33 research outputs found

    Gestión de mejora del sistema de iluminación de los faros frontales del automóvil

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    En el mundo actual la tecnología ha condicionado y moldeado la forma de vida de las personas. El automóvil es uno de los elementos tecnológicos que se ha vuelto indispensable para el transporte de pasajeros a nivel terrestre, generando una creciente demanda que trae consigo la innovación en las medidas de seguridad para minimizar los riesgos de accidente en las carreteras. A pesar de las medidas que se toman en este sentido, se ha podido establecer que existen deficiencias en materia de iluminación en las carreteras atribuibles al aspecto tecnológico y que son adaptables a la mejora. Para encontrar una solución a este problema, se ha realizado el presente trabajo de investigación, utilizando la mecatrónica como recurso tecnológico para optimizar la iluminación lateral de los automóviles y la seguridad en las carreteras

    Multi Jet Fusion PA12 manufacturing parameters for watertightness, strength and tolerances

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    The aim of this paper is to explore the watertightness behaviour for high pressure applications using Multi Jet Fusion technology and polyamide 12 as a material. We report an efficient solution for manufacturing functional prototypes and final parts for water pressure applications and provide manufacturing rules for engineers in the pressurized product development process for up to 10 MPa of nominal pressure. The research findings show manufacturers the possibility of using additive manufacturing as an alternative to traditional manufacturing. Water leakage was studied using different printing orientations and wall thicknesses for a range of pressure values. An industrial ball valve was printed and validated with the ISO 9393 standard as also meeting tolerance requirements. This paper is a pioneering approach to the additive manufacturing of high-performance fluid handling components. This approach solves the problem of leakage caused by porosity in additive manufacturing technologies.Postprint (published version

    Ball-burnishing effect on deep residual stress on AISI 1038 and AA2017-T4

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    Ball-burnishing induces compressive residual stresses on treated materials by the effect of plastic deformation. The result is an increase in the fatigue life of the treated part, retarding the initiation of cracks on the surface. Compressive residual stresses have been previously measured by X-ray diffraction near the surface, revealing considerably high values at the maximum analyzed depth, in relation to other finishing processes such as shot peening. However, the maximum analyzed depth is very limited by using this technique. In this paper, the incremental hole drilling (IHD) technique is tested to measure residual stresses, being able to reach a 2-mm measuring depth. To that objective, a commercial strain gage is used and calibrated using finite element model simulations. A second Finite Element Model based on material removal rate is developed to obtain the equations to calculate the strain release through IHD. Finally, residual stresses are measured experimentally with that technique on two different materials, confirming that ball-burnishing increases the compressive residual stresses in layers up to 0.5¿mm deep for the testing conditions, which is a good response to industrial needs. The method proves to be suitable, simple and inexpensive way to measure the value of these tensions.Preprin

    A statistical analysis of nanocavities replication applied to injection moulding

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    The purpose of this paper is to investigate both theoretically and experimentally how nanocavities are replicated in the injection moulding manufacturing process. The objective is to obtain a methodology for efficiently replicate nanocavities. From the theoretical point of view, simulations are carried out using a submodeling approach combining Solidworks Plastics for a first macrosimulation and Fluent solver for a subsequent nanosimulation. The effect of the four main factors (melt temperature, mould temperature, filling time and cavity geometry) are quantified using an statistical 2 factorial experiment. It is found that the main effects are the cavity length, the mould temperature and the polymer temperature, with standardized effects of 5, 3 and 2.6, respectively. Filling time has a negative 1.3 standardized effect. From the experimental point of view, Focused Ion Beam technique is used for mechanizing nanocavities in a steel mould. The replication achieved in polycarbonate injection is quantified using an Atomic Force Microscope. It is observed how both the geometry and the position of the cavities in the mould affect its replication

    Incidencia de los problemas relacionados con los medicamentos antirretrovirales para el tratamiento de la infección por HIV en pacientes hospitalizados en el Hospital Santa Clara de Bogotá

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    Introduction: The antiretroviral therapy for the treatment of the human immunodeficiency virus (HIV) is a therapeutic strategy linked to drug-related problems that cause or can cause the appearance of negative results associated with the medication. It is important, therefore, to identify their incidence, characterize them, and classify them to design strategies to minimize their impact.Objective: To estimate the overall incidence and the incidence of each one of the antiretroviral drugs-related problems in the treatment of the HIV infection in a cohort of hospitalized patients in Bogotá, Colombia.Materials and methods: We conducted a descriptive, retrospective cohort study in patients aged 18 years or more diagnosed with HIV infection and under antiretroviral treatment hospitalized between January 1st, 2015, and December 31st, 2016, in the Hospital Santa Clara, Bogotá.Results: The overall incidence of antiretroviral drug-related problems was 0.90 (95% CI: 0.85-0.93). The incidence of drug-drug interactions was 0.85 (95% CI: 0.80-0.90), 0.28 (95% CI: 0.22-0.35) for adverse reactions, and 0.12 (CI 95%: 0.08-0.17) for prescription errors.Conclusion: Drug-related problems should be studied, diagnosed, prevented, and treated. Their knowledge can enable health care professionals to anticipate their emergence, reduce their incidence, implement risk management plans, and optimize adherence to antiretroviral treatment.Introducción. El tratamiento antirretroviral de la infección por el virus de la inmunodeficiencia humana (HIV) se ha relacionado con diversos problemas de los medicamentos que causan o pueden causar la aparición de resultados negativos. En este contexto, es importante determinar su incidencia, caracterizarlos y clasificarlos para diseñar estrategias que minimicen su impacto.Objetivo. Estimar la incidencia global y de cada uno de los problemas relacionados con los medicamentos antirretrovirales utilizados en el tratamiento del HIV en una cohorte de pacientes hospitalizados en una institución de tercer nivel de Bogotá.Materiales y métodos. Se hizo un estudio descriptivo y retrospectivo de cohorte en pacientes de 18 años o más de edad con diagnóstico de infección por el HIV y en tratamiento antirretroviral, hospitalizados entre el 1° enero de 2015 y el 31 de diciembre de 2016 en el Hospital Santa Clara de Bogotá.Resultados. La incidencia global de los problemas relacionados con los medicamentos antirretrovirales fue de 0,90 (IC95% 0,85-0,93). La incidencia de las interacciones medicamentosas fue de 0,85 (IC95% 0,80-0,90), la de las reacciones adversas de 0,28 (IC95% 0,22-0,35) y la del error de prescripción de 0,12 (IC95% 0,08-0,17).Conclusión. Los problemas relacionados con los medicamentos deben estudiarse, diagnosticarse, prevenirse y tratarse para que el personal de salud pueda anticiparse a su aparición, disminuir su incidencia, implementar planes de manejo del riesgo y optimizar el cumplimiento del tratamiento antirretroviral

    Replication of nanoscale surface gratings via injection molding

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    Nanostructured gratings fabricated on silicon chips have been successfully transferred to polypropylene plastic parts by means of injection molding. Different sets of experiments were carried out along with a repeatability analysis in order to study the effect in the replication of process parameters such as maximum injection pressure, injection time, charge and polymer temperature, geometric factors such as width and separation between lines of the gratings and flow direction as well as demolding conditions. Among all factors, the one with a larger effect is the separation between consecutive trenches, which was studied in detail through Computational Fluid Dynamics simulations. In addition, a previously not reported sinking effect in the nanostructured area and a shrinking of the pattern period were characterized and simulated

    Adverse prognostic impact of complex karyotype (≥3 cytogenetic alterations) in adult T-cell acute lymphoblastic leukemia (T-ALL)

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    The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of ≥3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with ≥3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corresponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying karyotypes with ≥3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), independently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Additional molecular analyses of patients carrying ≥3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients

    Adverse prognostic impact of complex karyotype (≥3 cytogenetic alterations) in adult T-cell acute lymphoblastic leukemia (T-ALL)

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    © 2021 The Author(s).The potential prognostic value of conventional karyotyping in adult T-cell acute lymphoblastic leukemia (T-ALL) remains an open question. We hypothesized that a modified cytogenetic classification, based on the number and type of cytogenetic abnormalities, would allow the identification of high-risk adult T-ALL patients. Complex karyotype defined by the presence of ≥3 cytogenetic alterations identified T-ALL patients with poor prognosis in this study. Karyotypes with ≥3 abnormalities accounted for 16 % (22/139) of all evaluable karyotypes, corresponding to the largest poor prognosis cytogenetic subgroup of T-ALL identified so far. Patients carrying karyotypes with ≥3 cytogenetic alterations showed a significantly inferior response to therapy, and a poor outcome in terms of event-free survival (EFS), overall survival (OS) and cumulative incidence of relapse (CIR), independently of other baseline characteristics and the end-induction minimal residual disease (MRD) level. Additional molecular analyses of patients carrying ≥3 cytogenetic alterations showed a unique molecular profile that could contribute to understand the underlying molecular mechanisms of resistance and to evaluate novel targeted therapies (e.g. IL7R directed) with potential impact on outcome of adult T-ALL patients.This project was supported by the AECC (GC16173697BIGA); ISCIII (PI19/01828) co-funded by ERDF/ESF "A way to make Europe"/ "Investing in your future", CERCA/Generalitat de Catalunya SGR 2017 288 (GRC)/ “La Caixa” P. Barba was supported by the Instituto de Salud Carlos III FIS16/01433 and PERIS 2018-2020 from Generalitat de Catalunya (BDNS357800)

    Chemotherapy or allogeneic transplantation in high-risk Philadelphia chromosome–negative adult lymphoblastic leukemia

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    The need for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adults with Philadelphia chromosome–negative (Ph−) acute lymphoblastic leukemia (ALL) with high-risk (HR) features and adequate measurable residual disease (MRD) clearance remains unclear. The aim of the ALL-HR-11 trial was to evaluate the outcomes of HR Ph− adult ALL patients following chemotherapy or allo-HSCT administered based on end-induction and consolidation MRD levels. Patients aged 15 to 60 years with HR-ALL in complete response (CR) and MRD levels (centrally assessed by 8-color flow cytometry) <0.1% after induction and <0.01% after early consolidation were assigned to receive delayed consolidation and maintenance therapy up to 2 years in CR. The remaining patients were allocated to allo-HSCT. CR was attained in 315/348 patients (91%), with MRD <0.1% after induction in 220/289 patients (76%). By intention-to-treat, 218 patients were assigned to chemotherapy and 106 to allo-HSCT. The 5-year (±95% confidence interval) cumulative incidence of relapse (CIR), overall survival (OS), and event-free survival probabilities for the whole series were 43% ± 7%, 49% ± 7%, and 40% ± 6%, respectively, with CIR and OS rates of 45% ± 8% and 59% ± 9% for patients assigned to chemotherapy and of 40% ± 12% and 38% ± 11% for those assigned to allo-HSCT, respectively. Our results show that avoiding allo-HSCT does not hamper the outcomes of HR Ph− adult ALL patients up to 60 years with adequate MRD response after induction and consolidation. Better postremission alternative therapies are especially needed for patients with poor MRD clearance

    Estructura económica de Risaralda

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    Para conocer la historia de un país, también es indispensable conocer como han estado conformadas sus ciudades y cómo ha sido su recorrido a través del tiempo para tener una perspectiva mucho más amplia de su economía durante cada coyuntura. Es por esto, que la Historia Económica de Risaralda busca poner a disposición y resaltar una visión bastante amplia de su recorrido histórico y económico, partiendo desde los primeros habitantes y estructuras económicas del territorio, datadas desde tiempo precoloniales, y atravesando por las diferentes transformaciones que fueron afectando a Risaralda durante la colonia y en los años posteriores a esta, especialmente con acontecimientos como la colonización antioqueña, que dejó arraigada la actividad agrícola como la más importante de la economía departamental, aunque la misma con el pasar de los años en el siglo XX fue perdiendo importancia a causa del auge manufacturero, y especialmente del auge de la terciarización sustentada en la actividad comercial. Este fenómeno de terciarización económica será considerado de forma tanto histórica como actual, identificando cual es la situación económica vigente de Risaralda, y a partir de ello darse una idea de lo que le puede deparar al territorio en los próximos años, donde los objetivos de sostenibilidad y calidad de vida parecen ser las claves de toda iniciativa
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