Nanoscale, conductive wires fabricated from organic molecules have attracted considerable attention in recent years due to their anticipated applications in the next generation of optical and electronic devices. Such highly ordered 1D nanostructures could be made from a number of routes. One route of particular interest is to self-assemble the wires from biomolecules due to the wide range of assembly methods that can be adapted from nature. For example, biomolecules with aromatic motifs can be self-assembled so that good π-π stacking is achieved in the resultant nanostructure. An additional advantage of using biomolecules is that it enables the interface of the electronic materials with biological systems, which is important for many applications, including nerve cell communication and artificial photosynthesis. In this study, nanowires were prepared by the molecular self-assembly of oligopeptides that were coupled to aromatic components. In order to achieve charge transport though the nanowires, it was imperative that the aromatic components were arranged so that there was π-π stacking with very few structural defects. Therefore, enzymes were used to control the formation of the hydogelators which subsequently self-assembled to produce nanowire networks. Two main systems were studied in this thesis.In the first system, hydrogelators were produced from aromatic peptide amphiphiles via the enzymatic hydrolysis of the methyl ester of fluorenylmethoxycarbonyl (Fmoc)-di/tripeptides. These hydrogelators formed nanostructures due to π-π stacking between the Fmoc groups and H-bonding between the peptides. The nanostructures in turn produced macroscale gel networks. The nanostructures were analyzed by wide angle X-ray diffraction and fluorescence spectroscopy. A combination of Fourier transform infra-red (FTIR), Transmission Electron Microscopy (TEM), Cryo-TEM, and Atomic Force Microscopy (AFM) was used to characterize the networks. The charge transport properties of the dried networks were studied using impedance spectroscopy. Fmoc-L₃ was found to assemble into nanotubes whose walls consisted of 3 self-assembled layers and possessed inner and outer diameters of ~ 9 nm and ~ 18 nm, respectively. The Fmoc-L₃ networks were structurally stabile and were electronically conductive under a vacuum. The sheet resistance of the peptide networks increased with relative humidity due to the increasing ionic conductivity. The resistance of the networks was 0.1 MΩ/sq in air and 500 MΩ/sq in vacuum (pressure: 1.03 mbar) at room temperature. The networks had a band gap of between 1 to 4 eV as measured by UV-Vis spectroscopy and the temperature-impedance studies. Possible routes for aligning the Fmoc-L3 networks were studied in an attempt to improve their conductivity in one direction. In particular, the peptides were assembled under an electric field (0 to 3.75 kV/cm). Random networks were produced at low field strengths, whereas a degree of alignment was obtained at a field strength of 3.75 kV/cm. The conductivity of the aligned networks in the direction of alignment was a factor of three times higher than that of the random networks.The second system studied was Fmoc-dipeptide-OMe hydrogels produced by the enzymatic condensation of an Fmoc-amino acid and an amino acid ester. Preliminary results found that Fmoc-SF-OMe assembled into nanosheets, nanoribbons and spherulites, depending on the temperature at which self-assembly occurred. The Fmoc-XY-OMe films possessed an extremely high resistance (1012 Ω).

Due to an increased environmental awareness and thus, concerns over the use of fossil-based monomer for polymer production, there is an ongoing effort to find alternatives to non-renewable traditional monomers. This has ushered in the rapid growth in the development of bio-based materials such as green monomers and biodegradable polymers from vegetable and animal resources. Glycerol, as a renewable bio-based monomer, is an interesting candidate for sustainable polymer production. Glycerol is a renewable material that is a by-product of the transesterification of vegetable oils to biodiesel. Utilization of the excess glycerol derived from the growing biodiesel industry is important to oleochemical industries. The main objective of this thesis was to produce high molecular weight polyglycerol from glycerol and synthesize stimuli-responsive polyglycerol hydrogels. The work began with an investigation of the step-growth polymerization of glycerol to relatively high molecular weight polyglycerol using several catalysts. The catalytic reaction mechanisms were compared and the polymer products were fully analyzed. High molecular weight partially branched polyglycerol with multimodal molecular weight distributions was obtained. The polymerization of glycerol proceeded fastest with sulphuric acid as catalyst as indicated by the highest observed conversion of monomer along with the highest molecular weights. Theoretical models were used to predict the gel point and to calculate monomer functionality. High molecular weight polyglycerol was used to synthesize novel stimuli-responsive hydrogels. Real-time monitoring of step-growth polymerization of glycerol was investigated using in-line and off-line Attenuated Total Reflectance/Fourier Transform infrared (ATR-FTIR) technique.

Cell behavior is influenced to a large extent by the surrounding microenvironment. Therefore, in the body, the cellular microenvironment is highly controlled with cells growing within well-defined tissue architectures. However, traditional culture techniques allow only for the random placement of cells onto culture dishes and biomaterials. Cell micropatterning strategies aim to control the spatial localization of cells on their underlying material and in relation to other cells. Developing such strategies provides us with tools necessary to eventually fabricate the highly-controlled microenvironments found in multicellular organisms. Employing natural extracellular matrix (ECM) materials in patterning techniques can increase biocompatibility. In the future, with such technologies, we can hope to conduct novel studies in cell biology or optimize cell behavior and function towards the development of new cell-based devices and tissue engineering constructs. Herein, a novel cell patterning platform was developed on a hydrogel base of crosslinked hyaluronic acid (HA). Hydrogels are often employed in tissue engineering due to their ability to mimic the physicochemical properties of natural tissues. HA is a polymer present in all connective tissues. Cell-adhesive regions on the hydrogel were created using the RGDS peptide sequence, found within the cell-adhesive ECM protein, fibronectin. The peptide was bound to a 2-nitrobenzyl “caging group” via a photolabile bond to render the peptide light-responsive. Finally, this “caged” peptide was covalently bound to the hydrogel to form a novel HA hydrogel with a cell non-adhesive surface which could be activated with near-UV light to become adhesive. In this way, we successfully formed chemically patterned cell-adhesive regions on a HA hydrogel using light as a stimulus to form controlled cell patterns. While the majority of cell patterning strategies to date are limited to patterning one cell population and cannot be changed with time, our strategy was novel in using small, adhesive, caged peptides combined with multiple, aligned light exposure steps to allow for dynamic chemical cell patterning on a hydrogel. Multiple cell populations, even held apart from one another, were successfully patterned on the same hydrogel. Furthermore, cell patterns were deliberately modified with time to direct cell growth and/or migration on the hydrogel base.

In recent years a great deal of research has focussed on understanding and exploiting self assembling peptides as they form fibrillar hydrogels for use in a variety of different applications, such as tissue engineering and drug delivery. A particular class of such peptide systems are ionic-complementary peptides, composed of alternating hydrophobic and hydrophilic amino acids. Their simple structure is generally seen to assemble into β sheet rich fibrils, and easy modification of the primary structure is possible to allow the inclusion of recognition motifs tailored for a specific use. This can be done simply via physical mixing. To maximise the potential of such systems it is important to understand the interactions that govern the self-assembly behaviour. Here a variety of different peptides have been studied to elucidate control of peptide conformation and fibril morphology. The ability to easily tune the mechanical strength of the hydrogel has been explored by mixing peptide systems. The peptide FEFEFKFK (FEKII) was seen to assemble into β sheet rich fibrils of ~3 nm in diameter. Control of pH and hence the charge state of the E and K side chains altered sample properties. Gelation at pH 2.8 occurred at a concentration between 20 30 mg ml 1. At pH 4, 5 and 10 where the peptide has a lower net charge gelation was lowered to ~10 mg ml 1. Mechanical properties varied with G' values of 20-1200 Pa as pH was altered. Stronger gels were formed with lower net peptide charge. Hierarchical fibre assembly was observed for positively charged peptides, with fibres forming from lateral association of fibrils. Negatively charged peptides at pH 10 showed no such hierarchical assembly, and lower fibril persistence length. This was related to the change in charge along the fibril structure. At pH 7, where the peptide has no net charge, precipitation occurred. This showed a net charge was required on the peptide to disperse fibrils and prevent aggregation. The work showed the importance of ionic-interactions in determining both network morphology and bulk properties, and also elucidated control of such behaviour. AEAEAKAK (AEKII) was shown to assemble into α helix fibres. Alanine (A) is less hydrophobic than F, and is a known helix former. The role of F and A in assembly was assessed by the design of peptides FEAEFKAK (FAIEKII) and FEFEAKAK (FAIIEKII). Mixing A with F disrupted the peptides' ability to form a β sheet network by lowering the driving force for assembly given by the F residues. Trace amounts of β sheet were observed at low concentration, but at a critical concentration β sheet content increased and gelation occurred. This was found to be pH dependent. FAIEKII formed β-sheet fibrils at a lower concentration than FAIIEKII. While FAIEKII was able to assemble into different fibril structures, FAIIEKII showed no specific aggregation. This not only highlighted the importance of Hydrophobicity as a key driving force to assembly but also how the grouping of these amino acids in the primary sequence can determine the overall assembly characteristics of the peptide. The peptides FEFEFKFKGGFEFEFKFK (FEKII18-1) and FEFEFKFKGGFKFKFEFE (FEKII18-2) were designed to co-assemble with FEKII. Individually both peptides were seen to assemble into β sheet fibrils. FEKII18-1 formed fibrils of 2.3 3.1 nm in size, a result of folding along the chain caused by intra molecular attractive ionic interactions. FEKII18-2 formed larger fibrils of 4.4 5.2 nm from a straightened peptide chain given by the change in charge distribution. When co assembled with FEKII mechanical properties were enhanced, with G' increasing from 40 Pa at 20 mg ml 1 to 2400 Pa, depending on the concentration of FEKII18-1/FEKII18-2 added to the system. This was a result of these peptides providing fibril connections acting as cross links. This work has detailed control over the assembly process via peptide conformation and fibril interactions and the effect this has on overall macroscopic sample properties. This is vital in determining the viability of such systems in various biomedical applications.

Orientadores: Cecilia Amelia de Carvalho Zavaglia, Marcelo de Carvalho Reis / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-04T01:42:37Z (GMT). No. of bitstreams: 1 Bavaresco_VanessaPetrilli_D.pdf: 14276021 bytes, checksum: d5ab24900afcc34fe160b1d9a55fa2bd (MD5) Previous issue date: 2004 / Resumo: O desenvolvimento de próteses articulares com superfície complacente, capaz de favorecer ou permitir a lubrificação entre os componentes das juntas artificiais, como acontece nas juntas naturais, vem despertando grande interesse visto que diminui o coeficiente de atrito entre as superfícies, favorecendo o deslizamento entre as mesmas e minimizando o desgaste. A proposta deste trabalho foi estudar e melhorar as propriedades mecânicas de hidrogéis poliméricos de poli (metacrilato de 2-hidroxietila) (pREMA) e poli (álcool vinílico) (PVA) reconhecidamente utilizados no estudo de reparadores da cartilagem articular natural. Para tanto foram obtidos copolímeros de pREMA e n-vinil pirrolidona (NVP) (polímero hidrofílico de reforço) variando-se a concentração de agente de reticulação e blendas de poliHEMA com o copolímero poli(metacrilato de metila-co-ácido acrílico) (75:25) enquanto que, os hidrogéis a base de poli (álcool vinílico) foram reticulados com radiação ionizante de feixe de elétrons. O estudo envolveu a caracterização térmica, mecânica e morfológica desses materiais bem como sua caracterização quanto ao desgaste em um equipamento do tipo PIN-ON-DISK com uma contra-superficie de metal em condições próximas à fisiológica com movimento relativo rotativo e, ainda, com movimento recíproco ou alternado / Abstract: There is an increasing interest in the development of soft layered articular prostheses, which favour sliding between components, as natural joints do, thus reducing contact stresses and wear. The purpose of this work was to characterize and improve the mechanical properties of poly (2-hydroxyethyl metacrylate) (pHEMA) and polyvinyl alcohol (PVA) hydrogels. These hydrogels are extensively studied for articular cartilage repair. Samples of pHEMA and n-vinyl pirrolidone (NVP) copolymers with different amounts of trimethylol propane trimethacrylate (TMPTMMA) crosslinking agent, and samples of pHEMA/poly (methyl metacrylate-co-acrylic acid) blends were prepared by thermal polymerization. Additionally, PVA based hydrogels were prepared by means of electron beam ionizing radiation. Hydrogel samples were characterized by indentation creep test, equilibrium water content (EWC) and Differential Scanning Calorimetry (DSC). The tribological characterization of hydrogels was performed under nearly looading physiological conditions at room temperature on a pin-on-disc equipment, Plint TE67, using a stainless steel 316L disc counter surface / Doutorado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Made available in DSpace on 2016-01-26T18:56:22Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 522956 bytes, checksum: d101f87ae1a8c7420ba8560bf5fd3f0c (MD5) Previous issue date: 2011-03-17 / The Brazilian production of sugar cane in the harvest that begins in 2010 is estimated at 664.34 million tonnes grown on 20.0 million acres. This volume exceeds 9.9% in the last harvest, or 59.82 million tons additional. The South-Central region accounts for 90% of the crop in Brazil and Sao Paulo state is expected to 384.6 million tonnes in an area of 10.9 million acres. The cultivars can produce unwanted features, such as problems in the regrowth, lower productivity, lower sugar content, the occurrence of pith, among others, these problems can usually be associated with climatic factors. Most of the areas planted with sugar cane in western São Paulo state are subject to moisture stress. In order to study the reduction or elimination of problems arising from water stress, was investigated the interaction of soil conditioner (hydrogel polymer) with the addition of straw in two tillage systems. The experiment was located on the campus II of UNOESTE , whose soil was characterized as Acrisol Distroferric typical A moderate, medium-textured clay. The climate is classified as Aw, and the summer rainy season and dry season in winter. The variety RB 86 7515 was planted on December 2007 and harvested in June 2009 (18 months), sprouting of this cultivar was used in the study, statistical scheme was split-plot (2x4), two planting systems used in 2007 when the installation process of culture (windrow and grooves), were four doses of hydrogel polymer, (0, 10.79, 21.58 and 32.38 kg of polymer per acres) plots with the dose of polymer, were divided into four treatments with straw in ratoon sugarcane (no leaves, dry leaves, the dose of 2.02 t acres-1, green leaves, at a dose of 6.75 t acres-1, mixture of green leaves and more leaves at a dose of 8.77 t acres-1). To check the moisture in the soil for different treatments, we performed the analysis directly in the soil in each plot using TDR instrument with rods of 0.20 m. To measure the temperature of the soil in each plot, we used analog thermometer deep, with stems to 0.20 m, making the measurement in lines and in between lines. The biometric analysis were: height of tillers, average stem diameter, number of tillers per meter, number of leaves positive, negative, dry leaves and number of leaves. Were performed using analysis of solids and made the determination of technological parameters (Fiber, Pol. Brix, RS, and TRS). Were analyzed for total biomass yield, stalk yield and productivity of trash. All data were subjected to analysis of variance (ANOVA, p <0.05) and the comparison test of means Scott-Knott (p <0.05). The planting in windrow promoted greater tillering, reaching optimal values, also caused higher temperatures in the soil, both on line and in between lines, provided smaller values of TRS compared with traditional cropping system in the groove and did not cause differences in productivity values. The use of polymer showed higher vegetative growth, higher productivity, higher values of RS especially when using mixed coverage. The use of polymer did not alter the levels of soil moisture and decreased temperature in the line as the leading, resulted in higher leaf production due to use of polymer. The use of cover, mainly leaves mixed in a greater biometric growth, especially in the planting furrow, equaled the TRS between Windrow and groove, which was always smaller than in windrow, promoted greater soil moisture in both windrow and in the groove, between the lines this occurred only to groove. The fiber content was higher in bare soil using polymer. The use of cover resulted in lower temperatures both windrow and in the groove. / A produção brasileira de cana-de-açúcar, na safra que iniciou em 2010, está estimada em 664,34 milhões de toneladas cultivados em 8,1 milhões de hectares. Esse volume supera em 9,9% a colheita passada, ou seja, 59,82 milhões de toneladas adicionais. A região Centro-Sul é responsável por 90% da colheita no País e em São Paulo espera-se 384,6 milhões toneladas em uma área de 4,4 milhões de hectares. Os cultivares podem apresentar características não desejadas, como problemas na rebrota, menor produtividade, menor teor de açúcar, ocorrência de isoporização, entre outros. Normalmente estes problemas podem estar associados a fatores climáticos. A maioria das áreas plantadas com cana-de-açúcar na região oeste do estado de São Paulo está sujeita à ocorrência de veranico. Com o intuito de estudar a redução ou eliminação dos problemas oriundos do estresse hídrico, foi pesquisada a interação de condicionadores de solo (polímeros hidroabsorventes) com a adição de palhiço em dois sistemas de plantio. O experimento foi implantado no Campus II da UNOESTE, cujo solo foi caracterizado como Arenoso Vermelho-Amarelo Distroférrico, típico A moderado, textura médio-argilosa. O clima da região se classifica em Aw, sendo a estação chuvosa no verão e estação seca no inverno.O cultivar RB 86 7515 foi plantado em dezembro de 2007 e colhido em junho de 2009 (18 meses) e a soqueira deste cultivar foi utilizada no estudo. O esquema estatístico foi o de parcelas subdivididas (2x4) sendo dois os sistemas de plantios utilizados, em 2007, quando do processo de instalação da cultura (leira e sulco) quatro foram às doses do polímero hidroabsorvente, ( 0; 26,67; 53,33 e 80,00 kg do polímero por hectare). As parcelas com as doses utilizadas de polímero, foram subdivididas em quatro tratamentos com palhiço, na soqueira da cana (sem folhas, folhas secas, na dose de 5 t ha-1, folhas verde, na dose de 16,67 t ha-1, e mistura de folhas verdes mais folhas secas, na dose de 21,67 t ha-1). Para verificar a umidade presente nos diferentes tratamentos, foram efetuadas análises diretamente no solo, em cada subparcela utilizando aparelho TDR com hastes de 0,20 m. Para aferição da temperatura do solo, em cada subparcela, utilizou-se termômetro analógico de profundidade, com hastes de 0,20 m, realizando a medição na linha e na entrelinha da cultura. As análises biométricas realizadas foram: Altura dos perfilhos, Diâmetro médio colmo, Número de perfilhos por metro linear, Número de folhas positivas,folhas negativas, folhas secas e número de folhas totais. No caldo Foram realizadas as análises de brix e realizada na cana a determinação dos parâmetros tecnológicos (Fibra, Pol. Brix. AR, e ATR). Analisou-se produtividade de biomassa total, produtividade de colmos e produtividade de palhiço. Todos os dados foram submetidos à análise de variância (ANOVA, p<0,05) e ao teste de comparação de médias Scott-Knott (p<0,05). O plantio em leira promoveu maior perfilhamento, atingindo valores ideais. As temperaturas no solo, tanto na linha como na entrelinha, foram iguais para leira e sulco. O plantio em leira proporcionou menores valores de ATR, quando comparado com sistema de plantio tradicional, em sulco, e não proporcionou diferenças nos valores de produtividades. A utilização de polímero proporcionou maior desenvolvimento vegetativo, maiores produtividades, valores maiores de AR, principalmente quando utilizando cobertura mista. A utilização de polímero alterou os teores de umidade do solo para plantio em sulco e diminuiu a temperatura, tanto na linha como na entrelinha, para ambos os plantios. Ocorreu maior produção de folhas devido ao uso do polímero. A utilização de cobertura, principalmente folhas misturadas, proporcionou maior crescimento biométrico, no plantio em sulco, igualou o ATR entre leira e sulco, que sempre foi menor em leira, promoveu maior umidade do solo para plantio em sulco. O teor de fibra foi maior em solo nu com a utilização de polímero. O uso de cobertura proporcionou menores temperaturas tanto em leira como em sulco.

Made available in DSpace on 2016-07-18T17:51:06Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 522956 bytes, checksum: d101f87ae1a8c7420ba8560bf5fd3f0c (MD5) Previous issue date: 2011-03-17 / The Brazilian production of sugar cane in the harvest that begins in 2010 is estimated at 664.34 million tonnes grown on 20.0 million acres. This volume exceeds 9.9% in the last harvest, or 59.82 million tons additional. The South-Central region accounts for 90% of the crop in Brazil and Sao Paulo state is expected to 384.6 million tonnes in an area of 10.9 million acres. The cultivars can produce unwanted features, such as problems in the regrowth, lower productivity, lower sugar content, the occurrence of pith, among others, these problems can usually be associated with climatic factors. Most of the areas planted with sugar cane in western São Paulo state are subject to moisture stress. In order to study the reduction or elimination of problems arising from water stress, was investigated the interaction of soil conditioner (hydrogel polymer) with the addition of straw in two tillage systems. The experiment was located on the campus II of UNOESTE , whose soil was characterized as Acrisol Distroferric typical A moderate, medium-textured clay. The climate is classified as Aw, and the summer rainy season and dry season in winter. The variety RB 86 7515 was planted on December 2007 and harvested in June 2009 (18 months), sprouting of this cultivar was used in the study, statistical scheme was split-plot (2x4), two planting systems used in 2007 when the installation process of culture (windrow and grooves), were four doses of hydrogel polymer, (0, 10.79, 21.58 and 32.38 kg of polymer per acres) plots with the dose of polymer, were divided into four treatments with straw in ratoon sugarcane (no leaves, dry leaves, the dose of 2.02 t acres-1, green leaves, at a dose of 6.75 t acres-1, mixture of green leaves and more leaves at a dose of 8.77 t acres-1). To check the moisture in the soil for different treatments, we performed the analysis directly in the soil in each plot using TDR instrument with rods of 0.20 m. To measure the temperature of the soil in each plot, we used analog thermometer deep, with stems to 0.20 m, making the measurement in lines and in between lines. The biometric analysis were: height of tillers, average stem diameter, number of tillers per meter, number of leaves positive, negative, dry leaves and number of leaves. Were performed using analysis of solids and made the determination of technological parameters (Fiber, Pol. Brix, RS, and TRS). Were analyzed for total biomass yield, stalk yield and productivity of trash. All data were subjected to analysis of variance (ANOVA, p <0.05) and the comparison test of means Scott-Knott (p <0.05). The planting in windrow promoted greater tillering, reaching optimal values, also caused higher temperatures in the soil, both on line and in between lines, provided smaller values of TRS compared with traditional cropping system in the groove and did not cause differences in productivity values. The use of polymer showed higher vegetative growth, higher productivity, higher values of RS especially when using mixed coverage. The use of polymer did not alter the levels of soil moisture and decreased temperature in the line as the leading, resulted in higher leaf production due to use of polymer. The use of cover, mainly leaves mixed in a greater biometric growth, especially in the planting furrow, equaled the TRS between Windrow and groove, which was always smaller than in windrow, promoted greater soil moisture in both windrow and in the groove, between the lines this occurred only to groove. The fiber content was higher in bare soil using polymer. The use of cover resulted in lower temperatures both windrow and in the groove. / A produção brasileira de cana-de-açúcar, na safra que iniciou em 2010, está estimada em 664,34 milhões de toneladas cultivados em 8,1 milhões de hectares. Esse volume supera em 9,9% a colheita passada, ou seja, 59,82 milhões de toneladas adicionais. A região Centro-Sul é responsável por 90% da colheita no País e em São Paulo espera-se 384,6 milhões toneladas em uma área de 4,4 milhões de hectares. Os cultivares podem apresentar características não desejadas, como problemas na rebrota, menor produtividade, menor teor de açúcar, ocorrência de isoporização, entre outros. Normalmente estes problemas podem estar associados a fatores climáticos. A maioria das áreas plantadas com cana-de-açúcar na região oeste do estado de São Paulo está sujeita à ocorrência de veranico. Com o intuito de estudar a redução ou eliminação dos problemas oriundos do estresse hídrico, foi pesquisada a interação de condicionadores de solo (polímeros hidroabsorventes) com a adição de palhiço em dois sistemas de plantio. O experimento foi implantado no Campus II da UNOESTE, cujo solo foi caracterizado como Arenoso Vermelho-Amarelo Distroférrico, típico A moderado, textura médio-argilosa. O clima da região se classifica em Aw, sendo a estação chuvosa no verão e estação seca no inverno.O cultivar RB 86 7515 foi plantado em dezembro de 2007 e colhido em junho de 2009 (18 meses) e a soqueira deste cultivar foi utilizada no estudo. O esquema estatístico foi o de parcelas subdivididas (2x4) sendo dois os sistemas de plantios utilizados, em 2007, quando do processo de instalação da cultura (leira e sulco) quatro foram às doses do polímero hidroabsorvente, ( 0; 26,67; 53,33 e 80,00 kg do polímero por hectare). As parcelas com as doses utilizadas de polímero, foram subdivididas em quatro tratamentos com palhiço, na soqueira da cana (sem folhas, folhas secas, na dose de 5 t ha-1, folhas verde, na dose de 16,67 t ha-1, e mistura de folhas verdes mais folhas secas, na dose de 21,67 t ha-1). Para verificar a umidade presente nos diferentes tratamentos, foram efetuadas análises diretamente no solo, em cada subparcela utilizando aparelho TDR com hastes de 0,20 m. Para aferição da temperatura do solo, em cada subparcela, utilizou-se termômetro analógico de profundidade, com hastes de 0,20 m, realizando a medição na linha e na entrelinha da cultura. As análises biométricas realizadas foram: Altura dos perfilhos, Diâmetro médio colmo, Número de perfilhos por metro linear, Número de folhas positivas,folhas negativas, folhas secas e número de folhas totais. No caldo Foram realizadas as análises de brix e realizada na cana a determinação dos parâmetros tecnológicos (Fibra, Pol. Brix. AR, e ATR). Analisou-se produtividade de biomassa total, produtividade de colmos e produtividade de palhiço. Todos os dados foram submetidos à análise de variância (ANOVA, p<0,05) e ao teste de comparação de médias Scott-Knott (p<0,05). O plantio em leira promoveu maior perfilhamento, atingindo valores ideais. As temperaturas no solo, tanto na linha como na entrelinha, foram iguais para leira e sulco. O plantio em leira proporcionou menores valores de ATR, quando comparado com sistema de plantio tradicional, em sulco, e não proporcionou diferenças nos valores de produtividades. A utilização de polímero proporcionou maior desenvolvimento vegetativo, maiores produtividades, valores maiores de AR, principalmente quando utilizando cobertura mista. A utilização de polímero alterou os teores de umidade do solo para plantio em sulco e diminuiu a temperatura, tanto na linha como na entrelinha, para ambos os plantios. Ocorreu maior produção de folhas devido ao uso do polímero. A utilização de cobertura, principalmente folhas misturadas, proporcionou maior crescimento biométrico, no plantio em sulco, igualou o ATR entre leira e sulco, que sempre foi menor em leira, promoveu maior umidade do solo para plantio em sulco. O teor de fibra foi maior em solo nu com a utilização de polímero. O uso de cobertura proporcionou menores temperaturas tanto em leira como em sulco.

O diabetes mellitus é um transtorno metabólico que leva a uma deficiência na secreção de insulina, na sua ação ou em ambos. O mau controle glicêmico pode acarretar em diversas complicações, entre elas, o pé diabético, que é o responsável pela maior parte de amputações não traumáticas dos membros inferiores e gera um custo muito alto para o tratamento de feridas e de cicatrização das amputações. A tecnologia tem proporcionado a criação de novos métodos de tratamento, como as membranas de hidrogel veiculadoras de fármaco. Com isso o nosso objetivo foi testar a eficiência do hidrogel com papaína no tratamento de úlceras em pés diabéticos. A pesquisa foi realizada no município de Porto Nacional (TO) com todos os pacientes portadores de pé diabéticos que deram entrada no HRPPN de 01 de outubro de 2014 a 31 de outubro de 2015, que se encaixavam dentro dos critérios de inclusão do trabalho e assinaram o TCLE. Para a análise socioeconômica aplicou-se um questionário com perguntas objetivas. Para a aplicação da membrana, as feridas foram lavadas com soro fisiológico a 0,9% e os curativos foram realizados de acordo com o protocolo do hospital e trocados a cada 24 horas. Utilizou-se uma planilha de diagnóstico para realizar o acompanhamento diário das feridas. Dezoito pacientes participaram do estudo, sendo que, 16 deles foram internados devido ao pé diabético e ao DM descompensado. 50% dos pacientes eram do sexo feminino e 50% do masculino, todos com idade entre 29 anos e 80 anos. 22% fazem uso de hipoglicemiante oral e insulina e os outros 78% usam apenas hipoglicemiante oral. 82% têm companheiro ou é casado e a maior parte não possui renda ou recebe até um salário mínimo (61%). Quanto à escolaridade, 28% são analfabetos e 34% não concluíram o ensino médio. 50% dos pacientes são naturais de Porto Nacional e 11% de outros estados. Quanto ao conhecimento que os pacientes tinham das complicações que tem como causa o DM, o pé diabético foi a única citada por todos, as demais complicações eram desconhecidas por muitos; somente um paciente tem ciência de todas as complicações. Dos 18 pacientes, 7 puderam ser tratados com a membrana de hidrogel com papaína, mas como não houve melhora significativa, a membrana teve que ser substituída pelo curativo convencional. A membrana não aderiu à pele saudável e nem na ferida, uma vez que apresentou rigidez, fato que pode ter retardado o processo de cicatrização, já que o curativo não envolveu a ferida completamente. A membrana também apresentou baixa taxa de absorção do exsudato, fazendo com que as feridas ficassem maceradas. A cisteína, composto presente na membrana, fez com que ela liberasse um forte odor que causou repulsa nos pacientes e seus familiares, fato que desmotivou o paciente a querer realizar o tratamento. Dados estes resultados, infere-se que a utilização do hidrogel com papaína não trouxe melhora para as feridas do pé diabético, houve um leve desbridamento em algumas feridas, mas sem cicatrização. / Diabetes mellitus is a metabolic disorder that leads to a deficiency in insulin secretion, its action or both. Poor glycemic control can lead to a number of complications, including diabetic foot, which is responsible for most non- traumatic lower limb amputations and generates a very high cost for wound healing and amputation healing. The technology has provided the creation of new treatment methods, such as drug-bearing hydrogel membranes. Our aim is to test the efficiency of papain hydrogel in the treatment of diabetic foot ulcers. The study was carried out in the municipality of Porto Nacional (TO) with all patients with diabetic foot who entered the HRPPN from October 1, 2014 to October 31, 2015, who fit within the inclusion criteria of the work and signed The TCLE. For the socioeconomic analysis a questionnaire with direct questions was applied. For the application of the membrane the wounds were washed with 0.9% saline and the dressings were performed according to the hospital protocol and changed every 24 hours. A diagnostic worksheet was used to perform the daily follow-up of the wounds. Eighteen patients participated in the study, and 16 of them were hospitalized due to diabetic foot and decompensated DM. 50% of the patients were female and 50% were male, all aged between 29 years and 80 years. 22% use oral hypoglycemic and insulin and the other 78% only use oral hypoglycemic. 82% have a partner or are married and most of them have no income or receive up to a minimum wage (61%). As for schooling, 28% are illiterate and 34% did not finish high school. 50% of the patients are from Porto Nacional and 11% from other states. As for the patients\' knowledge of the complications caused by DM, the diabetic foot was the only one mentioned by all, the other complications were unknown by many; only one patient is aware of all the complications. From 18 patients, 7 could be treated with the papain hydrogel membrane, but as there was no significant improvement, the membrane had to be replaced by the conventional dressing. The membrane did not adhere to healthy skin or even to the wound, since it presented rigidity, a fact that may have delayed the healing process since the dressing did not involve the wound completely. The membrane also had a low absorption rate of the exudate, causing the wounds to become macerated. The cysteine, a compound present in the membrane, caused it to release a strong odor that caused disgust in patients and their families, a fact that discouraged the patient from wanting to perform the treatment. Given these results, it was inferred that the use of the papain hydrogel did not improve the wounds of the diabetic foot, there was a slight debridement in some wounds, but without healing.

abstract: BioMEMS has the potential to provide many future tools for life sciences, combined with microfabrication technologies and biomaterials. Especially due to the recent corona 19 epidemic, interest in BioMEMS technology has increased significantly, and the related research has also grown significantly. The field with the highest demand for BioMEMS devices is in the medical field. In particular, the implantable device field is the largest sector where cutting-edge BioMEMS technology is applied along with nanotechnology, artificial intelligence, genetic engineering, etc. However, implantable devices used for brain diseases are still very limited because unlike other parts of human organs, the brain is still unknow area which cannot be completely replaceable.To date, the most commercially used, almost only, implantable device for the brain is a shunt system for the treatment of hydrocephalus. The current cerebrospinal fluid (CSF) shunt treatment yields high failure rates: ~40% within first 2 years and 98% within 10 years. These failures lead to high hospital admission rates and repeated invasive surgical procedures, along with reduced quality of life. New treatments are needed to improve the disease burden associated with hydrocephalus. In this research, the proposed catheter-free, completely-passive miniaturized valve is designed to alleviate hydrocephalus at the originating site of the disorder and diminish failure mechanisms associated with current treatment methods. The valve is composed of hydrogel diaphragm structure and polymer or glass outer frame which are 100% bio-compatible material. The valve aims to be implanted between the sub-arachnoid space and the superior sagittal sinus to regulate the CSF flow substituting for the obstructed arachnoid granulations. A cardiac pacemaker is one of the longest and most widely used implantable devices and the wireless technology is the most widely used with it for easy acquisition of vital signs and rapid disease diagnosis without clinical surgery. But the conventional pacemakers with some wireless technology face some essential complications associated with finite battery life, ultra-vein pacing leads, and risk of infection from device pockets and leads. To solve these problems, wireless cardiac pacemaker operating in fully-passive modality is proposed and demonstrates the promising potential by realizing a prototype and functional evaluating. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21997号 / 医博第4511号 / 新制||医||1037(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 妹尾 浩, 教授 伊達 洋至 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM