3,669 research outputs found

    Investigación para el desarrollo de un protocolo para fabricación aditiva de modelos anatómicos en centros de salud

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    [ES] La fabricación aditiva, también llamada impresión 3D, ha tenido un gran impacto en la industria. La capacidad de fabricar modelos complejos y personalizados a bajo coste se adapta muy bien para algunas aplicaciones, sustituyendo procesos de fabricación tradicional y ofreciendo nuevas oportunidades. En medicina, la fabricación personalizada de modelos complejos ha encontrado muchas aplicaciones, desde réplicas de patologías para la educación hasta implantes hechos a medida y remplazo de órganos. De todas las posibilidades de esta tecnología en medicina, la fabricación de modelos anatómicos a partir de imágenes médicas ofrece un excelente balance entre facilidad de implementación y beneficio, esto la hace una aplicación perfecta para ser usada ampliamente en los hospitales. La fabricación aditiva de modelos anatómicos es un campo que ha suscitado considerable entusiasmo en los últimos años. La comunidad médica ve esta herramienta como el siguiente paso generacional en la visualización clínica, ofreciendo grandes beneficios para los pacientes y el sistema de salud. Debido al gran interés, hay muchos investigadores que han evaluado el impacto de esta tecnología en la práctica médica, midiendo los beneficios médicos que puedan tener estos modelos anatómicos. En general, los resultados muestran que hay reducción de tiempo de quirófano, menor morbilidad y mortalidad al igual que menor estrés y denuncias por parte de pacientes. A pesar de estos resultados prometedores, no hay muchos estudios realizados sobre cuál debe ser el proceso para garantizar la reproducibilidad y seguridad de estos modelos, un tema que es de gran importancia para poder cumplir con las regulaciones actuales, que exigen protocolos de fabricación y sistemas de calidad para este proceso. Debemos observar que, aunque el proceso para obtener modelos anatómicos es más fácil que otras aplicaciones de esta tecnología, no es un proceso trivial. Es un trabajo complejo con múltiples pasos que Involucra a varios especialistas para su correcta realización. Actualmente el hospital es el entorno ideal para poder fabricar estos modelos, permite un mayor control del proceso, facilita la colaboración multidisciplinar necesaria y reduce considerablemente los requisitos legales que rigen los dispositivos médicos. El objetivo de esta investigación es desarrollar un protocolo detallado y optimizado que cumpla con los requisitos técnicos, médicos y legales para poder implementar esta tecnología emergente de forma segura y eficiente en centros de salud. Para alcanzar este objetivo, las metodologías observadas fueron la revisión por literatura, la investigación doctrinal legal y la investigación acción empleada en los diferentes casos estudiados. Los casos se han elegido buscando la mayor diversidad posible bajo el criterio de conveniencia en el horizonte temporal contemplado, dada la diversidad compleja del estudio realizado. Gracias a la colaboración con varias instituciones médicas y de educación, este protocolo se pudo implementar en diversos contextos, mejorándolo progresivamente al ponerlo a prueba con casos reales, mediante el trabajo continuo con los expertos. El resultado es un protocolo que incluye varios años de experiencia y que ha sido aplicado en un amplio rango de especialidades. Este protocolo es relativamente sencillo de seguir y cumple con los principales requisitos para ser implementado en hospitales.[CA] La fabricació additiva, també anomenada impressió 3D, ha tingut un gran impacte en la indústria. La capacitat de fabricar models complexos i personalitzats a baix cost s' adapta molt bé per a algunes aplicacions, substituint processos de fabricació tradicional i oferint noves oportunitats. En medicina, la fabricació personalitzada de models complexos ha trobat moltes aplicacions, des de rèpliques de patologies per a l'educació fins a implants fets a mida i òrgans. De totes les possibilitats d'aquesta tecnologia en medicina, la fabricació de models anatòmics a partir d'imatges mèdiques ofereix un excel·lent balanç entre facilitat d'implementació i benefici, això la fa una aplicació perfecta per ser usada àmpliament als hospitals. La fabricació additiva de models anatòmics és un camp que ha suscitat considerable entusiasme en els últims anys. La comunitat mèdica veu aquesta eina com el següent pas generacional en la visualització clínica, oferint grans beneficis per als pacients i el sistema de salut. A causa del gran interès, hi ha molts investigadors que han avaluat l'impacte d'aquesta tecnologia en la pràctica mèdica, mesurant els beneficis mèdics que puguen tenir aquests models anatòmics. En general, els resultats mostren que hi ha reducció de temps de quiròfan, menor morbiditat i mortalitat igual que menor estrès i denúncies per part de pacients. Malgrat aquests resultats prometedors, no hi ha molts estudis realitzats sobre quin ha de ser el procés per garantir la reproduïbilitat i seguretat d' aquests models, un tema que és de gran importància per poder complir amb les regulacions actuals, que exigeixen protocols de fabricació i sistemes de qualitat per a aquest procés. Hem d'observar que, tot i que el procés per obtenir models anatòmics és més fàcil que altres aplicacions d'aquesta tecnologia, no és un procés trivial. És un treball complex amb múltiples passos que Involucra diversos especialistes per a la seva correcta realització. Actualment l'hospital és l'entorn ideal per poder fabricar aquests models, permet un major control del procés, facilita la col·laboració multidisciplinària necessària i redueix considerablement els requisits legals que regeixen els dispositius mèdics. L'objectiu d'aquesta investigació és desenvolupar un protocol detallat i optimitzat que compleix amb els requisits tècnics, mèdics i legals per poder implementar aquesta tecnologia emergent de forma segura i eficient en centres de salut. Per assolir aquest objectiu, les metodologies observades van ser la revisió per literatura, la investigació doctrinal legal i la investigació acció emprada en els diferents casos estudiats. Els casos s' han triat buscant la major diversitat possible sota el criteri de conveniència en l' horitzó temporal contemplat, atesa la diversitat complexa de l' estudi realitzat. Gràcies a la col·laboració amb diverses institucions mèdiques i d'educació, aquest protocol es va poder implementar en diversos contextos, millorant-lo progressivament en posar-lo a prova amb casos reals, mitjançant el treball continu amb els experts. El resultat és un protocol que inclou diversos anys d' experiència i que ha estat aplicat en un ampli rang d' especialitats. Aquest protocol és relativament senzill de seguir i compleix amb els principals requisits per ser implementat en hospitals.[EN] Additive manufacturing, also called 3D printing, has had a huge impact on the industry. The ability to manufacture complex and customized models at a low cost is well suited for some applications, replacing traditional manufacturing processes and offering new opportunities. In medicine, the custom manufacture of complex models has found many applications, from replicas of pathologies for education to custom-made implants and organ replacement. Of all the possibilities of this technology in medicine, the manufacture of anatomical models from medical images offers an excellent balance between ease of implementation and benefit, this makes it a perfect application to be widely used in hospitals. Additive manufacturing of anatomical models is a field that has attracted considerable enthusiasm in recent years. The medical community sees this tool as the next generational step in clinical visualization, offering great benefits for patients and the healthcare system. Due to the great interest, there are many researchers who have evaluated the impact of this technology on medical practice, measuring the medical benefits that these anatomical models may have. In general, the results show that there is a reduction in operating room time, lower morbidity and mortality as well as less stress and complaints from patients. Despite these promising results, there are not many studies conducted on what the process should be to guarantee the reproducibility and safety of these models, an issue that is of great importance to be able to comply with current regulations, which require manufacturing protocols and quality systems for this process. We should note that although the process for obtaining anatomical models is easier than other applications of this technology, it is not a trivial process. It is a complex work with multiple steps that involves several specialists for its correct realization. Currently the hospital is the ideal environment to be able to manufacture these models, it allows greater control of the process, facilitates the necessary multidisciplinary collaboration, and considerably reduces the legal requirements that govern medical devices. The objective of this research is to develop a detailed and optimized protocol that meets the technical, medical, and legal requirements to implement this technology in hospitals. To achieve this objective, the methodologies observed consisted of literature review, legal doctrinal research and action research used in the multiple cases studied. The cases have been selected seeking the greatest possible diversity under the criterion of convenience in the time horizon contemplated, given the complex diversity of the study carried out. Thanks to the collaboration with several medical and educational institutions, this protocol could be implemented in various contexts, progressively improving it by testing it with real cases, through continuous work with experts. The result is a protocol that includes several years of experience and has been applied in a wide range of specialties. It is relatively simple to follow and complies with most requirements to be implemented in hospitals.De Rossi Estrada, M. (2022). Investigación para el desarrollo de un protocolo para fabricación aditiva de modelos anatómicos en centros de salud [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/18330

    Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model

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    [EN] The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy dissipation purposes, which brings the importance of physical modeling into the spotlight. However, despite the importance of stilling basins in engineering, bibliographic studies have traditionally focused on the classical hydraulic jump. Therefore, the objective of this research was to study the characteristics of the hydraulic jump in a typified USBR II stilling basin, through a physical model. The free surface profile and the velocity distribution of the hydraulic jump developed within this structure were analyzed in the model. To this end, an experimental campaign was carried out, assessing the performance of both, innovative techniques such as the time-of-flight camera and traditional instrumentation like the Pitot tube. The results showed a satisfactory representation of the free surface profile and the velocity distribution, despite some discussed limitations. Furthermore, the instrumentation employed revealed the important influence of the energy dissipation devices on the flow properties. In particular, relevant di erences were found for the hydraulic jump shape and the maximum velocity positions within the measured vertical profiles, when compared to classical hydraulic jumps.This research was funded by 'Generalitat Valenciana predoctoral grants (Grant number [2015/7521])', in collaboration with the European Social Funds and by the research project: 'La aireacion del flujo y su implementacion en prototipo para la mejora de la disipacion de energia de la lamina vertiente por resalto hidraulico en distintos tipos de presas' (BIA2017-85412-C2-1-R), funded by the Spanish Ministry of Economy.Macián Pérez, JF.; Vallés-Morán, FJ.; Sánchez Gómez, S.; De-Rossi-Estrada, M.; García-Bartual, R. (2020). Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model. Water. 12(6):1-20. https://doi.org/10.3390/w12061758S120126Valero, D., Viti, N., & Gualtieri, C. (2018). Numerical Simulation of Hydraulic Jumps. Part 1: Experimental Data for Modelling Performance Assessment. Water, 11(1), 36. doi:10.3390/w11010036Bayon, A., Valero, D., García-Bartual, R., Vallés-Morán, F. ​José, & López-Jiménez, P. A. (2016). Performance assessment of OpenFOAM and FLOW-3D in the numerical modeling of a low Reynolds number hydraulic jump. Environmental Modelling & Software, 80, 322-335. doi:10.1016/j.envsoft.2016.02.018Wang, H., & Chanson, H. (2015). Experimental Study of Turbulent Fluctuations in Hydraulic Jumps. Journal of Hydraulic Engineering, 141(7), 04015010. doi:10.1061/(asce)hy.1943-7900.0001010Padulano, R., Fecarotta, O., Del Giudice, G., & Carravetta, A. (2017). Hydraulic Design of a USBR Type II Stilling Basin. Journal of Irrigation and Drainage Engineering, 143(5), 04017001. doi:10.1061/(asce)ir.1943-4774.0001150Macián-Pérez, J. F., García-Bartual, R., Huber, B., Bayon, A., & Vallés-Morán, F. J. (2020). Analysis of the Flow in a Typified USBR II Stilling Basin through a Numerical and Physical Modeling Approach. Water, 12(1), 227. doi:10.3390/w12010227Montes, J. S., & Chanson, H. (1998). Characteristics of Undular Hydraulic Jumps: Experiments and Analysis. Journal of Hydraulic Engineering, 124(2), 192-205. doi:10.1061/(asce)0733-9429(1998)124:2(192)Ohtsu, I., Yasuda, Y., & Gotoh, H. (2001). Hydraulic condition for undular-jump formations. Journal of Hydraulic Research, 39(2), 203-209. doi:10.1080/00221680109499821Ohtsu, I., Yasuda, Y., & Gotoh, H. (2003). Flow Conditions of Undular Hydraulic Jumps in Horizontal Rectangular Channels. Journal of Hydraulic Engineering, 129(12), 948-955. doi:10.1061/(asce)0733-9429(2003)129:12(948)Bakhmeteff, B. A., & Matzke, A. E. (1936). The Hydraulic Jump in Terms of Dynamic Similarity. Transactions of the American Society of Civil Engineers, 101(1), 630-647. doi:10.1061/taceat.0004708Chachereau, Y., & Chanson, H. (2011). Free-surface fluctuations and turbulence in hydraulic jumps. Experimental Thermal and Fluid Science, 35(6), 896-909. doi:10.1016/j.expthermflusci.2011.01.009Zhang, G., Wang, H., & Chanson, H. (2012). Turbulence and aeration in hydraulic jumps: free-surface fluctuation and integral turbulent scale measurements. Environmental Fluid Mechanics, 13(2), 189-204. doi:10.1007/s10652-012-9254-3Montano, L., Li, R., & Felder, S. (2018). Continuous measurements of time-varying free-surface profiles in aerated hydraulic jumps with a LIDAR. Experimental Thermal and Fluid Science, 93, 379-397. doi:10.1016/j.expthermflusci.2018.01.016Montano, L., & Felder, S. (2020). LIDAR Observations of Free-Surface Time and Length Scales in Hydraulic Jumps. Journal of Hydraulic Engineering, 146(4), 04020007. doi:10.1061/(asce)hy.1943-7900.0001706Rajaratnam, N. (1965). The Hydraulic Jump as a Well Jet. Journal of the Hydraulics Division, 91(5), 107-132. doi:10.1061/jyceaj.0001299McCorquodale, J. A., & Khalifa, A. (1983). Internal Flow in Hydraulic Jumps. Journal of Hydraulic Engineering, 109(5), 684-701. doi:10.1061/(asce)0733-9429(1983)109:5(684)Viti, N., Valero, D., & Gualtieri, C. (2018). Numerical Simulation of Hydraulic Jumps. Part 2: Recent Results and Future Outlook. Water, 11(1), 28. doi:10.3390/w11010028Blocken, B., & Gualtieri, C. (2012). Ten iterative steps for model development and evaluation applied to Computational Fluid Dynamics for Environmental Fluid Mechanics. Environmental Modelling & Software, 33, 1-22. doi:10.1016/j.envsoft.2012.02.001Carrillo, J. M., Castillo, L. G., Marco, F., & García, J. T. (2020). Experimental and Numerical Analysis of Two-Phase Flows in Plunge Pools. Journal of Hydraulic Engineering, 146(6), 04020044. doi:10.1061/(asce)hy.1943-7900.0001763Heller, V. (2011). Scale effects in physical hydraulic engineering models. Journal of Hydraulic Research, 49(3), 293-306. doi:10.1080/00221686.2011.578914Chanson, H. (2006). Bubble entrainment, spray and splashing at hydraulic jumps. Journal of Zhejiang University-SCIENCE A, 7(8), 1396-1405. doi:10.1631/jzus.2006.a1396Hager, W. H., & Bremen, R. (1989). Classical hydraulic jump: sequent depths. Journal of Hydraulic Research, 27(5), 565-585. doi:10.1080/00221688909499111Meftah, M. B., De Serio, F., Mossa, M., & Pollio, A. (2008). Experimental study of recirculating flows generated by lateral shock waves in very large channels. Environmental Fluid Mechanics, 8(3), 215-238. doi:10.1007/s10652-008-9057-8Ben Meftah, M., Mossa, M., & Pollio, A. (2010). Considerations on shock wave/boundary layer interaction in undular hydraulic jumps in horizontal channels with a very high aspect ratio. European Journal of Mechanics - B/Fluids, 29(6), 415-429. doi:10.1016/j.euromechflu.2010.07.002Hager, W. H., Bremen, R., & Kawagoshi, N. (1990). Classical hydraulic jump: length of roller. Journal of Hydraulic Research, 28(5), 591-608. doi:10.1080/00221689009499048Kirkgöz, M. S., & Ardiçlioğlu, M. (1997). Velocity Profiles of Developing and Developed Open Channel Flow. Journal of Hydraulic Engineering, 123(12), 1099-1105. doi:10.1061/(asce)0733-9429(1997)123:12(1099

    Detection of Leishmania infantum DNA mainly in Rhipicephalus sanguineus male ticks removed from dogs living in endemic areas of canine leishmaniosis

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    Background: Sand flies are the only biologically adapted vectors of Leishmania parasites, however, a possible role in the transmission of Leishmania has been proposed for other hematophagous ectoparasites such as ticks. In order to evaluate natural infection by Leishmania infantum in Rhipicephalus sanguineus ticks, taking into account its close association with dogs, 128 adult R. sanguineus ticks removed from 41 dogs living in endemic areas of canine leishmaniosis were studied. Methods: Individual DNA extraction was performed from each tick and whole blood taken from dogs. Dog sera were tested for IgG antibodies to L. infantum antigen by ELISA and L. infantum real-time PCR was performed from canine whole blood samples and ticks. Results: Leishmania infantum PCR was positive in 13 ticks (10.1%) including one female, (2.0%) and 12 males (15.2%), and in only five dogs (12.2%). Male ticks had a significantly higher infection rate when compared to female R. sanguineus. The percentage of L. infantum seroreactive dogs was 19.5%. All but two PCR positive dogs were seroreactive. Leishmania infantum PCR positive ticks were removed from seropositive and seronegative dogs with a variety of PCR results. Conclusions: This study demonstrates high prevalence of L. infantum DNA in R. sanguineus ticks removed from L. infantum seropositive and seronegative dogs. The presence of L. infantum DNA was detected mainly in male ticks possibly due to their ability to move between canine hosts and feed on several canine hosts during the adult life stage. Additional studies are needed to further explore the role of R. sanguineus ticks and in particular, male adults, in both the epidemiology and immunology of L. infantum infection in dogs in endemic areas

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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