Aplicación de la dinamometría isocinética para establecer perfiles de riesgo de lesión isquiosural en futbolistas profesionales. [The use of isokinetic dynamometry to establish risk profiles of hamstring injury in professional football players].

<p align="justify">Las lesiones en la musculatura isquiosural son frecuentes en el fútbol profesional y han sido relacionadas con el desequilibrio entre la fuerza de los flexores y extensores de rodilla. El objetivo de nuestro estudio fue comprobar si la ratio de fuerza máxima excéntrica de flexores/concéntrica de extensores (ratio Flexexc30/Extcon240) y el ángulo de rodilla donde la musculatura isquiosural alcanza su máximo momento de fuerza, son variables útiles para establecer perfiles de riesgo de lesión isquiosural en futbolistas profesionales. Veinte jugadores de un equipo de la Segunda División de la Liga de Fútbol Profesional realizaron bilateralmente un test isocinético de flexión excéntrica de rodilla a 30º/s y extensión concéntrica de rodilla a 240º/s durante la pretemporada. Tras calcular la ratio Flexexc30/Extcon240 y el ángulo de máximo momento de fuerza, se registraron las lesiones sufridas por los jugadores a lo largo de la temporada. Los resultados mostraron que dos de los cinco jugadores lesionados presentaron ratios Flexexc30/Extcon240 menores de 0.89, valor que ha sido utilizado previamente para determinar el desequilibrio entre la musculatura flexora y extensora de rodilla y el riesgo de lesión (Croisier, Ganteaume, Binet, Genty, y Ferret, 2008). Además, otros dos de los jugadores lesionados obtuvieron ratios entre 0.93 y 1.00. Por otro lado, no se encontraron diferencias en el ángulo de máximo momento de fuerza entre jugadores lesionados y no lesionados. Estos resultados indican que la ratio Flexexc30/Extcon240 puede ser un índice útil para determinar el riesgo de lesión isquiosural en futbolistas profesionales.</p>Abstract<p align="justify">Hamstring injuries are common in professional football and have been related to the imbalance between knee flexor and extensor strength. The aim of our study was to establish whether the flexor eccentric/extensor concentric strength ratio (Flexexc30/Extcon240 ratio) and the knee angle where the peak torque of the hamstring musculature was found, are useful variables to establish risk profiles for hamstring injury in professional football players. Twenty players of a Second Division team of the Liga de Fútbol Profesional bilaterally performed an isokinetic test of eccentric knee flexion at 30º/s and concentric knee extension at 240º/s during the pre-season. The Flexexc30/Extcon240 ratio and the knee angle of peak torque were calculated, and the players’ injuries were registered throughout the season. The results showed that two of the five injured players had Flexexc30/Extcon240 ratios lower than 0.89, value that has been previously used to determine the imbalance between knee flexor and extensor strength and the risk of injury (Croisier, Ganteaume, Binet, Genty, and Ferret, 2008). In addition, another two injured players obtained ratios between 0.93 and 1.00. On the other hand, no differences in the knee angle of peak torque between injured and non-injured players were found. These results indicate that the Flexexc30/Extcon240 ratio may be a useful index to determine the risk of hamstring injury in professional football players.</p>http://dx.doi.org/10.5232/ricyde2013.0340

Electrophoresis of a rod macroion under polyelectrolyte salt: Is mobility reversed for DNA?

By molecular dynamics simulation, we study the charge inversion phenomenon of a rod macroion in the presence of polyelectrolyte counterions. We simulate electrophoresis of the macroion under an applied electric field. When both counterions and coions are polyelectrolytes, charge inversion occurs if the line charge density of the counterions is larger than that of the coions. For the macroion of surface charge density equal to that of the DNA, the reversed mobility is realized either with adsorption of the multivalent counterion polyelectrolyte or the combination of electrostatics and other mechanisms including the short-range attraction potential or the mechanical twining of polyelectrolyte around the rod axis.Comment: 8 pages, 5 figures, Applied Statistical Physics of Molecular Engineering (Mexico, 2003). Journal of Physics: Condensed Matters, in press (2004). Journal of Physics: Condensed Matters, in press (2004

Novel spatial domain integral equation formulation for the analysis of rectangular waveguide steps close to arbitrarily shaped dielectric and/or conducting posts

[EN] In this paper, a novel integral equation formulation expressed in the spatial domain is proposed for the analysis of rectangular waveguide step discontinuities. The important novelty of the proposed formulation is that which allows to easily take into account the electrical influence of a given number of arbitrarily shaped conducting and dielectric posts placed close to the waveguide discontinuity. For the sake of simplicity, and without loss of generality, the presented integral equation has been particularized and solved for inductive rectangular waveguide geometry. In this case, the integral equation mixed-potentials kernel is written in terms of parallel plate Green¿s functions with an additional ground plane located on the waveguide step. Therefore, the unknowns of the problem are reduced to an equivalent magnetic surface current on the step aperture and equivalent magnetic and electric surface currents on the dielectric and conducting posts close to the discontinuity. The numerical solution of the final integral equation is efficiently computed after the application of acceleration techniques for the slowly convergent series representing the Green¿s functions of the problem. The numerical method has been validated through several simulation examples of practical microwave devices, including compact size band-pass cavity filters and coupled dielectric resonators filters. The results have been compared to those provided by commercial full-wave electromagnetic simulation software packages, showing in all cases a very good agreement, and with substantially enhanced numerical efficiencies.This research work has been financially supported by the Spanish Ministerio de Economia y Competitividad in the frame of the projects "Demostradores Tecnologicos de Filtros y Multiplexores con Respuestas Selectivas y Sintonizables en Nuevas Guias Compactas para Aplicaciones Espaciales (COMPASSES)" with Ref. TEC2016-75934-C4-1-R, and "Analisis y Diseno de Nuevos Componentes en Microondas y Milimetricas para Comunicaciones por Satelite (MILISAT)" with Ref. TEC2016-75934-C4-4-R. As an additional financial source we thank the regional agency Fundacion Seneca from Region de Murcia under the research project "Desarrollo de Antenas y Componentes Pasivos de Microondas para Sistemas Avanzados de Comunicaciones" with Ref. 19494/PI/14 and Ref. 20147/EE/17, and the PhD scholarship granted by the Spanish national Ministerio de Educacion, Cultura y Deporte with Ref. FPU15/02883. All results of this paper can be reproduced by using the data and information contained in the drawings and in the captions of the figures included in the paper.Quesada Pereira, FD.; Gomez Molina, C.; Alvarez Melcon, A.; Boria Esbert, VE.; Guglielmi, M. (2018). Novel spatial domain integral equation formulation for the analysis of rectangular waveguide steps close to arbitrarily shaped dielectric and/or conducting posts. Radio Science. 53(4):406-419. https://doi.org/10.1002/2017RS006429S406419534Arcioni , P. Bressan , M. Conciauro , G. Perregrini , L. 1997 Generalized Y-matrix of arbitrary H-plane waveguide junctions by the BI-RME method IEEE MTT-S International Microwave Symposium Digest 211 214 DenverCapolino, F., Wilton, D. R., & Johnson, W. A. (2005). Efficient computation of the 2-D Green’s function for 1-D periodic structures using the Ewald method. IEEE Transactions on Antennas and Propagation, 53(9), 2977-2984. doi:10.1109/tap.2005.854556Catina, V., Arndt, F., & Brandt, J. (2005). Hybrid surface integral-equation/mode-matching method for the analysis of dielectric loaded waveguide filters of arbitrary shape. IEEE Transactions on Microwave Theory and Techniques, 53(11), 3562-3567. doi:10.1109/tmtt.2005.857343Fructos, A. L., Boix, R. R., Mesa, F., & Medina, F. (2008). An Efficient Approach for the Computation of 2-D Green’s Functions With 1-D and 2-D Periodicities in Homogeneous Media. IEEE Transactions on Antennas and Propagation, 56(12), 3733-3742. doi:10.1109/tap.2008.2007281Guglielmi, M., & Newport, C. (1990). Rigorous, multimode equivalent network representation of inductive discontinuities. IEEE Transactions on Microwave Theory and Techniques, 38(11), 1651-1659. doi:10.1109/22.60012Hu, Y. L., Li, J., Ding, D. Z., & Chen, R. S. (2016). Analysis of Transient EM Scattering From Penetrable Objects by Time Domain Nonconformal VIE. IEEE Transactions on Antennas and Propagation, 64(1), 360-365. doi:10.1109/tap.2015.2501437Kalantari, M., & Paran, K. (2017). Analysing Metamaterial Layer by Simpler Approach Based on Mode Matching Technique. IET Microwaves, Antennas & Propagation, 11(5), 607-616. doi:10.1049/iet-map.2016.0687Mrvić, M., Potrebić, M., & Tošić, D. (2016). CompactEplane waveguide filter with multiple stopbands. Radio Science, 51(12), 1895-1904. doi:10.1002/2016rs006169Pérez-Soler, F. J., Quesada-Pereira, F. D., Cañete Rebenaque, D., Pascual-García, J., & Alvarez-Melcon, A. (2007). Efficient integral equation formulation for inductive waveguide components with posts touching the waveguide walls. Radio Science, 42(6). doi:10.1029/2006rs003591POGGIO, A. J., & MILLER, E. K. (1973). Integral Equation Solutions of Three-dimensional Scattering Problems. Computer Techniques for Electromagnetics, 159-264. doi:10.1016/b978-0-08-016888-3.50008-8Quesada Pereira , F. Boria , V. E. Gimeno , B. Cañete Rebenaque , D. Pascual Garcia , J. Alvarez Melcon , A. 2006 Investigation of multipaction phenomena in inductively coupled passive waveguide components for space applications IEEE MTT-S International Microwave Symposium Digest 246 249 San Francisco, CAPereira, F. D. Q., Esbert, V. E. B., Garcia, J. P., Ana Vidal Pantaleoni, Melcon, A. A., Tornero, J. L. G., & Gimeno, B. (2007). Efficient Analysis of Arbitrarily Shaped Inductive Obstacles in Rectangular Waveguides Using a Surface Integral-Equation Formulation. IEEE Transactions on Microwave Theory and Techniques, 55(4), 715-721. doi:10.1109/tmtt.2007.893673Quesada Pereira, F. D., Vera Castejón, P., Álvarez Melcón, A., Gimeno, B., & Boria Esbert, V. E. (2011). An efficient integral equation technique for the analysis of arbitrarily shaped capacitive waveguide circuits. Radio Science, 46(2), n/a-n/a. doi:10.1029/2010rs004458Stumpf, M., & Leone, M. (2009). Efficient 2-D Integral Equation Approach for the Analysis of Power Bus Structures With Arbitrary Shape. IEEE Transactions on Electromagnetic Compatibility, 51(1), 38-45. doi:10.1109/temc.2008.2009223Wei, X.-C., Li, E.-P., Liu, E.-X., & Cui, X. (2008). Efficient Modeling of Rerouted Return Currents in Multilayered Power-Ground Planes by Using Integral Equation. IEEE Transactions on Electromagnetic Compatibility, 50(3), 740-743. doi:10.1109/temc.2008.924392Huapeng Zhao, En-Xiao Liu, Jun Hu, & Er-Ping Li. (2014). Fast Contour Integral Equation Method for Wideband Power Integrity Analysis. IEEE Transactions on Components, Packaging and Manufacturing Technology, 4(8), 1317-1324. doi:10.1109/tcpmt.2014.232724

Observation of a topologically protected state in a magnetic domain wall stabilized by a ferromagnetic chemical barrier

The precise control and stabilization of magnetic domain walls is key for the development of the next generation magnetic nano-devices. Among the multitude of magnetic configurations of a magnetic domain wall, topologically protected states are of particular interest due to their intrinsic stability. In this work, using XMCD-PEEM, we have observed a topologically protected magnetic domain wall in a ferromagnetic cylindrical nanowire. Its structure is stabilized by periodic sharp alterations of the chemical composition in the nanowire. The large stability of this topologically protected domain wall contrasts with the mobility of other non-protected and non-chiral states also present in the same nanowire. The micromagnetic simulations show the structure and the conditions required to find the topologically protected state. These results are relevant for the design of future spintronic devices such as domain wall based RF oscillators or magnetic memories

On the nature of long-range contributions to pair interactions between charged colloids in two dimensions

We perform a detailed analysis of solutions of the inverse problem applied to experimentally measured two-dimensional radial distribution functions for highly charged latex dispersions. The experiments are carried out at high colloidal densities and under low-salt conditions. At the highest studied densities, the extracted effective pair potentials contain long-range attractive part. At the same time, we find that for the best distribution functions available the range of stability of the solutions is limited by the nearest neighbour distance between the colloidal particles. Moreover, the measured pair distribution functions can be explained by purely repulsive pair potentials contained in the stable part of the solution.Comment: 6 pages, 5 figure

Pranlukast Antagonizes CD49f and Reduces Sternness in Triple-Negative Breast Cancer Cells

Introduction: Cancer stem cells (CSCs) drive the initiation, maintenance, and therapy response of breast tumors. CD49f is expressed in breast CSCs and functions in the maintenance of stemness. Thus, blockade of CD49f is a potential therapeutic approach for targeting breast CSCs. In the present study, we aimed to repurpose drugs as CD49f antagonists. Materials and Methods: We performed consensus molecular docking using a subdomain of CD49f that is critical for heterodimerization and a collection of pharmochemicals clini-cally tested. Molecular dynamics simulations were employed to further characterize drug-target binding. Using MDA-MB-231 cells, we evaluated the effects of potential CD49f antagonists on 1) cell adhesion to laminin; 2) mammosphere formation; and 3) cell viability. We analyzed the effects of the drug with better CSC-selectivity on the activation of CD49f-downstream signaling by Western blot (WB) and co-immunoprecipitation. Expressions of the stem cell markers CD44 and SOX2 were analyzed by flow cytometry and WB, respectively. Transactivation of SOX2 promoter was evaluated by luciferase reporter assays. Changes in the number of CSCs were assessed by limiting-dilution xenotransplantation. Results: Pranlukast, a drug used to treat asthma, bound to CD49f in silico and inhibited the adhesion of CD49f+ MDA-MB-231 cells to laminin, indicating that it antagonizes CD49f-containing integrins. Molecular dynamics analysis showed that pranlukast binding induces con-formational changes in CD49f that affect its interaction with β1-integrin subunit and constrained the conformational dynamics of the heterodimer. Pranlukast decreased the clonogenicity of breast cancer cells on mammosphere formation assay but had no impact on the viability of bulk tumor cells. Brief exposure of MDA-MB-231 cells to pranlukast altered CD49f-dependent signaling, reducing focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K) activation. Further, pranlukast-treated cells showed decreased CD44 and SOX2 expression, SOX2 promoter transacti-vation, and in vivo tumorigenicity, supporting that this drug reduces the frequency of CSC. Conclusion: Our results support the function of pranlukast as a CD49f antagonist that reduces the CSC population in triple-negative breast cancer cells. The pharmacokinetics and toxicology of this drug have already been established, rendering a potential adjuvant therapy for breast cancer patients

Chronic and acute effects on skin temperature from a sport consisting of repetitive impacts from hitting a ball with the hands

Valencian handball consists in hitting the ball with the hands and it may contribute to injury development on the hands. This study aimed to analyze skin temperature asymmetries and recovery after a cold stress test (CST) in professional players of Valencian handball before and after a competition. Thirteen professional athletes and a control group of ten physically active participants were measured. For both groups, infrared images were taken at the baseline condition; later they underwent a thermal stress test (pressing for 2 min with the palm of the hand on a metal plate) and then recovery images were taken. In athletes, the images were also taken after their competition. Athletes at baseline condition presented lower temperatures (p < 0.05) in the dominant hand compared with the non-dominant hand. There were asymmetries in all regions after their match (p < 0.05). After CST, a higher recovery rate was found after the game. The regions with the most significant differences in variation, asymmetries and recovery patterns were the index, middle and ring fingers, and the palm of the dominant hand. Taking into account that lower temperatures and the absence of temperature variation may be the consequence of a vascular adaptation, thermography could be used as a method to prevent injuries in athletes from Valencian handball

Genetic study of atypical femoral fractures using exome sequencing in three affected sisters and three unrelated patients

Objectives: Atypical femoral fractures (AFF) are rare, often related to long-term bisphosphonate (BPs) tre- atment. Their pathogenic mechanisms are not precisely known and there is no evidence to identify patients with a high risk of AFF. The aim of this work is to study the genetic bases of AFFs. Material and methods: Whole-exome sequencing was carried out on 3 sisters and 3 unrelated additional patients, all treated with BPs for more than 5 years. Low frequency, potentially pathogenic variants sha- red by the 3 sisters, were selected, were selected and a network of gene and protein interactions was constructed with the data found. Results: We identified 37 rare variants (in 34 genes) shared by the 3 sisters, some not previously descri- bed. The most striking variant was the p.Asp188Tyr mutation in the enzyme geranylgeranyl pyrophos- phate synthase (encoded by the GGPS1 gene), from the mevalonate pathway and essential for osteoclast function. Another noteworthy finding was two mutations (one in the 3 sisters and one in an unrelated patient) in the CYP1A1 gene, involved in the metabolism of steroids. We identified other variants that could also be involved in the susceptibility to AFFs or in the underlying osteoporotic phenotype, such as those present in the SYDE2, NGEF, COG4 and FN1 genes. Conclusions: Our data are compatible with a model where the accumulation of susceptibility variants could participate in the genetic basis of AFFs