Hemangioma intramuscular: (aportación de 6 casos y revisión de la literatura)

Se presentan seis casos de hemangioma intramuscular. Se discute la etiología, histopatología, métodos diagnósticos y el tratamiento óptimo. El tratamiento de elección debe ser la escisión ampliada siempre que ésta sea posible, siendo los resultados satisfactorios.Six cases of haemangioma arising in skeletal muscle are described. The aetiology, pathology, diagnosis and treatment of thes e tumours are discussed. Wide excision remains the treatment of choice whereve r possible with satisfactory results

Cirugía abierta frente a cirugía artroscópica en el tratamiento de la inestabilidad anterior de hombro

Se analizan los resultados de una técnica convencional, técnica de Bankart, para el tratamiento de la luxación recidivante anterior de hombro frente a una intervención artroscópica descrita por Rose. Se seleccionan quince pacientes para cada grupo de estudio con un seguimiento postoperatorio medio en torno a los dos años. Los pacientes de cirugía artroscópica se han seleccionado en base a criterios de exclusión preoperatorios e intraoperatorios que requieren la exploración de la estabilidad bajo anestesia y el examen artroscó- pico inicial. En el grupo de cirugía abierta no existe ningún caso de recidiva de la lesión, sólo un paciente no recuperó su nivel de actividad prelesional pero el 73 % de los pacientes presentan restricciones leves de la rotación externa a 90 ° de abducción. En el caso de la cirugía artroscópica un paciente sufrió un nuevo episodio de luxación, dos pacientes no recuperaron su nivel previo de actividad y el 86% presentaban una movilidad completa. Los resultados animan a los autores a continuar desarrollando las técnicas de estabilización artroscópica.We review the results of a conventional technique, Bankart repair, for the treatment of recurrent anterior shoulder instabüity versus an arthroscopic technique developed by Rose. Fifteen patients have been selected for each study group with an average postoperative follow-up around two years. Gandidates for arthroscopic surgery have been selected based on preoperative and intraoperative exclusion criteria. Intraoperative criteria required evaluation of stability under anesthesia and diagnostic arthroscopy. In the open surgery group no redislocations happened. Only one patient did not recover bis previous activity level but 73% had slight restriction to external rotation at 90 ° abduction. In the arthroscopic surgery patients, one of them suffered a redislocation, two cases did not recover their previous activity level but 8 6% kept full shoulder motion. The results encourage the authors to continue the developing trend of arthroscopic stabilization techniques

Impact behavior of sandwich structures made of flax/epoxy face sheets and agglomerated cork

The unremitting quest of natural and renewable materials able to replace their synthetic counterparts in high-performance applications has involved also sandwich structures. In this regard, the aim of this work is to characterize the impact response, in both high- and low-velocity conditions, of green sandwich structures made of agglomerated cork as core and flax/epoxy laminates as face sheets. Both bare cork, flax skins, and complete sandwich structures were subjected to impacts at three different energy levels representing the 25%, 50%, and 75% of the respective perforation thresholds. A gas gun was instead used to assess the high-velocity impact behavior of these green sandwich structures and evaluate their ballistic limit. This study shows that the buckling of cell walls of agglomerated cork enables to tailor the damage extension through-the-thickness in low-velocity impacts compared to traditional synthetic foams coupled with a considerable amount of energy absorption

Verificación artroscópica del diagnóstico por resonancia magnética de las lesiones meniscales

La utilización de la Imagen por Resonancia Magnética (IRM) como prueba diagnóstica en la patología de la rodilla, se presenta como alternativa no invasiva fundamental. Se ha diseñado un protocolo a doble ciego junto al servicio de radiodiagnóstico de nuestro hospital a través del cual se han evaluado un total de 31 pacientes donde los hallazgos de la IRM son contrastados con la exploración artroscópica posterior. Para el menisco interno, la precisión diagnóstica de la IRM es del 93 % y del 87% para el externo. Como conclusiones de mayor relieve, la sensibilidad de la exploración fue del 90% para el interno y del 75% para el externo y respecto a la especificidad, en el interno resultó ser del 100% y del 91% en el externo. Los valores predictivo negativo y positivo fueron respectivamente del 85 y 100% en el menisco interno y del 84 y 75% en el externo. Se encontró mayor dificultad diagnóstica en la porción anterior del menisco externo y falta de precisión ocasional en definir el tipo y extensión de la lesión.The use of Magnetic Resonance Imaging (MIR) as a diagnostic trial in the pathology of the knee, has become an important non invasive alternative. We have designed a double blind protocol with the Department of Radiology through we have evaluated 31 patients analyzing the MRI results in relation with the arthroscopic findings. For the medial meniscus, the accuracy of the MRI was 93 % and 87% for the lateral. As main conclusions, the sensibility was 90% for the medial meniscus and 75% for the lateral one and about specificity, we found a result of 100% for the medial meniscus and 91% for the lateral. The negative and positive predictive values were respectively 85% and 100% for the medial and 84% and 75% for the lateral. We noted more diagnostic difficulties in the anterior portion of lateral meniscus and lack of precission in the determination of the type and extension of the meniscal injury

Reconstrucción del ligamento cruzado anterior con plastia mixta de semitendinoso y fibra de Kennedy-Lad

—Se han evaluado los resultados de la reconstrucción del ligamento cruzado anterior (LCA) con una plastia mixta de tendón del semitendinoso y fibra sintética de KennedyLAD en veinticinco pacientes con un mínimo de dos años de seguimiento postoperatorio (media de treinta y ocho meses). Se trataba en todos los casos de lesiones crónicas donde la cirugía consistió en la reconstrucción del LCA y meniscectomías parciales cuando fueron necesarias. La evaluación se llevó a cabo mediante pruebas funcionales (Lysholm) y clínicas (Marshall), pruebas de estabilidad manual (Lachman, pivot, cajón neutro anterior), medidas instrumentales de estabilidad con artrómetro (KT-1000), índice de actividad y apreciación subjetiva. Los datos indican que el comportamiento de la plastia es adecuado en el 92% de los casos proporcionando a los pacientes una función articular satisfactoria en su vida diaria incluyendo la actividad deportiva.The authors assess the results of the anterior cruciate ligament (ACL) reconstruction by means of a semitendinous tendon and Kennedy LAD composite graft. Minimum followup has been two years (mean of thirty eight months). In every cases the lesion was considered as chronic and surgery consisted of ACL reconstruction and partial meniscectomy if neccessary. Studies performed to asses the results included: functional (Lysholm) and clinical (Marshall) tests, manual stability tests (Lachman, pivot-shift, neutral anterior drawer), instrumented stability measurement (KT-1000 arthrometer), activity score and subjective patient self-assessment. The data collected indicate that the performance of the composite graft is adequate in 92% of the cases, allowing the patients a satisfactory knee joint function in their daily life including sporting activities

Renormalization Group Analysis of a Quivering String Model of Posture Control

Scaling concepts and renormalization group (RG) methods are applied to a simple linear model of human posture control consisting of a trembling or quivering string subject to damping and restoring forces. The string is driven by uncorrelated white Gaussian noise intended to model the corrections of the physiological control system. We find that adding a weak quadratic nonlinearity to the posture control model opens up a rich and complicated phase space (representing the dynamics) with various non-trivial fixed points and basins of attraction. The transition from diffusive to saturated regimes of the linear model is understood as a crossover phenomenon, and the robustness of the linear model with respect to weak non-linearities is confirmed. Correlations in posture fluctuations are obtained in both the time and space domain. There is an attractive fixed point identified with falling. The scaling of the correlations in the front-back displacement, which can be measured in the laboratory, is predicted for both the large-separation (along the string) and long-time regimes of posture control.Comment: 20 pages, 13 figures, RevTeX, accepted for publication in PR

Fracturas de Astrágalo: Evaluación Clínico-Quirúrgica

Se han revisado 13 pacientes diagnosticados de fractura de astrágalo recogidos en nuestro Servicio de Urgencias y tratados quirúrgicamente en todos los casos. De ellos se ha realizado un seguimiento clínico y radiológico. En el 46% de los casos se obtuvieron resultados satisfactorios (23% excelentes y 23% buenos). Los restantes se repartieron entre regulares (38%) y malos (16%). La necrosis avascular apareció en 3 de los 13 casos, discutiéndose el origen de esta seria complicación. Siguiendo la clasificación de WEBER, los tipos de fractura más frecuentes fueron el tipo III (38%) y el II (31%). La congruencia articular postquirúrgica del astrágalo fracturado y el tiempo de demora en la cirugía que debe ser de urgencia, se muestran como factores a considerar en la evolución ulterior del "Aviators astragalus". Se discute así mismo el valor del signo de Hawkins.Areview of 13 patients diagnosed of Talus fracture has been colected in our service of trauma emergency. All of them have been managed by surgical methods and clinical and radiologically followed up. Satisfactory results wer e obtained in 46% of the cases (23%, excellents and 23%, good results). The rest wer e regular (38%) and bad (16%). Avascular necrosis was observed in 3 of the 13 cases, discussing the origin of this serious complication. The most frequent types of fracture were type III (38%) ant type II (31%) following Weber's classification. The postsurgical articular congruency of the fractured talus and the delayed time on the surgery which must be an emergency, seem to be factors to conside r in the later evolution of the "aviators astragalus". The value of Hawkins sign is also discussed

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations