725 research outputs found
Fibroma desmoplásico del hueso: aportación de un nuevo caso
Se presenta un caso de Fibroma Desmoplásico localizado en cuello femoral en
un paciente adulto joven de 34 años, al cual se le practicó una resección amplia de la lesión
y una reconstrucción por medio de un compuesto de aloinjerto intercalar proximal y prótesis
total de cadera (aloprótesis). Un año después de la intervención no hay recidiva local de la
lesión y se objetiva una buena incorporación del aloinjerto al huésped; con buena función de
la cadera. Se revisa la literatura y se discuten algunas consideraciones diagnósticas y terapéuticas
de la lesión.A case of Desmoplastic Fibroma of the Bone, located in the femoral neck, in
a 34 year old male patient is reported. The tumor was treated by wide resection, the reconstruction
beem performed with an allograft-prostheses composite. One year after surgery, there was
no local recurrence and a good is incorporation of the allograft to the host was observed. The
patient showed a good hip function. The literature is reviewed and diagnostic and therapeutic
considerations are discussed
Enchondroma versus Low-Grade Chondrosarcoma in Appendicular Skeleton: Clinical and Radiological Criteria
Objectives. To determine the validity of clinical and radiological features of enchondroma and low grade chondrosarcoma, and contrast the biopsy results with the clinical diagnosis based on the history and imaging. Material and Method. The study included 96 patients with cartilage type lesions suggestive of an enchondroma (E) or an low grade chondrosarcoma (LGC) according to the clinical and imaging data. The hypotheses were contrasted with the biopsy. Results. Of the 82 patients studied completely, 56 were considered E (68.29%), 8 as LGC (8.33%) and in 18 (18.75%) were doubtful cases and considered as suspected LGC. Of these, the biopsy showed 4 E (25%), 10 LGC (50%) and 4 were not definitive. On the other hand, of the 56 cases diagnosed as E, 15 were biopsied, 5 of these biopsies turned out to be LGC (33.3%). The 8 cases diagnosed as LGC, were also biopsied and only 4 biopsies (50%) confirmed the initial diagnosis. Features analyzed in the study showed no statistically significant difference. Correlation analysis between the diagnosis issued initially and the biopsy result gave a value of 0.69 (kappa coefficient), which was considered a good correlation. Conclusion. Features analyzed did not have any statistical significance. However, there was a good correlation between initial diagnosis and biopsy's result
Fracturas patológicas en la región de la cadera
Entre 1973 y 1992, fueron tratados en nuestra institución 20 casos de fracturas
patológicas a nivel de la cadera, secundarias a metástasis esqueléticas. Se realizó tratamiento
quirúrgico mediante osteosíntesis o artroplastias según la localización y la extensión de la lesión.
En 8 casos, la fractura fué subcapital, en 6 fué pertrocantérea y en otros 6 casos fué
subtrocantérea. En el tratamiento quirúrgico, se recalca la importancia de la fijación interna
inmediata con la adición de metilmetacrilato y el uso de la radioterapia postoperatoria. Siempre
se obtuvo la mejoría del dolor y un resultado funcional bueno en el 70% de los casos.
En 7 casos, aparecieron complicaciones locales. El tratamiento quirúrgico debe ser agresivo
en estos pacientes, ya que la rehabilitación inmediata es primordial en su calidad de vida.From 1973 to 1992, 20 cases of pathological fractures around the hip secondary
to skeletal metastases were treated in our institution. The surgical treatment was performed
by internal fixation or arthroplasty according the location and extension of the lesion. In 8
cases the fracture was located in the femoral neck, 6 cases were intertrochanteric fractures
and 6 cases were subtrochanteric fractures. In the surgical management the importance of inmediately
internal fixation, with the use of methylnietacrilate and post surgical radiotherapy
are justified. Always the pain was relieved and the functional result was good in 70%. In 7
cases were local complications. The surgical treatment should be more agresive in these special
patients, because the inmediately rehabilitation is essential in your quality lifes
Brain processing of visual metaphors: An electrophysiological study
Metaphors are pervasive in everyday language and often used in advertisements to draw attention and persuade consumers to purchase products or services. Despite it, there are many open questions regarding how metaphors are processed in the brain. In general, there are three possible models: the standard model, the parallel hypothesis, and the context-dependent hypothesis. According to the first model, metaphors take longer to process than literal statements because metaphoric interpretation should be sought only when literal interpretations are defective. The parallel hypothesis model argues that both metaphoric and literal meanings are processed concurrently and involve the same mechanisms. Finally, the context-dependent hypothesis postulates that the metaphorical meaning is directly accessed when this is made obligatory by the context.This research was carried out thanks to Alicante University’s emerging research grant system (GRE-26), the Bidons Egara Research Chair of the University Miguel Hernández and grant MAT2015-69967-C3-1-R
Role of outsiders in the family firms
Las características del consejo de administración, su funcionamiento y composición, son en la mayoría
de las empresas familiares un reflejo de la estructura del poder, experiencia, inquietudes y cultura que
posee esa empresa. La presencia de externos en el consejo no ha de suponer la pérdida de control por
parte de la familia. Esto último, pondría en peligro la transmisión de la cultura y valores de la empresa,
de la visión de la familia y su materialización en la estrategia. En este trabajo se recogen una serie de
recomendaciones sobre la adecuada incorporación de outsiders en la empresa familiar dependiendo del
resultado de la combinación de la distribución de la propiedad y del tipo de gestión.The characteristics of the Board of Directors, its running and composition reflect, for most family
firms, their structure of power, experience, interests and culture. The presence of outsiders in the board
does not necessarily imply a loss of power by the family, as this will impair the transfer of the culture
and values of the firm, the vision of the family and its strategic implementation. This work includes a
series of recommendations on the most adequate way to integrate outsiders in family firms depending
on the combination of ownership distribution and kind of management
Factors of staff turnover in textile businesses in Colombia
The Colombian textile sector, which represents 3% of the gross domestic product, has staff turnover problems. When a worker quits, an immediate replacement is needed in order to not affect productivity. Companies often recruit people without training or even experience. In this paper is analyses job turnover of businesses in the textile sector in Barranquilla (Colombia) through internal, external and contextual factors with their respective indicators. The investigation is quantitative with a correlational scope and a cross-sectional design. The methodology consisted of reliability testing (Cronbach’s alpha and McDonald’s omega) and construct validity (exploratory factor analysis) for the measurement instrument. This was followed by a descriptive analysis, with measures in relation to central tendency and dispersion for each factor indicator, concluding a confirmatory factor analysis with maximum likelihood estimates to observe causality, covariation and incidence relationships. The results established that the relevant indicators are commitment and satisfaction, sickness and company flexibility. The strongest covariance is between internal and contextual factors. Consistent with the theory, it was possible to statistically validate the theoretical model applied and a tool to measure job turnover
Evaluación de calidad de agua en un sistema ribereño utilizado para riego agrícola de subsistencia
En la evaluación del impacto de la contaminación en el ambiente, existen diversas herramientas y técnicas que se aplican para conocer la calidad ambiental de los recursos naturales. El objetivo de este trabajo fue evaluar la calidad del agua en un sistema ribereño en San Luis Potosí, México asociado al impacto del uso agrícola, urbano e industrial. Fueron establecidos cinco puntos de muestreo asociado a diversos usos y descargas residuales en donde se evaluaron 28 muestras durante cuatro días de muestro. Estas fueron distribuidas a los 20, 40, 60, 80, 100 y 120 minutos del trayecto determinando con un medidor multiparámetro los sólidos
disueltos totales (SDT), temperatura (T), conductividad eléctrica (CE), pH y oxígeno disuelto (OD). El resultado más destacado de las 28 muestras diarias y del total de 112 que los promedios oxígeno disuelto indican condición hipoxia que indica la desaparición de organismos y especies sensibles, concluyendo que el área ribereña requiere un constante monitoreo y diversificación de parámetros para evaluar su condición para actividades agrícolas.In the assessment of the impact of pollution on the environment, there are various tools and techniques that are applied to know the environmental quality of natural resources. The objective of this work was to evaluate water quality in a river system in San Luis Potosí, Mexico associated with the impact of agricultural, urban and industrial use. Five sampling points associated to various uses and residual discharges were established where 28 samples were evaluated during four days of sampling. The total dissolved solids (SDT), temperature (T), electrical conductivity (CE), pH and dissolved oxygen (OD) were distributed at 20, 40, 60, 80, 100 and 120 minutes of the path. The most outstanding result of the 28 daily samples and the total of 112 that dissolved oxygen averages indicate hypoxia condition indicating the disappearance of sensitive organisms and species, concluding that the riparian area requires constant monitoring and diversification of parameters to evaluate agricultural activities.Fil: Alcalá Jáuregui, J. A.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Acosta Doporto Geiler, A.
Instituto Tecnológico Superior de los Ríos de Balancan (México)Fil: Rodríguez Ortiz, J.C.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, A.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Martínez Carretero, Eduardo.
Consejo Nacional de Investigaciones Científicas y TécnicasFil: Filippini, Maria Flavia.
Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Díaz Flores, P. E.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Lara Mireles, J. L.
Universidad Autónoma de San Luis Potosí. Facultad de Agronomí
Split-range control for improved operation of solar absorption cooling plants
This paper proposes the first application of a split-range control technique on a concentrating solar collector to improve an absorption plant production. Solar absorption plants have solar power availability in phase with cooling demand under design conditions. Thus, it is a powerful cooling technology in the context of renewable energy and energy efficiency. These plants need control systems to cope with solar irradiance intermittency, reject irradiation disturbances, manage fossil fuels backup systems and dump closed-loop thermal-hydraulic oscillations. In this work, control techniques are proposed and simulated in an absorption plant in Spain. The plant consists of a concentrating Fresnel solar collector connected to an absorption chiller. The objectives are to operate with 100% renewable solar energy and avoid safety defocus events while reducing temperature oscillations and control actuators effort. Firstly, the current available plant controllers are defined, then two modifications are proposed. The first modification is a split-range controller capable of manipulating both flow and defocus of the Fresnel collector, the second modification is a PI controller to substitute the original chiller on-off controller. The results compare, through validated models, the different control systems and indicate that using both proposed controllers reduces 94% of the sum of actuators effort and 43% of the integral of absolute set-point tracking error compared to the plant's factory pre-set controllers. The suggested controllers increase 66% of energy production and 63% of exergy production. Besides, the split-range technique can be extended to any concentrating solar collector control.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Finance Code 001Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) 304032/2019–0Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) PID2019-104149RB-I00/10.13039/501100011033Consejo Europeo de Investigación (ERC) OCONTSOLAR 78905
The thirty gigahertz instrument receiver for the QUIJOTE experiment: preliminary polarization measurements and systematic-error analysis
This paper presents preliminary polarization measurements and systematic-error characterization of the Thirty Gigahertz Instrument receiver developed for the QUIJOTE experiment. The instrument has been designed to measure the polarization of Cosmic Microwave Background radiation from the sky, obtaining the Q, U, and I Stokes parameters of the incoming signal simultaneously. Two kinds of linearly polarized input signals have been used as excitations in the polarimeter measurement tests in the laboratory; these show consistent results in terms of the Stokes parameters obtained. A measurement-based systematic-error characterization technique has been used in order to determine the possible sources of instrumental errors and to assist in the polarimeter calibration process.The authors would like to thank Spanish Ministry for Economy and Competitiveness for the financial support provided under the CONSOLIDER-INGENIO 2010 program under the reference CSD2010-00064 and the project under reference AYA2012-39475-C02-01
Sol-gel deposition of hydroxyapatite coatings on porous titanium for biomedical applications
The stress shielding and the poor osseointegration in titanium implants are still
problems to be resolved. In this context, this work proposes a balanced solution.
Titanium samples were fabricated, with a porosity of 100-200 µm of pore size
employing space-holder technique (50 vol. % NH4HCO3, 800 MPa at 1250 ºC during 2h
under high vacuum conditions), obtaining a good equilibrium between stiffness and
mechanical resistance. The porous titanium substrates were coated with hydroxyapatite,
obtained by sol-gel technique: immersion, dried at 80ºC and heat treatment at 450ºC
during 5h under vacuum conditions. Phases, surface morphology and interfacial
microstructure of the transverse section were analyzed by Micro-Computed
Tomography, SEM and confocal laser, as well as the infiltration capability of the
coating into the metallic substrate pores. The FTIR and XRD showed the crystallinity of
the phases and the chemical composition homogeneity of the coating. The size and
interconnected pores obtained allow the infiltration of hydroxyapatite (HA), possible
bone ingrowth and osseointegration. The scratch resistance of the coating corroborated
a good adherence to the porous metallic substrate. The coated titanium samples have a
biomechanical and biofunctional equilibrium, as well as a potential use in biomedical
applications (partial substitution of bone tissue).Junta de Andalucía-FEDER (Spain) Project Ref. P12-TEP-1401Spanish Ministry of Economy and Competitiveness Grant No. MAT2015-71284-
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