EducaFarma 9.0

Memoria ID-020 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021

Study of nanocomposite and polymer eletrolyte by magnetic resonance

Foram realizadas pesquisas em uma série de condutores iônicos que apresentam aplicações na área dos dispositivos eletroquímicos de estado sólido, utilizando-se basicamente a técnica de Ressonância Magnética Nuclear (RMN). A primeira parte deste trabalho é dedicada aos compostos de intercalação baseados na matriz de dissulfeto de molibdênio (MoS2) onde as espécies intercalantes (íons de lítio e moléculas de aminas) são inseridas num espaço de dimensionalidade reduzida gerado pela matriz. Já a segunda parte envolve os condutores iônicos poliméricos do tipo compósitos, nos quais foram utilizadas nanopartículas de carbono (Carbon Black) e titânio (TiO2) no eletrólito formado pelo poli(óxido de etileno) (POE) e o perclorato de lítio (LiClO4). Todos estes sistemas apresentam, em geral, uma considerável complexidade estrutural, o que significa que os movimentos moleculares e de difusão iônica se produzem num meio semicristalino (caso dos compósitos) ou num meio de dimensionalidade reduzida (caso dos intercalados). A espectroscopia de RMN dos núcleos de 7Li e 1H é uma técnica conveniente para o estudo destes materiais, pois é possível avaliar, através dos resultados obtidos das medidas dos tempos de relaxação e formas de linha, os efeitos provocados pela baixa dimensionalidade dos movimentos em estruturas laminares (caso dos intercalados), bem como identificar e aferir as interações e os mecanismos de relaxação resultantes dos diferentes graus de liberdade dos movimentos (iônicos e moleculares), fornecer parâmetros estruturais (distâncias interatômicas) que auxiliam na proposta de possíveis modelos estruturais e caracterizar completamente a escala temporal dos movimentos iônicos e moleculares.Nuclear Magnetic Resonance (RMN) techniques were used to study a series of ionic conductor materials, which present applications in the area of the solid-state electrochemical devices. The first part of this work is dedicated to the study of intercalation compounds based on the molybdenum disulfide matrix (MoS2), where the intercalated species (lithium ion and amine molecule) are inserted in the low-dimensionality space generated by the matrix. The second part involves the study of a composite polymer electrolyte, employing fillers like Carbon Black and titanium dioxide (Tio2) nano particles in the electrolyte formed by the poly(ethy1ene oxide) and a lithium salt (LiClO4). In general, these systems present a considerable structural complexity, meaning that the molecular movements and ionic diffusion are produced in a semicrystalline environment (case of the composites) or in an environment of reduced dimensionality (case of intercalates). The 7Li and 1H NMR spectroscopy is a convenient technique for the study of these materials. Relaxation time and line shape measurements may provide a tool to investigate the effects provoked by the low-dimensionality of the movements in laminate structures (case of intercalate), to identify the interactions and relaxation mechanisms of the ionic and molecular motions, to supply structural parameters (interatomic distances) that would help the proposal of possible structural models, and finally, to characterize the time scale of the ionic and molecular movements completely

Study of nanocomposite and polymer eletrolyte by magnetic resonance

Foram realizadas pesquisas em uma série de condutores iônicos que apresentam aplicações na área dos dispositivos eletroquímicos de estado sólido, utilizando-se basicamente a técnica de Ressonância Magnética Nuclear (RMN). A primeira parte deste trabalho é dedicada aos compostos de intercalação baseados na matriz de dissulfeto de molibdênio (MoS2) onde as espécies intercalantes (íons de lítio e moléculas de aminas) são inseridas num espaço de dimensionalidade reduzida gerado pela matriz. Já a segunda parte envolve os condutores iônicos poliméricos do tipo compósitos, nos quais foram utilizadas nanopartículas de carbono (Carbon Black) e titânio (TiO2) no eletrólito formado pelo poli(óxido de etileno) (POE) e o perclorato de lítio (LiClO4). Todos estes sistemas apresentam, em geral, uma considerável complexidade estrutural, o que significa que os movimentos moleculares e de difusão iônica se produzem num meio semicristalino (caso dos compósitos) ou num meio de dimensionalidade reduzida (caso dos intercalados). A espectroscopia de RMN dos núcleos de 7Li e 1H é uma técnica conveniente para o estudo destes materiais, pois é possível avaliar, através dos resultados obtidos das medidas dos tempos de relaxação e formas de linha, os efeitos provocados pela baixa dimensionalidade dos movimentos em estruturas laminares (caso dos intercalados), bem como identificar e aferir as interações e os mecanismos de relaxação resultantes dos diferentes graus de liberdade dos movimentos (iônicos e moleculares), fornecer parâmetros estruturais (distâncias interatômicas) que auxiliam na proposta de possíveis modelos estruturais e caracterizar completamente a escala temporal dos movimentos iônicos e moleculares.Nuclear Magnetic Resonance (RMN) techniques were used to study a series of ionic conductor materials, which present applications in the area of the solid-state electrochemical devices. The first part of this work is dedicated to the study of intercalation compounds based on the molybdenum disulfide matrix (MoS2), where the intercalated species (lithium ion and amine molecule) are inserted in the low-dimensionality space generated by the matrix. The second part involves the study of a composite polymer electrolyte, employing fillers like Carbon Black and titanium dioxide (Tio2) nano particles in the electrolyte formed by the poly(ethy1ene oxide) and a lithium salt (LiClO4). In general, these systems present a considerable structural complexity, meaning that the molecular movements and ionic diffusion are produced in a semicrystalline environment (case of the composites) or in an environment of reduced dimensionality (case of intercalates). The 7Li and 1H NMR spectroscopy is a convenient technique for the study of these materials. Relaxation time and line shape measurements may provide a tool to investigate the effects provoked by the low-dimensionality of the movements in laminate structures (case of intercalate), to identify the interactions and relaxation mechanisms of the ionic and molecular motions, to supply structural parameters (interatomic distances) that would help the proposal of possible structural models, and finally, to characterize the time scale of the ionic and molecular movements completely

Study by NMR of polymeric electrolytes, based on blends of PEO:PEG

Eletrólitos poliméricos formados à partir de PIE e um sal de metal alcalino (LiBF4, LiClO4, LiCF3SO3) tem despertado grande interesse devido ao enorme potencial de aplicação em dispositivos eletroquímicos. Nestes sistemas sólidos, a macromolécula atua como solvente para o sal que fica parcialmente dissociado na matriz polimérica originando a condutividade iônica. Na tentativa de se obter complexos cada vez mais condutivos, novos sistemas tem sido propostos. Dentre eles destacam-se a formação das blendas poliméricas. Neste trabalho foram feitas investigações por Ressonância Magnética Nuclear (RMN) para se estudar a dinâmica (iônica e molecular) das blendas [POEx:PEG1-x]8LiBF4 (x=0.75, 0.50 e 0.25). Para isso realizaram-se medidas de largura de linha e taxa de relaxação dos núcleos de 1H e 19F entre - 80°C à + 80°C na freqüência de 36 MHz. Também foram feitas medidas de análise térmica (DSC) e condutividade (?). Em algumas das composições de blendas, os dados extraídos das medidas da taxa de relaxação do 1H, revelaram dinâmicas das cadeias poliméricas do POE e PEG ocorrendo separadamente. Foi observado através da análise das medidas de ressonância do 19F, que os movimentos parecem ocorrer de forma independente aos movimentos segmentários das cadeias.Polymeric electrolytes made from POE and a alkaline metal salt (LiBF4, LiClO4, LiCF3SO3) have shown great potential in the application of electrochemical devices. In this solid systems, a macromolecule act as solvent for a salt to become partially dissociated in the polymeric matrix originating an ionic conductivity. In the attempt to obtain complexes even more conductive, new systems are proposed. Among these complexes one has distinction, polymeric blends. Investigations have been made by use of Ressonance Magnetic Nuclear (NMR), to study the ionic and molecular dynamics of this blends [POEx:PEG1-x]8LiBF4 (x=0.75, 0.50 e 0.25). For this, measurements of line width and relaxation rates of 1H and 19F in the range of -80°C to + 80°C with frequency of 36 MHz, have been done and also measurements of thermal analyse (DSC) and conductivity (?). For some blend compositions, the relaxation rate of the 1H revel that polymeric chain dynamics of POE and PEG occurs separately. It was seen by the analyse of NMR 19F measurements that the movements of the groups (BF4)- , dissociated by the polymeric matrix, seem to occur independently of the segmentary movements of the chains

Study by NMR of polymeric electrolytes, based on blends of PEO:PEG

Eletrólitos poliméricos formados à partir de PIE e um sal de metal alcalino (LiBF4, LiClO4, LiCF3SO3) tem despertado grande interesse devido ao enorme potencial de aplicação em dispositivos eletroquímicos. Nestes sistemas sólidos, a macromolécula atua como solvente para o sal que fica parcialmente dissociado na matriz polimérica originando a condutividade iônica. Na tentativa de se obter complexos cada vez mais condutivos, novos sistemas tem sido propostos. Dentre eles destacam-se a formação das blendas poliméricas. Neste trabalho foram feitas investigações por Ressonância Magnética Nuclear (RMN) para se estudar a dinâmica (iônica e molecular) das blendas [POEx:PEG1-x]8LiBF4 (x=0.75, 0.50 e 0.25). Para isso realizaram-se medidas de largura de linha e taxa de relaxação dos núcleos de 1H e 19F entre - 80°C à + 80°C na freqüência de 36 MHz. Também foram feitas medidas de análise térmica (DSC) e condutividade (?). Em algumas das composições de blendas, os dados extraídos das medidas da taxa de relaxação do 1H, revelaram dinâmicas das cadeias poliméricas do POE e PEG ocorrendo separadamente. Foi observado através da análise das medidas de ressonância do 19F, que os movimentos parecem ocorrer de forma independente aos movimentos segmentários das cadeias.Polymeric electrolytes made from POE and a alkaline metal salt (LiBF4, LiClO4, LiCF3SO3) have shown great potential in the application of electrochemical devices. In this solid systems, a macromolecule act as solvent for a salt to become partially dissociated in the polymeric matrix originating an ionic conductivity. In the attempt to obtain complexes even more conductive, new systems are proposed. Among these complexes one has distinction, polymeric blends. Investigations have been made by use of Ressonance Magnetic Nuclear (NMR), to study the ionic and molecular dynamics of this blends [POEx:PEG1-x]8LiBF4 (x=0.75, 0.50 e 0.25). For this, measurements of line width and relaxation rates of 1H and 19F in the range of -80°C to + 80°C with frequency of 36 MHz, have been done and also measurements of thermal analyse (DSC) and conductivity (?). For some blend compositions, the relaxation rate of the 1H revel that polymeric chain dynamics of POE and PEG occurs separately. It was seen by the analyse of NMR 19F measurements that the movements of the groups (BF4)- , dissociated by the polymeric matrix, seem to occur independently of the segmentary movements of the chains

Determination of Very Slow Diffusion of Paramagnetic Ions by NMR Spectroscopy

In this paper, we propose a new method of measuring the very slow paramagnetic ion diffusion coefficient using a commercial high-resolution spectrometer. If there are distinct paramagnetic ions influencing the hydrogen nuclear magnetic relaxation time differently, their diffusion coefficients can be measured separately. A cylindrical phantom filled with Fricke xylenol gel solution and irradiated with gamma rays was used to validate the method. The Fricke xylenol gel solution was prepared with 270 Bloom porcine gelatin, the phantom was irradiated with gamma rays originated from a (60)Co source and a high-resolution 200 MHz nuclear magnetic resonance (NMR) spectrometer was used to obtain the phantom (1)H profile in the presence of a linear magnetic field gradient. By observing the temporal evolution of the phantom NMR profile, an apparent ferric ion diffusion coefficient of 0.50 mu m(2)/ms due to ferric ions diffusion was obtained. In any medical process where the ionizing radiation is used, the dose planning and the dose delivery are the key elements for the patient safety and success of treatment. These points become even more important in modern conformal radio therapy techniques, such as stereotactic radiosurgery, where the delivered dose in a single session of treatment can be an order of magnitude higher than the regular doses of radiotherapy. Several methods have been proposed to obtain the three-dimensional (3-D) dose distribution. Recently, we proposed an alternative method for the 3-D radiation dose mapping, where the ionizing radiation modifies the local relative concentration of Fe(2+)/Fe(3+) in a phantom containing Fricke gel and this variation is associated to the MR image intensity. The smearing of the intensity gradient is proportional to the diffusion coefficient of the Fe(3+) and Fe(2+) in the phantom. There are several methods for measurement of the ionic diffusion using NMR, however, they are applicable when the diffusion is not very slow.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao PauloComissao Nacional de Energia Nuclear (CNEN)Comissão Nacional de Energia Nuclear (CNEN)IPENInstituto de Pesquisas Energéticas e Nucleares (IPEN

Metabolic profile of dystrophic mdx mouse muscles analyzed with in vitro magnetic resonance spectroscopy (MRS)

Duchenne muscular dystrophy (DMD) is a recessive X-linked form of muscular dystrophy characterized by progressive and irreversible degeneration of the muscles. The mdx mouse is the classical animal model for DMD, showing similar molecular and protein defects. The mdx mouse, however, does not show significant muscle weakness, and the diaphragm muscle is significantly more degenerated than skeletal muscles. In this work, magnetic resonance spectroscopy (MRS) was used to study the metabolic profile of quadriceps and diaphragm muscles from mdx and control mice. Using principal components analysis (PCA), the animals were separated into groups according to age and lineages. The classification was compared to histopathological analysis. Among the 24 metabolites identified from the nuclear MR spectra, only 19 were used by the PCA program for classification purposes. These can be important key biomarkers associated with the progression of degeneration in mdx muscles and with natural aging in control mice. Glutamate, glutamine, succinate, isoleucine, acetate, alanine and glycerol were increased in mdx samples as compared to control mice, in contrast to carnosine, taurine, glycine, methionine and creatine that were decreased. These results suggest that MRS associated with pattern recognition analysis can be a reliable tool to assess the degree of pathological and metabolic alterations in the dystrophic tissue, thereby affording the possibility of evaluation of beneficial effects of putative therapies. (C) 2012 Elsevier Inc. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Sao PauloConselho Nacional de Desenvolvimento Cientifico e TecnologicoConselho Nacional de Desenvolvimento Cientifico e TecnologicoCoordenacao de Aperfeicoamento de Pessoal de Nivel SuperiorCoordenacao de Aperfeicoamento de Pessoal de Nivel Superio

Production and characterization of fibroin hydrogel using waste silk fibers

reserved6siThe use of natural resources, especially processing wastes, as low cost and environmentally friendly alternative aiming high value-added applications is a subject of broad interest. Since the Brazilian silk production annually generates a large amount of waste during the silk fibers processing, this work explores the preparation and characterization of silk fibroin hydrogels using spinning waste silk fibers from textile processing and the processed ones. Hydrogels were obtained directly by dialyzing silk fibroin solutions against frequent changes of water until the gelation point and then lyophilized and characterized in terms of their morphology, crystallinity, thermal resistance and secondary structure. X-ray diffraction analysis revealed the presence of β-sheet conformation related to sol-gel transition. FT-IR spectra indicated the coexistence of random coil (silk I) and β-sheet (silk II) structures, with predominance of β-sheet conformation for hydrogels from processed silk fibers. From thermogravimetric analysis the presence of β-sheet secondary conformation was demonstrated by a degradation peak around 292 °C for both hydrogels. Freeze-dried hydrogels presented sheet or leaf like morphology and no significant change was observed among the hydrogels from waste silk fibers and processed ones. These characteristics suggest that silk fibroin hydrogels prepared from spinning waste silk fibers and obtained directly by dialysis can be potential candidates for biomaterials application, such as drug delivery systems and for wound dressings.mixedBexiga, Natalia Marchesan; Bloise, Antonio Carlos; de Moraes, Mariana Agostini; Converti, Attilio; Beppu, Marisa Masumi; Polakiewicz, BronislawBexiga, Natalia Marchesan; Bloise, Antonio Carlos; de Moraes, Mariana Agostini; Converti, Attilio; Beppu, Marisa Masumi; Polakiewicz, Bronisla

Atherosclerotic plaque characterization by NMR spectroscopy

Background: High resolution Magnetic Resonance Spectroscopy (MRS) in vitro was used to investigate the correlation between the chemical composition of atheromatous plaques and their stability (vulnerability to rupture) which is of fundamental importance and is a rather controversial point in literature. Methods: In this study five tissues were collected from ex vivo human abdominal aortas and divided in three groups according to their atherosclerotic lesion using the American Heart Association Committee on Vascular Lesions. Due to the semi-solid nature of the plaques, Magic Angle Spinning (MAS) and heteronuclear Decoupling (DEC) were used to acquire six 13C spectra with appreciable high resolution for five samples and the solvent. The 1H high resolution spectra also were obtained for the same samples. Results: The most common fatty acids present in the samples were identified and also the relative amounts of polyunsaturated (PUFA), unsaturated (UFA) and saturated fatty acids associated with the progress of the deterioration process of atheromatous plaques. Conclusions: NMR results show that the lipidic composition of atheromatous plaque evolves from a state with high levels of PUFA and UFA for a subject with lower classification to a new state containing, 6 and 4 times less unsaturated fatty acids respectively than those subjects with more stenotic lesions. In addition, average rate of conversion of PUFA to UFA is approximately two times higher in more stenotic lesions. These results suggest that the lipidic components of atheromatous plaque can be related to its vulnerability to rupture, which clearly demonstrate the importance of the method to study this disease.FAPES