Fallo recurrente tipo IV de un inserto acetabular retentivo sin disociación del anillo de bloqueo

Se describe un caso de luxación recurrente con dos insertos acetabulares constreñidos Duofit IPR en la misma cadera. En ambas ocasiones el acetábulo y vástago no cementados estaban en adecuada posición y sin aflojamiento, y el inserto acetabular estaba bien fijado dentro del acetábulo metálico y sin daño. El anillo de bloqueo estaba bien colocado con completo engranaje en el inserto, pero presentaba una pequeña "muesca" y deformidad plástica en los polos superior e inferior. Estos hallazgos sugerían que había habido un impacto entre el cuello del vástago y el reborde del anillo durante la flexión de cadera, el llamado fallo tipo IV. Requirió recambio acetabular a una prótesis modular con mega-cabeza, sin revisión del vástago. No hemos encontrado referencias respecto al fallo de este implante.We report recurrent dislocation with two failed Duofit IPR constrained liners in the same hip. Both times, the cementless cup and stem were well fixed and well positioned, and the constrained liner was found to be well fixed within the cup and undamaged. The locking ring was well positioned with complete seating into the liner, but had a small "scratch" and a plastic deformation of superior and inferior poles, respectively. This finding suggested that impingement between the neck and the rim of the ring had occurred, especially during flexion, so-called failure type IV. It required revision to a large-diameter metal-on-metal modular articulation. The well-fixed and wellpositioned femoral stem was left in place. We are not aware of any other published reports concerning failure of this implant

Síndrome doloroso del trocánter mayor.Resultados a corto plazo con el tratamiento artroscópico

Objetivo : Evaluar los resultados clínicos de la cirugía artroscópica de cadera en el tratamiento del síndrome doloroso del trocánter mayor tras fracaso del tratamiento conservador. Material y Método : Estudio prospectivo de 15 pacientes tratados mediante cirugía artroscópica de cadera por síndrome doloroso del trocánter mayor. Para valoracion clínica se utilizó la escala modificada de Harris. Resultados : La edad media de los pacien - tes fue de 53,2 años. Se detectó rotura del glúteo medio en el 73,3% de los casos. El seguimiento medio de los pacientes fue de 16,3 meses. La puntuación media de la escala modificada de Harris pasó de 55,4 puntos preope - ratoriamente a 83,8 puntos al final del seguimiento. Discusión : La artroscopia de cadera ha permitido la mejoría clínica de los pacientes con síndrome doloroso del trocánter mayor que no responde al tratamiento conservador. Un mayor seguimiento de los pacientes es preciso para confirmar la estabilidad de los resultados obtenidosObjective: Evaluate the outcomes of hip arthroscopy as a treatment for greater throcanter pain syndrome after conservative treatment failed. Material and methods: Prospective study with 15 patients under - going hip arthroscopy for greater trochanter pain syndrome. Modified Harris Hip Score scale was used for clini - cal assessment. Results: The mean age of patients was 53.2 years. Gluteus medium tears was detected in 73.3%. The average follow-up was 16.3 months. The mean modified Harris Hip score increased from 55.4 points preop to 83.8 points postoperative. Discusion: Hip arthroscopy resulted in improvement in hip functional outcome in patients with greater trochanter pain syndrome after conservative treatment failed. Further follow-up is essential to confirm the stability of the clinical outcome

Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Numerical simulation to assess the elastic-strain energy distribution in a silicon rubber disk subjected to a punch shear test (PST)

Finite element method simulations were implemented to understand how the strain energy is distributed in a disk-like sample during a punch shear test. Material’s Young modulus can be estimated from this test; however, there is not enough available information about the distribution of the strain energy inside the sample during the deformation process. The proposed methodology seeks to give insight into the deformation process. Experimental results for a cured silicon rubber sample were used to validate the simulation results. It was found that the estimation of the Young modulus with the punch shear test depends on the ratio between the span-to-punch diameters. This conclusion applies to the simulated results, following Timoshenko’s theory for the deformation of thin plates. Understanding how energy is accumulated during a punch shear test is an important and useful characteristic in terms of the design of armor systems.Simulaciones por el método de elementos finitos fueron empleadas para comprender como se distribuye la energía de deformación al interior de muestras con forma de disco durante un ensayo de punzonado. El módulo de Young puede calcularse a partir de este ensayo; sin embargo, no hay suficiente información disponible sobre la manera en la cual se distribuye la energía de deformación en una muestra durante el proceso de deformación. La metodología propuesta busca dar luces alrededor del proceso de deformación. Resultados experimentales obtenidos con muestras de cauchos siliconados curados fueron usados para validar los resultados de las simulaciones. Se encontró que el valor estimado para del módulo de Young depende de la relación entre el diámetro de la muestra y el diámetro del punzón. Entender como la energía se acumula durante el ensayo de punzonado es un aspecto importante y útil para el diseño de sistemas de protección balística

Development of Materials for Naval, Fluvial and Military Applications

A platform to design composite materials of a polymeric matrix, that are specifically for military applications on fluvial and naval navigation, has been developed using energy dissipation and storage mechanisms. Our composites are designed to generate synergy between the dissipation capacities of ceramics and high-performance fibers, which are used as the reinforced material in the lightweight laminates. The composite design is combined with processing tools and advanced characterization techniques that result in laminates with reliability, traceability and quality. The platform begins with the identification of energy dissipation mechanisms and the detailed characterization of the polymeric resin. It includes the Time – Temperature – Transformation Diagram (TTT- Diagram) that supplies the optimal processing conditions. Our designs open new paths for military applications including a wide spectrum of protective systems together with geometric versatility, high mechanical resistance and reliabilityUtilizando los múltiples mecanismos de disipación de la energía de impacto a alta velocidad, hemos desarrollado una plataforma de diseño de materiales compuestos de matriz polimérica, especiales para aplicaciones militares en navegación fluvial y marítima.  Nuestros compuestos pretenden hacer sinergia entre las capacidades de disipación de cerámicos y fibras de alto desempeño, los cuales son utilizados como los elementos de refuerzo en los laminados de bajo peso.  El diseño del material es combinado con herramientas de procesamiento y técnicas avanzadas de caracterización que resultan en laminados consistentes de alta repetibilidad, trazabilidad y alta calidad.  La plataforma parte de la identificación de los mecanismos de disipación y de una caracterización detallada de la resina polimérica, el cual incluye un diagrama de Tiempo-Temperatura-Transformación que provee las condiciones óptimas de procesamiento.  Nuestros diseños abren rutas novedosas para aplicaciones militares, los cuales incluyen amplios portafolios de protección, versatilidad geométrica, resistencia mecánica y confiabilida

Pharmacogenomic study in patients with multiple sclerosis: Responders and nonresponders to IFN-β.

OBJECTIVES: We aimed to investigate the association between polymorphisms located in type I interferon (IFN)-induced genes, genes belonging to the toll-like receptor (TLR) pathway, and genes encoding neurotransmitter receptors and the response to IFN-β tr

IL28B polymorphisms are not associated with the response to interferon-beta in multiple sclerosis

Recent studies have revealed an association between interleukin 28B (IL28B) and response to IFN-alpha treatment in hepatitis C patients. Here we investigated the influence of IL28B polymorphisms in the response to interferon-beta (IFNβ) in multiple sclerosis (MS) patients. We genotyped two SNPs of the IL28B gene (rs8099917 and rs12979860) in 588 MS patients classified into responders (n=281) and non-responders (n=307) to IFNβ. Combined analysis of the study cohorts showed no significant associations between SNPs rs8099917 and rs12979860 and the response to treatment. These findings do not support a role of IL28B polymorphisms in the response to IFNβ in MS patients