Assessing the insulating properties of an ultrathin SrTiO3shell grown around GaAs nanowires with molecular beam epitaxy.

We have studied electronic transport in undoped GaAs/SrTiO3core-shell nanowires standing on their Si substrate with two-tip scanning tunneling microscopy in ultrahigh vacuum. The resistance profile along the nanowires is proportional to the tip separation with resistances per unit length of a few GΩ/µm. Examination of the different transport pathways parallel to the nanowire growth axis reveals that the measured resistance is consistent with a conduction along the interfacial states at the GaAs{110} sidewalls, the 2 nm thick SrTiO3shell being as much as resistive, despite oxygen deficient growth conditions. The origin of the shell resistivity is discussed in light of the nanowire analysis with transmission electron microscopy and Raman spectroscopy, providing good grounds for the use of SrTiO3shells as gate insulators.

Cirugía del sueño: Definición de una especialidad emergente, propuesta de una clasificación anatomofuncional integral e indicaciones

Resumen Los trastornos respiratorios del sueño (ronquido primario y síndrome de apnea-hipopnea obstructiva del sueño) han sido tratados mediante múltiples modalidades a lo largo de la historia. Sin embargo, la cirugía de la vía aérea superior siempre ha estado presente, dando cabida a la aparición de múltiples técnicas para este fin. El estudio adecuado de los sitios anatómicos de estrechez o colapso de la vía aérea superior y sus contribuyentes (bajo el concepto de topodiagnóstico) y el mejor entendimiento de los mecanismos de acción de los diferentes procedimientos descritos, ha permitido el nacimiento de una nueva disciplina, dedicada al manejo quirúrgico planificado de este grupo de patologías: la cirugía del sueño.

Abstract Sleep-related breathing disorders (primary snoring and obstructive sleep apnea-hypopnea syndrome) have been treated with multiple modalities throughout history. However, upper airway surgery has always been present, giving appearance of multiple techniques for this purpose. The adequate study of the anatomical sites of upper airway narrowness or collapse and its contributors (under the concept of topodiagnosis) and a better understanding of the different procedures, has allowed the birth of a new discipline, dedicated to a planned surgical management for this group of pathologies: sleep surgery.

Faringoplastía de reposición con suturas barbadas como tratamiento quirúrgico en pacientes con síndrome de apnea-hipopnea obstructiva del sueño / Barbed sutures reposition pharyngoplasty as surgical treatment in obstructive sleep apnea-hypopnea syndrome

INTRODUCCIÓN: La planificación de cirugías para el manejo del síndrome de apneahipopnea obstructiva del sueño (SAHOS) ha incrementado su precisión desde la introducción de la endoscopía del sueño inducido por fármacos (DISE). OBJETIVO: Evaluar la técnica de faringoplastía de reposición con suturas barbadas (BRP) para el colapso velofaríngeo y/o de paredes laterales orofaríngeas evaluado mediante DISE en pacientes con SAHOS. MATERIAL Y MÉTODO: Ochenta y ocho pacientes fueron evaluados para cirugía mediante antropometría, escala de somnolencia de Epworth (ESS) y poligrafía respiratoria. Veinte y seis de 88 pacientes fueron seleccionados. De los 26, 14 accedieron al tratamiento quirúrgico, el que se seleccionó en base a la DISE. En todos los casos, se realizó BRP. RESULTADOS: A los 3 meses de la cirugía hubo mejoría en 10/14 pacientes (criterios de Sher, disminución del índice de apnea-hipoapnea a <20 o 50% del basal). La ESS bajó en promedio de 12 a 5 puntos (p <0,05). No se reportaron incidentes en el posoperatorio y no han ocurrido eventos adversos. CONCLUSIÓN: La técnica de BRP es una técnica sencilla y útil para la expansión anterior y lateral del paladar blando y orofaringe, con una tasa de éxito similar en esta cohorte a la reportada internacionalmente.

INTRODUCTION: Surgical planning for the management of obstructive sleep apneahypopnea syndrome (OSAHS) has changed since the introduction of drug induced sleep endoscopy (DISE). AIM: To evaluate the technique of barbed sutures reposition pharyngoplasty (BRP) for velopharyngeal collapse and/or oropharyngeal lateral walls after DISE evaluation in OSAHS patients. MATERIAL AND METHOD: 88 patients were evaluated for surgery by anthropometry, Epworth sleepiness scale (ESS) and respiratory polygraphy. 26 of 88 patients were selected. Of the 26, 14 agreed to surgical treatment, which was selected on DISE findings. In all cases, BRP was performed. RESULTS: Three months after surgery there was improvement in 10/14 patients (Sher criteria, apnea-hypopnea index reduction at <20 or 50% of baseline). The ESS improved on average 12 to 5 (p <0.05). No incidents were reported in the post-operative period and no adverse events were reported. CONCLUSION: The BRP technique is a simple and useful technique for the anterior and lateral expansion of the soft palate and oropharynx, with a similar success rate in this cohort to that internationally reported.

Tumor triquilemal proliferante: reporte de un caso y revisión de la literatura / Trichilemmal proliferating tumor: case report and literature review

RESUMEN El tumor triquilemal proliferante es una neoplasia poco frecuente, usualmente sólida o parcialmente quística que se origina de la vaina externa de la raíz de un folículo piloso. Ocurre principalmente como una lesión solitaria en el cuero cabelludo de mujeres mayores. Presentamos el caso de una mujer de 56 años con un tumor cervical de nueve años de evolución. El estudio de la pieza de resección confirmó el diagnóstico.

ABSTRACT Trichilemmal proliferating tumor is an infrequent neoplasia, usually solid or partially cystic, originating in the external root sheath of hair follicle. It occurs mainly as a solitary lesion in the scalp in older women. We report the case of a 56 years old woman with a cervical tumor of nine years of growth. Histology of the resection specimen confirmed the diagnosis.

Publisher Correction: Large anisotropy of ferroelectric and pyroelectric properties in heteroepitaxial oxide layers.

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Large anisotropy of ferroelectric and pyroelectric properties in heteroepitaxial oxide layers.

Epitaxial PbZr0.52Ti0.48O3 (PZT) layers were integrated on Si(001) with single PZT {001} orientation, mosaïcity below 1° and a majority of a-oriented ferroelectric domains (∼65%). Ferroelectric and pyroelectric properties are determined along both the out-of-plane and in-plane directions through parallel-plate capacitor and coplanar interdigital capacitor along the <100>PZT direction. A large anisotropy in these properties is observed. The in-plane remnant polarization (21.5 µC.cm-2) is almost twice larger than that measured along the out-of-plane direction (13.5 µC.cm-2), in agreement with the domain orientation. Oppositely, the in-plane pyroelectric coefficient (-285 µC.m-2.K-1) is much lower than that measured out-of-plane (-480 µC.m-2.K-1). The pyroelectric anisotropy is explicated in term of degree of structural freedom with temperature. In particular, the low in-plane pyroelectric coefficient is explained by a two-dimensional clamping of the layers on the substrate which induces tensile stress (from thermal expansion), competing with the decreasing tetragonality of a-domains (shortening of the polar c-axis lattice parameter). Temperature-dependent XRD measurements have revealed an increased fraction of a-domains with temperature, attesting the occurrence of a partial two-dimensional clamping. These observed properties are of critical importance for integrated pyroelectric devices.

GaAs nanowires with oxidation-proof arsenic capping for the growth of an epitaxial shell.

We propose an arsenic-capping/decapping method, allowing the growth of an epitaxial shell around the GaAs nanowire (NW) core which is exposed to an ambient atmosphere, and without the introduction of impurities. Self-catalyzed GaAs NW arrays were firstly grown on Si(111) substrates by solid-source molecular beam epitaxy. Aiming for protecting the active surface of the GaAs NW core, the arsenic-capping/decapping method has been applied. To validate the effect of this method, different core/shell NWs have been fabricated. Analyses highlight the benefit of the As capping-decapping method for further epitaxial shell growth: an epitaxial shell with a smooth surface is achieved in the case of As-capped-decapped GaAs NWs, comparable to the in situ grown GaAs/AlGaAs NWs. This As capping method opens a way for the epitaxial growth of heterogeneous material shells such as functional oxides using different reactors.

GaAs Core/SrTiO3 Shell Nanowires Grown by Molecular Beam Epitaxy.

We have studied the growth of a SrTiO3 shell on self-catalyzed GaAs nanowires grown by vapor-liquid-solid assisted molecular beam epitaxy on Si(111) substrates. To control the growth of the SrTiO3 shell, the GaAs nanowires were protected using an arsenic capping/decapping procedure in order to prevent uncontrolled oxidation and/or contamination of the nanowire facets. Reflection high energy electron diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were performed to determine the structural, chemical, and morphological properties of the heterostructured nanowires. Using adapted oxide growth conditions, it is shown that most of the perovskite structure SrTiO3 shell appears to be oriented with respect to the GaAs lattice. These results are promising for achieving one-dimensional epitaxial semiconductor core/functional oxide shell nanostructures.

Glioma nasal gigante, reporte de un caso: a case report / Giant nasal glioma

Los gliomas nasales son restos de tejido neuroglial que se presentan como una masa craneofacial. Es poco frecuente y no tiene características malignas, pero local-mente es bastante agresivo. Se encuentra dentro del diagnóstico diferencial de masas congénitas de la línea media. Se presenta el caso de un recién nacido que presenta un pólipo nasal derecho y distrés respiratorio. La RNM revela una masa intranasal sin conexión intracraneal. Vía endoscópica se realiza exéresis de la masa sin complicaciones. Biopsia confirma diagnóstico de glioma.

Nasal gliomas are glial tissue residues presented as a craniofacial mass. It is rare and has no malignant features, but locally it is quite aggressive. It is included in the differential diagnosis of congenital midline masses. The case of a newborn is reported which presents a right nasal polyp and respiratory distress. The MRI reveals an intracranial mass with no intranasal connection. Endoscopic resection of the mass is done with no complications. Biopsy confirms glioma diagnosis.

Carcinoma mioepitelial ex adenoma pleomorfo de parótida: reporte de un caso y revisión de la literatura / Myoepithelial carcinoma ex pleomorphic adenoma of parotid: a case report and review of literature

El carcinoma mioepitelial (CME), es una neoplasia infrecuente, representando el1% de los tumores malignos de las glándulas salivales (GS). El diagnóstico se basa en sus características tanto morfológicas como inmunohistoquímicas, siendo la combinación de vimentina, proteína S-100 y calponina lo más frecuente. El tratamiento consiste en exéresis con márgenes libres y en algunos casos disección cervical sumado a radioterapia posoperatoria. Se ha documentado que un adenoma pleomorfo recurrente se malignice a CME, pero no al realizar el diagnóstico patológico inicial. Se presenta un caso y revisión de la literatura.

Myoepithelial carcinoma is a rare neoplasm, representing about 1% of malignant tumours from salivary glands. Diagnosis is based on morphological and inmunohistochemical features. Vimentin, S-100 protein and calponin are the most frecuent immunohistochemical findings. Treatment is based on surgical removal with free margins, and sometimes, neck dissection and postoperative radiotherapy. It has been reported that recurrent pleomorphic adenoma could transform into a myoepithelial carcinoma, but in our report, we present a case with this particular malignant transformation within the first tumor presentation and review of literature.

Tumor miofibroblástico inflamatorio de arteria carótida interna resecado con embolización selectiva previa: reporte de caso / Inflammatory myofibroblastic tumor related to the internal carotid artery, extirpated after an arterial selective embolization

El tumor miofibroblástico inflamatorio es una lesión infrecuente, cuya importancia radica en ser diagnóstico diferencial de otras neoplasias. Se le ha relacionado con Infecciones, traumas, cirugías previas e ínmunosupresión, pero se cree que éstos sólo serían el evento ínidal que daría lugar a una serie de cascadas autoinmunes que perpetuarían al cuadro. Afecta a población infantil y adulta joven, con una edad media de aparición de 10 años, sin distinción de género. A continuación se presenta el caso de una mujer de 45 años de edad con diagnóstico de tumor miofibroblástico inflamatorio de arteria carótida interna, resecado con embolización arterial selectiva previa. Además, se revisa la literatura al respecto.

The inflammatory myofibroblastic tumor is a rare condition, and its' relevant for being a differential diagnosis of many other neoplasms. It has been related with different infections, traumas, previous surgeries and immune deficiencies, but there are studies that support the theory that these factors are only the initial event of an autoimmune reaction that perpetuates the disease. It affects childs and young adults, with an average of 10 years old at the moment of presentation, without differences between genre. In this case, we reporta 45 year old woman, with an histological diagnosis of inflammatory myofibroblastic tumor related to the internal carotid artery, extirpated after an arterial selective embolization. Besides, we review the literature.