964 resultados para support material
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This work describes the synthesis of nanosized metal sulfides and respective SiO2 and/or TiO2 composites in high yield via a straightforward process, under ambient conditions (temperature and pressure), by adding to aqueous metals a nutrient solution containing biologically generated sulfide from sulfate-reducing bacteria (SRB). The nanoparticles‘ (NPs) morphological properties were shown not to be markedly altered by the SRB growth media composition neither by the presence of bacterial cells. We further extended the work carried out, using the effluent of a bioremediation system previously established. The process results in the synthesis of added value products obtained from metal rich effluents, such as Acid Mine Drainage (AMD), when associated with the bioremediation process. Precipitation of metals using sulfide allows for the possibility of selective recovery, as different metal sulfides possess different solubilities. We have evaluated the selective precipitation of CuS, ZnS and FeS as nanosized metal sulfides. Again, we have also tested the precipitation of these metal sulfides in the presence of support structures, such as SiO2. Studies were carried out using both artificial and real solutions in a continuous bioremediation system. We found that this method allowed for a highly selective precipitation of copper and a lower selectivity in the precipitation of zinc and iron, though all metals were efficiently removed (>93% removal). This research has also demonstrated the potential of ZnS-TiO2 nanocomposites as catalysts in the photodegradation of organic pollutants using the cationic dye, Safranin-T, as a model contaminant. The influence of the catalyst amount, initial pH and dye concentration were also evaluated. Finally, the efficiency of the precipitates as catalysts in sunlight mediated photodegradation was investigated, using different volumes of dye-contaminated water (150 mL and 10 L). This work demonstrates that all tested composites have the potential to be used as photocatalysts for the degradation of Safranin-T.
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The Internet and new communication technologies are deeply affecting healthcare systems and the provision of care. The purpose of this article is to evaluate the possibility that cyberhealth, via the development of widespread easy access to wireless personal computers, tablets and smartphones, can effectively influence intake of medication and long-term medication adherence, which is a complex, difficult and dynamic behaviour to adopt and to sustain over time. Because of its novelty, the impact of cyberhealth on drug intake has not yet been well explored. Initial results have provided some evidence, but more research is needed to determine the impact of cyberhealth resources on long-term adherence and health outcomes, its user-friendliness and its adequacy in meeting e-patient needs. The purpose of such Internet-based interventions, which provide different levels of customisation, is not to take over the roles of healthcare providers; on the contrary, cyberhealth platforms should reinforce the alliance between healthcare providers and patients by filling time-gaps between visits and allowing patients to upload and/or share feedback material to be used during the visits. This shift, however, is not easily endorsed by healthcare providers, who must master new eHealth skills, but healthcare systems have a unique opportunity to invest in the Internet and to use this powerful tool to design the future of integrated care. Before this can occur, however, important issues must be addressed and resolved, for example ethical considerations, the scientific quality of programmes, reimbursement of activity, data security and the ownership of uploaded data.
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The number of HIV-infected persons with children and caregiving duties is likely to increase. From this statement, the present study was designed to establish how HIV infected caregivers organise their parenting routines and to determine their support needs. A further aim was to ascertain caregivers' perception of conspicuous behaviours displayed by their children. Finally, it sought to determine the extent to which the caregivers' assessment of their parenting activity is influenced by the required support and their children's perceived conspicuous behaviours. The study design was observational and cross-sectional. Sampling was based on the 7 HIV Outpatient Clinics associated with the national population-based Swiss HIV Cohort Study. It focused on persons living with HIV who are responsible for raising children below the age of 18. A total of 520 caregivers were approached and 261 participated. An anonymous, standardised, self-administered questionnaire was used for data collection. The data were analysed using descriptive statistical procedures and backward elimination multiple regression analysis. The 261 respondents cared for 406 children and adolescents under 18 years of age; the median age was 10 years. The caregivers' material resources were low. 70% had a net family income in a range below the median of Swiss net family income and 30% were dependent on welfare assistance. 73% were undergoing treatment with 86% reporting no physical impairments. The proportion of single caregivers was 34%. 92% of the children were living with their HIV infected caregivers. 80% of the children attended an institution such as a school or kindergarten during the day. 89% of the caregivers had access to social networks providing support. Nevertheless, caregivers required additional support in performing their parenting duties and indicated a need for assistance on the material level, in connection with legal problems and with participation in the labour market. 46% of the caregivers had observed one or more conspicuous behaviours displayed by their children, which indicates a challenging situation. However, most of these caregivers assessed their parenting activity very favourably. Backward elimination multiple regression analysis indicated that a smaller number of support needs, younger age of the eldest child and fewer physical impairments on the part of the caregiver enhance the caregivers' assessment of their parenting activity. Physicians should speak to caregivers living with HIV about their parenting responsibilities and provide the necessary scope for this subject in their consultation sessions. Physicians are in a position to draw their patients' attention to the services available to them.
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These folder contains all the handout material for my Wednesday morning slots.
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Este recurso para el profesor ayuda en la preparación de clases, ofrece ideas para lecciones y actividades basadas en el libro del alumno, así como, material diseñado para maximizar la utilidad del libro del alumno y que, además, puede ser fotocopiado. Cumple con los requisitos exigidos en la materia de Tecnologías de la Información y Comunicación (TIC) para la preparación del General Certificate Secondary Education (GCSE) en el Reino Unido.
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Libro del profesor con material de apoyo al fomento de la lectura en las etapas de educación primaria y educación secundaria (niveles del 2 al 5 del Curriculum Nacional en Inglaterra). Presenta lecturas recomendadas y adaptadas a los distintos niveles educativos y ejercicios relacionados para el reconocimiento de palabras y desarrollo del lenguaje, compresión del lenguaje, y habilidades lectoras y de escritura.
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El foc bacterià és una malaltia que afecta a plantes de la família de la rosàcies, causada pel bacteri Erwinia amylovora. El seu rang d'hostes inclou arbres fruiters, com la perera, la pomera o el codonyer, i plantes ornamentals de gran interès comercial i econòmic. Actualment, la malaltia s'ha dispersat i es troba àmpliament distribuïda en totes les zones de clima temperat del món. A Espanya, on la malaltia no és endèmica, el foc bacterià es va detectar per primer cop al 1995 al nord del país (Euskadi) i posteriorment, han aparegut varis focus en altres localitzacions, que han estat convenientment eradicats. El control del foc bacterià, és molt poc efectiu en plantes afectades per la malaltia, de manera que es basa en mesures encaminades a evitar la dispersió del patogen, i la introducció de la malaltia en regions no endèmiques. En aquest treball, la termoteràpia ha estat avaluada com a mètode d'eradicació d'E. amylovora de material vegetal de propagació asimptomàtic. S'ha demostrat que la termoteràpia és un mètode viable d'eradicar E. amylovora de material de propagació. Gairebé totes les espècies i varietats de rosàcies mantingudes en condicions d'humitat sobrevivien 7 hores a 45 ºC i més de 3 hores a 50 ºC, mentre que més d'1 hora d'exposició a 50 ºC amb calor seca produïa danys en el material vegetal i reduïa la brotació. Tractaments de 60 min a 45 ºC o 30 min a 50 ºC van ser suficients per reduir la població epífita d'E. amylovora a nivells no detectables (5 x 102 ufc g-1 p.f.) en branques de perera. Els derivats dels fosfonats i el benzotiadiazol són efectius en el control del foc bacterià en perera i pomera, tant en condicions de laboratori, com d'hivernacle i camp. Els inductors de defensa de les plantes redueixen els nivells de malaltia fins al 40-60%. Els intervals de temps mínims per aconseguir el millor control de la malaltia van ser 5 dies pel fosetil-Al, i 7 dies per l'etefon i el benzotiadiazol, i les dosis òptimes pel fosetil-Al i el benzotiadiazol van ser 3.72 g HPO32- L-1 i 150 mg i.a. L-1, respectivament. Es millora l'eficàcia del fosetil-Al i del benzotiadiazol en el control del foc bacterià, quan es combinen amb els antibiòtics a la meitat de la dosi d'aquests últims. Tot i que l'estratègia de barrejar productes és més pràctica i fàcil de dur a terme a camp, que l'estratègia de combinar productes, el millor nivell de control de la malaltia s'aconsegueix amb l'estratègia de combinar productes. Es va analitzar a nivell histològic i ultrastructural l'efecte del benzotiadiazol i dels fosfonats en la interacció Erwinia amylovora-perera. Ni el benzotiadiazol, ni el fosetil-Al, ni l'etefon van induir canvis estructurals en els teixits de perera 7 dies després de la seva aplicació. No obstant, després de la inoculació d'E. amylovora es va observar en plantes tractades amb fosetil-Al i etefon una desorganització estructural cel·lular, mentre que en les plantes tractades amb benzotiadiazol aquestes alteracions tissulars van ser retardades. S'han avaluat dos models (Maryblyt, Cougarblight) en un camp a Espanya afectat per la malaltia, per determinar la precisió de les prediccions. Es van utilitzar dos models per elaborar el mapa de risc, el BRS-Powell combinat i el BIS95 modificat. Els resultats van mostrar dos zones amb elevat i baix risc de la malaltia. Maryblyt i Cougarblight són dos models de fàcil ús, tot i que la seva implementació en programes de maneig de la malaltia requereix que siguin avaluats i validats per un període de temps més llarg i en àrees on la malaltia hi estigui present.
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Materials used in current technological approaches for the removal of mercury lack selectivity. Given that this is one of the main features of supramolecular chemistry, receptors based on calix[4]arene and calix[4]resorcarene containing functional groups able to interact selectively with polluting ions while discriminating against biologically essential ones were designed. Thus two receptors, a partially functionalized calix[4]arene derivative, namely, 5,11,17,23-tetra-tert-butyl [25-27-bis(diethyl thiophosphate amino)dihydroxy] calix[4]arene (1) and a fully functionalized calix[4]resorcarene, 4,6,10,12,16,18,22,24-diethyl thiophosphate calix[4]resorcarene (2) are introduced. Mercury(II) was the identified target due to the environmental and health problems associated with its presence in water Thus following the synthesis and characterization of 1 and 2 in solution ((1)HNMR) and in the solid state (X-ray crystallography) the sequence of experimental events leading to cation complexation studies in acetonitrile and methanol ((1)H NMR, conductance, potentiometric, and calorimetric measurements) with the aim of assessing their behavior as mercury selective receptors are described. The cation selectivity pattern observed in acetonitrile follows the sequence Hg(II) > Cu(II) > Ag(I). In methanol 1 is also selective for Hg(II) relative to Ag(I) but no interaction takes place between this receptor and Cu(II) in this solvent. Based on previous results and experimental facts shown in this paper, it is concluded that the complexation observed with Cu(II) in acetonitrile occurs through the acetonitrile-receptor adduct rather than through the free ligand. Receptor 2 has an enhanced capacity for uptaking Hg(II) but forms metalate complexes with Cu(II). These studies in solution guided the inmobilization of receptor 1 into a silica support to produce a new and recyclable material for the removal of Hg(II) from water. An assessment on its capacity to extract this cation from water relative to Cu(II) and Ag (I) shows that the cation selectivity pattern of the inmobilized receptor is the same as that observed for the free receptor in methanol. These findings demonstrate that fundamental studies play a critical role in the selection of the receptor to be attached to silicates as well as in the reaction medium used for the synthesis of the new decontaminating agent.
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The thesis Distance learning and didactic material: a study about the course Media in the education in Natal shows a research about the didactic material and its insertion in the distance training course to teachers. In this sense, this research aims to contribute to some universities with reflections about the way to elaborate the didactic material to the distance training course of teachers with the following specific objectives: a) identify some aspects in the didactic material in the extension course Media in the Education that difficult media usage by the teachers members of the course in the pedagogical practice; b) discuss about the way how didactic material to the distance training course to teachers has been created; c) stimulate teachers/members to integrate media in their teacher practice. For that reason, we have developed an action-research (THIOLLENT, 2011; FRANCO, 2005), based on it we elaborated a proposal do complement activities to the course Media in the Education that were applied to two classes during the fifth edition of this course. This research is presented in four steps: 1st) analyze of the course modules; 2nd) creation of a proposal to complement the activities; 3rd) applying the proposal to the students during the fifth edition to the course; 4th) analyze of forums and log books written by teachers/students. Data was analyzed by the contents perspective of Bardin (2011). As a theoretical support, we have Tardif (2012), about teachers knowledge; Dewey (1959; 2011) and Freire (2001; 2009; 2010a; 2010b; 2012) related to learning perspective; Candau (2002), Rays (2003) and Freire (2010a), about the relation theory x practice in the teacher training; Andrade (2003; 2009) and Belloni (2010) about distance teacher training; Bérvot; Belloni (2009), Neves; Medeiros (2005) and Prado (2005), related to Media integration. This research revealed the didactic material of the course Media in the Education has not a proposal to articulate theory and practice, due to this, this course opposed the Media integration. For that reason, teachers/members have real problems to integrate Media in their scholar routine. This research confirmed the way this didactic material was formulated did not help the teachers/students to integrate media in their pedagogical activities
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Use of natural fibres as a reinforcement material in the manufacture of composites show a series of advantages: availability, biodegradability, low weight and regeneration in relation to synthetic fibres, thus justifying its utilization. In the present research work, composites were developed with chicken feathers (KF), using unsaturated polyester resin as matrix, for diversified applications, mainly in the furniture/timber industry.At present, in Brazil the chicken feathers are used as part of the animal feed, even though this material possesses low aggregated value. The chicken feathers are hollow, light and resistant. After washing with water at room temperature, a part of the chicken feathers were treated with 2% NaOH. Composites were manufactured using treated and untreated chicken feathers with unsaturated orthothalic polyester resin and 1% peroxide as catalyser, obtained in the commerce. Samples with size 150x25x3 mm for mechanical tests were cut by laser in the composite plate. Mechanical analyses were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN. All the analyses were in accordance with ASTM standards. SEM analyses were also carried out on the samples.In the analyses of the results obtained, it was observed that the composites made with untreated chicken feathers showed better results (Traction 11.406 MPa and 9.107 MPa Bending 34.947 and 20.918 MPa for samples with and without treatment respectively) compared to the composite with treated feathers. Very low values of the water absorption results, evidenced the impermeability characteristic of the feathers. From the SEM images, the structure, fracture and the fibre/matrix adsorption can be evidenced. In the flammability test, it was observed that despite the feathers having sulfur as a constituent, natural inhibitor of flame, no burning support of the composites, because the manufacturing process of the composite
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The nucleolar material of Chariesterus armatus was analyzed during spermiogenesis in cell preparations impregnated with silver nitrate. Nucleolar corpuscles were observed in spermatids at the beginning of the process, showing that this organoid is also maintained after meiosis. In addition, nucleoli were seen in the round spermatids connected to the X-chromosome (bearer of the nucleolar organizer in C. armatus), indicating de novo synthesis of nucleolar material. This differs from the reorganization of ribosomal granules, transported from meiotic spermatocytes to round spermatids, where they would support protein synthesis, which is reported for other species. We also observed connections of nucleolar corpuscles to the nuclear membrane regions where the tail and the acrosome will be formed, suggesting close involvement of the nucleolar material in the formation of these structures. In addition to the nucleolar bodies, we detected silver-positive structures, which will require new approaches to clarify their role. One of these structures, observed in the cytoplasm, appears to correspond to the chromatoid body, which has been found in several organisms, but is still poorly understood; another is a complex structure to which the tail appears to be connected. We conclude that C. armatus is an appropriate model for understanding not only the synthesis of rRNA in the spermiogenesis, but also the functional meaning of the close relationship of nucleolar material with other structures during this process.
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Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters. © 2013 Elsevier Ltd.
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This work describes the influence of the preparation method and the carbon support using a low contentof cerium oxide nanoparticles (CeO2/C 4%) on H2O2electrogeneration via the oxygen reduction reac-tion (ORR). For this purpose, the polymeric precursor (PPM) and sol-gel (SGM) methods with Vulcan XC72R (V) and Printex L6 (P) supports were employed. The materials were characterized by X-ray diffrac-tion (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). TheXRD analysis identified two phases comprising CeO2and CeO 2-x. The smallest mean crystallite size wasexhibited for the 4% CeO2/C PPM P material, which was estimated using the Debye-Scherrer equation tobe 6 nm and 4 nm for the CeO2and the CeO 2-xphases, respectively, and was determined by TEM to be5.9 nm. XPS analysis was utilized to compare the oxygen content of the 4% CeO2/C PPM P to Printex L6.The electrochemical analysis was accomplished using a rotating ring-disk electrode. The results showedthat the 4% CeO2/C specimen, prepared by PPM and supported on Printex L6, was the best electrocatalystfor H2O2production in 1 mol L -1NaOH. This material showed the highest ring current, producing 88%H2O2and transferring 2.2 electrons per O 2molecule via the ORR at the lowest onset potential. Addition-ally, the ring-current of the 4% CeO2/C PPM P material was higher than that of Vulcan XC 72R and PrintexL6, the reference materials for H2O 2production, indicating the highest electrocatalytic activity for the 4%CeO2/C PPM P material. © 2013 Elsevier Ltd. All rights reserved.
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Pós-graduação em Educação - IBRC