Reducción de riesgo de cáncer de mama: Nuevos avances, nuevas preguntas

La medicina actual está cambiando su orientación, pues junto a la curación de la enfermedad, está desplazando su atención hacia la reducción del riesgo frente a la misma. De hecho, esta segunda estrategia parece particularmente eficaz en las patologías crónicas que más claramente determinan mortalidad y morbilidad, como son las enfermedades cardiovasculares y el cáncer. Lógicamente, esta opción sólo resulta factible si se acompaña de un buen conocimiento de los factores de riesgo y si se dispone de armas eficaces para modificarlos. La información sobre los niveles de riesgo a nivel individual ha crecido espectacularmente, como resultado de una mayor disponibilidad de estudios epidemiológicos de calidad, con un alto número de participantes y un diseño correcto. Por otro lado, la genética está creciendo de tal forma que ya comienza a ser una realidad el conocimiento del perfil de susceptibilidad de un individuo frente a ciertas enfermedades. Ésta es la base del actual concepto de medicina predictiva y personalizada, que tanta atención está recibiendo en nuestros días

Simulació i verificació experimental d'un rectificador 'boost' de tres nivells tipus NPC

En el present projecte es presenta l'estudi d'un rectificador elevador ('boost') de 3 nivells, de topologia Neutral Point Clamped (NPC) en les seves versions monofàsic i trifàsic. Aquest estudi està dividit en dues parts. La part I del projecte versa sobre el rectificador monofàsic, descrivint principalment les equacions matemàtiques que governen el funcionament d'un convertidor de 3 nivells i definint l'estratègia de commutació utilitzada per fer un posterior control del funcionament del rectificador. S'indica també, fent referència als annexes, el software, hardware i equip experimental de què es disposa al laboratori per realitzar aquesta tasca. A partir d'aquests coneixements es realitzen diversos tipus de control al rectificador. En primer lloc es dissenya un control PLL que permet generar un sinus en fase amb la tensió alterna sinusoïdal d'entrada del rectificador. En segon lloc, es dissenya el regulador de corrent a partir del qual es defineix el corrent d'entrada, així com també el factor de potència de treball del convertidor. En tercer lloc, es dissenya el regulador de tensió a partir de la metodologia utilitzada pel control del corrent, i amb el qual es defineix la tensió de sortida del bus de contínua amb independència de la càrrega o càrregues resistives connectades al bus de contínua. Finalment i tenint en compte que l'equilibri del bus de contínua és una de les preocupacions principals en l'estudi dels convertidors multinivell, es desenvolupen dos tipus de sistemes d'equilibri de les tensions del bus de contínua segons la connexió de les càrregues al bus. Aquests dissenys es comproven mitjançant software de simulació i realitzant proves experimentals en el rectificador real, fent una comparació de resultats. La part II del projecte versa sobre el rectificador trifàsic, que és una ampliació del convertidor tractat a la part I. En aquesta segona part s’explica un altre tipus d’estratègia de commutació basada en la teoria SVM, diferent a la utilitzada pel rectificador monofàsic. A més, es detallen les ampliacions realitzades respecte el rectificador monofàsic. A partir d'aquest anàlisi, es dissenyen els nous reguladors de corrent i tensió adaptats al cas trifàsic que són degudament comprovats amb software de simulació i amb proves experimentals amb el rectificador trifàsic real, realitzant les comparacions oportunes. Finalment s’inclouen els annexes, on es detallen tots aquells informes, resultats, figures i informació complementària a la memòria d'utilitat pel lector

eFlora and DialGraph, tools for enhancing identification processes in plants

This document describes in some detail the eFlora web application, a powerful tool for the identification of plant species. It incorporates the corpus of Flora Iberica, a scientific description of the vascular plants living in the Iberian Peninsula, which is treated as unstructured information and therefore indexed by a full text search engine tool, in our case Lucene. eFlora also includes dichotomous keys, which are displayed using Hyperbolic Geometry. By making intelligent use of the keys, we have created two original and useful features, the comparison of arbitrarily chosen species, which is resolved by a dynamic generation of subkeys applied to these selected species, and the presentation of dichotomous keys in the form of a Virtual Assistant, or conversational robot, using our solution DialGraph, which allows to nonacademic users an approach in Natural Language, such as chat, or voice recognition, Text to Speech Synthesis (TTS) or even Automatic Translation when dealing with a multilanguage context. Concerning the configuration of the Virtual Assistant, we provide a very intuitive BPM-like graphical design. This approach to dichotomous keys helps teaching biodiversity science, enhances the awareness of its importance, and makes citizens emotionally closer to science

Exploiting hybrid parallelism in the kinematic analysis of multibody systems based on group equations

Computational kinematics is a fundamental tool for the design, simulation, control, optimization and dynamic analysis of multibody systems. The analysis of complex multibody systems and the need for real time solutions requires the development of kinematic and dynamic formulations that reduces computational cost, the selection and efficient use of the most appropriated solvers and the exploiting of all the computer resources using parallel computing techniques. The topological approach based on group equations and natural coordinates reduces the computation time in comparison with well-known global formulations and enables the use of parallelism techniques which can be applied at different levels: simultaneous solution of equations, use of multithreading routines, or a combination of both. This paper studies and compares these topological formulation and parallel techniques to ascertain which combination performs better in two applications. The first application uses dedicated systems for the real time control of small multibody systems, defined by a few number of equations and small linear systems, so shared-memory parallelism in combination with linear algebra routines is analyzed in a small multicore and in Raspberry Pi. The control of a Stewart platform is used as a case study. The second application studies large multibody systems in which the kinematic analysis must be performed several times during the design of multibody systems. A simulator which allows us to control the formulation, the solver, the parallel techniques and size of the problem has been developed and tested in more powerful computational systems with larger multicores and GPU.This work was supported by the Spanish MINECO, as well as European Commission FEDER funds, under grant TIN2015-66972-C5-3-

On the use of a new class of simplified multi-window iris notch in the design of ultra-compact high-rejection waveguide filters for satellite links

This work introduces a simplified multi-aperture iris notch suitable for designing waveguide filters having an extremely improved compactness/rejection ratio, regarding available solutions, and adequate pass-band performances. The proposed iris architecture, analyzed for the first time, exhibits a unique transmission zero in the waveguide mono-mode bandwidth which can be easily located below or above the pass-band. The frequency of this transmission zero is evaluated in terms of the iris dimensions thus providing useful guidelines for designing filters with suitable responses. As a consequence of this simplified topology, any designed filter can be easily manufactured by cutting along its E-field symmetry plane. This strategy greatly improves the filter’s insertion loss regarding classical implementations based on more complicated arrangements with piled thin metallic sheets. Two exemplary filters have been designed and tested to be used in a high-performance X-band SATCOM terminal with an 80% size reduction with respect to the existing systems. Both filters covering the Rx (7.25–75 GHz) and Tx (7.9–8.4 GHz) sub-bands show a reflection of −25 dB with insertion losses below 1 dB in the pass-band, whereas they present a very sharp out-of-band rejection of at least 90 dB, that is, a 600 dB/GHz slope at X band.This work was supported by the State Research Agency, Spanish Ministry of Economy, Industry and Competitiveness, through project TEC2017-83343-C4-1-R and FEDER funds from the EU

Cataract surgery astigmatism incisional management. Manual relaxing incision versus femtosecond laser-assisted arcuate keratotomy. A systematic review

Purpose: This systematic review aims to compare corneal astigmatism correction in cataract surgery through corneal relaxing incision, manually and femtosecond laser assisted. Methods: The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. We used PubMed, Scopus, and Web of Science (WOS) as databases from January 2010 to March 30, 2021. Patients with keratoconus, corneal ectasia, and a previous history of eye surgery were excluded because our aim was to analyze only healthy eyes. Results: A total of 1025 eyes were evaluated from 946 patients (mean age was 68.90 ± 5.12) in manual incision group articles, while 1905 eyes of 1483 patients (mean age was 65.05 ± 4.57) were evaluated in femtosecond laser arcuate keratotomy (FLAK) articles. The mean uncorrected distance visual acuity (UDVA) was 0.19 ± 0.12 and 0.15 ± 0.05 logMAR for manual incision and FLAK articles, respectively (p = 0.39). The mean correction index (CI) was similar in both groups: 0.77 ± 0.18 in manual incision and 0.79 ± 0.17 in femtosecond laser assisted incision (p = 0.70). Refractive stability was found after 3 months and no serious complications were reported during the follow-up in any group. Conclusion: Both techniques are safe and moderately effective in corneal astigmatism correction in cataract surgery. FLAK represents a more precise and predictable approach. However, since visual and refractive outcomes appear to be similar in both cases, the cost-benefit analysis is controversial

Análisis cientimétrico de la productividad en la Revista de Investigación Educativa (1983-2000)

This study informs about the evaluation of the Spanish educational research from a scientometric approach. So, a representative journal is analyzed, concretely, the Revista de Investigación Educativa (Review of Educational Research). This scientometric analysis is carried out by means of one of the modalities of evaluations available: bibliometric analysis of its productions and indexes related to the case, during the period 1983 (year of appearance) until the year 2000.Este estudio informa sobre el tópico de la evaluación de la investigación educativa española desde una perspectiva cientimétrica, analizando, para ello, una revista representativa del campo de la educación española, cual es la Revista de Investigación Educativa. En concreto, se realiza un análisis cientimétrico mediante una de las modalidades evaluativas disponibles: análisis bibliométrico de sus producciones e índices aplicables al caso, durante el período 1983 (año de aparición) hasta el año 2000

Improvement of transformer liquid insulation using nanodielectric fluids: a review

During the last 20 years, the search for new applications for nanotechnology has become one of the busiest in science, engineering, and manufacturing. New nanotechnology-based materials with superior properties have been developed and are already used in many everyday products and processes. The application of nanotechnology to high-voltage engineering has been mainly oriented towards the development and characterization of the so-called nanodielectric materials [1]. In 1994, Lewis [2] suggested that "a major field of study in the future development of dielectrics will concern their properties when relatively few molecules are involved. Such smallness arises naturally at interfaces of nanometric thickness and will occur also when dielectrics are employed in the nano-technical devices of the future." The physical phenomena that govern the behavior of materials at sub-microscopical scale are outlined in this publication [2]. The term "nanodielectric" was introduced by Frechette [3], [4], who defined nanodielectrics as "multicomponent dielectrics possessing nanostructures, the presence of which results in the change of one or several of its dielectric properties".This work has been supported by the Spanish Ministry of Economy and Competitiveness within the project DPI2015-71219-C2-2-R.Publicad

Single-photon source over the terahertz regime

We present a proposal for a tunable source of single photons operating in the terahertz (THz) regime. This scheme transforms incident visible photons into quantum THz radiation by driving a single polar quantum emitter with an optical laser, with its permanent dipole enabling dressed THz transitions enhanced by the resonant coupling to a cavity. This mechanism offers optical tunability of properties such as the frequency of the emission or its quantum statistics (ranging from antibunching to entangled multi-photon states) by modifying the intensity and frequency of the drive. We show that the implementation of this proposal is feasible with state-of-the-art photonics technology.Comment: 18 pages, 14 figure