1,146 research outputs found
Actualización en el tratamiento de la cadera degenerativa en el adulto joven
El tratamiento de la patología degenerativa de la cadera en el adulto joven es un desafío para el
cirujano ortopeda dadas las expectativas de función y calidad de vida que solicitan estos pacientes. En la última
década se ha experimentado un cambio hacia la implantación de técnicas quirúrgicas de preservación de la articulación. La selección adecuada de los pacientes candidatos a estas técnicas nos permitirá obtener excelentes
resultados y retrasar la necesidad de la cirugía protésica. La prótesis total de cadera sigue siendo la técnica de
elección en los pacientes jóvenes con enfermedad degenerativa moderada o severa, aunque es necesario una
mejora en los biomateriales y pares de fricción para aumentar la supervivencia del implante y la percepción de
calidad de vida por parte del pacienteThe orthopaedic treatment of young patients with hip osteoarthritis is a challenge for the orthopaedic surgeon, as young patients have higher expectation for function and quality of life. Surgical treatment has
evolved to joint preservation surgery in the past decade. The proper selection of patients for these techniques
allows us to obtain excellent results and delay the need for prosthetic surgery. Total hip replacement is the technique of choice in young patients with moderate or severe hip osteoarthritis. Improvement in biomaterials and
bearing surfaces are required to improve the prosthesis survival rates and the quality of life of these patient
Existence results for Gradient elliptic systems with nonlinear boundary conditions
We prove the existence of nontrivial solutions to the system Δpu = |u|p-2u, Δqv = |v| q-2v, on a bounded set of ℝN, with nonlinear coupling at the boundary given by |∇u|p-2∂u/∂ν = F u(x, u, v), |∇u|q-2∂v/∂ν = F v(x, u, v). The proofs are done under suitable assumptions on the potential F, and based on variational arguments. Our results include subcritical, resonant and critical growth on F. © 2007 Birkhäuser Verlag.Fil:Martínez, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Rossi, J.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Autopistas de la información. Aplicación en cirugía ortopédica
El término autopistas de información describe los servicios de telecomunicaciones
que estarán disponibles dentro de 10-15 años. El embrión de estas autopistas es Internet. Internet
ofrece 2 clases de servicios: a) comunicación entre usuarios de todo el mundo, y b) acceso a
servicios de información. En el primer grupo de estos servicios encontramos el correo electrónico
y los grupos de discusión. En el segundo podemos encontrar servicios como logon remoto,
transferencia de ficheros, Gopher o WWW. Describimos cada uno de estos servicios y su aplicación
a la ortopedia.Information highway describes the telecomunication services will be working in
the next 10-15 years. The embryo of this highway is Internet. Internet offers two kinds of services:
a) communication between users around the worid, and b) access to information services. In the
first group of this services we can find electronic mail and news group. In the second group we
can find services such as telnet, file transfer, Gopher and World Wide Web. We describe each of
this kind of services and their applications in orthopaedic surgery
Variational description of Gibbs-non-Gibbs dynamical transitions for spin flip systems with a Kac-type interaction
We continue our study of Gibbs-non-Gibbs dynamical transitions. In the present paper we consider a system of Ising spins on a large discrete torus with a Kac-type interaction subject to an independent spin-¿ip dynamics (in¿nite-temperature Glauber dynamics). We show that, in accordance with the program outlined in [11], in the thermodynamic limit Gibbs-non-Gibbs dynamical transitions are equivalent to bifurcations in the set of global minima of the large-deviation rate function for the trajectories of the empirical density conditional on their endpoint. More precisely, the time-evolved measure is non-Gibbs if and only if this set is not a singleton for some value of the endpoint. A partial description of the possible scenarios of bifurcation is given, leading to a characterization of passages from Gibbs to non-Gibbs and vice versa, with sharp transition times. Our analysis provides a conceptual step-up from our earlier work on Gibbs-non-Gibbs dynamical transitions for the Curie-Weiss model, where the mean-¿eld interaction allowed us to focus on trajectories of the empirical magnetization rather than the empirical density
Sundman transformation and alternative tangent structures
A geometric approach to Sundman transformation defined by basic functions for systems of second-order differential equations is developed and the necessity of a change of the tangent structure by means of the function defining the Sundman transformation is shown. Among other applications of such theory we study the linearisability of a system of second-order differential equations and in particular the simplest case of a second-order differential equation. The theory is illustrated with several examples
Análisis corológico y novedades florísticas de la Sierra de los Filabres (Andalucía Oriental, España)
El conocimiento básico sobre la diversidad vegetal a escala local o regional es primordial para afrontar la conservación de la diversidad genética a mayor escala. En Andalucía oriental, la sierra de Los Filabres había quedado al margen de estudios intensivos sobre su flora. Abordamos la notificación de los taxones que resultan novedosos para la provincia de Almería y los que son interesantes ampliaciones de área de distribución. Analizamos la corología de los taxa que emanan del catálogo florístico, considerada una forma de medir la gamma diversidad del territorio. La flora de Los Filabres es primordialmente mediterránea, pero destaca un alto porcentaje de especies de área restringida, entre ellos los que también se presentan en el norte de África, y especialmente los endemismos. Por otro lado, en un área tan conspicua del sur ibérico que constituye una interesante encrucijada biogeográfica, resalta destacable el número de especies no citadas hasta el momento. En el caso de muchas especies que se encuentran en listados de protección, esta información corológica debe ser incorporada en los estudios de evaluación de su grado de amenaza. Muchos taxones son raros en esta sierra, por ser límite de área de distribución o por tener pocas poblaciones o por presentar pocos efectivos poblacionales. Por ello, la conservación a escala local resulta esencial para abordar la planificación y las estrategias de preservación de la biodiversidad global.Basic knowledge on plant diversity at local or regional scale is necessary to face the genetic diversity conservation at widest scale. In eastern Andalusia, Los Filabres Mountain had been to margin of intensive studies on its flora. We approached the notification of new taxa records in Almería province and those that are interesting enlargement of their distribution area. We analyzed the taxa chorology that emanates of the floristic catalogue, considered a gamma diversity measure of the territory. The flora from Los Filabres is fundamentally mediterranean, but restricted area distribution species emphasizes with high percentages, among them, those that also inhabit in North Africa, those that are endemics. On the other hand, in a so conspicuous area of the Iberian south that constitutes an interesting biogeography crossroads, the number of species no referenced until the moment stands out remarkable. In the case of many species that are in “red lists”, this chorological information should be incorporated in the studies of threat evaluation. Many taxa are rare in this mountain range, because of being limit of distribution area or because of have few populations or because of display few population individuals. For this reason, the local scale conservation is essential to approach the planning and the strategies of preservation of the global biodiversity
Características palinológicas del Cretácico Superior y del tránsito Cretácico-Terciario en los Pirineos Sur-Centrales
XV lnternational A.P.L.E. Symposium of Palynolog
Fracturas diafisarias de húmero en adultos: estudio retrospectivo de 53 casos
Se estudian retrospectivamente 53 pacientes adultos con fractura diafisaria de
húmero, 36 de los cuales siguieron el tratamiento ortopédico funcional. En otros 17 casos,
pacientes politraumatizados o con fracturas de tercio medio transversas, realizamos tratamiento
quirúrgico. La edad media de los pacientes fue 48 ± 2 2 años. Se afectó más el lado derecho,
siendo el antecedente etiológico más frecuente el accidente casual. No hubo diferencia entre
el tiempo de consolidación con el tratamiento ortopédico-funcional (60 ± 14 días) y el tratamiento
quirúrgico (56 ±1 2 días). Como complicaciones hubo 7 pseudoartrosis (4 tras tratamiento
ortopédico-funcional y 3 tratamiento quirúrgico). La edad media de los pacientes con
pseudoartrosis fue superior a la de los pacientes con consolidación completa. Ocho casos cursaron
con lesión del nervio radial, obteniendo una recuperación funcional del 100% en un
tiempo medio de 38 ± 30 semanas. Valorando los resultados con arreglo a los criterios de Gayet,
hemos obtenido un 80% de buenos y muy buenos resultados con tratamiento ortopédico
funcional y un 70% con tratamiento quirúrgico.Fifty three adult patients with fracture of the humeral shaft were retrospectively
studied. Orthopaedic-functional treatment was applied in 36 cases. Seventeen patients with
either multiple injuries or transverse middle-shaft fractures were surgically treated. The mean
age of patients was 48 ± 21 years. Right side was most frecuently affected and casual fall was
the predominated etiology. There were no differences regarding the average consolidation period
between fractures treated conservatively (60 ± 14 days) and those undergoing surgery (56 ± 12
days). As complications, there were 7 monounions (4 conservative and 3 operative treatment).
The mean age of patients with non-unions was higther than those with complete fracture consolidation.
Radial nerve injury was seen in 8 cases. In all there patients, a complete functional
were recovery was obtained with a mean average time of 38 ± 30 weeks. When evaluating functional
results according to Gayet, satisfactory results were found in 80 per cent of patients with
conservative treatment and 70 per cent of those surgically treated
Aplasia del arco posterior del Atlas
Las anomalías congénitas del arco posterior del Atlas son poco frecuentes. Se
presenta el caso de una paciente, que tras sufrir un accidente se diagnosticó de aplasia parcial
del atlas. Esta lesión es considerada como una variante anatómica benigna de la región cráneovertebral.
Se expone el desarrollo y el significado de esta anomalía.Congenital anomalies of the posterior arch of the atlas are uncommon. This
paper presents the case of a patient who, as result of an accident, was diagnosed as having a
congenital partial agenesia of the posterior arch of the atlas. This finding is considered as a
benign anatomical variation of the craniovertebral junction region. The development and clinical
significance of this anomaly are discussed
Solubility of gases in fluoroorganic alcohols. Part III. Solubilities of several non-polar gases in water¿+¿1, 1, 1, 3, 3, 3-hexafluoropropan-2-ol at 298.15¿K and 101.33¿kPa
Solubilities of the non-polar gases H2, N2, O2, CH4, C2H6, C2H4, CF4, SF6, and CO2 in the mixture (water + 1, 1, 1, 3, 3, 3-hexafluoropropan-2-ol) at the temperature of 298.15 K and 101.33 kPa partial pressure of gas are reported. A polynomial dependence of the solubilities on the molar fraction of the binary liquid mixture is found. The Henry''s constants at the vapor pressure of water, the standard changes in the Gibbs energy for the solution process and for the solvation process, and the so-called excess Henry''s constant are calculated. The results have been compared with those obtained by Scaled Particle Theory (SPT). A method to compare the solubility of a gas in different liquids is proposed and applied to 2, 2, 2-trifluoroethanol and 1, 1, 1, 3, 3, 3-hexafluoropropan-2-ol
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