Efectividad de la deslaminación mecánica con bisturí en la eliminación de helomas e hiperqueratosis

Introducción El motivo principal por el que acuden los pacientes a las consultas de podología es el dolor producido por los callos y callosidades plantares. El dolor producido por las callosidades y callos plantares provocan en el paciente cambios de presiones y alteraciones en el apoyo, dificultando la deambulación correcta. Existen numerosos estudios sobre la eliminación de callosidades en pacientes diabéticos, con AR, pero pocos en personas sanas. La eliminación de estos callos y callosidades se puede realizar mediante deslaminación mecánica con bisturí o mediante queratolíticos. Objetivos Objetivo principal Analizar el efecto de la deslaminación mecánica con bisturí de las callosidades y callos plantares sobre el dolor y la calidad de vida en sujetos sanos Objetivos secundarios Determinar la existencia de modificaciones en los parámetros de la marcha con la eliminación de callosidades y callos plantares Observar las diferencias y efectividad de tratamientos de la eliminación de callosidades plantares mediante la técnica de deslaminación mecánica con bisturí versus parches de ácido salicílico Comprobar los cambios producidos en los parámetros psíquicos y fiscos del paciente antes y después de las diferentes técnicas de eliminación de las callosidades empleadas Método Se realizan dos estudios: un estudio cuasi experimental aleatorizado no controlado, en el que a un grupo de 34 pacientes con callosidades plantares dolorosas se les mide el dolor con una escala visual analógica y para analizar los parámetros de la marcha, la paltaformaWin-Track, antes del tratamiento de deslaminación mecánica con bisturí y a las 24 horas. El segundo estudio es un ensayo clínico aleatorizado inscrito en Australian New ZelandClinicalstrials y aprobado por el Comité ético de la Universidad de Málaga, en el que 62 participantes con callosidades plantares dolorosas se dividieron en dos grupos de tratamiento. El grupo A recibió tratamiento con parche de ácido salicílico y el grupo B recibió tratmiento de deslaminación con bisturí. Se utilizó la escala visual analógica para la medida de dolor antes, inmediatamente después de la intervención, a las 2 semanas y a las 6 semanas. Para el dolor y la discapacidad funcional del pie se utilizó el cuestionario Manchester FootPain and Disability antes del tratamiento, a las 2 semanas y a las 6 semanas. Para medir la calidad de vida general se utilizó el cuestionario SF-12 Conclusiones La deslaminación mecánica con bisturí de los callos y callosidades plantares es efectiva para su eliminación a nivel de la sensación de dolor, aunque no tanto en lo que se refiere a la mejora de calidad de vida. No hay resultados significativos de que la eliminación mecánica con bisturí de callos y callosidades plantares modifican los parámetros de la marcha medido con la plataforma Win-track. Se observa como la deslaminación mecánica con bisturí para la eliminación de callos y callosidades plantares pueden ser más efectiva a corto plazo que la eliminación mediante parche con ácido salicílico. Se observa cómo se modifica los paramentos psíquicos en el grupo de tratamiento con parche con ácido salicílico, aunque con una significación baja. Bibliografía Balanowski, K. R., & Flynn, L. M. (2005). Effect of painful keratoses debridement on foot pain, balance and function in older adults. Gait & Posture, 22(4), 302-307. http://doi.org/10.1016/j.gaitpost.2004.10.006 Collins, S. L., Moore, R. A., &McQuay, H. J. (1997). The visual analogue pain intensity scale: what is moderate pain in millimetres? Pain, 72(1-2), 95-97. Coughlin, M. J. (2000).Common Causes of Pain in the Forefoot in Adults. Journal of Bone & Joint Surgery, British Volume, 82-B(6), 781-790. Farndon, L. J., Vernon, W., Walters, S. J., Dixon, S., Bradburn, M., Concannon, M., & Potter, J. (2013). The effectiveness of salicylic acid plasters compared with «usual» scalpel debridement of corns: a randomised controlled trial. Journal of Foot and Ankle Research, 6(1), 40. http://doi.org/10.1186/1757-1146-6-40 Freeman, D. B. (2002). Corns and calluses resulting from mechanical hyperkeratosis. American FamilyPhysician, 65(11), 2277-2280. Gijon-Nogueron, G., Ndosi, M., Luque-Suarez, A., Alcacer-Pitarch, B., Munuera, P. V., Garrow, A., & Redmond, A. C. (2014). Cross-cultural adaptation and validation of the Manchester Foot Pain and Disability Index into Spanish. Quality of Life Research: An International Journal of Quality of Life Aspects of Treatment, Care and Rehabilitation, 23(2), 571-579. http://doi.org/10.1007/s11136-013-0507-5 Grouios, G. (2005). Footedness as a potential factor that contributes to the causation of corn and callus formation in lower extremities of physically active individuals. The Foot, 15(3), 154-162. http://doi.org/10.1016/j.foot.2005.05.003 Landorf, K. B., Morrow, A., Spink, M. J., Nash, C. L., Novak, A., Potter, J., &Menz, H. B. (2013). Effectiveness of scalpel debridement for painful plantar calluses in older people: a randomized trial. Trials, 14, 243. http://doi.org/10.1186/1745-6215-14-243 Lang, L. M. G., Simmonite, N., West, S. G., & Day, S. (1994). Salicylic acid in the treatment of corns. The Foot, 4(3), 145-150. http://doi.org/10.1016/0958-2592(94)90019-1 Luo, X., Lynn George, M., Kakouras, I., Edwards, C. L., Pietrobon, R., Richardson, W., & Hey, L. (2003). Reliability, validity, and responsiveness of the short form 12-item survey (SF-12) in patients with back pain. Spine, 28(15), 1739-1745. http://doi.org/10.1097/01.BRS.0000083169.58671.96 Ramachandra, P., Maiya, A. G., & Kumar, P. (2012). Test-retest reliability of the Win-Track platform in analyzing the gait parameters and plantar pressures during barefoot walking in healthy adults. Foot & Ankle Specialist, 5(5), 306-312. http://doi.org/10.1177/1938640012457680 Siddle, H. J., Redmond, A. C., Waxman, R., Dagg, A. R., Alcacer-Pitarch, B., Wilkins, R. A., &Helliwell, P. S. (2013). Debridement of painful forefoot plantar callosities in rheumatoid arthritis: the CARROT randomised controlled trial. Clinical Rheumatology, 32(5), 567-574. http://doi.org/10.1007/s10067-012-2134-x

Estudo da zircônia reforçado com alumina

Ceramics materials have good properties including chemical stability, high hardness and wear resistance. Moreover, due to its fragility, can suffer failure under relatively low levels of tension. Actually zirconia is the material of choice in metal free dental prostheses used in dentistry due its inertia in physiological environment, good bending strength, hardness and fracture toughness. The alumina and mixed tungsten and titanium carbides additions, acting as reinforcement elements in the zirconia matrix, have as their main objective the improvement of mechanical properties of this material. In this work, samples of zirconia, zirconia with 30% wt of alumina and zirconia with 30% wt mixed carbides were analyzed. The samples were sintered by uniaxial hot pressing on 30 MPa pressure, for 1 hour in an argon atmosphere. They were physically characterized by porosity and density measurements, and mechanically by 3-points bending strength and Vickers microhardness. The X-ray diffraction was used for the phase identifications and microstructure was examined by scanning electron microscopy (SEM). The addition of mixed carbides as reinforcement elements in zirconia matrix provides improvements in all properties analyzed in this work. The alumina addition has dropped the zirconia strength, although it caused improvement in other properties

Caracterização termo-mecânica de interconectores metálicos recobertos com filmes de LaCrO3

The cells unitaria of the solid oxide fuel cell are separated by means of interconnects, which serve as electrical contact between the cells. Lanthanum Chromite (LaCrO3) has been the most common material used as interconnect in solid oxide fuel cells. Reducing the operating temperature around 800 º C of cells to solid oxide fuel make possibilite the use of metallic interconnects as an alternative to ceramic LaCrO3. Metallic interconnects have advantages over ceramic interconnects such as high thermal conductivity, electricity, good ductility, low cost, good physical and mechanical properties. In this work evaluate the thermo-mechanical properties of the metallic substrate and coated metallic substrate with the ceramic LaCrO3 film via spray-pyrolysis, in order to demonstrate the feasibility of using this material as a component of a fuel cell solid oxide. The materials were characterized by X-ray diffraction, oxidation behavior, mechanical strength, optical microscopy (OM) and scanning electron microscopy (SEM). The X-ray diffraction proved the formation phase of the LaCrO3 on the metallic substrate and the identification of the phases formed after the oxidative test and mechanical strength at high temperature. The oxidation behavior showed the increased oxidation resistance of the coated metallic substrate. It was noted that the mechanical resistance to bending of the coated metallic substrate only increases at room temperature. The optical microscopy (OM) has provided an assessment of both the metallic substrate and the LaCrO3 film deposited on the metal substrate that, in comparison with the micrographs obtained from SEM. The SEM one proved the formation of Cr2O3 layer on the metallic substrate and stability of LaCrO3 film after oxidative test, it can also observe the displacement of the ceramic LaCrO3 film after of mechanical testing and mapping of the main elements as chromium, manganese, oxygen, lanthanum in samples after the thermo-mechanical tests.

Física conceptos básicos de la mecánica

Me alegra escribir esta primera lección con el rigor y la precisión de su documento cuyo compromiso es con la información y la formación al estudiante, y por ello debo estar atento y ser exigente en los temas aquí tratados. Esta y las demás lecciones recogen lo más importante en el área de la Física que los profesionales docentes casi nunca han puesto por escrito y al público; sus preparaciones de clase ordenadas, organizadas, y los resultados de sus trabajos, sus propuestas, sus consultas, sus reflexiones. Generalmente poco se considera que la experiencia propia, la experiencia personal es tan trascendental y tan válida como los resultados de una investigación. Este es un nuevo reto que, como sucede con las Lecciones de Matemáticas, dará fruto y excelente resultado, proporcionando los conocimientos y conceptos básicos de Física para fundamentar su estatus académico en la comunidad estudiantil. Así nos sentiremos satisfechos por dar sentido al trabajo realizado reconociendo hacia dónde caminar, en qué profundizar, cómo crear adaptaciones y darles perfil a las aplicaciones, intentando mejorar la relación enseñanza aprendizaje y dar así respuesta a necesidades del entorno. Agradezco a aquellos que deseen aportar sus sugerencias para que en un futuro tengamos un texto mejor para una excelente formación científica de nuestros estudiantes.

Otimização e análise mecânica de pastas geopoliméricas para uso em poços sujeitos à injeção cíclica de vapor

Oil wells subjected to cyclic steam injection present important challenges for the development of well cementing systems, mainly due to tensile stresses caused by thermal gradients during its useful life. Cement sheath failures in wells using conventional high compressive strength systems lead to the use of cement systems that are more flexible and/or ductile, with emphasis on Portland cement systems with latex addition. Recent research efforts have presented geopolymeric systems as alternatives. These cementing systems are based on alkaline activation of amorphous aluminosilicates such as metakaolin or fly ash and display advantageous properties such as high compressive strength, fast setting and thermal stability. Basic geopolymeric formulations can be found in the literature, which meet basic oil industry specifications such as rheology, compressive strength and thickening time. In this work, new geopolymeric formulations were developed, based on metakaolin, potassium silicate, potassium hydroxide, silica fume and mineral fiber, using the state of the art in chemical composition, mixture modeling and additivation to optimize the most relevant properties for oil well cementing. Starting from molar ratios considered ideal in the literature (SiO2/Al2O3 = 3.8 e K2O/Al2O3 = 1.0), a study of dry mixtures was performed,based on the compressive packing model, resulting in an optimal volume of 6% for the added solid material. This material (silica fume and mineral fiber) works both as an additional silica source (in the case of silica fume) and as mechanical reinforcement, especially in the case of mineral fiber, which incremented the tensile strength. The first triaxial mechanical study of this class of materials was performed. For comparison, a mechanical study of conventional latex-based cementing systems was also carried out. Regardless of differences in the failure mode (brittle for geopolymers, ductile for latex-based systems), the superior uniaxial compressive strength (37 MPa for the geopolymeric slurry P5 versus 18 MPa for the conventional slurry P2), similar triaxial behavior (friction angle 21° for P5 and P2) and lower stifness (in the elastic region 5.1 GPa for P5 versus 6.8 GPa for P2) of the geopolymeric systems allowed them to withstand a similar amount of mechanical energy (155 kJ/m3 for P5 versus 208 kJ/m3 for P2), noting that geopolymers work in the elastic regime, without the microcracking present in the case of latex-based systems. Therefore, the geopolymers studied on this work must be designed for application in the elastic region to avoid brittle failure. Finally, the tensile strength of geopolymers is originally poor (1.3 MPa for the geopolymeric slurry P3) due to its brittle structure. However, after additivation with mineral fiber, the tensile strength became equivalent to that of latex-based systems (2.3 MPa for P5 and 2.1 MPa for P2). The technical viability of conventional and proposed formulations was evaluated for the whole well life, including stresses due to cyclic steam injection. This analysis was performed using finite element-based simulation software. It was verified that conventional slurries are viable up to 204ºF (400ºC) and geopolymeric slurries are viable above 500ºF (260ºC)

Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

Formulação de pastas cimentícias com adição de suspensões de quitosana para cimentação de poços de petróleo

Primary cementing is one of the main operations in well drilling responsible for the mechanical stability and zonal isolation during the production of oil. However, the cement sheath is constantly under mechanical stresses and temperature variations caused by the recovery of heavy oil. In order to minimize fracture and wear of the cement sheath, new admixtures are developed to improve the properties of Portland cement slurries and avoid environmental contamination caused by leaking gas and oil. Polymers with the ability to form polymeric films are candidates to improve the properties of hardened cement slurries, especially their fracture energy. The present study aimed at evaluating the effect of the addition of a chitosan suspension on cement slurries in order to improve the properties of the cement and increase its performance on heavy oil recovery. Chitosan was dissolved in acetic ac id (0.25 M and 2 M) and added to the formulation of the slurries in different concentrations. SEM analyses confirmed the formation of polymeric films in the cementitious matrix. Strength tests showed higher fracture energy compared to slurries without the addition of chitosan. The formation of the polymeric films also reduced the permeability of the slurry. Therefore, chitosan suspensions can be potentially used as cementing admixtures for heavy oil well applications

Fabricación y caracterización físico-mecánica de biocomposites reforzados con fibras naturales. Aplicaciones en el sector náutico.

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Utilização de nanosílica como aditivo estendedor para pastas cimentantes de baixa densidade destinadas à cimentação de poços petrolíferos

Cementing operations are conducted at different times of the well s life and they have high importance, because the functions are fundamental to keep good properties during a long life of the well, such as, maintain the mechanical stability of the well, to promote the isolation hydraulic and support the tubing. In some situations, the rocky zones have low fractures pressures and require the use of lightweight slurries to prevent the hydrostatic pressure in the formation is greater than the pressure of fracture. There are three ways to reduce the density of cement slurries: exterders water additives, microspheres and foamed slurries. The most used extender water additive is sodium bentonite, which is a clay with a good capacity of water absorption and expansion of its volume, the main disadvantage of this additive is the reduction of the strength. Currently, the use of nanoscale particles has received special attention, mainly because they get new functionalities. Following this trend, this paper aims to use a colloidal solution of nano-silica as an exterders water additives for use in oil wells. Slurries were designed with fixed 13lb/gal density and concentration of nano silica 0.1 gpc; 0.4 gpc; 0.7 and 1gpc, the influence of nano-silica was studied at these levels in isolation and combined varying concentrations of CaCl2,. Tests including rheology, stability, strength, thickening time, porosity and permeability. Besides the API tests, microstructural characterizations were performed after 28 days of the slurries, X-ray diffraction (XRD) and scanning electron microscopy (SEM)

Efeito da incorporação de diatomita na estabilidade e permeabilidade de compósitos cimentíceos espumados aplicados a poços de petróleo

Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

Fratura traumática do osso temporal : diagnóstico, sequelas e tratamento

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Ing. Aurelio Salvador Fernández González : director de la EIAO que elevó mecánica a facultad

Aurelio Fernández G, fue alumno fundador de la Preparatoria Técnica “Álvaro Obregón” de la que llegó a ser su director luego de titularse en la Escuela Superior de Ingeniería Mecánica y Eléctrica y al tiempo de desarrollar su trayectoria profesional en el Departamento de Laminados de Fundidora Monterrey.