184 research outputs found
Diferencias biológicas y de supervivencia según el método de detección en pacientes con cáncer de mama
Existe consenso general en que los programas de “screening” o cribado con mamografía puede reducir la mortalidad por cáncer de mama un 20%; sin embargo, dichos programas están sometidos a varios sesgos como el de adelanto diagnóstico (“lead bias”) que se relaciona sobre todo con el tamaño tumoral, y el de duración de la enfermedad (“length bias”), relacionado con características biológicas y de proliferación de los tumores.
Numerosos artículos han mostrado una relación entre tumores diagnosticados por cribado y menor tamaño, condiciones biológicas más favorables y mayor supervivencia, a pesar de lo cual el método de detección de la enfermedad parece ser un factor pronóstico independiente de dichas variables.
El objetivo de este estudio fue medir las características biológicas implicadas en la génesis tumoral y la progresión del cáncer de mama en los carcinomas sintomáticos y los de cribado para identificar posibles diferencias, distinguiendo además entre tumores diagnosticados en la primera (prevalencia) y sucesivas rondas de screening (incidentes).
Para este fin, se evaluaron parámetros clínico-patológicos y actividades de proliferación y apoptosis en una serie de 130 casos sintomáticos y 161 tumores detectados mediante cribado, de los que 76 fueron prevalentes, 65 incidentes y se incluyeron 20 casos de falso negativo.
Tras ajustar por el tamaño pequeño de los carcinomas detectados mediante cribado en comparación con los cánceres sintomáticos, los detectados en el programa de cribado presentaron mayor supervivencia libre de enfermedad (RR = 0,43 IC = 0,19 - 0,96) y tenían concentraciones de receptores de estrógeno y progesterona más a menudo que los cánceres sintomáticos (OR = 3,38 IC = 1,72-6,63 y OR = 3,44 IC = 1,94-6,10, respectivamente). Además, la expresión de bcl-2, un marcador de buen pronóstico en el cáncer de mama, fue mayor y la expresión de HER2 / neu fue menor en los cánceres detectados mediante cribado que en los cánceres sintomáticos (OR = 1,77 IC = 1.1 - 3.23 y OR = 0,64 IC = 0,40-0,98, respectivamente). Sin embargo, al comparar carcinomas detectados mediante cribado prevalentes vs incidentes, los tumores prevalentes fueron de mayor tamaño (OR = 2,84, IC = 1.05- 7.69), tenían menos probabilidades de ser HER2 / neu positivo (OR = 0,22, IC = 0,08-0,61) y presentaron menor expresión Ki67 (OR = 0,36 IC = 0,17 - 0,77). Además, los tumores incidentes presentaron un tiempo de supervivencia más corta que los prevalentes (RR = 4,88 IC = 1,12 - 21,19).
Conclusiones: Los carcinomas de incidencia incluyen una variedad de carcinomas detectados por screening que presentan diferencias en la biología y el pronóstico en relación con carcinomas prevalentes. El método de detección es importante y debe tenerse en cuenta cuando se toman decisiones de terapia adyuvante
Efficient Spectral Domain Analysis of Generalized Multistrip Lines in Stratified Media Including Thin, Anisotropic, and Lossy Substrates
This paper deals with the full-wave analysis of multiconductor microstrip lines used in electrooptic modulators (EOM), MMIC or high speed VLSI applications. An arbitrary number of coupled coplanar strips are embedded in a stratified medium involving iso/anisotropic dielectric and/or semiconductor layers. The numerical aspects of the computation of the propagation constants using the spectral domain analysis (SDA) are stressed. An efficient scheme is used to accurately compute attenuation and propagation constants and current distributions with reasonable CPU times. Convergence problems due to the existence of very thin layers adjacent to the metallized interface has been explicitly considered. An algorithm to compute the modal characteristic impedances is provided regardless of the number and nature of substrate layers. A reciprocity related definition of modal impedances is used in this paper. The use of this definition ensures the symmetry of the multiport scattering matrix associated to the structure
On the efficient implementation of SDA for boxed strip-like and slot-like structures
This paper reports on an enhanced implementation of the spectral-domain analysis (SDA) of boxed multistrip or multislot transmission lines embedded in a layered medium, including biaxial materials. Very high numerical efficiency is attained by a suitable basis and mixed SDA and spatial-domain technique to calculate the entries of the Galerkin matrix. Convergence properties of SDA are drastically improved, making it competitive with other analytical techniques [such as regular singular integral equation (RSIE)]. The method allows quick and accurate computation of current/field distributions.Watkins-Johnson D2010200-1
Systematic Computation of the Modal Spectrum of Boxed Microstrip, Finline, and Coplanar Waveguides Via an Efficient SDA
This work reports an efficient and systematic procedure to obtain the complete modal spectrum of multilayer boxed planar lines. The complex propagation constants are obtained by computing the zeros of a properly built analytic complex function. This function is the product of two factors. One of them is the determinant function provided by the spectral domain—Galerkin analysis (SDA). The other factor is a function which cancels out the poles of the former factor without introducing additional poles nor zeros. The elimination of the poles overcomes numerical difficulties usually found in the zero searching process. In addition, powerful zero—searching integral techniques can be applied without problems. The numerical aspects involved in the computation of the spectral series are considered to speed up the computations. The features of an arbitrary number of propagating, evanescent, backward or complex modes of three important boxed structures (microstrip, finline, and coplanar waveguide) can be systematically studied with our method
Un algoritmo híbrido para el problema NRP con interdependencias
En este artículo presentamos un algoritmo híbrido para una variante del problema de la siguiente versión (NRP). En esta variante existe un conjunto de requisitos para los que se dispone de una estimación del esfuerzo necesario para su implementación y de la satisfacción percibida por los potenciales clientes con la inclusión de dichos requisitos. Entre estos requisitos existen relaciones de interdependencia, que establecen a ciertos requisitos como prerequisitos de otros, o que obligan a implementar determinados requisitos simultáneamente en caso de incluirse alguno de ellos en la siguiente versión del producto a desarrollar. Dado un límite superior de esfuerzo prefijado, el objetivo es seleccionar un subconjunto de requisitos que cumpla todas las restricciones y maximice la satisfacción global de los clientes. La propuesta combina heurísticas con técnicas exactas para una versión simplificada del problema. El rendimiento del algoritmo resultante en distintos escenarios realistas se compara con el de otras técnicas metaheurísticas previamente empleada
Monitoring hygienic measures for decreasing salmonella occurrence in scalding tank water of a Turkey slaughterhouse
The objective of this work was to test different treatments based on the temperature and acidification of scalding tank water throughout the day in a turkey slaughterhouse under industrial conditions in order to decrease the occurrence of Salmonella. After controlling the scalding tank water under usual conditions, the following measures were taken: (a) the temperature was increased to 60 °C and 70 °C for 15 min at the halfway point of the day; (b) the scalding water was acidified and six different initial pH levels were tested. Both measures which were tested (heating and acidification of scalding water) showed efficiency in reducing the occurrence of Salmonella during the scalding step. In order to prevent the disadvantages associated with the hardest measures in each case, we propose that scalding water be heated to 70 °C for 15 min without carcasses, which can be repeated if the disadvantages of the exposed costs and resources of processing are acceptable. Regarding acidification, a suitable measure would be an initial pH of 4.0 or any treatment that keeps the pH of the scalding water below 4.5, using acid that does not affect the final quality of the products and/or the elements involved
On the Quasi-TEM and Full-Wave Approaches Applied to Coplanar Multistrip on Lossy Dielectric Layered Media
The characteristic parameters of coplanar multistrip lines embedded in multilayered lossless/lossy substrates are commonly computed by using either quasi-TEM or full-wave models. Several methods are provided in the literature to deal with this type of structure. In this paper a comparative study of quasi-TEM and rigorous solutions is carried out in order to establish criteria for the validity of the quasi-TEM approach. Reliable quasi-TEM and full-wave numerical data have been properly generated by applying an enhanced spectral domain analysis. We conclude that the quasi-TEM model yields satisfactory results for many MIC and MMIC practical cases. However, significant errors arise when high conductivity substrates are involved in MMIC applications. A discussion about the computation of the dynamic modal characteristic impedance is also reported, showing how the insertion of the modal orthogonality can save computational effort in a lossy multiport system
Oral manifestations of ellis-van creveld syndrome. A rare case report
Ellis-van Creveld syndrome (EVC) or chondroectodermal dysplasia is an autosomal recessive disorder, characterized by dwarfism, polydactyly, hypoplastic fingernails and congenital heart defects, finding in most of the cases orofacial anomalies. We describe a clinical case of a 9 year old male patient diagnosed with EVC who visited our Maxillofacial private consultation at Alcorcon Southern Hospital, presenting typical oral manifestations such as dental agenesis, delayed eruption, hypoplasia of the enamel, dental dysmorphism, taurodontism and supernumerary teeth. EVC syndrome is a rare disease and requires a multidisciplinary approach. Oral features are constant and requires the jointly performance of Odontologist and Maxillofacial surgeon aiming to get an appropriate treatment sequence surgery-orthodontics in order to achieve a suitable functional result to improve the quality of life of these patients
Moving towards a ‘statistical culture’ for economists. Improvement Cycle in the Advanced Statistics Classroom (how to make statistics applied to economics understandable and useful)
Conectar el proceso de enseñanza-aprendizaje a los problemas o preocupaciones
existentes en el contexto social, a las inquietudes y expectativas de los
estudiantes, es fundamental si se quiere avanzar a través de él con ciertas garantías
de éxito. Esto es aún más necesario, si cabe, si la materia que se imparte es
percibida, a priori, como algo artificialmente incorporado al currículo, de escasa
utilidad tanto para la formación recibida cuanto para el posterior quehacer profesional.
El aprendizaje, por tanto, vinculado a problemas o situaciones presentes
en el día a día, constituye una herramienta especialmente útil para superar
estos obstáculos. En este ciclo de mejora en aula (CIMA) la asignatura de Estadística,
impartida en el Grado de Marketing e Investigación de Mercados, adolece
de estas limitaciones. El reto, por tanto, el objetivo principal de este CIMA consiste
en conseguir que esta materia, importante en el desarrollo curricular, pero
de escasa popularidad entre los estudiantes en general, termine conectando con
estos, que lleguen a comprenderla y, sobre todo, que encuentren la utilidad que
tiene para su formación específica como futuros economistas y, al mismo tiempo,
para su condición de ciudadanos bien informados.Connecting the teaching-learning process to the problems or concerns existing
in the social context, to the interests and expectations of the students, is
fundamental if one wants to progress through it with certain guarantees of success.
This is even more necessary, if possible, if the subject taught is perceived, a
priori, as something artificially incorporated into the curriculum, of little usefulness
both for the training received and for subsequent professional work. Learning,
therefore, linked to everyday problems or situations, is a particularly useful
tool for overcoming these obstacles. In this improvement cycle in classroom (ICC),
the subject of Statistics, taught in the Degree in Marketing and Market Research,
suffers from these limitations. The challenge, therefore, the main objective of this
ICC, is to ensure that this subject, which is important in curricular development
but not very popular among students in general, ends up connecting with them,
that they come to understand it and, above all, that they find it useful for their
specific training as future economists and, at the same time, for their condition
as well-informed citizens
Reducing emergence services arrival time by using vehicular communications and Evolution Strategies
Nowadays, traffic jams in urban areas have become a problem that keeps growing every year since the number of vehicles in our cities is continuously increasing. One of the most common causes producing traffic jams are vehicle accidents. Moreover, the arrival time of the emergency services could be raised due to traffic congestion. Intelligent Transportation Systems (ITS) have a key role in order to reduce or mitigate this problem. In this paper, we propose four different approaches addressing the traffic congestion problem, comparing them to obtain the best solution. Using V2I communications, we are able to accurately estimate the traffic density in a certain area, which represents a key parameter to perform efficient traffic redirection, thereby reducing the emergency services arrival time, and avoiding traffic jams when an accident occurs. Specifically, we propose two approaches based on the Dijkstra algorithm, and two approaches based on Evolution Strategies. Notice that, when an accident occurs, time is a critical issue, and the strategies here proposed contribute to find the optimal solution within a short time period.This work was partially supported by the Ministerio de Ciencia e Innovacion, Spain, under Grant TIN2011-27543-C03-01, as well as by the Fundacion Universitaria Antonio Gargallo, the Obra Social de Ibercaja, under Grant 2013/B010, and by the Government of Aragon and the European Social Fund (T91 Research Group).Barrachina, J.; Garrido, P.; Fogue, M.; Martínez, FJ.; Cano Escribá, JC.; Tavares De Araujo Cesariny Calafate, CM.; Manzoni, P. (2014). Reducing emergence services arrival time by using vehicular communications and Evolution Strategies. Expert Systems with Applications. 41(4):1206-1217. https://doi.org/10.1016/j.eswa.2013.08.004S1206121741
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