At the site where the project was implemented, there is a natural lagoon, thereby enabling a comparative study of the two systems (natural and artificial) regarding the efficiency of both in the reduction/ removal of the referred pollutants. The study aimed to assist and cooperate in the ongoing investigation at the company Aquatest, in terms of field work conducted in Zlaté Hory and in terms of research methodologies used in it. Thereby, it was carried out a survey and analysis of available data from 2005 to 2008, being complemented by the treatment of new data from 2009 to 2010. Moreover, a theoretical study of the chemical and biological processes that occurs in both systems was performed. Regarding the field work, an active participation in the collection and in situ sample analyzing of water and soil from the natural pond has been attained, with the supervision of Engineer, Irena Šupiková. Laboratory analysis of water and soil were carried out by laboratory technicians. It was found that the natural lagoon is more efficient in reducing iron and manganese, being obtained removal percentages of 100%. The artificial lagoon had a removal percentage of 90% and 33% for iron and manganese respectively. Despite the minor efficiency of the constructed wetland, it must be pointed out that this system was designed for the treatment and consequent reduction of iron. In this context, it can conclude that the main goal has been achieved. In the case of sulphates, the removal optimization is yet a goal to be achieved not only in the Czech Republic but also in other places where this type of contamination persists. In fact, in the natural lagoon and in the constructed wetland, removal efficiencies of 45% and 7% were obtained respectively. It has been speculated that the water at the entrance of both systems has different sources. The analysis of the collected data shows at the entrance of the natural pond, a concentration of 4.6 mg/L of total iron, 14.6 mg/L of manganese and 951 mg/L of sulphates. In the artificial pond, the concentrations are 27.7 mg/L, 8.1 mg/L and 382 mg/L respectively for iron, manganese and sulphates. During 2010 the investigation has been expanded. The study of soil samples has started in order to observe and evaluate the contribution of bacteria in the removal of heavy metals being in its early phase. Summarizing, this technology has revealed to be an interesting solution, since in addition to substantially reduce the mentioned contaminants, mostly iron, it combines the low cost of implementation with an reduced maintenance, and it can also be installed in recreation parks, providing habitats for plants and birds.

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This paper aims at putting into perspective the recent, post 9/11 debate on the United States‘ alleged exceptionalism and its impact on the definition of American foreign policy. It reminds the readers that the United States was born as a result of a similar debate, at a time when a crucial choice for its future was to be made. Indeed, the Founding Fathers discarded the revolutionary idea that America was altogether different from other (European) nations and, as such, could succeed in saving republicanism and concentrate on domestic affairs. As Gordon Wood and Harvey Mansfield have shown, the 1787 version of republicanism stood as a departure from its earlier version, and such a change was necessary to the creation of a full-fledged federation, therefore paving the way to the current powerful Federal Republic. The early failure of the exceptionalist creed did not cause its disappearance, as the contemporary form of exceptionalism demonstrates, but created conditions that made an enduring and powerful influence very difficult.

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Radiotherapy (RT) is one of the most important approaches in the treatment of cancer and its performance can be improved in three different ways: through the optimization of the dose distribution, by the use of different irradiation techniques or through the study of radiobiological initiatives. The first is purely physical because is related to the physical dose distributiuon. The others are purely radiobiological because they increase the differential effect between the tumour and the health tissues. The Treatment Planning Systems (TPS) are used in RT to create dose distributions with the purpose to maximize the tumoral control and minimize the complications in the healthy tissues. The inverse planning uses dose optimization techniques that satisfy the criteria specified by the user, regarding the target and the organs at risk (OAR’s). The dose optimization is possible through the analysis of dose-volume histograms (DVH) and with the use of computed tomography, magnetic resonance and other digital image techniques.

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A detailed analysis of fabrics of the chilled margin of a thick dolerite dyke (Foum Zguid dyke, Southern Morocco) was performed in order to better understand the development of sub-fabrics during dyke emplacement and cooling. AMS data were complemented with measurements of paramagnetic and ferrimagnetic fabrics (measured with high field torque magnetometer), neutron texture and microstructural analyses. The ferrimagnetic and AMS fabrics are similar, indicating that the ferrimagnetic minerals dominate the AMS signal. The paramagnetic fabric is different from the previous ones. Based on the crystallization timing of the different mineralogical phases, the paramagnetic fabric appears related to the upward flow, while the ferrimagnetic fabric rather reflects the late-stage of dyke emplacement and cooling stresses. (C) 2014 Elsevier B.V. All rights reserved.

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The treatment of relapsing chronic infections (RCI) encounters many difficulties. In the present study, the use of the immuno adjuvant P40 either alone or in association with vaccinotherapy for the treatment of RCI turned out to be very effective, whereas vaccinotherapy alone was not. It is hypothesized that cell-mediated immunity may play a major role in controlling RCI, since the clinical improvement of the patients kept up with the positivation of previously negative skin tests carried out with either the specific infecting agent or with recall-anti gens.

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Eucalyptus globulus sapwood and heartwood showed no differences in lignin content (23.0% vs. 23.7%) and composition: syringyl-lignin (17.9% vs. 18.0%) and guaiacyl-lignin (4.8% vs. 5.2%). Delignification kinetics of S- and G-units in heartwood and sapwood was investigated by Py-GC–MS/FID at 130, 150 and 170 °C and modeled as double first-order reactions. Reactivity differences between S and G-units were small during the main pulping phase and the higher reactivity of S over G units was better expressed in the later pulping stage. The residual lignin composition in pulps was different from wood or from samples in the initial delignification stages, with more G and H-units. S/G ratio ranged from 3 to 4.5 when pulp residual lignin was higher than 10%, decreasing rapidly to less than 1. The S/H was initially around 20 (until 15% residual lignin), decreasing to 4 when residual lignin was about 3%.

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Additional apple juice extraction with pulsed electric field pretreated apple cubes towards control samples is evaluated. Monopolar and bipolar shaped pulses are compared and their effect is studied with variation of electric field, pulse width and number of pulses. Variation of electric field strength is ranged from 100 V/cm to 1300 V/cm, pulse width from 20 mu s to 300 mu s and number of pulses from 10 to 200, at frequency of 200Hz. Two pulse trains separated by 1 second are applied to all samples. Bipolar pulses showed higher apple juice yields with all studied parameters. Calculation of specific energies consumed was assessed and a threshold where higher energy inputs do not increase juice yield is found for a number of used parameters. Qualitative parameters of total soluble matter (Brix) and absorbance at 390 nm wavelength were determined for each sample and results show that no substantial differences are found for PEF pre-treated and control samples.