Tratamiento del deslizamiento epifisiario capital femoral con fijación in situ versus luxación quirúrgica

Introducción: El Deslizamiento Epifisiario Capital Femoral es la enfermedad de la cadera más común en adolescentes entre los 9 y 16 años. Es de causa idiopática, más frecuente en hombres, se clasifica en 4 estadios según criterios clínicos y radiológicos. Se buscó evaluar la evolución de los deslizamientos moderados y severos tratados con una de las dos técnicas propuestas. Metodología Se realizó un estudio descriptivo con pacientes que fueron llevados a fijación in situ o luxación controlada entre 2008 y 2011. Resultados: Se incluyeron 26 pacientes, los cuales el 65.4% se les realizó luxación quirúrgica controlada y el 34.6% fijación in situ. El 70,6% de pacientes tenían DECF inestable y 70,5% tenían desplazamiento severo. La evaluación de la escala WOMAC para dolor, rigidez y capacidad funcional encontró mejores beneficios para el grupo de fijación in situ, estadísticamente significativos (p<0,05), no solo en términos de dolor, rigidez y capacidad funcional sino menor frecuencia de complicaciones. Las complicaciones más frecuentes en el grupo de luxación quirúrgica controlada fueron un caso de infección, 7 casos (41,2%) de necrosis avascular de cabeza femoral, 5 casos (29,4%) de condrolisis y 2 casos (11,8%) de pseudoartrosis; En el grupo de fijación in situ, solo 1 (11,1%) presentó Infección del Sitio Operatorio y 1 (11,1%) Condrolisis. Resultados significativos solo para necrosis avascular. Discusión: Los pacientes con deslizamientos moderados y severos manejados con fijación in situ tuvieron una mejor resultado con menor proporción de complicaciones.

Low-frequency volatility of real estate securities in relation to macroeconomic risk

Real estate securities have a number of distinct characteristics that differentiate them from stocks generally. Key amongst them is that under-pinning the firms are both real as well as investment assets. The connections between the underlying macro-economy and listed real estate firms is therefore clearly demonstrated and of heightened importance. To consider the linkages with the underlying macro-economic fundamentals we extract the ‘low-frequency’ volatility component from aggregate volatility shocks in 11 international markets over the 1990-2014 period. This is achieved using Engle and Rangel’s (2008) Spline-Generalized Autoregressive Conditional Heteroskedasticity (Spline-GARCH) model. The estimated low-frequency volatility is then examined together with low-frequency macro data in a fixed-effect pooled regression framework. The analysis reveals that the low-frequency volatility of real estate securities has strong and positive association with most of the macroeconomic risk proxies examined. These include interest rates, inflation, GDP and foreign exchange rates.

Synthesis of L1(0) Fe-Pd films by electrodeposition and thermal annealing

Fe-Pd alloy films have been prepared by electrochemical deposition from an alkaline electrolyte containing Fe sulfate, Pd chloride and 5-sulfosalicylic acid onto polycrystalline titanium substrates. The as-deposited films were nanocrystalline and magnetically soft (coercivity similar to 25 Oe). L1(0) Fe-Pd films with a (111) preferred orientation were obtained by post-deposition thermal annealing of films with composition about 37 at% Fe in an (Ar + 5% H-2) gas flow at 500 degrees C. Such films exhibit hard magnetic properties, with a coercivity up to 1880 Oe, and a slightly anisotropic magnetic response, with a larger in-plane remanence. Preliminary magnetic investigations support magnetization switching through pinning of domain walls. (c) 2008 Elsevier B.V. All rights reserved.

Depinning do fluxo de Josephson em compósitos YBa 2 Cu 3 O 7-delta/Ag

Apresenta-se neste trabalho um estudo experimental da dinâmica do fluxo magnético intergranular no cuprato supercondutor Y Ba2Cu3O7 e nos compósitos Y Ba2CU3O7 fi/Ag para várias concentrações de prata. Verificou-se que sob certas condições é possível separar os efeitos da dinâmica do fluxo de Josephson daqueles resultantes da dinâmica de Abrikosov. Através da técnica de medidas de magnetização DC foram obtidas as linhas de depinning inicial e de irreversibilidade magnética em campo magnético aplicado até 120 Oe. O revestimento dos grãos supercondutores aparentemente não afeta a energia de acoplamento dos elos fracos entre os grãos e o potencial de pinning até 16.1 % em peso de prata. A vantagem da mistura da prata é que esta melhora as propriedades mecânicas dos óxidos supercondutores além de melhorar as correntes críticas do sistema. Observamos que o depinning do fluxo de Josephson começa numa temperatura bem definida, dependendo do campo magnético aplicado e gradualmente aumenta com a temperatura até ou muito próximo do limite de irreversibilidade, acima do qual todo o fluxo intergranular (e intragranular) está livre. As linhas de irreversibilidade das nossas amostras podem ser entendidas dentro do modelo do Vidro supercondutor.

Ultra-som pulsado de baixa intensidade em fraturas diafisárias: aplicação clínica em cães

Os efeitos da estimulação ultra-sônica sobre a consolidação óssea têm sido demonstrados por trabalhos experimentais e clínicos. Este estudo teve por objetivo investigar a aplicação clínica do ultra-som pulsado de baixa intensidade como tratamento adjuvante de fraturas diafisárias em cães. Foram utilizados 16 cães de raças variadas, com faixa etária entre sete meses e seis anos, peso corpóreo entre 2,5 e 43kg, portadores de fraturas diafisárias fechadas recentes localizadas no rádio e ulna, fêmur ou tíbia e fíbula, estabilizadas por procedimentos de osteossíntese (fixação esquelética externa, pinos intramedulares ou a associação desses métodos). Os cães foram divididos em dois grupos: fraturas estabilizadas tratadas por ultra-som de baixa intensidade (grupo tratado, n=8); fraturas estabilizadas, não tratadas por estimulação ultra-sônica, (grupo controle, n=8). Os animais foram avaliados por exames clínicos e radiográficos nos períodos pré-operatório, pós-operatório imediato e a cada 30 dias posteriores aos procedimentos cirúrgicos. Realizou-se tratamento com ultra-som pulsado (sinal senoidal com freqüência de 1,5MHz, largura de pulso de 200µs e freqüência de repetição de 1kHz) de baixa intensidade (30mW cm-2), aplicado de modo estacionário no foco de fratura. A terapia ultra-sônica foi realizada 20 minutos por dia, durante 21 dias consecutivos, a partir do período compreendido entre o 1° e o 9° dia pós-operatório. O teste t de Student, empregado na análise estatística, mostrou diferença significante (P<0,001 e alfa=0,05) entre as médias dos parâmetros de tempo para consolidação óssea observadas nos animais dos grupos tratado (média de 67,5 dias) e controle (média de 106 dias). Este protocolo de estimulação ultra-sônica promoveu sinais clínicos e radiográficos acelerados da consolidação óssea nas fraturas tratadas. Os resultados deste estudo sugerem que o ultra-som pulsado de baixa intensidade pode ser indicado como terapia adjuvante de fraturas diafisárias recentes em cães.

Vortex-Antivortex Dynamics in a Mesoscopic Superconducting Prism with a Centered Antidot

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Vortex-antivortex annihilation dynamics in a square mesoscopic superconducting cylinder

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reintrodução na natureza do tamanduá-bandeira (Myrmecophaga tridactyla)após osteossíntese de rádio e ulna

A female, adult, 27 kg Giant Anteater (Myrmecophaga tridactyla) was directed to the veterinary hospital by the Center ofSelection of Wild Animals (Cetas) of the Brazilian Institute for the Environment and Renewable Natural Resources (Ibama), afterit was found on a highway. After clinical and radiologic examination, radius and ulna fractures of the left thoracic memberwere observed. Taking in consideration to the physical status of the animal, its size, the type of fracture and resources availablein the hospital veterinary, internal fixation with Intramedullary Pinning (on the Radius and Ulna) was the treatment methodchosen. About 35 days after the surgery the animal was walking without difficulties and by x-ray it was possible to observeformation of callus. The presence of decurrent bony deformities due to the type of fixation was not found. As the animal presentedno more difficulties in walking, we opted for its reintroduction to its original environment. The aim of the present casestudy is sharing the results of the Intramedullary Pinning implantation technique, widely used in dogs and cats, now used in a Giant Anteater (Myrmecophaga tridactyla).

Influence of ball-milled low purity boron powder on the superconductivity of MgB2

MgB2 samples were prepared using as-supplied commercial 96% boron with strong crystalline phase and the same 96% boron (B) after ball milling. The effects of the properties of the starting B powder on the superconductivity were evaluated. We observed that samples using ball-milled 96% B, in comparison with the one made from the as-supplied 96% B, were character- ized by small grain size, broadened full width at half maximum (FWHM), and enhanced magnetic critical current density (J(c)). J(c) reached 2 x 10(3) Acm(-2) at 5 K and 8 T. The improved pinning of these samples seems to be caused by enhanced grain boundary pinning at high field.

Addition of Ca-compounds nanoparticles in melt-textured Bi : 2212

Superconducting BSCCO samples made by melt-texturing process were prepared with the addition of calcium zirconate and calcium silicate nanoparticles. Bi:2212 melt-textured composites prepared with I wt.% of either addition showed different behavior for the critical current density as a function of the applied field, indicating that for each additional compound the improvement can be associated to different enhancement mechanisms, such as the creation of pinning centers and the increase on the connectivity of the grains. The estimated pinning forces indicated higher values for the calcium compound containing samples. (c) 2007 Elsevier B.V. All rights reserved.

The effect of microwave annealing on the electrical characteristics of lanthanum doped bismuth titanate films obtained by the polymeric precursor method

Lanthanum doped bismuth titanate thin films (Bi3.25La0.75Ti3O12-BLT) were produced by the polymeric precursor method and crystallized in a domestic microwave oven and in conventional furnace. Using platinum coated silicon substrates configuration, ferroelectric properties of the films were determined with remanent polarization P-r and a coercive field E-c of 3.9 mu C/cm(2) and 70 kV/cm for the film annealed in the microwave oven and 20 mu C/cm(2) and 52 kV/cm for the film annealed in conventional furnace, respectively. The films annealed in conventional furnace exhibited excellent retention-free characteristics at low infant periods indicating that BLT thin films can be a promise material for use in nonvolatile memories. on the other hand, the pinning of domains wall causes a strong decay at low infant periods for the films annealed in the microwave furnace which makes undesireable the application for future FeRAMS memories. (c) 2005 Elsevier B.V. All rights reserved.

Surface effects on moving vortices in superconducting stripes

Size and surface dynamical effects are investigated in thin superconducting stripes with variable width. We perform numerical simulations of the vortex dynamics, with the inclusion of the surface confining potential and a random distribution of pinning centers. To fully characterize the vortex flow, we calculate the differential resistance, the transverse diffusion coefficient, the structure factor and the intensity of the Bragg peaks, as functions of the transport force. We found that surface effects induce a premature ordering of the flux line lattice, and the system displays plastic and smectic behavior only in a very narrow range of forces. (c) 2007 Elsevier B.V. All rights reserved.

Structural and dielectric properties of Ba0.5Sr0.5(SnxTi1-x)O-3 ceramics obtained by the soft chemical method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of Boron powder purity on superconducting properties of bulk MgB2

In order to study the influence of the amorphous Boron powder on the superconducting properties, MgB2 bulk samples were prepared using 96% and 99% pure commercial Boron powder as well as 92% commercial Boron powder after purification process. The results showed that the original 96% and the purified 92% powders have larger particle size compared to the pure 99% Boron powder, which leads to reduce magnetic critical current densities. In order to get higher performance MgB2, the purified low grade Boron powder need further control of their microstructure such as smaller particle size to enhance flux pinning from the grain boundaries which represent effective pinning centers. © 2007 Elsevier B.V. All rights reserved.

Nucleation of superconductivity in a thin disk with a ring-like defect

We report on the influence of a circular defect on the vortex configuration in a mesoscopic superconducting sample. Effects associated with the pinning force of the circular defect on the configuration and on the vortex entry fields are studied for a very thin disk. We calculate the magnetization loop, vorticity, free energy and superconducting electrons for the disk in presence of an external magnetic field applied perpendicular to the disk plane. The magnetization curves are hysteretic, with paramagnetic response in part of the downward branch, also, in this part we found a vortex-anti-vortex state. © 2013 World Scientific Publishing Company.