RESUMEN
We characterize universal features of the sample-to-sample fluctuations of global geometrical observables, such as the area, width, length, and center-of-mass position, in random growing planar clusters. Our examples are taken from simulations of both continuous and discrete models of kinetically rough interfaces, including several universality classes, such as Kardar-Parisi-Zhang. We mostly focus on the scaling behavior with time of the sample-to-sample deviation for those global magnitudes, but we have also characterized their histograms and correlations.
RESUMEN
We consider the isochrone curves in first-passage percolation on a 2D square lattice, i.e., the boundary of the set of points which can be reached in less than a given time from a certain origin. The occurrence of an instantaneous average shape is described in terms of its Fourier components, highlighting a crossover between a diamond and a circular geometry as the noise level is increased. Generally, these isochrones can be understood as fluctuating interfaces with an inhomogeneous local width which reveals the underlying lattice structure. We show that once these inhomogeneities have been taken into account, the fluctuations fall into the Kardar-Parisi-Zhang universality class with very good accuracy, where they reproduce the Family-Vicsek Ansatz with the expected exponents and the Tracy-Widom histogram for the local radial fluctuations.
RESUMEN
We consider the statistical properties of arrival times and balls on first-passage percolation (FPP) two-dimensional square lattices with strong disorder in the link times. A previous work showed a crossover in the weak disorder regime, between Gaussian and Kardar-Parisi-Zhang (KPZ) universality, with the crossover length decreasing as the noise amplitude grows. On the other hand, this work presents a very different behavior in the strong-disorder regime. An alternative crossover length appears below which the model is described by bond-percolation universality class. This characteristic length scale grows with the noise amplitude and diverges at the infinite-disorder limit. We provide a thorough characterization of the bond-percolation phase, reproducing its associated critical exponents through a careful scaling analysis of the balls, which is carried out through a continuous mapping of the FPP passage time into the occupation probability of the bond-percolation problem. Moreover, the crossover length can be explained merely in terms of properties of the link-time distribution. The interplay between the characteristic length and the correlation length intrinsic to bond percolation determines the crossover between the initial percolation-like growth and the asymptotic KPZ scaling.
RESUMEN
OBJECTIVE: The objective of this study is to compare hearing improvements in the air-bone gap (ABG) after type III tympanoplasties, comparing between incus transposition (IT) and partial ossicular replacement prosthesis (PORP). MATERIALS AND METHODS: Publications in English were searched in PUBMED database and were systematically reviewed. A total of 14 articles were included, obtaining 1055 patients, 614 for the IT group and 441 for the PORP group. Preoperative ABG, postoperative ABG, dB gain and ABG closure rate were compared. RESULTS: IT group: preoperative ABG of 31.74 dB (SD 10.51); postoperative ABG of 18.97 dB (SD 10.6); dB gain of 12.76 dB (SD 14.97); and ABG closure rate of 64.48%. PORP group: preoperative ABG of 28.02 dB (SD 10.47); postoperative ABG of 16.27 dB (SD 10.45); dB gain of 11.75 (SD 15.02); and ABG closure rate of 71.32%. No significant statistical difference was found in dB mean gain between groups (p > .05), although a difference was found in the ABG closure rate between groups favouring PORP series (p < .05). CONCLUSION: An improvement in hearing results was observed within both groups after type III tympanoplasty. There is no difference in decibels gained between both ossiculoplasty materials, but a better closure rate (%) was observed in the PORP group.
Asunto(s)
Audición , Timpanoplastia/estadística & datos numéricos , Humanos , Yunque/cirugía , Reemplazo Osicular , Timpanoplastia/métodosRESUMEN
Since the turn of the century, percutaneous tracheostomy (PT) has become an alternative to the classic open technique and is an elective procedure in intensive care units at most centers. We conducted a prospective study to identify and quantify the complication rate with PT and to analyze this procedure's association with potential risk factors. Our study population was made up of 114 patients-83 men (72.8%) and 31 women (27.2%), aged 18 to 81 years (mean: 57 ± 15)-who underwent PT at our center over an 18-month period. We sought to determine if there were any associations between PT complications and sex, previous fibroscopy, cervical length, cervical risk factors, and general risk factors. Generally minor complications were noted in 15 patients (13.2%); 13 patients experienced hemorrhage, 1 exhibited subcutaneous emphysema, and 1 had a vagal reaction that resolved with medical treatment. Only 3 of these cases (2.6%) were considered to be clinically relevant: 1 hemorrhage (which was treated with ligation), the emphysema (which resolved spontaneously), and the vagal reaction (which resolved with medical treatment). Statistically, we found that PT complications were significantly correlated with two factors: coagulopathy (p = 0.015) and hemodynamic instability (p = 0.017). Even so, these complications were not clinically significant, and they resolved with conservative treatment measures. Given the low incidence and mild degree of these complications, we consider PT to be a safe procedure, even in patients with a high risk of hemorrhage or cervical anatomic difficulties.
Asunto(s)
Traqueostomía/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Hemorragia/etiología , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Prospectivos , Factores de Riesgo , Enfisema Subcutáneo/etiología , Traqueostomía/métodos , Nervio Vago/fisiopatología , Adulto JovenRESUMEN
No disponible
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Humanos , Masculino , Persona de Mediana Edad , Linfoma/patología , Neoplasias de la Parótida/cirugía , Ensayo del Nódulo Linfático Local , Metástasis Linfática/patología , Escisión del Ganglio Linfático/métodosRESUMEN
No disponible
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Humanos , Femenino , Adulto , Rinitis/etiología , Sinusitis/etiología , Diente no Erupcionado/complicaciones , EndoscopíaRESUMEN
INTRODUCTION AND OBJECTIVES: To compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. METHODS: This was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4 centimetres) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. RESULTS: We highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. CONCLUSIONS: The results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach.
Asunto(s)
Neuroma Acústico/cirugía , Procedimientos Quirúrgicos Otorrinolaringológicos/métodos , Adulto , Anciano , Traumatismos del Nervio Facial/prevención & control , Parálisis Facial/etiología , Femenino , Pérdida Auditiva Unilateral/etiología , Humanos , Hidrocefalia/etiología , Complicaciones Intraoperatorias/prevención & control , Masculino , Persona de Mediana Edad , Neurofibromatosis 2/cirugía , Neuroma Acústico/complicaciones , Procedimientos Quirúrgicos Otorrinolaringológicos/estadística & datos numéricos , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento , Carga Tumoral , Adulto JovenRESUMEN
No disponible
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Adulto , Femenino , Humanos , Trompa Auditiva/patología , Neoplasias del Oído/diagnóstico , Teratoma/diagnósticoAsunto(s)
Neoplasias del Oído/diagnóstico , Trompa Auditiva/diagnóstico por imagen , Teratoma/diagnóstico , Adulto , Enfermedad Crónica , Quiste Dermoide/diagnóstico , Diagnóstico Diferencial , Neoplasias del Oído/complicaciones , Neoplasias del Oído/diagnóstico por imagen , Trompa Auditiva/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Apófisis Mastoides/cirugía , Otitis/etiología , Teratoma/complicaciones , Teratoma/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
No disponible
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Adulto , Masculino , Persona de Mediana Edad , Humanos , Neuralgia del Trigémino/diagnóstico , Neuralgia del Trigémino/tratamiento farmacológico , Toxinas Botulínicas Tipo A/administración & dosificación , Toxinas Botulínicas Tipo A/uso terapéutico , Toxinas Botulínicas Tipo A/efectos adversos , Arteria Basilar/anomalías , Arteria Vertebral/anomalías , Espasmo Hemifacial/diagnóstico , Espasmo Hemifacial/tratamiento farmacológico , Blefaroespasmo/diagnóstico , Blefaroespasmo/tratamiento farmacológico , Espectroscopía de Resonancia MagnéticaAsunto(s)
Blefaroespasmo/etiología , Aneurisma Intracraneal/complicaciones , Trastornos de Tic/etiología , Insuficiencia Vertebrobasilar/complicaciones , Amitriptilina/uso terapéutico , Benzotiazoles/uso terapéutico , Toxinas Botulínicas Tipo A/uso terapéutico , Clonazepam/uso terapéutico , Músculos Faciales/inervación , Músculos Faciales/fisiopatología , Humanos , Imagenología Tridimensional , Aneurisma Intracraneal/diagnóstico , Aneurisma Intracraneal/diagnóstico por imagen , Angiografía por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pramipexol , Pregabalina/uso terapéutico , Trastornos de Tic/tratamiento farmacológico , Trastornos de Tic/fisiopatología , Insuficiencia Vertebrobasilar/diagnóstico , Insuficiencia Vertebrobasilar/diagnóstico por imagenRESUMEN
No disponible
Asunto(s)
Animales , Cóclea , Cisplatino/toxicidad , /diagnóstico , Modelos AnimalesAsunto(s)
Adenoma/patología , Neoplasias del Oído/patología , Oído Medio/patología , Tumores Neuroendocrinos/patología , Adenoma/cirugía , Neoplasias del Oído/cirugía , Oído Medio/cirugía , Femenino , Pérdida Auditiva Conductiva/etiología , Humanos , Inmunohistoquímica , Queratinas/metabolismo , Persona de Mediana Edad , Tumores Neuroendocrinos/cirugía , Procedimientos Quirúrgicos Otológicos , Sinaptofisina/metabolismo , Acúfeno/etiologíaRESUMEN
Introducción y objetivos: Comparar los resultados obtenidos en la resección de 21 schwanomas vestibulares gigantes, mediante vía retrosigmoidea y combinada retrosigmoidea/translaberíntica en cuanto a complicaciones intra y postoperatorias, preservación del nervio facial y secuelas posquirúrgicas. Métodos: Se realiza un estudio retrospectivo de 21 pacientes a los que se practicó resección de neurinoma vestibular gigante según la escala de Tos & Thomsen (igual o mayor a 4cm), en un hospital de tercer nivel en el periodo entre 2000 y 2008. Se presentan las características más significativas de la serie estudiada, y se analizan las ventajas e inconvenientes de los distintos abordajes, comparando los resultados obtenidos. Asimismo, se analizan los resultados en cuanto a la preservación de la función del nervio facial. Resultados: Destaca la ausencia de mortalidad en el grupo de 21 pacientes estudiado. No hubo complicaciones intraoperatorias importantes. Se consiguió la resección total de la lesión en el 87% de los casos, con una preservación anatómica del nervio facial del 73% en el abordaje combinado retrosigmoideo/translaberíntico, respecto a un 40% en el retrosigmoideo. La función del nervio facial a los dos años fue aceptable o buena en un 67% (incluyendo los resultados de las anastomosis heteronerviosas). Se observó un porcentaje global del 14,3% de fístula de líquido cefalorraquídeo y un 9,5% de meningitis. Conclusiones: nuestros resultados demuestran que el abordaje combinado retrosigmoideo translaberíntico para el tratamiento de schwannomas gigantes ofrece mayor preservación del nervio facial y disminución de la morbilidad, siendo una importante opción en el tratamiento de estos tumores, gracias a un enfoque multidisciplinar(AU)
Introduction and objectives: To compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. Methods: This was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4 centimetres) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. Results: We highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. Conclusions: The results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach(AU)
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Neuroma Acústico/cirugía , Vestíbulo del Laberinto/patología , Procedimientos Quirúrgicos Otorrinolaringológicos/métodos , Estudios Retrospectivos , Traumatismos del Nervio Facial/prevención & controlRESUMEN
La traqueotomía percutanea por dilatación (TPD) es una popular alternativa a la traqueotomía quirúrgica. En nuestro hospital es realizada de manera rutinaria en la Unidad de Cuidados Intensivos. El objetivo de nuestro estudio es analizar la técnica y sus complicaciones tanto precoces como tardías. Realizamos un estudio prospectivo de 60 TPD realizadas en diferentes unidades de cuidados intensivos, entre septiembre del 2002 y julio de 2003. El tiempo intraoperatorio para la TPD fue de unos 8 minutos de media. Hubo 7 casos de hemorragia intraoperatoria, 6 leves y uno moderado, 2 casos de hemorragia postoperatoria y un caso de enfisema subcutaneo. Respecto a las lesiones traqueales apreciamos un 25 por ciento de afectación en la exploración precoz, que desciende a la mitad en la exploración tardía. La TPD es una buena alternativa a la traqueotomía quirúrgica, fácil, segura, rápida y eficaz.
Asunto(s)
Humanos , Masculino , Adulto , Femenino , Persona de Mediana Edad , Traqueotomía , Otolaringología , VenezuelaRESUMEN
Las adenopatías cervicales por carcinoma prostático son infrecuentes en la clínica diaria. Presentamos el caso de un hombre de 84 años que después de una retención aguda de orina fue diagnosticado de un adenocarcinoma de próstata con adenopatías supraclaviculares (AU)
Asunto(s)
Anciano , Masculino , Humanos , Adenocarcinoma/diagnóstico , Adenocarcinoma/complicaciones , Adenocarcinoma/patología , Retención Urinaria/complicaciones , Retención Urinaria/diagnóstico , Cistoscopía/métodos , Tomografía Computarizada de Emisión/métodos , Hormonas/uso terapéutico , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/complicaciones , Metástasis de la Neoplasia/fisiopatología , Metástasis de la Neoplasia/patología , Hematuria/complicaciones , Hematuria/diagnóstico , Prostatectomía/métodos , Metástasis Linfática/diagnóstico , Metástasis Linfática/patología , Neoplasias Primarias Múltiples/diagnóstico , Neoplasias Primarias Múltiples/fisiopatologíaRESUMEN
Los Tumores de Células Granulares (TCG) son tumores raros que pueden aparecer en cualquier parte del cuerpo con clara predilección por la región de cabeza y cuello. El TCG de laringe es un inusual tumor laríngeo, que constituye aproximadamente un 6-10 per cent de los casos descritos. La hiperplasia pseudoepiteliomatosa puede predisponer a confusión del TCG con el Carcinoma Escamoso. El origen de estos tumores es tema de debate, pero la mayoría de los autores cree que es de origen nervioso. Presentamos 1 casos de este tumor en laringe y revisamos sus características (AU)