• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 3
  • 2
  • 2
  • 1
  • Tagged with
  • 22
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Del etnovaivén al etnobúmeran: identidad cultural, estrategias de resistencia e impronta literaria del subalterno en el Perú

Otero Luque, Frank 15 May 2017 (has links)
In my dissertation, I explore social strategies that Peruvian subalterns have developed to survive against racism and discrimination. I have identified and coined one of these strategies as etnovaivén (ethno-sway), which I define as a pendulum-like approach that allows subalterns to swing/sway from blanqueamiento to cholificación, and vice versa. In this context, blanqueamiento (whitening) mainly refers to the subaltern's willingness and efforts to assimilate the white culture in order achieve upward social mobility, whereas cholificación depicts the reluctance of Indian and mestizo subalterns to assimilate the cultural norms of the dominant group in certain circumstances, while asserting their own ethnic identity. Conversely, etnobúmeran (ethno-boomerang) is a self-inflicted boycott to one’s own ethnic groups. I claim that Peruvian subalterns shape their cultural singularity between ethno-sway and ethno-boomerang. My research has examined these social phenomena as reflected in the Inca Garcilaso de la Vega’s Comentarios reales (1609), Clorinda Matto de Turner’s Aves sin nido (1889), and Enrique López Albújar’s Matalaché (1928). In addition, in La ciudad y los perros (1963) by Mario Vargas Llosa, Montacerdos (1981) by Cronwell Jara, La violencia del tiempo (1991) by Miguel Gutiérrez, and Hienas en la niebla (2010) by Juan Morillo, I have analyzed the historical connection between miscegenation, discrimination, inequality and violence, which progressively led to the Internal Conflict (1980-2000), the goriest and longest war in Peru’s republican history that resulted in the assassination of approximately 70 000 persons, most of them Quechua-speaking, ordinary civilians. Highlanders fleeing from terrorism during those two decades account for the depopulation of over 2/3 of the Andean region. This study is both relevant and pertinent because it intersects with contemporary debates about national identity formation, and because it provides a means to understand the aftermath of political violence, a phenomenon that periodically threatens the lives of Peruvians. My work contests the traditional thesis of racial and cultural miscegenation as the foundation of Peruvian national identity (the "melting pot" metaphor), which has proven to be ineffective. Instead, I propose a more inclusive identity concept that celebrates cultural diversity and accepts the coexistence of multiple ethnic and cultural groups within the confines of the nation.
22

SÃntese de Microesferas e NanopartÃculas de Quitosana e Goma do Chichà (Sterculia striata) como Matriz para LiberaÃÃo Controlada de FÃrmaco para Tratamento da MalÃria

Guilherme Augusto Magalhaes Junior 20 April 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Este trabalho tem como objetivo a sÃntese e caracterizaÃÃo de nano e micropartÃculas para liberaÃÃo de fÃrmaco para tratamento da malÃria. Microesferas de quitosana de alta massa molar (QTa) e goma do chichà (CH) foram sintetizadas por complexaÃÃo polieletrolÃtica e reticuladas com glutaraldeÃdo. Os diÃmetros das microesferas reticuladas e nÃo-reticuladas foram de 544  3 μm e 558  2 μm, respectivamente. As esferas reticuladas nÃo foram solÃveis em meio Ãcido (pH 1,2). Ensaios de intumescimento mostraram que as microesferas intumesciam mais em pH 1,2 do que em pH 7,4 e que as reticuladas possuÃam menor intumescimento do que as nÃo reticuladas. A liberaÃÃo sequenciada de cloroquina, a partir das microesferas, foi realizada por 2 h em pH 1,2 seguida por uma liberaÃÃo em pH 7,4. A microesfera reticulada liberou 64% da cloroquina em pH 1,2, com um total do fÃrmaco liberado de 92%. O perfil de liberaÃÃo da mesma amostra em pH 7,4 apresenta uma liberaÃÃo controlada do fÃrmaco por cerca de 50 h. NanopartÃculas de QT e CH foram produzidas utilizando como rotas de sÃntese a complexaÃÃo polieletrolÃtica e formaÃÃo de base de Schiff. Na formaÃÃo de complexos polieletrolÃticos parÃmetros como massa molar da quitosana, razÃo molar de carga (n+/n-), ordem de adiÃÃo e concentraÃÃo dos polieletrÃlitos influenciam no tamanho, potencial zeta, Ãndice de polidispersividade e estabilidade das nanopartÃculas em soluÃÃo. O potencial zeta das partÃculas com excesso de QT à positivo e quando se diminui a razÃo molar de carga (n+/n-) para 0,1 o potencial torna-se negativo devido o excesso de chichÃ. Os diÃmetros das nanopartÃculas variaram de 80 a 1200 nm dependendo da concentraÃÃo dos polieletrÃlitos e da quitosana utilizada. NanopartÃculas formadas por quitosana de baixa massa molar (QTb) possuem tamanho maior do que as formadas por quitosana de alta massa molar (QTa). Quando a razÃo de cargas (n+/n-) e a concentraÃÃo dos polieletrÃlitos diminuem o tamanho das nanopartÃculas tambÃm diminui. Na liberaÃÃo da cloroquina em matrizes de CH, QTa e QTb de razÃo 5 e 0,1 duraram cerca 15 dias liberando atà 99% do fÃrmaco, porÃm apenas a razÃo de cargas influenciou no perfil da liberaÃÃo. NanopartÃculas formadas via base de Schiff foram preparadas. A influÃncia de parÃmetros tais como: grau de oxidaÃÃo da goma do chichÃ, massa molar da quitosana, ordem de adiÃÃo e razÃo entre as massas dos polissacarÃdeos foram investigados em relaÃÃo ao tamanho, potencial zeta e estabilidade. O potencial zeta mostrou-se positivo para partÃculas com excesso de QT e negativo para partÃculas com excesso de CH. Os diÃmetros das partÃculas variaram de 30 a 450 nm, dependendo do grau de oxidaÃÃo do CH e da massa molar de QT. Para goma do chichà com menor grau de oxidaÃÃo nanopartÃculas de QTa apresentaram-se maiores do que as formadas por QTb, e para a goma com maior grau de oxidaÃÃo nanopartÃculas de QTb possuÃam maiores tamanhos do que as formadas por QTa. / The aim of this work was the synthesis and characterization of nano and microparticles for malaria drug delivery system. Chitosan microspheres of high molar mass (QTa) and chichà gum (CH) were synthesized by polyelectrolyte complexation and crosslinked with glutaraldehyde. The diameters of the microspheres crosslinked and non-crosslinked were 544  3 μm and 558  2 μm, respectively. The crosslinked beads were not soluble in acidic medium (pH 1.2). The swelling of microspheres was higher in pH 1.2 and that the crosslinked beads have less swelling than non-crosslinked. The sequential release of chloroquine from the microspheres was performed for 2 h followed by a release in pH 7.4. The crosslinked microsphere released 64% of chloroquine at pH 1.2, with a total of drug released of 92%. The release profile of the same sample at pH 7.4 provides a controlled release of the drug for about 50h. QT and CH nanoparticles were prepared using polyelectrolyte complexation and formation of Schiff base. In the formation of polyelectrolyte complex, parameters such as molecular weight of chitosan, the molar ratio of charge (n+/ n-), order of addition and concentration of the polyelectrolyte influence the size, zeta potential, polydispersity index and stability of the nanoparticles in solution. The zeta potential of particles in excess of QT was positive and when the charg molar ratio (n+/ n ) decreases to 0.1 the potential becomes negative due to the excess of CH. The nanoparticles diameters vary from 80 to 1,200 nm depending on the concentration of the polyelectrolyte and the chitosan used. Chitosan nanoparticles formed by a low molecular weight (QTb) were larger than those formed by chitosan of high molecular weight (QTa). The decrease of the charge ratio (n+/n-) and the polyelectrolyte concentrations lead to small size nanoparticle. The release of chloroquine in matrices of CH, QTa and QTb ratio ratio 5 and 0.1 lasted 15 days by releasing up to 99% of the drug, however only the ratio influenced the release profile. Nanoparticles formed by Schiff base reaction were produced. The influence of parameters such as degree of oxidation of CH, chitosan molar mass, addition and masses ration of polysaccharides on size, zeta potential and stability were investigated. The zeta-potential was positive for particles with an excess of QT and negative with excess CH. The particle diameters ranged from 30 to 450 nm, depending on the degree of oxidation of CH and the molar mass of QT. Particle formed with low oxidation of CH and high molar mass chitosan are bigger than those formed with low molar mass chitosan. A inverse behavior was observed when high oxidated CH was used.

Page generated in 0.0238 seconds