105 research outputs found

    Metrological Analysis of 3D Printed Materials

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    Leading the industrial sector is what every company seeks. Inside the metal business there are a lot of competing parties that are on a constant searching for the best characteristics. New material properties or the latest technology are key factors that have an influence on riding high or not. One of the most recent building processes that is being slowly implemented on the modern industry of this century is the 3D manufacturing. This method puts an end to huge traditional building machines machines such as the ones used in conventional milling or forming processes, and forgets about joints and unnecessary wastes of material, being able to create difficult shapes that would otherwise be impossible to build. Apart from its engaging theory, the other side of the coin shows a not so charming face. A big ignorance arises with this technology, as the lack of investigations and experiments leads to a disbelief that the metals will behave properly during service. This research intention is to continue with the small existing previous work, testing metals and checking its behavior under several circumstances. In order to help with this task, a profilometer will be used as the main equipment, a machine that is able to take images of a few micrometers and retrieve important data that can be further analyzed. Stainless Steel specimens with two different porosities are going to be built and tested with Uniaxial Tensile Tests at three different temperatures, and their main breakage characteristics are going to be examined together with their porosity features. Variables to analyze will include roughness, fracture surface and necking. With this information, a study of the ductility of the material is going to be done, checking if there are differences in the Stainless Steel behavior in the whole range of the pieces.Ingeniería Aeroespacia

    Desarrollo de una herramienta de planificación para redes WiMAX

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    Las comunidades que habitan en las áreas rurales de países con bajos o medios ingresos se encuentran muchas veces aisladas de los procesos de desarrollo del país debido a las deficiencias en las comunicaciones con los núcleos urbanos. En este escenario las Tecnologías de la Información y las Comunicaciones (TIC) han demostrado tener un efecto multiplicador en el desarrollo humano dotando de conectividad a escuelas, centros de salud, ayuntamientos o telecentros, y mejorando así la calidad de vida de esas comunidades. Actualmente se está investigando en soluciones tecnológicas apropiadas y con un coste reducido que permitan ofrecer la mencionada conectividad. En esta línea, la tecnología WiMAX, basada en el estándar 802.16-2009, permite desplegar redes inalámbricas punto-multipunto de largo alcance empleando bandas libres o licenciadas. Sin embargo, el diseño y planificación de este tipo de redes requiere de un conocimiento detallado del estándar o disponer de herramientas de diseño que tienen un coste alto en el mercado. En este estudio se ha desarrollado una herramienta de planificación de redes WiMAX para bandas libres y de bajo coste. El objetivo ha sido reducir el coste del diseño y planificación de este tipo de redes, facilitando así su despliegue en países en desarrollo. En primer lugar se ha efectuado un estudio del estándar 802.16-2009 y una revisión bibliográfica sobre el problema del cálculo del throughput y la latencia de un flujo. A partir de este estudio se ha propuesto un modelo para el cálculo del throughput basado en el estudio del estándar. También se ha desarrollado un modelo para el cálculo de la latencia basado en el funcionamiento de los sistemas TDMA y en el análisis de medidas empíricas mediante un estimador MMSE. Después se ha llevado a cabo una revisión de herramientas gratuitas de análisis de radioenlaces que calcularan la SNR y la longitud de los enlaces usando datos sobre el terreno. Tras comparar estas herramientas, se ha decidido trabajar con Radio Mobile en este proyecto porque dispone de un interfaz gráfico y soporta redes inalámbricas con decenas de usuarios. Empleando el lenguaje JAVA se ha implementado la herramienta de planificación de redes WiMAX que aplica los modelos propuestos de cálculo de throughput y latencia. Esta herramienta lee los datos sobre el enlace (SNR y longitud) de un fichero exportado de Radio Mobile y distribuye los recursos que ofrece la tecnología WiMAX en función de los flujos definidos por el usuario. Finalmente se ha validado el funcionamiento de la herramienta y los resultados que proporciona a través de medidas empíricas sobre escenarios de pruebas. El análisis de estas medidas demuestra que la herramienta desarrollada permite diseñar y planificar redes WiMAX con un error bajo y acotado.Ingeniería de Telecomunicació

    Unit commitment with analytical underfrequency load-shedding constraints for island power systems

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    This letter presents a corrective frequency-constrained UC (C-FCUC) for island power systems implementing analytical constraints on underfrequency load shedding (UFLS). Since UFLS is inevitable for sufficiently large disturbances, one can argue that less spinning reserve could be held back since UFLS takes place anyway. Congruently, the reserve criterion should consider UFLS likely to occur under disturbances. The C-FCUC can be converted into a preventive frequency-constrained UC (P-FCUC) or the standard unit commitment (UC) and the C-FCUC is thus a generalization. The proposed formulation is successfully applied to a Spanish island power system

    A mutual regulatory loop between miR-155 and SOCS1 influences renal inflammation and diabetic kidney disease

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    Diabetic kidney disease (DKD) is a common microvascular complication of diabetes, a global health issue. Hyperglycemia, in concert with cytokines, activates the Janus kinase (JAK)/ signal transducer and activator of transcription (STAT) pathway to induce inflammation and oxidative stress contributing to renal damage. There is evidence of microRNA-155 (miR-155) involvement in diabetes complications, but the underlying mechanisms are unclear. In this study, gain- and loss-of-function experiments were conducted to investigate the interplay between miR-155-5p and suppressor of cytokine signaling 1 (SOCS1) in the regulation of the JAK/STAT pathway during renal inflammation and DKD. In experimental models of mesangial injury and diabetes, miR-155-5p expression correlated inversely with SOCS1 and positively with albuminuria and expression levels of cytokines and prooxidant genes. In renal cells, miR-155-5p mimic downregulated SOCS1 and promoted STAT1/3 activation, cytokine expression, and cell proliferation and migration. Conversely, both miR-155-5p antagonism and SOCS1 overexpression protected cells from inflammation and hyperglycemia damage. In vivo, SOCS1 gene delivery decreased miR-155-5p and kidney injury in diabetic mice. Moreover, therapeutic inhibition of miR-155- 5p suppressed STAT1/3 activation and alleviated albuminuria, mesangial damage, and renal expression of inflammatory and fibrotic genes. In conclusion, modulation of the miR-155/ SOCS1 axis protects kidneys against diabetic damage, thus highlighting its potential as therapeutic target for DKDThis research was funded by grants from Spanish Ministry of Science and Innovation (RTI2018-098788-B-I00 and PID2021-127741OBI00) to C.G.-G., Instituto de Salud Carlos III (PI20/00487) to J.E, CIBERDEM (postdoctoral contract) to I.P., and Conacyt-Mexico (CB-2015-01 256639 and FOP02-2022-02 321869) to O.L.-F. The authors thank Ana Melgar and Patricia Saperas (IIS-FJD, Madrid) for technical support in mouse sample processing and histology, and Carmen Liliana Peña for technical assistant with in vitro experiment

    The TUCAN3G project: wireless technologies for isolated rural communities in developing countries based on 3G small-cell deployments

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    Recent years have witnessed a massive penetration of cellular systems in developing countries. However, isolated rural areas (sparsely inhabited by low-income population) have been disregarded because classical access and backhaul technologies do not ensure the return on investment. This article presents innovative techno-economical solutions to provide these areas with cellular voice and data services. We first analyze the general characteristics of isolated rural communities, and based on this information, low-cost solutions are designed for both access (using 3G access points) and backhaul networks (using non-carrier grade equipment as WiFi for long distances or WiMAX in non-licensed bands). Subsequently, a study of population-dependent income vs. costs is presented, and a new business model is proposed involving mobile network operators, rural operators, and infrastructure providers. In order to test these solutions, we have built two demonstration platforms in the Peruvian jungle that have allowed validation of the technical feasibility of the solution, verifying the business model assumptions and the scalability of the initiative.Peer ReviewedPostprint (author's final draft

    SOCS1-derived peptide administered by eye drops prevents retinal neuroinflammation and vascular leakage in experimental diabetes

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    Diabetic retinopathy; Neuroinflammation; Suppressors of cytokine signalingRetinopatía diabética; Neuroinflamación; Supresores de señalizadores de citoquinasRetinopatia diabètica; Neuroinflamació; Supressors de senyalitzadors de citoquinesCurrent treatments for diabetic retinopathy (DR) target late stages when vision has already been significantly affected. Accumulating evidence suggests that neuroinflammation plays a major role in the pathogenesis of DR, resulting in the disruption of the blood-retinal barrier. Suppressors of cytokine signaling (SOCS) are cytokine-inducible proteins that function as a negative feedback loop regulating cytokine responses. On this basis, the aim of the present study was to evaluate the effect of a SOCS1-derived peptide administered by eye drops (2 weeks) on retinal neuroinflammation and early microvascular abnormalities in a db/db mouse model. In brief, we found that SOCS1-derived peptide significantly reduced glial activation and neural apoptosis induced by diabetes, as well as retinal levels of proinflammatory cytokines. Moreover, a significant improvement of electroretinogram parameters was observed, thus revealing a clear impact of the histological findings on global retinal function. Finally, SOCS1-derived peptide prevented the disruption of the blood-retinal barrier. Overall, our results suggest that topical administration of SOCS1-derived peptide is effective in preventing retinal neuroinflammation and early microvascular impairment. These findings could open up a new strategy for the treatment of early stages of DR.This study was supported by grants from the Ministerio de Economia y Competitividad (PI16/00541, SAF2015-63696-R, PI14/00386, PI17/01495 and DTS-2017/00203). Cristina Sola-Adell is a recipient of a Predoctoral Research Grant from MINECO (BES-2013-064944). Joel Sampedro is a recipient of a Predoctoral Research Grant from AGAUR

    Important abnormalities of bone mineral metabolism are present in patients with coronary artery disease with a mild decrease of the estimated glomerular filtration rate

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    The final publication is avilable at: Journal of Bone and Mineral Metabolism 30.9 (2015): 1-34Chronic kidney disease (CKD)–mineral and bone disorder (MBD) is characterized by increased circulating levels of parathormone (PTH) and fibroblast growth factor 23 (FGF23), bone disease, and vascular calcification, and is associated with adverse outcomes. We studied the prevalence of mineral metabolism disorders, and the potential relationship between decreased estimated glomerular filtration rate (eGFR) and CKD-MBD in coronary artery disease patients in a cross-sectional study of 704 outpatients 7.5 ± 3.0 months after an acute coronary syndrome. The mean eGFR (CKD Epidemiology Collaboration formula) was 75.8 ± 19.1 ml/min/1.73 m2. Our patients showed lower calcidiol plasma levels than a healthy cohort from the same geographical area. In the case of men, this finding was present despite similar creatinine levels in both groups and older age of the healthy subjects. Most patients (75.6 %) had an eGFR below 90 ml/min/1.73 m2 (eGFR categories G2–G5), with 55.3 % of patients exhibiting values of 60–89 ml/min/1.73 m2 (G2). PTH (r = −0.3329, p < 0.0001) and FGF23 (r = −0.3641, p < 0.0001) levels inversely correlated with eGFR, whereas calcidiol levels and serum phosphate levels did not. Overall, PTH levels were above normal in 34.9 % of patients. This proportion increased from 19.4 % in G1 category patients, to 33.7 % in G2 category patients and 56.6 % in G3–G5 category patients (p < 0.001). In multivariate analysis, eGFR and calcidiol levels were the main independent determinants of serum PTH. The mean FGF23 levels were 69.9 (54.6–96.2) relative units (RU)/ml, and 33.2 % of patients had FGF23 levels above 85.5 RU/ml (18.4 % in G1 category patients, 30.0 % in G2 category patients, and 59.2 % in G3–G5 category patients; p < 0.001). In multivariate analysis, eGFR was the main predictor of FGF23 levels. Increased phosphate levels were present in 0.7 % of the whole sample: 0 % in G1 category patients, 0.3 % in G2 category patients, and 2.8 % in G3–G5 category patients (p = 0.011). Almost 90 % of patients had calcidiol insufficiency without significant differences among the different degrees of eGFR. In conclusion, in patients with coronary artery disease there is a large prevalence of increased FGF23 and PTH levels. These findings have an independent relationship with decreased eGFR, and are evident at an eGFR of 60–89 ml/min/1.73 m2. Then, mild decreases in eGFR must be taken in consideration by the clinician because they are associated with progressive abnormalities of mineral metabolismFondo de Investigaciones Sanitarias (PI10/00072, PI14/00386, PIE13/00051, PI05/0451, PI05/1497, PI05/52475, PI05/1043, PS09/01405, PI14/1567) y FRIAT, Spanish Society of Cardiology, Spanish Heart Foundation, Spanish Society of Arteriosclerosis, REDINREN (RD012/0021), Biobank grants from Instituto de Salud Carlos III FEDER, RD09/0076/00101 (FJD Biobank) and Abbvie Laboratories. PN I+D+I 2008-2011 and ISCIII co-financed by FEDER, CIBERDEM and e-PREDIC

    Haematuria increases progression of advanced proteinuric kidney disease

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    Background Haematuria has been traditionally considered as a benign hallmark of some glomerular diseases; however new studies show that haematuria may decrease renal function. Objective To determine the influence of haematuria on the rate of chronic kidney disease (CKD) progression in 71 proteinuric patients with advanced CKD (baseline eGFR <30 mL/min) during 12 months of follow-up. Results The mean rate of decline in eGFR was higher in patients with both haematuria and proteinuria (haemoproteinuria, HP, n=31) than in patients with proteinuria alone (P patients, n=40) (-3.8±8.9 vs 0.9±9.5 mL/min/1.73m2/year, p<0.05, respectively). The deleterious effect of haematuria on rate of decline in eGFR was observed in patients <65 years (-6.8±9.9 (HP) vs. 0.1±11.7 (P) mL/min/1.73m2/year, p65 years (-1.2±6.8 (HP) vs. 1.5±7.7 (P) mL/min/1.73m2/year). Furthermore, the harmful effect of haematuria on eGFR slope was found patients with proteinuria >0.5 g/24 h (-5.8±6.4 (HP) vs. -1.37± 7.9 (P) mL/min/1.73m2/year, p<0.05), whereas no significant differences were found in patients with proteinuria < 0.5 g/24 h (-0.62±7.4 (HP) vs. 3.4±11.1 (P) mL/min/1.73m2/year). Multivariate analysis reported that presence of haematuria was significantly and independently associated with eGFR deterioration after adjusting for traditional risk factors, including age, serum phosphate, mean proteinuria and mean serum PTH (β=-4.316, p=0.025) Conclusions The presence of haematuria is closely associated with a faster decrease in renal function in advanced proteinuric CKD patients, especially in younger CKD patients with high proteinuria levels; therefore this high risk subgroup of patients would benefit of intensive medical surveillance and treatmentThis work was supported by grants from FIS (Programa Miguel Servet: CP10/00479, PI13/ 00802 and PI14/00883) and Spanish Society of Nephrology to Juan Antonio Moreno. Fundacion Lilly, FRIAT (Fundación Renal Iñigo Alvarez de Toledo) and ISCIII fund PI14/00386 to Jesus Egid

    Monocyte chemoattractant protein-1 Is an independent predictor of coronary artery ectasia in patients with acute coronary syndrome

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    Our purpose was to assess a possible association of inflammatory, lipid and mineral metabolism biomarkers with coronary artery ectasia (CAE) and to determine a possible association of this with acute atherotrombotic events (AAT).We studied 270 patients who underwent coronary angiography during an acute coronary syndrome 6 months before. Plasma levels of several biomarkers were assessed, and patients were followed during a median of 5.35 (3.88–6.65) years. Two interventional cardiologists reviewed the coronary angiograms, diagnosing CAE according to previously published criteria in 23 patients (8.5%). Multivariate binary logistic regression analysis was used to search for independent predictors of CAE. Multivariate analysis revealed that, aside from gender and a diagnosis of dyslipidemia, only monocyte chemoattractant protein-1 (MCP-1) (OR = 2.25, 95%CI = (1.35–3.76) for each increase of 100 pg/mL, p = 0.001) was independent predictor of CAE, whereas mineral metabolism markers or proprotein convertase subtilisin/kexin type 9 were not. Moreover, CAE was a strong predictor of AAT during follow-up after adjustment for other clinically relevant variables (HR = 2.67, 95%CI = (1.22–5.82), p = 0.013). This is the first report showing that MCP-1 is an independent predictor of CAE, suggesting that CAE and coronary artery disease may share pathogenic mechanisms. Furthermore, CAE was associated with an increased incidence of AATThis work was supported by grants from the following: Fondo de Investigaciones Sanitarias (PI05/0451, PI05/1497, PI05/52475, PI05/1043, PS09/01405, and PI10/00072, PI14/01567, PI17/01615): http://www.isciii.es/ISCIII/ es/contenidos/fd-investigacion/fd-financiacion/convocatorias-ayudas-accion-estrategica-salud.shtml; Spanish Society of Cardiology; Spanish Heart Foundation. http://www.secardiologia.es/; Spanish Society of Arteriosclerosis.www.searteriosclerosis.org; CiberCV. http://www.cibercv.es/; RECAVA (RD06/0014/0035); www.recava.com; Fundación Lilly. https://www.lilly.es/nuestra-compania/fundacion-lilly-folder; Instituto de Salud Carlos III FEDER (FJD biobank: RD09/0076/00101); http://www.isciii.es/; and AbbVie Laboratories. http://www.abbvie.es/

    N-terminal pro-brain natriuretic peptide is associated with a future diagnosis of cancer in patients with coronary artery disease

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    Objective Several papers have reported elevated plasma levels of natriuretic peptides in patients with a previous diagnosis of cancer. We have explored whether N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels predict a future diagnosis of cancer in patients with coronary artery disease (CAD). Methods We studied 699 patients with CAD free of cancer. At baseline, NT-proBNP, galectin-3, monocyte chemoattractant protein-1, soluble tumor necrosis factor-like weak inducer of apoptosis, high-sensitivity C-reactive protein, and high-sensitivity cardiac troponin I plasma levels were assessed. The primary outcome was new cancer diagnosis. The secondary outcome was cancer diagnosis, heart failure requiring hospitalization, or death. Results After 2.15±0.98 years of follow-up, 24 patients developed cancer. They were older (68.5 [61.5, 75.8] vs 60.0 [52.0, 72.0] years; p=0.011), had higher NT-proBNP (302.0 [134.8, 919.8] vs 165.5 [87.4, 407.5] pg/ml; p=0.040) and high-sensitivity C-reactive protein (3.27 [1.33, 5.94] vs 1.92 [0.83, 4.00] mg/L; p=0.030), and lower triglyceride (92.5 [70.5, 132.8] vs 112.0 [82.0, 157.0] mg/dl; p=0.044) plasma levels than those without cancer. NT-proBNP (Hazard Ratio [HR]=1.030; 95% Confidence Interval [CI]=1.008-1.053; p=0.007) and triglyceride levels (HR=0.987; 95%CI=0.975-0.998; p=0.024) were independent predictors of a new cancer diagnosis (multivariate Cox regression analysis). When patients in whom the suspicion of cancer appeared in the first one-hundred days after blood extraction were excluded, NT-proBNP was the only predictor of cancer (HR=1.061; 95% CI=1.034-1.088; p<0.001). NT-proBNP was an independent predictor of cancer, heart failure, or death (HR=1.038; 95%CI=1.023-1.052; p<0.001) along with age, and use of insulin and acenocumarol. Conclusions NT-proBNP is an independent predictor of malignancies in patients with CAD. New studies in large populations are needed to confirm these findingsThis work was supported by grants from Fondo de Investigaciones Sanitarias (PI05/0451, PI05/1497,PI05/2475, PI05/1043, PS09/01405, PI10/ 00072, and PI10/0234, PI14/1567, Programa de Estabilización to LBC); Spanish Society of Cardiology and Spanish Heart Foundation; Spanish Society of Arteriosclerosis; RECAVA (RD06/0014/0035, www. recava.com); Fundación Lilly; and Instituto de Salud Carlos III FEDER (FJD biobank: RD09/0076/00101)
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