Marco Navarro

En el presente trabajo de investigacion se reporta el desarrollo de compositos de nanoparticulas de ferritas MFe2O4 (M = Co, Mn y Mg) en una matriz de quitosan, obtenidos mediante la co-precipitacion in situ de cationes metalicos Fe3+, Co2+, Mn2+ y Mg2+, proceso que fue logrado a partir de peliculas polimericas de quelatos de estos iones en quitosan. Realizando el estudio de dichos compositos, desde su preparacion, hasta su caracterizacion por tecnicas tales como difraccion de rayos X (DRX), microscopia electronica de transmision de alta resolucion (METAR), espectroscopia de infrarrojo (IR) y magnetometria, se demostro que es posible la sintesis de nanoparticulas de ferritas espinela, a partir de la metodologia propuesta en esta tesis. A partir de los resultados obtenidos de DRX y METAR se observo que las nanoparticulas MFe2O4 sintetizadas muestran una morfologia cuasi-esferica con tamanos de entre 2 y 5 nm. Asi mismo, a partir de los resultados obtenidos por IR, se concluyo que gracias a la adhesion de las cadenas de la matriz de quitosan a la superficie de estas particulas, la distribucion de sus tamanos, observada en imagenes de METAR y la calculada a partir de los datos de magnetometria, es estrecha e independiente de la concentracion de nanoestructuras en el composito. Bajo este contexto, el analisis realizado a los patrones de DRX obtenidos mostro que, debido al reducido tamano de las particulas sintetizadas, un considerable numero de cationes presentan una coordinacion incompleta en su superficie, e inducen una presion negativa sobre la estructura cristalina de las particulas, lo cual se traduce en un aumento en la magnitud de su parametro de red. El efecto de los cationes superficiales tambien fue observado a traves de los estudios de magnetometria, en los cuales se elucido que el acoplamiento de su momento magnetico con el nucleo ferrimagnetico de las particulas crea frustracion magnetica sobre la respuesta neta del sistema. Ademas de este efecto, se observo que dicha frustracion es tambien inducida por interacciones dipolares entre los momentos magneticos de las particulas.

(Spanish) Se analizo el comportamiento productivo en corral de engorda de 67 animales con diferente grado de encaste Simmental-Gyr: 1/2 Simmental (1/2, n= 25), 3/4 Simmental (3/4, n= 23) y 7/8 Simmental (7/8, n= 19); nacidos en la misma epoca de partos ...

High-concentration-capsaicin-patches (Qutenza®) have been put on the market as a treatment for peripheral neuropathic pain. A minimum infrastructure and a determinate skill set for its application are required. Our aim was to assess the feasibility of treatment with high-concentration-capsaicin-patches in clinical practice in a variety of refractory peripheral neuropathic pain syndromes in non-diabetic patients. Observational, prospective, single-center study of patients attended to in the Pain Unit of a tertiary hospital, ≥ 18 year-old non-responders to multimodal analgesia of both genders. The feasibility for the application of capsaicin patch in clinical practice was evaluated by means of the number of patients controlled per day when this one was applied and by means of the times used for patch application. Between October 2010 and September 2011, 20 consecutive non-diabetic patients (7 males, 13 females) with different diagnoses of refractory peripheral neuropathic pain syndrom...

Hearing loss induces plasticity in excitatory and inhibitory neurotransmitter systems in auditory brain regions. Excitatory-inhibitory balance is also influenced by a range of neuromodulatory regulatory systems, but less is known about the effects of auditory damage on these networks. In this work, we studied the effects of acoustic trauma on neuromodulatory plasticity in the auditory midbrain of CBA/J mice. Quantitative PCR was used to measure the expression of serotonergic and GABAergic receptor genes in the inferior colliculus (IC) of mice that were unmanipulated, sham controls with no hearing loss, and experimental individuals with hearing loss induced by exposure to a 116 dB, 10 kHz pure tone for 3 h. Acoustic trauma induced substantial hearing loss that was accompanied by selective upregulation of two serotonin receptor genes in the IC. The Htr1B receptor gene was upregulated tenfold following trauma relative to shams, while the Htr1A gene was upregulated threefold. In contras...

INTRODUCTION: Heart rate recovery (HRR) after maximal effort is an indicator of autonomic function and is related to mortality in different diseases. This study was aimed to estimate prevalence of autonomic dysfunction in patients with chronic obstructive pulmonary ...

... ESTUDO DA INFLUÊNCIA DA NATUREZA DE RETICULANTES E ADITIVOS ORGÂNICOS SOBRE O ... 14 g/L e 14,28 g/L) em acído acético 3% (v /v) . Os sistemas gelificantes foram preparados em tubos de ensaio (40x100mm) pela adição do agente de reticulação ...

Se reclutaron los pacientes antes de realizar una artroplastia total de rodilla. Se midió la fuerza muscular de los flexores y los extensores de la rodilla (FR, ER) con el dinamómetro NMMT, mediante un protocolo estándar, con una prueba isométrica y un diseño test-retest. Se calcularon ...

The objective of this retrospective study was to compare the maximumintercuspation (MI) and centric relation (CR) disharmony between 3 groups of postcomprehensive orthodontic patients. In group 1 (gnathologic, n = 11), diagnosis, treatment planning, and therapy were assessed and monitored using a gnathological treatment approach by using the Roth straight-wire appliance (A Company, San Diego, CA) and appropriate MI-CR conversions, model mountings, and pregnathologic positioner evaluation. Group 1 patients were evaluated for MI and CR harmony after placement of a gnathologic positioner and 3 weeks of 24-hour gnathological splint wear. Condylar position changes between MI and CR were recorded with the Panadent Condylar Position Indicator (CPI; Panadent Corp, Grand Terrace, CA). Group 2 patients (non-gnathologic, n = 14) were treated with a nongnathologic philosophy using the Roth straight-wire appliance. Diagnosis, treatment planning, and therapy were done using hand-held models trimm...