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Avaliação do comportamento mecânico de nanocompósito de PEEK/nHA sob curta e longa duração para aplicação como biomaterial
(Universidade Federal de São Carlos, 2012-04-27) Rego, Bruna Turino; Bretas, Rosario Elida Suman; https://lattes.cnpq.br/2805349172281345; https://lattes.cnpq.br/3217820661976976
The main objectives of this dissertation were to study the short (tensile and impact) and long-term (fatigue) mechanical behavior of nanocomposites of poly(ether-ether-ketone), PEEK, with nanohydroxyapatite, nHA, for application as biocompatible materials. First of all, a preliminary study was conducted to determine the influence of the addition of nHA in the rheological, thermal and dynamic mechanical properties of PEEK, in order to choose an optimal formulation for large-scale preparation. The chosen composition with 10wt% of nHA was prepared by melt mixing in a co-rotating twin screw extruder. The resulting structure and dispersion were characterized by scanning electron microscopy (SEM) and rheological properties. Subsequently, the materials (PEEK and PEEK/nHA nanocomposite) were injection molded at 3 different conditions by varying the flow rate. The resulting morphologies were evaluated by polarized light optical microscopy (PLOM) and the degree of crystallinity of the samples was evaluated by differential scanning calorimetry (DSC) and wide angle X-ray scattering (WAXS). The mechanical properties of tensile, impact and fatigue of PEEK and nanocomposite were measured and correlated with the results of dynamic mechanical thermal analysis (DMTA) and the resulting morphology. It was found that the variation of the injection conditions did not change the materials properties significantly; however, the obtained long and short-term mechanical properties of the nanocomposite were within the range of cortical bone properties and, therefore, the nanocomposite can mechanically be used for medium load bearing implant applications, due to their limited modulus. Finally, tests with adult stem cells to determine in vitro biological response of the biomaterial were performed, which indicated that these cells proliferated faster in PEEK/nHA, indicating that the biological response is most favorable to the nanocomposite than to pure PEEK.
Influência da orientação corporal no desenvolvimento do controle de cabeça de lactentes
(Universidade Federal de São Carlos, 2012-04-27) Lima-Alvarez, Carolina Daniel de; Tudella, Eloisa; https://lattes.cnpq.br/3207258034860219; https://lattes.cnpq.br/4144337339534625
Head movements play an important role in typical motor development because they form the basis for the emergence of fundamental motor skills such as reaching and sitting. In addition, the head is the first part of the body to develop antigravity control, and serve as a frame for the organization of postural control. The aims of this longitudinal study were: 1) to provide information about the behavioral (frequency of head movement; proportion of head initial position to the right, left and midline; proportion of movement type sideto- midline, midline-to-side and side-to-side) and kinematics (amplitude of head movement: flexion, inclination and rotation; duration of the movement; mean angular velocity; peak velocity; deceleration index; number of movement unit; number of movement unit after peak velocity; mean duration of movement unit; mean duration of movement unit after peak velocity; duration of the longest movement unit) changes during the acquisition of head control in supine position; 2) to verify and to describe the age-related changes observed in the spatial-temporal organization of the head movement; 3) to verify e if different body orientations (unsupported supine; supported supine head supported and semi flexed approximately to 15° over an infant pillow; and supported reclined- head supported and semi flexed approximately and the body reclined to 20° with the horizontal plane) and if external head support can improve the alignment between head and trunk, thus turning the head movement more controlled and 4) to verify if the body orientation can facilitate the head movement in younger infants (from birth to two months), as they head movement are not as controlled as older infants. To this end, 17 infants were longitudinally assessed once a month. They were presented with a black and white card that was moved sideward in front of their face in all the conditions (unsupported supine, supported supine and supported reclined. Results of study 1, focused in the age-related effect of head movement showed that with age, particularly from two months onwards, the head was more often held at body midline. A larger amount of head movements and an increase in amplitude and speed of the head movement accompanied this change between two and three months. Kinematic analysis also showed that head movements were organized in movement units that increased in number until three months of age, but significantly decreased afterwards (especially the number of movement units after peak velocity). The results about body orientation manipulation, study 2, showed that the behavioral and kinematic analyses in the supported supine and supported reclined conditions, showed an increase in the proportions of head positions at the body midline and midline-to-side head movements in comparison to the unsupported supine condition. Further, a lower mean angular velocity and a prolonged duration of the head movement and its constituent movement units (including the longest movement unit) were observed in the supported supine and reclined conditions. The results suggest that the velocity profile became more symmetrical with age, especially after two months-old onwards, which is indicative for better and more efficient control of the head movements. Importantly, many of the differences only occurred when infants were younger than three months of age. In sum, vii the head movement became more fluent and well-organized through age, especially after three months. The external support of the head led to an improvement in the alignment of head and trunk, which promoted better-controlled head movements, especially in the younger infants. This suggests that neck muscle strength is an important limiting factor in the development of head movements.
Toxicidade do cádmio em uma cadeia alimentar constituída por uma microalga (Scenedesmus quadricauda), um cladócero (Simocephalus serrulatus) e um peixe (Hyphessobrycon eques)
(Universidade Federal de São Carlos, 2012-04-27) Souza, Jaqueline Pérola de; Melão, Maria da Graça Gama; https://lattes.cnpq.br/8342306603661310; https://lattes.cnpq.br/2320506014760329
The effects of trace metals contamination in aquatic environments are of concern in the ecotoxicological point of view. In these environments the organisms are exposed to metals in the dissolved form and also through ingestion of contaminated food in the food chain. The phytoplanktonic organisms are the basis of food chains and are responsible for primary productivity. Zooplankton is a link between primary producers and higher trophic levels, such as fish. The exposure of these organisms to metals will cause changes in the physiology, affect productivity rates, and the balance and dynamics of aquatic communities. This study evaluated the effects of the metal cadmium (Cd) on an experimental freshwater food chain involving the algae Scenedesmus quadricauda, a cladoceran daphinidae, Simocephalus serrulatus, and the fish Hyphessobrycon eques. Cultures of S. quadricauda in exponential phase growth were exposed to 1.6x10-9; 3.2x10-8; 6.7x10-8; 1.6x10-7 and 1.3x10-6 mol L-1 of total dissolved Cd for 96 h. During exposure chlorophyll "a", population growth, coenobia size, and dry biomass were evaluated. Then the contaminated algae were given as food to the zooplankton S. serrulatus during the complete life cycle of the organisms in the concentration range of 3.8x10-14 to 5.9x10-12 g Cd cell-1. During the exposure the embryonic development time, age at first reproduction, time for egg production, generation time, longevity, fertility rates, feeding rates, secondary production, and recovery of the animals were evaluated. Then the cladocerans reared with Cd contaminated algae were used as food for the fish H. eques duruing a period of seven days. At the end of this exposure, we evaluated the histological structure of gills and liver, and the fresh weight of the animals. In S. quadricauda, there were damages on the chlorophyll content, and in the population growth at high concentrations of the metal. In the cladocerans were detected increase of the embryonic development time, age at first reproduction, and generation time, whereas a decrease of the longevity, fertility rates, feeding rates, and secondary production. The rate of secondary production showed recovery after removal the contaminated food. The histological patterns of gills and liver, as well as the fresh weight of the fish were not affected by the Cd exposure tested through the food chain considering the exposure period and concentrations tested. The results indicated that food can be considered an important vehicle in the Cd transfer from phytoplankton to zooplankton in aquatic food webs. Cd has a high potential for toxicity, impacting the producers and primary consumers. However, no Cd effects to the fish, the third trophic level, were detected. These studies are of great importance for understanding Cd behavior in aquatic environments, as well as its toxicity to the organisms. The understanding of these aspects contributes to adaptation strategies for the conservation of aquatic ecosystems in situations of contamination.
Imersões isométricas em produtos de duas formas espaciais
(Universidade Federal de São Carlos, 2012-04-27) Santos, Bruno Mendonça Rey dos; Figueiredo Junior, Ruy Tojeiro de; https://lattes.cnpq.br/9930999514347198; https://lattes.cnpq.br/0482550420604550
In this thesis we study isometric immersions into products of two space forms using the approach introduced by Lira et al in [18]. Parallel isometric immersions into products of two space forms with nonzero sectional curvatures are classified, and the classification of umbilical isometric immersions f : Mm Ñ On1 k1 _ On2 k2 , with m ¥ 3 and k1 􀀀 k2 _ 0, is reduced to that of umbilical isometric immersions of codimension two into On k _ R, k 0, where On k denotes the space form with dimension n and sectional curvature k. To accomplish this, we prove some results of independent interest on reduction of codimension of isometric immersions into products of two space forms.
Inovações na síntese enzimática de amoxicilina
(Universidade Federal de São Carlos, 2012-04-27) Pereira, Sandra Cerqueira; Giordano, Roberto de Campos; https://lattes.cnpq.br/9585582276164819
Penicillin G acylase (PGA, E.C.3.5.1.11) from Escherichia coli is an enzyme of great industrial importance, widely used for the hydrolysis of penicillin G, producing the 6-aminopenicillanic acid (6-APA), which is a key molecule for the synthesis of semi-synthetic penicillins. Among them, amoxicillin has a broad spectrum of activity against a variety of bacteriological infections. Industrially, amoxicillin is produced by chemical processes, which require drastic reaction conditions, several steps of protection and deprotection of reactive groups in order to prevent non-selective hydrolytic reactions, use of organochloride solvents with non-recyclable waste generation, which are toxic and harmful to the environment. The enzymatic synthesis is a more attractive alternative from the environmental point of view and economic. The tendency of the pharmaceutical industry is the development of enzymatic methods to produce these β-lactam semi-synthetic antibiotics, including amoxicillin. Nevertheless, a major obstacle to its industrial implementation is the limited yield, as a consequence of undesirable hydrolytic side-reactions, which lead to the formation of the by-product (p-hydroxyphenylglycine, POHPG) throughout the course of the reaction. This drawback can be partially avoided by reducing the water activity (aw) in the medium. For this purpose, ionic liquids (ILs) have emerged as an alternative to conventional organic media due to their high thermal and chemical stability, non-flammability, easy recycling, and negligible vapor pressure. Within this context, this work researched the development of an integrated green process for the recovery, reuse and recycle of the by-product (POHPG) of the kinetically controlled enzymatic synthesis of amoxicillin, employing PGA immobilized on Sepabeads® in a totally aqueous medium reaction (sodium phosphate buffer 100 mM, pH 6.5), and assessed the catalytic activity of this biocatalyst in the presence of different ILs as cosolvents for these synthetic reactions, in terms of selectivity (synthesis/hydrolysis, S/H ratio) and conversion of the substrate 6-aminopenicillanic acid (6-APA). The recovery of the by-product (POHPG) of the kinetically controlled enzymatic synthesis of amoxicillin in a totally aqueous reaction medium was done efficiently, achieving a final purity of 99% for the POHPG, which was successfully reused for the production of the substrate p-hydroxyphenylglycine ethyl ester (POHPGEE), achieving a conversion of 93%. Then, POHPGEE was recycled to the reactor (without any further purification) for another batch of enzymatic synthesis of amoxicillin, following the characteristic profile that is expected for these synthetic reactions. This integrated green process generated sodium chloride (NaCl) as waste, which is an inert and harmless salt. Moreover, the assessment of the use of ILs as cosolvents for the reactions of kinetically controlled enzymatic synthesis of amoxicillin presented promising results. An increase of 400% in the selectivity was observed for the reactions carried out in the presence of 1-butyl-3-methylimidazolium hexafluorophosphate (BMI.PF6), as cosolvent at a concentration of 75% (VIL/VWATER) in relation to the standard reaction performed in totally aqueous medium. Similarly, this figure reached more than 350% for reactions conducted in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI.NTf2) at the same volume fraction, while for 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) there was only a slight increase in selectivity (about 57%). The highest conversion of 6-APA was achieved using BMI.NTf2 as cosolvent at a concentration of 71% (VIL/VWATER), representing an increase of more than 36% compared to standard aqueous reaction. No deactivation of the enzyme was observed after the reactions in any of the ILs, and the physical integrity of the biocatalyst particles was entirely maintained. The results of this work collaborated for the advance in the study of the enzymatic synthesis of semi-synthetic penicillins through the use of technologies more green .
Estudo nutricional e sensorial de açúcares cristal, refinado, demerara e mascavo orgânicos e convencionais
(Universidade Federal de São Carlos, 2012-04-27) Faria, Daiara Aparecida Mendes; Verruma-Bernardi, Marta Regina; https://lattes.cnpq.br/3470912236544684; https://lattes.cnpq.br/3084939323677190
This study aimed to evaluate the nutritional and sensory quality of different types of sugars, were analyzed for both the physico-chemical and sensory analyzes of eight samples of sugars including conventional and organic. The samples of sugars were analyzed for pH, moisture, polarization, amino acids, reducing sugar, conductivity ash, ICUMSA color, phenolics, turbidity, minerals and heavy metals. We used the Quantitative Descriptive Analysis (QDA) with 15 trained judges and 30 judges to evaluate the visual preference and 21 panelists for the preference, color and sweetness of orange juice sweetened with sugars under study. A study was made of the profile and consumer behavior in relation to sugars. The results showed that the brown sugar had lower levels of Pol, to the ash content samples of raw sugar and brown sugar D G values were higher than in relation to others; samples of organic sugars (D and G) were Ca and Fe greater than conventional. As the descriptive analysis, the aroma and sweet flavor and darker color were higher in organic samples. The schooling interfere with the visual preference and understanding of the concept of organic product and its cost and brand.
Mulheres migrantes no contexto das fronteiras de gênero e arranjos familiares
(Universidade Federal de São Carlos, 2012-04-27) Angelin, Paulo Eduardo; Truzzi, Oswaldo Mário Serra; https://lattes.cnpq.br/5005536921435787; https://lattes.cnpq.br/8537328900369894
The objective of this research was to understand the trajectories of migrant families and, especially, the life trajectories and social roles assigned and represented in society and specifically in the processes of migration, women migrants and northeastern Paraná, living in a neighborhood of the city of São Carlos, São Paulo, called city Aracy, always considering the origin, the regional culture, socioeconomic status and family arrangements. For the achievement of this study were performed in a first phase, conversations with authors who discuss the theme of migration, whether international or domestic were performed. A dialogue with theorists who portray the issue of gender, male domination and sexual division of labor, as well as authors who address the notion of family arrangements was also made. Finally, we worked with authors who discuss women's participation in migratory flows and the coordination and mobilization of kinship networks. Then, through qualitative research, interviews were conducted with 33 migrant women, using a guide and semi-structured individual interviews, which was built as advanced research and theoretical literature. The research shows that women migrants women in question, according to the socio-cultural and family, play different social roles. Family and living arrangements decisively influence the representation of these social roles. But other factors such as the origin, regional culture, the weather conditions and socioeconomic status, may influence these representations, to the point of women from the same family arrangement, act differently in society in general and in the migration process.
Formação de mesoporosidade em zeólitas ZSM-5: avaliação do método de preparação e do potencial como catalisador ácido através do craqueamento de cicloexano
(Universidade Federal de São Carlos, 2012-04-27) Silva, Edilene Deise da; Urquieta-González, Ernesto Antonio; https://lattes.cnpq.br/3672771633840838; http://lattes.cnpq.br/2389975677904655
Due to their potential as acid catalyst and hydrothermal stability, USY, ZSM-5 and modernite zeolites are widely used in several processes of petroleum refining and petrochemical industries. With the discovery of new reserves in Brazil, the petroleum industry must adequate its technology to be able to process heavy oil fractions and satisfy the increased demand for more valuable derivatives (gasoline, diesel and olefins). To achieve this, a better performance of such zeolites needs to be reach by improvement of the active sites accessibility and/or diminishing the diffusion path inside of their microporous system. In this context, the objective of this research was to synthesize ZSM-5 zeolites with hierarchical pore structure and evaluate their potential as acid catalyst in the cracking of hydrocarbons, using cyclohexane as model molecule. In the synthesis of these materials, Black Pearls 2000 carbon and an organosilane surfactant molecule were employed as structure-directing agent for mesopores formation. Zeolites were characterized by X-ray fluorescence, X-ray diffraction, nitrogen physisorption, small-angle X-ray scattering, scanning electron microscopy, nuclear magnetic resonance of 27Al nucleus, Fourier transformed infrared spectroscopy and ammonium temperature programmed desorption. The properties and acid activity of the synthesized zeolites were compared with a ZSM-5 zeolite without mesopores. The results revealed that the used synthesis methodologies were effective in the formation of crystals of ZSM-5 zeolite containing the intrinsic micropores of the MFI structure combined with the presence of intracrystalline mesopores. The Black Pearls 2000 carbon generated mesopores that were an inverse replica of the carbon particles with an average diameter of 12 nm and the amphiphilic surfactant mesopores with diameters of about 4 nm. The cracking of cyclohexane showed that the solids with hierarchical structure of pores preserved the acid potential of ZSM-5 zeolites, with all the micro-mesoporous zeolites presenting similar catalytic behaviour related with the yield and selectivity in the considered reaction. Other hand, the presence of mesopores favoured the formation of products resulting from isomerization and hydrogen transfer reactions.