Made available in DSpace on 2014-12-17T15:41:43Z (GMT). No. of bitstreams: 1 AlyssonEGM.pdf: 4274696 bytes, checksum: 0f940193275b15ce59b4b1f45e3dc11c (MD5) Previous issue date: 2008-09-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Were synthesized different ferrites NixZn1-xFe2O4 (0,4 ≤ x ≤ 0,6) compositions by using citrate precursor method. Initially, the precursors citrates of iron, nickel and zinc were mixed and homogenized. The stoichiometric compositions were calcined at 350?C without atmosphere control and the calcined powders were pressed in pellets and toroids. The pressed material was sintered from 1100? up to 1200?C in argon atmosphere. The calcined powders were characterized by XRD, TGA/DTG, FTIR, SEM and vibrating sample magnetometer (VSM). All sintered samples were characterized using XRD, SEM, VSM and measurements of magnetic permeability and loss factor were obtained. It was formed pure ferromagnetic phase at all used temperatures. The Rietveld analyses allowed to calculate the cations level occupation and the crystallite size. The analyses obtained nanometric crystals (12-20 nm) to the calcined powder. By SEM, the sintered samples shows grains sizes from 1 to 10 μm. Sintered densities (ρ) were measured by the Archimedes method and with increasing Zn content, the bulk density decrease. The better magnetization results (105-110 emu/g) were obtained for x=0,6 at all sintering temperatures. The hysteresis shows characteristics of soft magnetic material. Two magnetization processes were considered, superparamagnetism at low temperature and the magnetic domains formation at high temperatures. The sintered toroids presents relative magnetic permeability (μr) from 7 to 32 and loss factor (tanδ) of about 1. The frequency response of toroids range from 0,3 kHz to 0,2 GHz. The composition x=0,5 presents both greater μr and tanδ values and x=0,6 the most broad range of frequency response. Various microstructural factors show influence on the behavior of μr and tanδ, such as: grain size, porosity across grain boundary and inside the grain, grain boundary content and domain walls movement during the process of magnetization at high frequency studies (0,3kKz 0,2 GHz) / Foram sintetizadas diferentes composi??es da ferrita Ni1-xZnxFe2O4 com 0,4 ≤ x ≤ 0,6 pelo uso do m?todo dos citratos precursores. Para se obter a fase estequiom?trica do sistema Ni1-xZnxFe2O4 foram misturados e homogeneizados os citratos precursores de ferro, n?quel e zinco. As composi??es estequiom?tricas foram calcinadas em atmosfera ambiente na temperatura de 350?C e depois prensadas em pastilhas e tor?ides. As amostras prensadas foram sinterizadas nas temperaturas de 1100?, 1150? e 1200?C em atmosfera de arg?nio. Os p?s calcinados foram caracterizados por DRX, TGA/DTG, FTIR, MEV e magnetometria de amostra vibrante (MAV) e as amostras sinterizadas por DRX, MEV, MAV, massa espec?fica e medidas de permeabilidade e perdas magn?ticas. Observou-se a forma??o de fase pura ferrimagn?tica em todas as temperaturas aplicadas. A an?lise pelo m?todo de Rietveld calculou o n?vel de ocupa??o dos c?tions e o tamanho de cristalito. Foram obtidos tamanhos de cristais nanom?tricos, de 12 a 20 nm para os p?s calcinados. Por MEV, as amostras sinterizadas apresentam tamanhos de gr?os na faixa de 1 a 10 μm. A massa espec?fica (ρ) do material sinterizado apresenta uma tend?ncia de diminui??o com a adi??o de Zn. Os melhores resultados de magnetiza??o foram obtidos para x=0,6 nas tr?s temperaturas de sinteriza??o, variando de 105 a 110 emu/g. As histereses mostram um perfil de materiais magn?ticos moles. Dois processos de magnetiza??o foram considerados, o superparamagnetismo a baixa temperatura (350?C) e a forma??o de dom?nios magn?ticos em altas temperaturas. Os materiais sinterizados apresentam permeabilidade (μ) de algumas unidades, de 7 a 30, e perdas magn?ticas (tanδ) por volta de 1. A resposta em freq??ncia dos n?cleos toroidais est? na faixa de 0,3 kHz a 0,2 GHz. Os maiores valores de μ e tanδ s?o para x=0,5 e a maior faixa de resposta em freq??ncia ? para x=0,6. V?rios fatores da microestrutura contribuem para o comportamento das grandezas μ e tanδ, tais como: os tamanhos dos gr?os, porosidade inter e intragranular, quantidade de contornos de gr?os e os aspectos da din?mica das paredes de dom?nios quando excitadas magneticamente sob alta freq??ncia

Hintergrund: Die regionale Citrat-Antikoagulation im Rahmen der Nierenersatztherapie hat bei interdisziplinären Intensivpatienten in den letzten Jahren zunehmend an Bedeutung gewonnen. Für Schwerbrandverletzte existieren bislang kaum Untersuchungen zu diesem Verfahren. Ziel dieser Arbeit war es, die kontinuierliche Nierenersatztherapie mit Citrat-Antikoagulation bei Intensivpatienten mit akutem Nierenversagen nach schwerem Verbrennungstrauma im Hinblick auf Praktikabilität, Effektivität und Komplikationshäufigkeit sowie die Stabilität von Elektrolyt- und Säure-Basen-Haushalt und Gerinnung zu untersuchen. Daneben sollten Aussagen zur Prävalenz des akuten Nierenversagens in dieser Patientengruppe und zu dessen Einfluss auf die Letalität getroffen werden. Methode: Im Rahmen einer retrospektiven Untersuchung wurden unter Verwendung von Patientenakten und Patientendatenmanagementsystem (PDMS) Daten von 27 Schwerbrandverletzten (VKOF ≥ 20% oder ABSI ≥ 8) mit akutem Nierenversagen ausgewertet, die zwischen Januar 2004 und Dezember 2009 im Verbrennungszentrum des Klinikums Sankt Georg Leipzig mit einer kontinuierlichen Nierenersatztherapie behandelt wurden. Bei allen Patienten kam ein Dialysegerät Prisma CFM (Gambro Hospal GmbH, Deutschland) mit einer Polyacrylnitril-Filtermembran (AN 69, Filterset M 100) der gleichen Firma zum Einsatz. Standardverfahren war eine kontinuierliche veno-venöse Hämodiafiltration (CVVHDF) im Prädilutionsmodus. Bei 18 Patienten wurde eine regionale Citrat-Antikoagulation als Antikoagulationsverfahren eingesetzt, bei 7 Patienten eine systemische Heparin-Antikoagulation, bei 2 Patienten kamen alternierend beide Verfahren zum Einsatz. Für die 18 Patienten unter regionaler Citrat-Antikoagulation erfolgte eine detaillierte Analyse des akuten Nierenversagens unter Einbeziehung des klinischen Verlaufes, der Laborparameter und der Behandlungsdaten des Nierenersatzverfahrens. Ergebnisse: Die Prävalenz eines akuten Nierenversagens mit Notwendigkeit zur Nierenersatztherapie bei Schwerbrandverletzten betrug 15,5%. Die Sterblichkeitsrate war in der Patientengruppe mit Nierenversagen etwa fünffach erhöht (25,9 vs. 4,8%). Die Letalitätsrate bei den Patienten unter systemischer Heparin-Antikoagulation war bei vergleichbarem Verbrennungsausmaß etwa fünfmal höher als unter regionaler Citrat-Antikoagulation (57,1 vs. 11.1%). Die Nierenersatztherapie wurde im Median nach 6 Tagen begonnen, die mediane Behandlungsdauer pro Patient betrug 7 Tage. Bei Start der CVVHDF wiesen 94,4% der Patienten einen Schockzustand mit Notwendigkeit einer Vasopressortherapie auf, 83,3% zeigten schwere Dysfunktionen in mindestens 3 Organsystemen, der SOFA-score lag im Median bei 14. Bei einer mittleren Citratkonzentration von 3,6 mmol/l Blut im Extrakorporalkreiskauf konnte eine mediane effektive Filterlaufzeit von 67 Stunden erreicht werden. Hypocalcämien (<0,9 mmol/l) fanden sich in 1,1%, Hypercalcämien (>1,3 mmol/l) in 0,4%. Hypernatriämien (<150 mmol) waren mit 0,4% ebenso selten wie metabolische Alkalosen (pH >7,50 und BE >4) mit 0,2%. Im Gesamtdialysezeitraum von 3790 Stunden gab es nur ein Blutungsereignis, die Gerinnungsparameter zeigten bis auf einen passageren Abfall der Thrombozytenzahl keine signifikanten Veränderungen. Die erzielte mittlere Dialysedosis war mit 35,1 ml/kg Körpergewicht/h ausreichend hoch. Neben einer Reduktion der Nierenretentionsparameter Serum-Creatinin und Serum-Harnstoff fanden sich unter dem Nierenersatzverfahren verbesserte Oxygenierungsindices und sinkende SOFA-scores. Keiner der überlebenden Patienten war zum Zeitpunkt der Entlassung dialysepflichtig. Zusammenfassung: Die CVVHDF unter regionaler Citrat-Antikoagulation ist bei Schwerbrandverletzten ein effektives und in Bezug auf Säure-Basen-Haushalt, Elektrolyte und Gerinnung sicheres Verfahren. Neben einer effektiven Elimination harnpflichtiger Substanzen konnten eine exzellente Stabilität von Elektrolyten und metabolischen Parametern sowie eine suffiziente Antikoagulation im Extrakorporalkreislauf mit niedrigem Blutungsrisiko und konstant langen Filterlaufzeiten nachgewiesen werden. Die Prävalenz des akuten Nierenversagens bei Schwerbrandverletzten ist hoch, die Letalität bei Vorliegen des Organversagens vier-bis fünffach erhöht.

Nanoparticles are used in various applications like medical diagnostics, drug delivery, energy technology, electronics, catalysis etc. Although particles of such small dimensions can be synthesized through various methods, the liquid phase synthesis methods stands out for their simplicity. Typically, these methods involve reaction of precursors to form solute. At high concentration of solute, nucleation commences and nuclei are formed. These nuclei grow in size by assimilating solute from the bulk. Stabilizers or capping agents compete with solute for adsorption on the surface of a growing particle. Two partially protected particles can form bigger particle by coagulation. Uncontrolled turbulent flow field in laboratory scale reactors combined with all the above quite fast and poorly understood steps often lead to poorly controlled synthesis of particles. In many a systems, it also leads to very poor reproducibility. Any attempt to synthesis nanoparticles at engineering scale, with good control on mean size and polydispersity, requires quantitative understanding of the synthesis process. It can then be combined with description of other transport processes in reactors to optimize synthesis protocols. Two main factors hinder progress in this direction: complex and often poorly understood chemistry, and inefficient tools to simulate particle synthesis. In the first part of the thesis, a quantitative model is developed for tannic acid method of synthesis of gold nanoparticles. It showcases the approach used to model a system with poorly understood chemistry and which defies an understanding through the widely used homogeneous nucleation based mechanism for particle synthesis. An organizer based mechanism in which tannic acid brings together nucleating species to facilitate nucleation is invoked. Simple reaction network based models however fail to explain the experimental findings. The underlying chemistry is explored to develop a comprehensive reaction network. This network is used as a guide to seek pathways which can mimic burst of nucleation, a characteristic of homogeneous nucleation based mechanism, through self-limiting nucleation, and various other features present in the experimental data. After successful prediction of all the features of the experimental data through this network, a minimal organizer based mechanism which leads to self-limiting nucleation is developed. The minimal organizer model offers itself as a competing and alternative mechanism to explain nanoparticle synthesis. A few new predictions made by the new model are verified by others in our group. Monte-Carlo (MC) simulations are used as a powerful tool to simulate stochastic processes. Their application to nanoparticle synthesis is limited by three problems: (i) zero initial rate of stochastic processes which leads to infinite time step at the beginning of the simulation, (ii) sensitively time dependent rate of stochastic processes, and (iii) computation intensive simulations. We propose a new approach to carry out MC simulations. It makes use of simulation results obtained with systems of extremely small sizes. These system size dependent predictions, obtained at substantially reduced computational cost are used to construct results for system of infinite size. The approach is based on a new power law scaling that we have found in this work. An efficient implementation of MC simulation for time dependent rate processes is also developed. In this method, an additional variable is introduced for inter-event evolution. It increases the number of differential equation by one, but significantly reduces the computational effort required to estimate the interval of quiescence for time dependent rate processes. All the above ideas are combined in the new approach to simulate complete size distribution for simultaneous nucleation and growth of nanoparticles for a system of infinite size from erroneous simulations carried out with three extremely small size systems. A new framework for solving multidimensional population balance equations (PBEs) which routinely arise in modeling of nanoparticle synthesis is also developed. The new framework advances the concept of minimal internal consistency of discretization. It suggests that an n dimensional PBE is a statement of evolution of population of particles while accounting for how n internal attributes of particles change in particulate events. Thus, a minimum of n + 1 attributes of particles, instead of 2n attributes used hitherto, need to be represented perfectly in discrete representation. This is termed as the concept of minimum internal consistency of discretization in this work. The elements used for discretization should therefore be triangles for 2-d, tetrahedrons for 3-d, and an object with n + 1 vertices in n-d space for the solution of a n-d PBE. The results presented for the solutions for 2-d and 3-d PBEs show the superiority of this framework over the earlier framework. The present work also shows that directionality of elements plays a critical role in the solution of multi-dimensional PBEs. A mere change in connectivity of pivots in space, which changes their directionality, is shown to influence numerical results. This work led to new radial discretization of space, which has been followed up by others in the group and demonstrated to be quite powerful. A physical model is developed to understand digestive ripening of nanoparticles, a technique which is in extensive use in the literature to improve monodispersity of nanoparticles. The physical model is based on critical analysis of the large body of experimental findings available in the literature on several variations of this technique. The physical model is the first one to consistently and qualitatively explain all the reported experimental findings.

In this study, a strategy called gene splicing by overlap extension, &ldquo / Gene SOEing&rdquo / , was used for the construction of the fusion proteins with the purpose of increasing the thermostability of mesophilic enzymes by incorporation of stability domain from a thermostable enzyme. Gene SOEing is a PCR-based approach for recombining DNA molecules at precise junctions irrespective of nucleotide sequences at the recombination site and without the use of restriction endonucleases or ligase. In fusion constructs, as the stability determinant Thermoplasma volcanium citrate synthase (CS) large domain has been used. This gene has recently been cloned in our laboratory. In two different fusions, as fusion partners, dehalogenase II (dehCII) gene of Pseudomonas sp. CBS3 and aminoglycoside-3&#039 / -phosphotransferase-II (APH(3&#039 / )-II) gene of E. coli were employed. Following the Gene SOEing, two fusion products, 1722 bp long CS Large Domain-dehCII and 1750 bp long CS Large Domain-APH(3&#039 / )-II were constructed. Also a 1586 bp long dehCII-APH(3&#039 / )-II fusion was prepared. Three fusion constructs were cloned in E. coli. Cloning was confirmed in each case, by restriction analysis of the isolated plasmids from recombinant colonies. APH(3&#039 / )-II gene associated with CS Large Domain-APH(3&#039 / )-II and dehCII-APH(3&#039 / )-II fusion constructs were successfully expressed in E. coli as revealed by enzyme assay and antibiotic agar plate assay. CS Large Domain-APH(3&#039 / )-II fusion protein retained 9.4% of the original APH(3&#039 / )-II activity after 10 minutes at 60&ordm / C. However, CS Large Domain-dehCII and dehCII-APH(3&#039 / )-II fusions did not display any dehalogenase activity.

A few abnormal cells found in a small piece of prostate tissue are most consequential for a man’s future. The prevalence of prostate cancer (PCa) is increasing globally. The main instigating factor for this cancer is not yet known, but it appears to be the consequence of many variables such as an increasingly older population, more frequent PSA-testing, and factors involving lifestyle. Prostate cancer screening, as an equivalent for breast cancer screening, has been suggested but unfortunately there are no accurate diagnostic tools available for this type of screening. The reason for this is simply that the prostate is one of the most difficult organs to diagnose and, consequently, PCa screening would generate far too many false-positive and false-negative results.  The prostate is not easily accessible as it is deeply-seated in the male pelvic area, wrapped around the urethra and surrounded by sensitive vital organs.  Furthermore, PCa is frequently multi-focal, and the cancer cells have a tendency of assimilating among normal cells and, thus, do not always form solid lumps.  Therefore, prostate tumors are often not felt by digital rectal examination (DRE) or identified by imaging.  The PSA-test is not reliable as it is more prostate-specific than cancer-specific.  Due to increasing prostate awareness, more early-stage and locally confined PCa are being detected. This is saving lives, although there is a high risk of over treatment and unnecessary side-effects.  The increased detection of PCa requires sophisticated diagnostic methods and highly skilled clinicians who can discern between indolent and aggressive cancers.  The current “gold-standard” for PCa diagnosis is biopsy grading by pathologists using the Gleason score system, which is a difficult task.  Therefore, innovative methods to improve the precision of prostate diagnosis, by increased biopsy sensitivity and tumor localization, are of essence. In light of these difficulties, the metabolomic approach using 1D and 2D high-resolution magic angle spinning (HRMAS) NMR spectroscopy combined with histopathology on intact prostatectomy specimens was evaluated in this research project.  The non-destructive nature of HRMAS NMR enables spectroscopic analysis of intact tissue samples with consecutive histological examinations under light microscope. Metabolomics aids in the unraveling and the discovery of organ-specific endogenous metabolites that have the potential to be reliable indicators of organ function and viability, extrinsic and intrinsic perturbations, as well as valuable markers for treatment response. The results may, therefore, be applied clinically to characterize an organ by utilizing biomarkers that have the capacity to distinguish between disease and health. The aim was to characterize the human and the rat prostate in terms of its intermediary metabolism, which I show here to differ between species and anatomical regions.  Furthermore, the aim is to seek the verification of HRMAS NMR derived metabolites which are known to be a part of the prostate metabolome such as, citrate, choline, and the polyamines which were performed, but also the identification of metabolites not previously identified as part of the local prostate metabolism, such as Omega-6, which was detected in tumors.  The extended aim was to elucidate novel bio-markers with clinical potential. In this study, the common phyto-nutrient, inositol, which appears to possess protective properties, was identified as being a potentially important PCa bio-marker for the distinction between the more indolent Gleason score 6 and the more aggressive Gleason score 7 in non-malignant prostate tissues with tumors elsewhere in the organ. Further studies in this area of PCa research are therefore warranted.

The aims of this thesis were to: 1) develop a new method for the determination of interstitial pH at rest and during exercise in vivo, 2) systematically explore the effects of different ingestion regimes of 300 mg.kg-1 sodium citrate on blood and urine pH at rest, and 3) to combine the new interstitial pH technique with the findings of the second investigation in an attempt to provide a greater understanding of H+ movement between the extracellular compartments. The purpose of the first study was to develop a method for the continuous measurement of interstitial pH in vastus lateralis was successfully developed using microdialysis and 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). To avoid the presence of an artificial alkalosis during exercise, it was necessary to add 25 mM HCO3- to the perfusate. The outlet of the probe was cut less than 10 mm from the skin and connected to a stainless steel tube completing the circuit to a microflow-through cuvette (8 fÝl) within a fluorescence spectrophotometer. This prevented the loss of carbon dioxide from the dialysate and any subsequent pH artefact. Interstitial pH was collected from six subjects before, during and after five minutes of knee-extensor exercise at three intensities 30, 50, and 70 W. Mean,,bSEM interstitial pH at rest was 7.38,,b0.02. Exercise reduced interstitial pH in an almost linear fashion. The nadir value for interstitial pH at 30, 50 and 70 W exercise was 7.27, 7.16 and 7.04, respectively. The lowest pH was obtained 1 min after exercise, irrespective of workload, after which the interstitial pH recovered in a nearly exponential manner. The mean half time of interstitial recovery was 5.2 min. The changes in interstitial pH exceeded the changes in venous blood pH. This study demonstrated that interstitial pH can be measured using microdialysis and that it is continuously decreased during muscle activity. The purpose of the second study was to establish an optimal ingestion regime for the ingestion of 300 mg.kg-1 of sodium citrate and maximise the alkalotic effect while minimising any side effects. Increasing the effectiveness of alkali ingestion may lead to further increases in muscle performance. Ingesting 300 mg.kg-1 sodium citrate at a rate of 300 mg.min-1 was identified as the optimal ingestion regime to maximise alkalosis at rest, which occurred 3.5 h post-ingestion. This was determined by monitoring eight human subjects ingesting 300 mg.kg-1 sodium citrate at five different rates, control (no ingestant), bolus, 300, 600 and 900 mg.kg.min-1 on five days separated by at least 48 hours. Sodium citrate was ingested in capsule form with water ad libitum, with the exception of bolus, which was combined with 400 ml less than 25 percent orange juice and consumed in less than 1 min. Arterialised blood (mean 71.3,,b3.5 mmHg) acid-base and electrolyte status was assessed via the withdrawal of ~5 ml of blood every 30 min across an eight hour duration, placed on ice and analysed within five minutes. No alkalotic difference was found between ingestion rates (mean 7.445,,b0.004, 7.438,,b0.004 and 7.442,,b0.004 for 300, 600 and 900 mg.min-1, respectively). All experimental ingestion regimes were associated with elevations in [HCO3-] (29.6, 29.7, 29.8, 29.9 and 26.3 mmol.l-1 for bolus, 300, 600, 900 and control, respectively). The 300 ingestion regime had the greatest impact on [H+], a 0.66 meq.l-1,,e10-8 change. Bolus ingestion (3.93,,b0.08 mmol.l-1) of sodium citrate had no effect on control (4.06,,b0.08 mmol.l-1) blood [K+], however, 300 mg.min-1 decreased blood [K+] (p less than 0.05). There was no effect of sodium citrate on blood [Cl-], but after 2.5 h blood [Cl-] was lower than pre-ingestion values (p less than0.05). All ingestion rates of sodium citrate increased (p less than 0.05) urine pH above control. This is the first study to investigate the effect of varying ingestion rates on acid-base status at rest in humans. The results suggest that ingesting sodium citrate in small doses in quick succession induce a greater blood alkalosis than the commonly practised bolus protocol. Using the interstitial pH technique described above and the optimal ingestion regime (300 mg.min-1) identified above, the final experiment was designed to assess the influence of sodium citrate ingestion on interstitial pH at both rest and during exercise. Five subjects ingested 300 mg.kg-1 sodium citrate at 300 mg.min-1 again in capsule form with water ad libitum. Prior to ingestion, each subject had a cannula placed into their cephalic vein and one microdialysis probe (CMA-60) inserted into their left thigh, orientated along the fibres of vastus lateralus. This probe was used for the measurement of pH as described above. At the end of this period, an exercise protocol required five subjects to perform light exercise (10 W) for 10 min, before starting an intense exercise period (~90-95% leg VO2peak) to exhaustion followed by a 15 min recovery period. Dialysate and blood samples were collected across all periods. Mean,,bSEM interstitial pH for placebo and alkalosis were 7.38,,b0.12 and 7.24,,b0.16, respectively. Sodium citrate ingestion was not associated with an interstitial alkalosis. An exercise induced acidosis was observed in the interstitium during placebo but not during alkalosis (p less than 0.05). Mean,,bSEM venous pH were 7.362,,b0.003 and 7.398,,b0.003 for placebo and alkalosis, respectively. Sodium citrate ingestion was not associated with a venous alkalosis. Sodium citrate ingestion was associated with an increase in mean,,bSEM venous [HCO3-] (placebo 25.5,,b0.2, alkalosis 28.1,,b0.2). This increase in the blood bicarbonate buffer system was not associated with an increase in time to exhaustion (placebo 352,,b71, alkalosis 415,,b171). This was the first study to investigate the effects of sodium citrate ingestion on interstitial pH. The results of this study demonstrated that an interstitial alkalosis does not ensue after alkali ingestion, however, it was associated with the lack of an exercise induced acidosis suggesting an improved pH regulation during exercise.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Revestimentos produzidos a partir de ligas de Zn-Co são comumente utilizados em indústrias (aeronáutica, de isoladores elétricos e automobilística, por exemplo) devido à sua ótima resistência à corrosão, principalmente quando comparados aos tradicionais revestimentos de Zn puro. Na co-deposição de zinco com metais, como o ferro, cobalto e níquel, ocorre o que se chama de deposição anômala, onde o metal menos nobre (zinco) é preferencialmente depositado, independente do modo de corrente aplicada (contínua ou pulsada). Recentemente, diversos trabalhos relacionam a produção de eletrodepósitos de liga Zn-Co a partir de banhos ambientalmente não agressivos, a fim de substituir os banhos alcalinos extremamente tóxicos, a base de cianeto. Na presente dissertação foram produzidos revestimentos de ligas de Zn-Co sobre substrato de aço carbono, empregando corrente contínua ou corrente pulsada simples, a partir de banhos contendo diferentes concentrações de Co2+ (0,05 mol/L e 0,10mol/L), 0,05 mol/l de Zn2+ e citrato de sódio (0,10 mol/L) como agente complexante, sob condições agitadas. Quatro diferentes valores de densidade de corrente (10 A/m2, 20 A/m2, 40 A/m2 e 80 A/m2) e de frequência de pulso (100 Hz, 500 Hz, 1000 Hz, 2000 Hz) foram aplicados para a produção da liga a partir dos dois banhos, tendo como objetivo avaliar a influência dos parâmetros de deposição(concentração de Co (II), densidade de corrente aplicada e, no caso de deposição por corrente pulsada simples, também da frequência de pulso), nas variáveis eficiência de corrente catódica, composição da liga, densidade de corrente de corrosão, microestrutura e morfologia dos depósitos de liga Zn-Co. As cores das camadas obtidas variaram do cinza claro ao escuro, quase sempre sem brilho, independente do modo de corrente empregado. Foi verificado que o processo normal de eletrodeposição foi prevalente na produção de revestimentos por corrente contínua, enquanto que apenas deposição anômala foi observada quando do uso de corrente pulsada. A maior eficiência de corrente catódica (60%) foi obtida, para corrente contínua, nas condições de menor concentração de Co2+ (0,05 mol/L) e maior densidade de corrente (80 A/m2). Nestas mesmas condições foi determinada uma eficiência de corrente catódica de 98% para corrente pulsada simples na freqüência de 2000 Hz. Maiores teores do metal mais nobre (cobalto) foram alcançados em maiores densidades de corrente para todas as condições empregadas. Os revestimentos assim obtidos apresentavam os menores valores de tamanho de grão, para cada uma das soluções estudadas. Os demais parâmetros estudados também influenciaram na granulometria e na morfologia das ligas obtidas. Revestimentos com melhor resistência à corrosão, contendo teores de cobalto entre aproximadamente 8 e 10% m/m, foram produzidos a partir do banho com maior concentração de Co2+, sob corrente pulsada simples / Zn-Co alloys coatings are commonly used in the industry (aerospace, automotive and electrical insulators, for example) due to their great corrosion resistance, mainly when compared to pure zinc coatings. In the zinc co-deposition with different metals, such as iron, cobalt or nickel, it is observed an anomalous deposition, in which the less noble metal (zinc) is preferably deposited, regardless the current type applied (direct or pulsed). Recently, several studies relate the production of electrodeposited Zn-Co alloys from environmentally non-aggressive baths to substitute the extremely toxic cyanide-based alkaline baths. In this dissertation, Zn-Co alloy coatings were produced on carbon steel substrate using direct or simple pulsed currents, from baths with different Co2+ concentrations (0.05 mol/L and 0.10 mol/L), 0.10 mol/L of Zn2+and sodium citrate (0.10 mol/L) as a complexing agent, under stirring. Four different current densities values (10 A/m2, 20 A/m2, 40 A/m2 and 80 A/m2) and four different pulse frequencies values (100 Hz, 500 Hz, 1000 Hz and 2000 Hz) were applied in order to obtain the alloys from both baths, aiming to assess the influence of the deposition parameters (Co (II) concentration, current density applied, and also pulse frequency, for the simple pulsed current process) in the variables cathodic current efficiency, alloy composition, current corrosion density, and Zn-Co alloy deposit microstructure and morphology. The obtained layers colours varied from light to dark grey, normally dull, regardless the current type used. Normal electrodeposition process was predominant when direct current was used, whereas only anomalous deposition was observed when using pulsed current. The highest cathodic current efficiency (60%) was obtained in direct current for the lowest Co2 + concentration (0.05 mol / L). Under these same conditions it was determined a cathodic current efficiency of 98% for single pulsed current, employing the frequency of 2000 Hz Higher content of the noblest metal (cobalt) were achieved for higher current densities for all conditions studied. These coatings presented the smallest grain sizes, for each of the evaluated solutions. The other studied parameters have also influenced in the granulometry and the morphology of the obtained alloys. Coatings presenting the best corrosion resistance, showing the cobalt content between 8 and 10% m/m, were obtained from the highest Co2+ concentration bath, using simple pulsed current

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-11T15:06:17Z No. of bitstreams: 1 LEONARDO FALCÃO FEITOSA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2258061 bytes, checksum: cdc233909fd365937aacd1ef5fa7c2cd (MD5) / Made available in DSpace on 2018-04-11T15:06:17Z (GMT). No. of bitstreams: 1 LEONARDO FALCÃO FEITOSA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2258061 bytes, checksum: cdc233909fd365937aacd1ef5fa7c2cd (MD5) Previous issue date: 2014-12-29 / Na terapia medicamentosa convencional o fármaco é administrado através de uma forma farmacêutica e produz um nível tecidual do fármaco que não se mantêm dentro da faixa terapêutica por um período prolongado de tempo. Desta forma, o êxito do tratamento vai depender de vários fatores como dosagens precisas e frequentes em horários específicos pré-determinados e adesão do paciente à terapêutica de modo que, a não obediência ao esquema terapêutico, pode resultar em utilização do fármaco em faixa não efetiva ou em níveis tóxicos Devido a grande problemática da manutenção de níveis séricos de fármacos no organismo humano, principalmente quando se tratam se fármacos relacionados ao tratamento de dores de moderadas a intensa, este trabalho propõe o desenvolvimento de membranas porosas a base de quitosana, que é um polímero natural biocompatível, capazes de promover a liberação controlada de fentanil. As matrizes obtidas foram caracterizadas por: MO, MEV, EDS, FTIR, DRX, Ensaio de Intumescimento, Ensaio de Biodegradação e Ensaio de Citotoxicidade. Por MO e MEV verificou-se uma superfície com poros aparentemente interconectados. A partir da análise por EDS pode-se verificar os elementos componentes da quitosana e do fármaco. Por FTIR e DRX notou-se a não alteração dos grupos funcionais e cristalinidade, respectivamente, do material devido a incorporação do fármaco. Baseado nos ensaios de intumescimentos e biodegradação verificou-se a capacidade de controlar as variáveis: razão de intumescimento e taxa de degradação exclusivamente pela variação da concentração de quitosana na membrana porosa. Verificou-se no ensaio de citotoxicidade que as membranas, mesmo com a incorporação do fármaco, não apresentaram citotoxicidade. Baseado nos resultados obtidos pôde-se concluir que é possível sintetizar uma matriz polimérica com promissoras propriedades para carrear fármaco e para testes in vivo. / In conventional medical therapy the drug is administered via a dosage form and produces a tissue level of the drug that is not maintained within the therapeutic range over an extended period of time. Thus, the success of the treatment will depend on several factors such as accurate and frequent dosing at predetermined specific times and patient adherence to therapy so that the non-compliance to the treatment regimen can result in use of the drug in not effective range or toxic levels Due to the great problem of maintaining serum levels of drugs in the human body, especially in the case if drugs related to the treatment of moderate to severe pain, this paper proposes the development of porous membranes chitosan base, which is a biocompatible natural polymer, capable of promoting the controlled release of fentanyl. The matrices obtained were characterized by: OM, SEM, EDS, FTIR, XRD, Swelling test, biodegradation test and Cytotoxicity Assay. For OM and SEM there was apparently a surface with interconnected pores. From the EDS analysis can verify the elements of chitosan and drug. FTIR and XRD noted not to change functional groups of crystallinity and, respectively, of the material due to the incorporation of the drug. Based on swellings and biodegradation tests verified the ability to control the following variables: swelling ratio and degradation rate solely by varying the concentration of the chitosan porous membrane. It was found that the cytotoxicity assay the membranes, even with the incorporation of the drug did not show cytotoxicity. Based on the results obtained it was concluded that it is possible to synthesize a polymer matrix with promising properties to adduce drug and in vivo tests.

Resumo: Gerbera jamesonii Bolus é uma espécie da família Compositae. O capítulo, com diâmetro de 8 - 14 cm, possui flores liguladas de cores vivas organizadas ao redor do centro, que contém os botões florais. Esta inflorescência é sustentada por uma haste longa e sem folhas. Atualmente é uma das dez flores mais comercializadas no Brasil e está entre as três principais flores de corte. A utilização de soluções conservantes, tratamentos de "pulsing", ou fortalecimento, e baixas temperaturas de armazenamento visa prolongar a vida e manter por mais tempo a qualidade das flores cortadas. Neste contexto, este trabalho teve por objetivos avaliar o efeito de diferentes práticas de manejo na pós-colheita sobre a fisiologia e conservação de inflorescências de gérberas. Para os quatro primeiro experimentos foi utilizada a gérbera cv. Suzanne, de coloração laranja. Os experimentos foram conduzidos em delineamento inteiramente casualizado, em esquema fatorial. No primeiro experimento, as inflorescências permaneceram nas seguintes soluções de manutenção: 1) Água destilada; 2) Cloro a 100 mg.L-1; 3) 8-hidroxiquinolina (8-HQC) a 100 mg.L-1; 4) 8-HQC a 200 mg.L-1; e 5) 8- HQC a 400 mg.L-1, cujas hastes foram mantidas em condição controlada de laboratório (20°C; 70% UR). Este experimento possibilitou observar danos nas bases das hastes, causados pelos tratamentos com cloro a 100 mg.L-1 e com as doses mais elevadas de 8-HQC. A manutenção da boa qualidade foi observada no tratamento com 8-HQC a 200 mg.L-1. A longevidade média foi de 12 dias em vaso. No segundo experimento foram utilizadas, durante o armazenamento a 20°C e 70% UR, as soluções: 1) Água destilada; 2) Ácido cítrico a 64 g.L-1; 3) Cloro a 25 mg.L-1 4) Cloro a 50 mg.L-1 5) 8-HQC a 25 mg.L- 1 e 6) 8-HQC a 50 mg.L-1. Com os resultados verificou-se a baixa eficiência do... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Gerbera jamesonii belongs to the Compositae family. The inflorescence, with diameter of 8 - 14 cm, is a capitulum with ligules with vivid color organized around de center, that contain flower buds, which can be in a variety of colors. This colorful flower is supported by a long stem, without leaves. Nowadays it is one of the ten most commercialized flowers in Brazil and is one of the three main cut flowers. The use of keeping-quality solutions, pulsing treatments and low temperature during the vase life seeks to prolong vase life and to maintain the quality of cut flowers. In this context, this research was conducted, at FCAV-UNESP, Jaboticabal, SP, Brazil, to evaluate the effects of several handling techniques on postharvest physiology gerbera cut flowers. The experiments followed complete randomized design, in factorial arrangement. On the first one, the inflorescences remained in the following solutions: 1) Distilled water; 2) Chlorine at 100 mg.L-1; 3) 8-hydroxyquinolin (8-HQC) at 100 mg.L-1; 4) 8-HQC at 200 mg.L-1; and 5) 8-HQC at 400 mg.L-1, which the stems remained in environmental conditions (20°C; 70% RH). On this experiment, it was possible to observe the damage caused by the treatments using chlorine at 100 mg.L-1 and high dosage of 8-HQC. The good quality where kept by using 8-HQC at 200 mg.L-1 and the average longevity of the experiment was 12 days. On the second experiment, the gerberas remained, during storage, in the following solutions: 1) Distilled water; 2) Citric acid at 64 g.L-1; 3) Chlorine at 25 mg.L-14) Chlorine at 50 mg.L-1; 5) 8-HQC at 25 mg.L-1 ; and 6) 8-HQC at 50 mg.L-1. With the results it was possible to verify the low efficiency of the citric acid at the used concentration and the lower damage by lower concentrations of chlorine and 8-HQC than the usually recommended, which kept the good quality of the flowers for... (Complete abstract, click electronic access below) / Orientador: Ben-Hur Mattiuz / Coorientadora: Teresinha de Jesus Deléo Rodrigues / Banca: Regina Maria Monteiro de Castilho / Banca: Carlos Eduardo Ferreira de Castro / Banca: Káthia Fernandes Lopes Pivetta / Banca: Pedro Luís da Costa Aguiar Alves / Doutor

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Revestimentos produzidos a partir de ligas de Zn-Co são comumente utilizados em indústrias (aeronáutica, de isoladores elétricos e automobilística, por exemplo) devido à sua ótima resistência à corrosão, principalmente quando comparados aos tradicionais revestimentos de Zn puro. Na co-deposição de zinco com metais, como o ferro, cobalto e níquel, ocorre o que se chama de deposição anômala, onde o metal menos nobre (zinco) é preferencialmente depositado, independente do modo de corrente aplicada (contínua ou pulsada). Recentemente, diversos trabalhos relacionam a produção de eletrodepósitos de liga Zn-Co a partir de banhos ambientalmente não agressivos, a fim de substituir os banhos alcalinos extremamente tóxicos, a base de cianeto. Na presente dissertação foram produzidos revestimentos de ligas de Zn-Co sobre substrato de aço carbono, empregando corrente contínua ou corrente pulsada simples, a partir de banhos contendo diferentes concentrações de Co2+ (0,05 mol/L e 0,10mol/L), 0,05 mol/l de Zn2+ e citrato de sódio (0,10 mol/L) como agente complexante, sob condições agitadas. Quatro diferentes valores de densidade de corrente (10 A/m2, 20 A/m2, 40 A/m2 e 80 A/m2) e de frequência de pulso (100 Hz, 500 Hz, 1000 Hz, 2000 Hz) foram aplicados para a produção da liga a partir dos dois banhos, tendo como objetivo avaliar a influência dos parâmetros de deposição(concentração de Co (II), densidade de corrente aplicada e, no caso de deposição por corrente pulsada simples, também da frequência de pulso), nas variáveis eficiência de corrente catódica, composição da liga, densidade de corrente de corrosão, microestrutura e morfologia dos depósitos de liga Zn-Co. As cores das camadas obtidas variaram do cinza claro ao escuro, quase sempre sem brilho, independente do modo de corrente empregado. Foi verificado que o processo normal de eletrodeposição foi prevalente na produção de revestimentos por corrente contínua, enquanto que apenas deposição anômala foi observada quando do uso de corrente pulsada. A maior eficiência de corrente catódica (60%) foi obtida, para corrente contínua, nas condições de menor concentração de Co2+ (0,05 mol/L) e maior densidade de corrente (80 A/m2). Nestas mesmas condições foi determinada uma eficiência de corrente catódica de 98% para corrente pulsada simples na freqüência de 2000 Hz. Maiores teores do metal mais nobre (cobalto) foram alcançados em maiores densidades de corrente para todas as condições empregadas. Os revestimentos assim obtidos apresentavam os menores valores de tamanho de grão, para cada uma das soluções estudadas. Os demais parâmetros estudados também influenciaram na granulometria e na morfologia das ligas obtidas. Revestimentos com melhor resistência à corrosão, contendo teores de cobalto entre aproximadamente 8 e 10% m/m, foram produzidos a partir do banho com maior concentração de Co2+, sob corrente pulsada simples / Zn-Co alloys coatings are commonly used in the industry (aerospace, automotive and electrical insulators, for example) due to their great corrosion resistance, mainly when compared to pure zinc coatings. In the zinc co-deposition with different metals, such as iron, cobalt or nickel, it is observed an anomalous deposition, in which the less noble metal (zinc) is preferably deposited, regardless the current type applied (direct or pulsed). Recently, several studies relate the production of electrodeposited Zn-Co alloys from environmentally non-aggressive baths to substitute the extremely toxic cyanide-based alkaline baths. In this dissertation, Zn-Co alloy coatings were produced on carbon steel substrate using direct or simple pulsed currents, from baths with different Co2+ concentrations (0.05 mol/L and 0.10 mol/L), 0.10 mol/L of Zn2+and sodium citrate (0.10 mol/L) as a complexing agent, under stirring. Four different current densities values (10 A/m2, 20 A/m2, 40 A/m2 and 80 A/m2) and four different pulse frequencies values (100 Hz, 500 Hz, 1000 Hz and 2000 Hz) were applied in order to obtain the alloys from both baths, aiming to assess the influence of the deposition parameters (Co (II) concentration, current density applied, and also pulse frequency, for the simple pulsed current process) in the variables cathodic current efficiency, alloy composition, current corrosion density, and Zn-Co alloy deposit microstructure and morphology. The obtained layers colours varied from light to dark grey, normally dull, regardless the current type used. Normal electrodeposition process was predominant when direct current was used, whereas only anomalous deposition was observed when using pulsed current. The highest cathodic current efficiency (60%) was obtained in direct current for the lowest Co2 + concentration (0.05 mol / L). Under these same conditions it was determined a cathodic current efficiency of 98% for single pulsed current, employing the frequency of 2000 Hz Higher content of the noblest metal (cobalt) were achieved for higher current densities for all conditions studied. These coatings presented the smallest grain sizes, for each of the evaluated solutions. The other studied parameters have also influenced in the granulometry and the morphology of the obtained alloys. Coatings presenting the best corrosion resistance, showing the cobalt content between 8 and 10% m/m, were obtained from the highest Co2+ concentration bath, using simple pulsed current