Fractura femoral en paciente portador de un clavo intramedular

Los autores presentan el caso de un paciente con una fractura femoral tratado con un clavo intramedular cerrojado que sufrió una nueva fractura antes de extraer el material de osteosíntesis.The authors present a patient with a femoral fracture treated by interlocking nail who underwent a new fracture of the femoral shaft before removal of the nail

Master Operators Govern Multifractality in Percolation

Using renormalization group methods we study multifractality in percolation at the instance of noisy random resistor networks. We introduce the concept of master operators. The multifractal moments of the current distribution (which are proportional to the noise cumulants $C_R^{(l)} (x, x^\prime)$ of the resistance between two sites x and $x^\prime$ located on the same cluster) are related to such master operators. The scaling behavior of the multifractal moments is governed exclusively by the master operators, even though a myriad of servant operators is involved in the renormalization procedure. We calculate the family of multifractal exponents ${\psi_l}$ for the scaling behavior of the noise cumulants, $C_R^{(l)} (x, x^\prime) \sim | x - x^\prime |^{\psi_l /\nu}$, where $\nu$ is the correlation length exponent for percolation, to two-loop order.Comment: 6 page

Human cachexia induces changes in mitochondria, autophagy and apoptosis in the skeletal muscle

Cachexia is a wasting syndrome characterized by the continuous loss of skeletal muscle mass due to imbalance between protein synthesis and degradation, which is related with poor prognosis and compromised quality of life. Dysfunctional mitochondria are associated with lower muscle strength and muscle atrophy in cancer patients, yet poorly described in human cachexia. We herein investigated mitochondrial morphology, autophagy and apoptosis in the skeletal muscle of patients with gastrointestinal cancer-associated cachexia (CC), as compared with a weight-stable cancer group (WSC). CC showed prominent weight loss and increased circulating levels of serum C-reactive protein, lower body mass index and decreased circulating hemoglobin, when compared to WSC. Electron microscopy analysis revealed an increase in intermyofibrillar mitochondrial area in CC, as compared to WSC. Relative gene expression of Fission 1, a protein related to mitochondrial fission, was increased in CC, as compared to WSC. LC3 II, autophagy-related (ATG) 5 and 7 essential proteins for autophagosome formation, presented higher content in the cachectic group. Protein levels of phosphorylated p53 (Ser46), activated caspase 8 (Asp384) and 9 (Asp315) were also increased in the skeletal muscle of CC. Overall, our results demonstrate that human cancer-associated cachexia leads to exacerbated muscle-stress response that may culminate in muscle loss, which is in part due to disruption of mitochondrial morphology, dysfunctional autophagy and increased apoptosis. To the best of our knowledge, this is the first report showing quantitative morphological alterations in skeletal muscle mitochondria in cachectic patients

Logarithmic Corrections in Dynamic Isotropic Percolation

Based on the field theoretic formulation of the general epidemic process we study logarithmic corrections to scaling in dynamic isotropic percolation at the upper critical dimension d=6. Employing renormalization group methods we determine these corrections for some of the most interesting time dependent observables in dynamic percolation at the critical point up to and including the next to leading correction. For clusters emanating from a local seed at the origin we calculate the number of active sites, the survival probability as well as the radius of gyration.Comment: 9 pages, 3 figures, version to appear in Phys. Rev.

Artroplastia total de tobillo

Presentamos un estudio retrospectivo de siete pacientes tratados con artroplastia total de tobillo en el período 1978-1988, realizando una revisión bibliográfica del tema. La serie la componen cinco hombres y dos mujeres con edades comprendidas entre 41 y 72 años. Cinco pacientes estaban afectos de artrosis postraumática, uno de artropatía gotosa y otro de espondilitis anquilopoyética. Los modelos protésicos utilizados fueron Smith en cuatro ocasiones e I.C.L.H. en tres. El seguimiento medio ha sido de once años, siendo evaluados según un sistema de puntuación creado por Mc Guire. En tres pacientes se ha obtenido un resultado excelente, en dos bueno y los dos restantes fueron reintervenidos realizándose una artrodesis.We have reported a retrospective study of seven patients with total ankle arthroplasty perfomed between 1978-1988. We have reviewed series published in the literature. There were five men and two women, the age range of this group was 41-72 years. Five of them suffered from posttraumatic arthrosis, one ankylosing spondylitis and the last had gouty arthritis. Four patients recieved the Smith total ankle and three the ICLH total ankle. The mean follow-up period was eleven years. Patients were evaluated using a scoring system (Mc Guire et al). Three patients had an excellent result, the result from two of them were good and the other two patients required revision and arthrodesis

On the relevance of percolation theory to the vulcanization transition

The relationship between vulcanization and percolation is explored from the perspective of renormalized local field theory. We show rigorously that the vulcanization and percolation correlation functions are governed by the same Gell--Mann-Low renormalization group equation. Hence, all scaling aspects of the vulcanization transition are reigned by the critical exponents of the percolation universality class.Comment: 9 pages, 2 figure

Percolation Threshold, Fisher Exponent, and Shortest Path Exponent for 4 and 5 Dimensions

We develop a method of constructing percolation clusters that allows us to build very large clusters using very little computer memory by limiting the maximum number of sites for which we maintain state information to a number of the order of the number of sites in the largest chemical shell of the cluster being created. The memory required to grow a cluster of mass s is of the order of $s^\theta$ bytes where $\theta$ ranges from 0.4 for 2-dimensional lattices to 0.5 for 6- (or higher)-dimensional lattices. We use this method to estimate $d_{\scriptsize min}$, the exponent relating the minimum path $\ell$ to the Euclidean distance r, for 4D and 5D hypercubic lattices. Analyzing both site and bond percolation, we find $d_{\scriptsize min}=1.607\pm 0.005$ (4D) and $d_{\scriptsize min}=1.812\pm 0.006$ (5D). In order to determine $d_{\scriptsize min}$ to high precision, and without bias, it was necessary to first find precise values for the percolation threshold, $p_c$: $p_c=0.196889\pm 0.000003$ (4D) and $p_c=0.14081\pm 0.00001$ (5D) for site and $p_c=0.160130\pm 0.000003$ (4D) and $p_c=0.118174\pm 0.000004$ (5D) for bond percolation. We also calculate the Fisher exponent, $\tau$, determined in the course of calculating the values of $p_c$: $\tau=2.313\pm 0.003$ (4D) and $\tau=2.412\pm 0.004$ (5D)

Logarithmic Corrections for Spin Glasses, Percolation and Lee-Yang Singularities in Six Dimensions

We study analytically the logarithmic corrections to the critical exponents of the critical behavior of correlation length, susceptibility and specific heat for the temperature and the finite-size scaling behavior, for a generic $\phi^3$ theory at its upper critical dimension (six). We have also computed the leading correction to scaling as a function of the lattice size. We distinguish the obtained formulas to the following special cases: percolation, Lee-Yang (LY) singularities and $m$-component spin glasses. We have compared our results for the Ising spin glass case with numerical simulations finding a very good agreement. Finally, and using the results obtained for the Lee-Yang singularities in six dimensions, we have computed the logarithmic corrections to the singular part of the free energy for lattice animals in eight dimensions.Comment: 18 pages. We have extended the computation to lattice animals in eight dimensions. To be published in Journal of Physics

Fracturas del primer metatarsiano. Valoración funcional a largo plazo

Hemos revisado la evolución y resultado final de 24 fracturas del primer metatarsiano tratadas y seguidas en nuestro Hospital «La Fe» de Valencia, durante el periodo comprendido entre 1982 y 1993. Los tratamientos fueron mediante osteosíntesis con agujas de Kirschner y enyesado en 10 casos y con enyesado solamente en 14 pacientes. Las causas más frecuentes fueron los accidentes de tráfico en un 66%. Las fracturas abiertas correspondieron al 37%. Los resultados tras un seguimiento medio de 7 años fueron malos en el 86% de los tratamiento conservadores y en el 70% de los tratamientos quirúrgicos. Las secuelas más frecuentes fueron las metatarsalgias en un 4 1 % de los pacientes.We reviewed the final results in 24 fractures of the first metatarsal bone treated in our hospital during a two-year period (1982-1983). The treatment consisted of Kirschner's wire fixation and plaster cast in 10 cases and only casting in 14 patients. The most frequent cause of fracture was traffic accident (66% of the cases). Open fractures were found in 37% of the cases. The results after a follow-up period of 7 years were poor in 86% of the conservative treatments and in 70% of the surgical treatments. The most frequent sequela was metatarsalgia in 41 % of the patients