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Extração de cefamicina C por sistema de duas fases aquosas e purificação por troca iônica
(Universidade Federal de São Carlos, 2013-04-26) Brites, Luciana Machado; Pasotto, Marlei Barboza
Cephamycin C is a β-lactam antibiotic that belongs to the cephalosporins. This antibiotic stands out from other cephalosporins because it has activity against gram-negative bacteria and for being resistent to β-lactamases produced by pathogenic microorganisms, and which represent one of the major mechanisms of bacterial resistance to β-lactam antibiotics. In view of the restricted information in the literature about the steps of the process, both from the point of view of research and of industrial production of cephamycin C, the study about its production and, consequently, the process of separation and purification becomes of great importance. Therefore, the main objective of this work was to develop a separation and purification process of cephamycin C from a fermentation broth produced by cultivations of Streptomyces clavuligerus in aired submerged processes. Extraction and separation processes of cephamycin C were performed by means of an aqueous two-phase system (ATPS) and ionexchange chromatography, respectively. Initially, studies on the stability of cephamycin C were performed in order to allow the establishment of conditions which minimize losses and increase the yield of the global process. In these studies, conditions at pH levels of 2.2, 3.0, 5.0, 6.0, 7.0, 7.6 and 8.7 at a temperature of 20 °C were evaluated. The smallest half-life was of 52.6 hours and was verified for pH 8.7; the longest half-life was of 459 hours for pH 6.0; and for the most acid pH (2.2), half-life was of 118.2 hours. The second step of the work was the study of the separation of cephamycin C and amino acids with the aqueous two-phase system composed by PEG/phosphate. The presence of ornithine, lysine and asparagine amino acids in the fermentation broth, even after the primary separation steps performed by filtration processes consisting of microfiltration and ultrafiltration, is due to the composition of the culture medium which is of complex origin. The experiments were carried out by varying the following parameters: molecular mass of PEG (400, 600, 1000 and 4000), pH (6, 7 and 8), tieline length (TLL 37 and 43) and phase volume ratio (rTLL 0.75, 1.00 and 1.25), in order to enable the determination of the best system for cephamycin C extraction. The best conditions obtained for this process were pH 8, PEG 400, TLL 43 and rTLL 1.00, where the highest partition coefficient, kp of 5.57, was acquired. For the separations of cephamycin C and the amino acids present in the broth, it was possible to verify the following separation efficiencies: 3.4 (ornithine), 6.9 (lysine) and 2.8 (asparagine). The last step of the work showed that it is possible to recover cephamycin C from the PEG phase promoting an even greater purification with the residual amino acids. The ion-exchange chromatography was used to propose so. For this proposal, we used the ion exchange chromatographic technique, with use of anionic resin Amberlite IRA 400. These experiments were performed under temperatures of 20, 25 and 30 °C and pH 2.8 and 6.8. The Amberlite IRA 400 Cl- resin showed affinity for cephamycin C, and in the experiments in fixed bed column, it was possible to separate cephamycin C from PEG, from the phosphate salt and from the amino acids present in the top phase. The results allowed the conclusion that the proposed process is an excellent alternative for the extraction, separation and purification of cephamycin C.
Redução de NO com CO sobre catalisadores de CuO, Fe2O3 e CuO-Fe2O3 suportados em TiO2, ZrO2 e TiO2-ZrO2 - efeito do vapor de água na atividade e seletividade a N2
(Universidade Federal de São Carlos, 2013-04-26) Nova Castelblanco, William; Urquieta-González, Ernesto Antonio; https://lattes.cnpq.br/7977413455765851; http://lattes.cnpq.br/2389975677904655
The combustion of petroleum fuels produces large emissions of NOX, SOX and other strong atmospheric pollutants. The abatement of NOX can be achieved by the nonselective catalytic reduction of NO with CO, for that, supported noble metals have been the most commonly used, with high cost as disadvantage. Transition metal oxides show good activity for this reaction, however, they have poor performance in the presence of SO2, O2 and water steam. Thus, this study aimed to prepare, characterize and evaluate catalysts based on CuO, Fe2O3 and CuO-Fe2O3 supported on TiO2, ZrO2 and their mixtures, in the reduction of NO to N2 with CO in the presence or absence of water steam. XRD data, N2 adsorption and H2-TPR showed that mixed oxides and their catalysts, prepared by sol-gel in-situ, presented specific surface areas between 30 to 60 m2/g, with Cu or Fe species highly distributed, having the last greater interaction with titanium. Rietveld refinement showed preferential formation of zirconium titanate, then showing a close interaction of these species in the mixed supports. All catalysts were highly active in the reduction of NO to N2. At temperatures below 500 °C a CuO catalysts were more active and selective for the formation of N2 than Fe2O3, with the formation of N2O being favored with the increase of zirconium in the support. At 600 °C, the high conversion of NO to N2 on CuO was not influenced by the content of TiO2 in the support. Also at 600 °C, an increasing in the content of titanium in the Fe2O3 catalysts resulted in a significant drop in the conversion of NO to N2. The presence of water steam during the reduction of NO with CO at 600 °C caused a significant decrease in the conversion of NO to N2 and CO to CO2 on the CuO catalyst on the support with higher titanium content. The water steam completely eliminates the activity for the reduction of NO to N2 on Fe2O3 catalysts, but keeping a high conversion of CO to CO2. The CuO and CuO-Fe2O3 catalysts on zirconium-rich supports showed high potential for the abatement of NOX in the presence of water steam at temperatures above 500 ºC.
Avaliação de técnicas com plasma acoplado indutivamente para a determinação de constituintes inorgânicos no ciclo produtivo do frango de corte e iodo em sal de cozinha
(Universidade Federal de São Carlos, 2013-04-26) Dionísio, Amália Geíza Gama; Nóbrega, Joaquim de Araújo; https://lattes.cnpq.br/8833989058164529; https://lattes.cnpq.br/7413783656311087
The aim of this thesis was the development of procedures for the determination of total arsenic, selenium and chromium in chicken production-related samples and iodine in table salt using inductively coupled plasma methods. The chemical speciation of arsenic and chromium was also studied. In the first study, microwave-assisted digestion was performed using diluted nitric acid solution followed by determination using inductively coupled plasma mass spectrometry (ICP-MS) with a collision-reaction interface. In this procedure sample preparation was performed using microwave-assisted digestion with nitric acid for determinations of the elements. The second procedure was performed microwave-assisted digestion using reaction vessels pressurized with oxygen in order to regenerate nitric acid and increase the efficiency of digestion with the addition of an auxiliary reagent. Residual carbon contents determined in digests varied from 500 to 900 mg L-1. Afterwards, speciation analysis was applied for obtaining information about mobility, bioavailability and essentiality of arsenic and chromium. Thus, the speciation analysis of arsenic in chicken feed samples employing microwave-assisted extraction was investigated. The specie found was As(V) with concentration of 0.35 ± 0.06 mg kg-1. In another study, chromium speciation with sample preparation in alkaline medium was evaluated, since studies in literature showed that no interconversion occurs between Cr(VI) and Cr(III) in alkaline medium. This procedure was performed using water-soluble tertiary amines solution (CFA-C 10% v v-1) for Cr(VI) determination. The concentration of Cr(VI) in the samples ranged from 8.09 to 10.56 mg kg-1. Finally, the improvement of the sensitivity in the determination of iodine by inductively coupled plasma optical emission spectrometry (ICP OES) using the flow-blurring® multinebulizer was evaluated. The high ionization energy of iodine implies in a low ionization of this element in the argon plasma and the absorption of radiation in the VUV region by components of air, such as oxygen and water vapor, hamper this element determination by ICP OES. One alternative for improving the efficiency of nebulization and atomization of the analyte and hence the detection limits for the determination of iodine is the generation of volatile species (I2 or HI) employing oxidizing agents and reducing agents. This study was performed using sodium tetrahydroborate in alkaline medium (reducing agent) and hydrogen peroxide (oxidizing agent) in acid medium and flow-blurring® multinebulizer. The concentration of iodine in one salt sample was 131 mg kg-1.
Influência do haleto/pseudohaleto na catálise de hidrogenação por complexos do tipo cis- [Ru(A)2(dppb)(N-N)]
(Universidade Federal de São Carlos, 2013-04-26) Ribeiro, Murillo Cardoso; Batista, Alzir Azevedo; https://lattes.cnpq.br/6469642481998660; https://lattes.cnpq.br/4768550929014572
THE INFLUENCE OF HALIDE/PSEUDOHALIDE IN HYDROGENATION CATALYSIS BY COMPLEX CIS-[RU(A)2(DPPB)(N-N)]. Ruthenium complexes, with general formula cis-[Ru(A)2(dppb)(N-N)], (A = pseudohalides CN-, N3 - e SCN-) were obtained from the respective precursors cis- [RuCl2(dppb)(N-N)] {N-N= 2,2’- bipiridine (bipy), 4,4’-dimetil-2,2’-bipiridine (Mebipy) and 4,4’-dimetoxi-2,2’-bipiridine (MeObipy)} and dppb = 1,4-bis(difenilfosfina) butane, and characterized. These new Ru(II) complexes were characterized by analytical and spectroscopical techniques, such as Absorption Spectroscopy in the Infrared Region (IV) and Ultraviolet/Visible (UV/Vis), Nuclear Magnetic Ressonance (RMN), Molar Conductivity, X-ray Diffraction, Elemental Analisys, Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Catalytic studies were realized on cyclic hexene hidrogenation reaction using complexes with general formula cis-[RuCl2(dppb)(N-N)], for which the results have shown to be dependent of the utilized solvent in the process. In order to support data for a possible suggestion of and catalytic mechanism of the reaction involved in the process complexes containing pseudohalides were also studied in the same conditions. The fact that these complexes did not present catalytic activity is coherent with the inert properties of the pseudohalide complexes, with respect their dissociation from the Ru(II) center, considering their good π receptor properties, able to form strong bond with metallic centers, and also shown that during the catalytic cyclic the bidentate ligands (dppb and N-N) do not have their binding with the metal broken, which could allow the formation of a possible coordination center for the metal, able do bind the substrate, conducting to a catalytic process, which was not observed in these cases. The results obtained in the studies realized with the complexes cis-[RuCl2(dppb)(N-N)] allowed us to suggest that the substrat convertion follow two different pathways, depending of the used solvent in the process to be protonic and coordinating, but labile (alchools) or non coordinating (dichloromethane or acetone). Strong coordinating solvents, such as DMSO and CH3CN (S) did not present catalytic results, suggesting that the dissociation of the chloride from the complexes produce non catalytic species, such as cis-[RuCl(S)(dppb)(N-N)]Cl.
Descrição da rede de saúde de São Carlos, SP, por meio de um estudo de caso sobre a experiência de uma pessoa afetada pelo câncer
(Universidade Federal de São Carlos, 2013-04-26) Villari, Ana Paula Silva; Souto, Bernardino Geraldo Alves; https://lattes.cnpq.br/7264826508407685; https://lattes.cnpq.br/5653207121617914
This study had the objective to discourse about the integrality of Sao Carlos-SP county care network, from the experience of a person with cancer, by means of a case study. From the narrative of subject's focal it has been done the triangulation of respective findings interviewing other two people identified as strategic for reaching mentioned objective, therefore appointed as units of analysis of subject s focal. It has been detected that local Health Care System of São Carlos-SP is under a transition process seeking for a model that proposes expanded and integral care for everyone without distinction. This system currently is overloaded and slow, facing attendance quality problems and discomfort of management responsible, care employees personal and health care system user. In order to overcome these problems, it will be necessary investment on Family Strategic Health program, practice of attendance humanization and health care professional qualification. It will also be necessary to increase the installed capacity, qualify the regulation strategic, improve the communication between management and attendance professionals, organize a care network oriented by care lines and agree on Health System building process with users and professional team.
Avaliação da relação entre as queixas e os agravos à saúde dos cortadores de cana de açúcar que buscam atendimento médico em serviço público de emergência (estudo de caso realizado em município da região de São José do Rio Preto SP)
(Universidade Federal de São Carlos, 2013-04-26) Custodio, Wilson José; Alves, Francisco José da Costa; https://lattes.cnpq.br/9183120186518337
This work aims to perform the analysis of complaints made by workers within the sugar cane cutting business and their correlation with clinical outlook during the emergency care in a public health unit and its relationship to work in the cane. The results found from the survey of the medical records, the laboratory tests, and the interviews with the workers, present the relationships between diagnoses and characteristics of the work process, in addition to determining the absence of care protocol directed to such worker, whom does not find in the public health system of which it is to him constitutionally guaranteed. The disorders related to the work/health relationship and the conditions found that it should allow for redemption of its homeostasis are presented here in order to provoke thought about this dissonance.
Narrativas de professores de inglês de escolas públicas e o seu caráter revelador
(Universidade Federal de São Carlos, 2013-04-26) Geraldo, Carla Cristiane; Silva, Ademar da; https://lattes.cnpq.br/9028512631572133; https://lattes.cnpq.br/4571478922761841
The aim of this study was to analyze narratives of English language teachers from public schools in São Carlos and Araraquara from the 1950s to 2012, so as to understand the changes that have occurred in the teaching of that language in public schools that led to the crisis it faces nowadays. This crisis is related to school violence, to widespread disaffection, and to dissatisfaction and low self-esteem of students, teachers and school leaders. The methodology used for data collection was the oral history of the teachers career paths. The data was analyzed qualitatively, allowing a panoramic view of the changes that have occurred in the teaching of English over the last 60 years. The analysis of the narratives revealed that the crisis results from a long historical process of changes, where two huge forces have affected negatively the pedagogical and social/personal dimension of the English language classroom. In this conflict the largest unbalancing factor falls upon the institutional changes, and the smallest falls upon the unavoidable force of the social and family values.
Determinantes da taxa básica de juros no Brasil: uma análise empírica no período de 2000 a 2011
(Universidade Federal de São Carlos, 2013-04-26) Schio, Thyago Américo; Figueiredo, Adelson Martins; https://lattes.cnpq.br/2582161065438214; https://lattes.cnpq.br/5060523188247779; Rodrigues, Rodrigo Vilela; http://lattes.cnpq.br/7066100737307566; Silva Filho, Edison Benedito da; http://lattes.cnpq.br/4348383152890244
The existence and maintenance for long years of high domestic interest rate is a phenomenon sweeping the Brazilian economic environment. Although in recent years the domestic interest rate derated, Brazil still is characterized as one of the countries with higher interest rate in the world. In order to contribute to the discussion and understanding of the factors that allows the existence and maintenance for long years of high domestic interest rate, it is investigated the hypothesis that even if the internal interest rate is influenced by the foreign interest rate, there are endogenous mechanisms to the Brazilian economy that allow the reduction of the internal interest rate. Aiming objective responses, it is used a Vector Error Correction (VEC) compounded of six endogenous variables and an exogenous variable. As results, it follows that although there is a relationship between domestic and foreign interest rates, there is space for the economic policy, enabling a continuous reduction in the domestic interest rate.
Estudo das propriedades ópticas e estruturais de nanocristais de ZnS, obtidos pelo método solvotérmico aquecido por microondas
(Universidade Federal de São Carlos, 2013-04-26) Santana, Yuri Vinicius Bruschi de; Longo, Elson; https://lattes.cnpq.br/9848311210578810; https://lattes.cnpq.br/0369677340547214
This work deals with the synthesis, characterization and study of nanostructures of zinc sulfide (ZnS) synthesized by microwave heated solvothermal method The synthesis method employed was extremely efficient leading to obtain the cubic and hexagonal structures of ZnS in shorter times and lower temperatures than those reported in the literature. Some synthesis parameters such as, synthesis time, temperature, and capping agent, were investigated in order to check the influence of these parameters on optical and structural properties of ZnS. The characterizations of the samples were performed by X-ray diffraction, absorption spectroscopy in the Uv-Vis, scanning electron microscopy, transmission electron microscopy and photoluminescence spectroscopy. Theoretical calculations were performed in collaboration to help explain the results. The results showed structural differences in the samples as well as different degrees of order-disorder in the material, directly related to certain parameters of synthesis. These differences were interpreted as the responsible for the modifications of the photoluminescent property.