283 research outputs found
SÃndrome de Mazabraud: Presentación de un caso clÃnico y revisión de la literatura
El sÃndrome de Mazabraud se define como la asociación de una tumoración de partes blandas, el mixoma intramuscular, y un tumor óseo, la displasia fibrosa. Se realiza una revisión bibliográfica de los casos publicados en la literatura, desde que en 1957, Mazabraud acuñó esta asociación como sÃndrome. El caso clÃnico corresponde a un varón de 43 años de edad con antecedentes de nódulo frÃo tiroideo, pigmentación cutánea y lesiones óseas en pelvis y tercio proximal fémur derecho, que acudió a la consulta por presentar una tumoración de partes blandas a nivel del muslo derecho de unos meses de evolución. Tras realizar biopsia de la misma se diagnosticó de mixoma intramuscular. El paciente se intervino quirúrgicamente practicándose resección amplia de la lesión. Hasta la fecha el enfermo no ha presentado recidiva de la lesión de partes blandas, y la displasia ósea no ha sufrido transformación maligna.Mazabraud's sÃndrome is the association of a soft-tissue tumour, intramuscular myxonma and a bone tumour, fibrous dysplasia. We review the literature since Mazabraud, in 1957 described this syndrome. We report a 43 years male who consulted for a soft-time mass in the right thigh. He also had bone lesions in pelvis and right femur that were diagnosted of fibrous dysplasia. We made a biopsy of soft-tissue tumour and it was diagnosed of intramuscular myxom. The patient was operated and the mass was removed. Till now, there is no recurrence of the myxom and there is no malignant degeneration of the fibrous dysplasia
The Simulated Ocular and Whole-body Distribution of Natural Sunlight to Kiteboarders: A High Risk Case of UVR Exposure for Athletes Utilizing Water Surfaces in Sport [Not yet published 14/01/20 MC]
Kiteboarding is an aquatic sporting discipline that has not yet been considered in the literature to date in terms of solar ultraviolet radiation (UVR) measurement. Kiteboarders need to look upward and are placed obliquely relative to the horizon when towed behind an overhead kite over a reflective water surface. This research defines the typical body surface orientation of a kiteboarder in motion through video vector analysis and demonstrates the potential risk to ocular and skin surface damage through practical measurement of solar UVR using a manikin model. Video analysis of 51 kiteboarders were made to construct skeletal wireframes showing the surface orientation of the leg, thigh, spine, humerus, lower arm and head of a typical kiteboarder. Solar UVR dosimeter measurements made using a manikin model demonstrate that the vertex and anterior surfaces of the knee, lower leg, and lower humerus received 89%, 90%, 80% and 63% of the available ambient UVR respectively for a typical kiteboarder who is tilted back more than 15o from vertical while in motion. Ocular (periorbital) exposures ranged from 56 to 68% of ambient. These new findings show that the anterior skin surfaces of kiteboarders and the eye are at elevated risk of solar UVR damage
Thermal characterization of Montmorillonite clays saturated with various cations
Emanation thermal analysis (ETA), thermogravimetry and high temperature XRD were used to characterize the thermal behavior during dehydration of natural Na montmorillonite (Upton Wyoming, USA) and homoionic montmorillonite (MMT) samples saturated with different cations, i.e. Li+, Cs+, NH 4 +, Mg2+ and Al3+. ETA results characterized radon mobility and microstructure changes that accompanied the mass loss of the samples due to dehydration on heating in air. A collapse of interlayer space between the silicate sheets after water release from the MMT samples was characterized by a decrease of the radon release rate, ΔE. Decreases in c-axis basal spacing (d 001) values determined from XRD patterns for the different montmorillonite samples follow the sequence: Mg−MMT>Al−MMT>Li−MMT>Na−MMT>NH4−MMT>Cs−MMT The decrease of the radon release rate (ΔE) determined by ETA that characterized microstructure changes due to collapse of interlayer space corresponded well to differences in the c-axis basal spacing (Δd 001) values determined from the XRD patterns before and after samples dehydration.Peer Reviewe
Thermal characterization of Montmorillonite clays saturated with various cations
Emanation thermal analysis (ETA), thermogravimetry and high temperature XRD were used to characterize the thermal behavior during dehydration of natural Na montmorillonite (Upton Wyoming, USA) and homoionic montmorillonite (MMT) samples saturated with different cations, i.e. Li+, Cs+, NH 4 +, Mg2+ and Al3+. ETA results characterized radon mobility and microstructure changes that accompanied the mass loss of the samples due to dehydration on heating in air. A collapse of interlayer space between the silicate sheets after water release from the MMT samples was characterized by a decrease of the radon release rate, ΔE. Decreases in c-axis basal spacing (d 001) values determined from XRD patterns for the different montmorillonite samples follow the sequence: Mg−MMT>Al−MMT>Li−MMT>Na−MMT>NH4−MMT>Cs−MMT The decrease of the radon release rate (ΔE) determined by ETA that characterized microstructure changes due to collapse of interlayer space corresponded well to differences in the c-axis basal spacing (Δd 001) values determined from the XRD patterns before and after samples dehydration.Ministry of Education of Czech Republic LA–292España Ministerio de educación MAT2004-0264
Improved procedural workflow for catheter ablation of paroxysmal AF with high-density mapping system and advanced technology: Rationale and study design of a multicenter international study
The antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low-voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions.The improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single-arm, international post-market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point-by-point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post-ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated.The DELETE AF trial will provide additional knowledge on long-term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143).© 2022 The Authors. Clinical Cardiology published by Wiley Periodicals LLC
A versatile CMOS transistor array IC for the statistical characterization of time-zero variability, RTN, BTI, and HCI
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Statistical characterization of CMOS transistor variability phenomena in modern nanometer technologies is key for accurate end-of-life prediction. This paper presents a novel CMOS transistor array chip to statistically characterize the effects of several critical variability sources, such as time-zero variability (TZV), random telegraph noise (RTN), bias temperature instability (BTI), and hot-carrier injection (HCI). The chip integrates 3136 MOS transistors of both pMOS and nMOS types, with eight different sizes. The implemented architecture provides the chip with a high level of versatility, allowing all required tests and attaining the level of accuracy that the characterization of the above-mentioned variability effects requires. Another very important feature of the array is the capability of performing massively parallel aging testing, thus significantly cutting down the time for statistical characterization. The chip has been fabricated in a 1.2-V, 65-nm CMOS technology with a total chip area of 1800 x 1800 µm².Peer ReviewedPostprint (author's final draft
Monitoring defects in III-V materials : a nanoscale CAFM study
The implementation of high mobility devices requires growing III-V materials on silicon substrates. However, due to the lattice mismatch between these materials, III-V semiconductors tend to develop structural defects affecting device electrical characteristics. In this study, the CAFM technique is employed for identification and analysis of nanoscale defects, in particular, Threading Dislocations (TD), Stacking faults (SF) and Anti-phase Boundaries (APB), in III-V materials grown over silicon wafers
Conductive-AFM topography and current maps simulator for the study of polycrystalline high-k dielectrics
In this work, a simulator of conductive atomic force microscopy (C-AFM) was developed to reproduce topography and current maps. In order to test the results, the authors used the simulator to investigate the influence of the C-AFM tip on topography measurements of polycrystalline high-k dielectrics, and compared the results with experimental data. The results show that this tool can produce topography images with the same morphological characteristics as the experimental samples under study. Additionally, the current at each location of the dielectric stack was calculated. The quantum mechanical transmission coefficient and tunneling current were obtained from the band diagram by applying the Airy wavefunction approach. Good agreement between experimental and simulation results indicates that the tool can be very useful for evaluating how the experimental parameters influence C-AFM measurements
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