10 research outputs found

    Demographic and clinical profile of idiopathic pulmonary fibrosis patients in Spain: the SEPAR National Registry

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    BackgroundLittle is known on the characteristics of patients diagnosed with idiopathic pulmonary fibrosis (IPF) in Spain. We aimed to characterize the demographic and clinical profile of IPF patients included in the IPF National Registry of the Spanish Respiratory Society (SEPAR).MethodsThis is a prospective, observational, multicentre and nationwide study that involved 608 IPF patients included in the SEPAR IPF Registry up to June 27th, 2017, and who received any treatment for their disease. IPF patients were predominantly males, ex-smokers, and aged in their 70s, similar to other registries.ResultsUpon inclusion, meanSD predicted forced vital capacity was 77.6%+/- 19.4, diffusing capacity for carbon monoxide was 48.5%+/- 17.7, and the 6-min walk distance was 423.5m +/- 110.4. The diagnosis was mainly established on results from the high-resolution computed tomography in the proper clinical context (55.0% of patients), while 21.2% of patients required invasive procedures (surgical lung biopsy) for definitive diagnosis. Anti-fibrotic treatment was prescribed in 69.4% of cases, 51.5% pirfenidone and 17.9% nintedanib, overall with a good safety profile.Conclusions The SEPAR IPF Registry should help to further characterize current characteristics and future trends of IPF patients in Spain and compare/pool them with other registries and cohorts

    Contribución del tablero y de la subestructura frente al pandeo global de pilas esbeltas de hormigón armado : determinación simplificada de una "coacción equivalente"

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    Las pilas de los puentes son elementos habitualmente verticales que, generalmente, se encuentran sometidos a un estado de flexión compuesta. Su altura significativa en muchas ocasiones y la gran resistencia de los materiales constituyentes de estos elementos – hormigón y acero – hace que se encuentren pilas de cierta esbeltez en la que los problemas de inestabilidad asociados al cálculo en segundo orden debido a la no linealidad geométrica deben ser considerados. Además, la mayoría de las pilas de nuestros puentes y viaductos están hechas de hormigón armado por lo que se debe considerar la fisuración del hormigón en las zonas en que esté traccionado. Es decir, el estudio del pandeo de pilas esbeltas de puentes requiere también la consideración de un cálculo en segundo orden mecánico, y no solo geométrico. Por otra parte, una pila de un viaducto no es un elemento que pueda considerarse como aislado; al contrario, su conexión con el tablero hace que aparezca una interacción entre la propia pila y aquél que, en cierta medida, supone una cierta coacción al movimiento de la propia cabeza de pila. Esto hace que el estudio de la inestabilidad de una pila esbelta de un puente no puede ser resuelto con la “teoría del pandeo de la pieza aislada”. Se plantea, entonces, la cuestión de intentar definir un procedimiento que permita abordar el problema complicado del pandeo de pilas esbeltas de puentes pero empleando herramientas de cálculo no tan complejas como las que resuelven “el pandeo global de una estructura multibarra, teniendo en cuenta todas las no linealidades, incluidas las de las coacciones”. Es decir, se trata de encontrar un procedimiento, que resulta ser iterativo, que resuelva el problema planteado de forma aproximada, pero suficientemente ajustada al resultado real, pero empleando programas “convencionales” de cálculo que sean capaces de : - por una parte, en la estructura completa: o calcular en régimen elástico lineal una estructura plana o espacial multibarra compleja; - por otra, en un modelo de una sola barra aislada: o considerar las no linealidades geométricas y mecánicas a nivel tensodeformacional, o considerar la no linealidad producida por la fisuración del hormigón, o considerar una coacción “elástica” en el extremo de la pieza. El objeto de este trabajo es precisamente la definición de ese procedimiento iterativo aproximado, la justificación de su validez, mediante su aplicación a diversos casos paramétricos, y la presentación de sus condicionantes y limitaciones. Además, para conseguir estos objetivos se han elaborado unos ábacos de nueva creación que permiten estimar la reducción de rigidez que supone la fisuración del hormigón en secciones huecas monocajón de hormigón armado. También se han creado unos novedosos diagramas de interacción axil-flector válidos para este tipo de secciones en flexión biaxial. Por último, hay que reseñar que otro de los objetivos de este trabajo – que, además, le da título - era cuantificar el valor de la coacción que existe en la cabeza de una pila debido a que el tablero transmite las cargas de una pila al resto de los integrantes de la subestructura y ésta, por tanto, colabora a reducir los movimientos de la cabeza de pila en cuestión. Es decir, la cabeza de una pila no está exenta lo cual mejora su comportamiento frente al pandeo. El régimen de trabajo de esta coacción es claramente no lineal, ya que la rigidez de las pilas depende de su grado de fisuración. Además, también influye cómo las afecta la no linealidad geométrica que, para la misma carga, aumenta la flexión de segundo orden de cada pila. En este documento se define cuánto vale esta coacción, cómo hay que calcularla y se comprueba su ajuste a los resultados obtenidos en el l modelo no lineal completo. The piers of the bridges are vertical elements where axial loads and bending moments are to be considered. They are often high and also the strength of the materials they are made of (concrete and steel) is also high. This means that slender piers are very common and, so, the instabilities produced by the second order effects due to the geometrical non linear effects are to be considered. In addition to this, the piers are usually made of reinforced concrete and, so, the effects of the cracking of the concrete should also be evaluated. That is, the analysis of the instabilities of te piers of a bridge should consider both the mechanical and the geometrical non linearities. Additionally, the pier of a bridge is not a single element, but just the opposite; the connection of the pier to the deck of the bridge means that the movements of the top of the pier are reduced compared to the situation of having a free end at the top of the pier. The connection between the pier and the deck is the reason why the instability of the pier cannot be analysed using “the buckling of a compressed single element method”. So, the question of defining an approximate method for analysing the buckling of the slender piers of a bridge but using a software less complex than what it is needed for analysing the “ global buckling of a multibeam structure considering all t”, is arisen. Then, the goal should be trying to find a procedure for analysing the said complex problem of the buckling of the slender piers of a bridge using a simplified method. This method could be an iterative (step by step) procedure, being accurate enough, using “normal” software having the following capabilities: - Related to the calculation of the global structure o Ability for calculating a multibesam strucutre using elastic analysis. - Related to the calculation of a single beam strcuture:: o Ability for taking into account the geometrical and mechanical () non linearities o Ability for taking into account the cracking of the concrete. o Ability for using partial stiff constraints (elastic springs) at the end of the elements One of the objectives of this document is just defining this simplified methodology, justifying the accuracy of the proposed procedure by using it on some different bridges and presenting the exclusions and limitations of the propose method. In addition to this, some new charts have been created for calculating the reduction of the stiffness of hollow cross sections made of reinforced concrete. Also, new charts for calculating the reinforcing of hollow cross sections under biaxial bending moments are also included in the document. Finally, it is to be said that another aim of the document – as it is stated on the title on the document – is defining the value of the constraint on the top of the pier because of the connection of the pier to the deck .. and to the other piers. That is, the top of the pier is not a free end of a beam and so the buckling resistance of the pier is significantly improved. This constraint is a non-elastic constraint because the stiffness of each pier depends on the level of cracking. Additionally, the geometrical non linearity is to be considered as there is an amplification of the bending moments due to the increasing of the movements of the top of the pier. This document is defining how this constraints is to be calculated; also the accuracy of the calculations is evaluated comparing the final results with the results of the complete non linear calculation

    Launching the Vicario Viaduct: Andalucia, Spain

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    The Vicario Viaduct is located in the A-44 motorway, in the South-East part of Spain. It crosses a natural gorge, near the town of Ízbor in the province of Granada. A single continuous steel concrete composite deck, 24 m wide and 175 m long, divided in two 87,5 m spans, has been built. The cross section is a single structural steel box, 8,00 m wide and 4,52 m deep. The total width of 24 m is reached adding a strut and tie system each 4,375 m on both sides of the box. The steel parts of the deck were entirely constructed in the workshop and then they were erected on site just behind one of the abutments. Finally a 27.5 m long steel nose was connected to launch the deck. The main problems have been the curved shape of the deck (1420 m radius in plan) producing a non symmetric transverse distribution of reactions on each support and the cantilever reaching 87,5 m long, producing a maximum deflection of 1500 m

    Doubling the width of the platform of the San Pedro bridge in Spain

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    The San Pedro Bridge has six spans and is 750 m (2460 ft) long, 88 m (290 ft) high, 12 m (39 ft) wide, and curved with a radius of 700 m (2300 ft). It was built in 1993 using the cantilever method. Its super - structure is a prestressed concrete box girder with main spans of 150 m (490 ft). In 2008 and 2009, the width of the platform was enlarged to 23 m (75 ft) using five movable sets of scaffolding. The bridge remained open to traffic during construction. The original platform was widened 6 m (20 ft) on each side by connecting a new lightweight concrete cantilever to the original upper slab. These cantilevers were supported by steelstruts. The tie into the upper slab was made with new transverse post-tensioned tendons. The original superstructure was strengthened to resist the additional dead load of the expansion and live loads of the extra traffic. An additional new central web and a composite concrete-steel section were constructed and connected to the concrete box and central web using vertical high-strength post-tensioning bars. Also, external post-tensioning cables were implemented. It was also necessary to strengthen the connection of the original concrete box section to the piers. Detailed calculations were performed to evaluate the load distribution transmitted to the piers by the webs and by the original inclined concrete walls of the box girder. Finally, a detailed second-order-analysis of the complete structure was made to guarantee the resistance of the piers compared with actual load

    Can Polyolefin Fibre Reinforced Concrete Improve the Sustainability of a Flyover Bridge?

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    The use of polyolefin fibre reinforced concrete (PFRC) as an alternative for reducing the reinforcing steel bars employed in reinforced concrete has become real in the past years. This contribution analyses the improvements in sustainability that a change in the aforementioned reinforcement configuration might provide in a flyover bridge. Economic, environmental and social parameters of both possibilities were studied by means of the integrated value model for sustainable assessment. Such model, which acronym is MIVES (Modelo Integrado de Valor para una Evaluación Sostenible, MIVES), is a multi-criteria decision-making method based on the value function concept and the seminars delivered by experts. The results of the MIVES method showed that the use of PFRC in combination with reinforced concrete (RC) has a sustainability index 22% higher. An analysis of the parameters that form this evaluation shows that there are no remarkable differences in the financial costs between the two possibilities studied. Nevertheless, social and environmental aspects provide with a better qualification the option of building a bridge by using PFRC combined with RC

    Demographic and clinical profile of idiopathic pulmonary fibrosis patients in Spain : The SEPAR National Registry

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    Little is known on the characteristics of patients diagnosed with idiopathic pulmonary fibrosis (IPF) in Spain. We aimed to characterize the demographic and clinical profile of IPF patients included in the IPF National Registry of the Spanish Respiratory Society (SEPAR). This is a prospective, observational, multicentre and nationwide study that involved 608 IPF patients included in the SEPAR IPF Registry up to June 27th, 2017, and who received any treatment for their disease. IPF patients were predominantly males, ex-smokers, and aged in their 70s, similar to other registries. Upon inclusion, mean ± SD predicted forced vital capacity was 77.6% ± 19.4, diffusing capacity for carbon monoxide was 48.5% ± 17.7, and the 6-min walk distance was 423.5 m ± 110.4. The diagnosis was mainly established on results from the high-resolution computed tomography in the proper clinical context (55.0% of patients), while 21.2% of patients required invasive procedures (surgical lung biopsy) for definitive diagnosis. Anti-fibrotic treatment was prescribed in 69.4% of cases, 51.5% pirfenidone and 17.9% nintedanib, overall with a good safety profile. The SEPAR IPF Registry should help to further characterize current characteristics and future trends of IPF patients in Spain and compare/pool them with other registries and cohorts

    Enfermedades vasculares del hígado. Guías Clínicas de la Sociedad Catalana de Digestología y de la Asociación Española para el Estudio del Hígado

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    Despite their relatively low prevalence, vascular diseases of the liver represent a significant health problem in the field of liver disease. A common characteristic shared by many such diseases is their propensity to cause portal hypertension together with increased morbidity and mortality. These diseases are often diagnosed in young patients and their delayed diagnosis and/or inappropriate treatment can greatly reduce life expectancy. This article reviews the current body of evidence concerning Budd-Chiari syndrome, non-cirrhotic portal vein thrombosis, idiopathic portal hypertension, sinusoidal obstruction syndrome, hepatic vascular malformations in hereditary haemorrhagic telangiectasia, cirrhotic portal vein thrombosis and other rarer vascular diseases including arterioportal fistulas. It also includes a section on the diagnostic imaging of vascular diseases of the liver and their treatment from a haematological standpoint (study of thrombotic diathesis and anticoagulation therapy). All recommendations are based on published studies extracted from PubMed. The quality of evidence and strength of recommendations were rated in accordance with the GRADE system (Grading of Recommendations, Assessment Development and Evaluation). In the absence of sufficient evidence, recommendations were based on the opinion of the committee that produced the guide.Las enfermedades vasculares hepáticas, a pesar de su relativamente baja prevalencia, representan un problema de salud importante en el campo de las enfermedades hepáticas. Una característica común a muchas de estas enfermedades es que pueden causar hipertensión portal, con la elevada morbimortalidad que ello conlleva. Con frecuencia estas enfermedades se diagnostican en pacientes jóvenes y el retraso en su diagnóstico y/o un tratamiento inadecuado pueden reducir de forma importante la esperanza de vida. El presente artículo revisa la evidencia actual en el síndrome de Budd-Chiari, la trombosis venosa portal en pacientes no cirróticos, la hipertensión portal idiopática, el síndrome de obstrucción sinusoidal, las malformaciones vasculares hepáticas en la telangiectasia hemorrágica hereditaria, la trombosis portal en la cirrosis, otras patologías vasculares menos frecuentes como las fístulas arterioportales, así como un apartado sobre el diagnóstico por imagen de las enfermedades vasculares hepáticas y su tratamiento desde el punto de vista hematológico (estudio de la diátesis trombótica y tratamiento anticoagulante). Las recomendaciones se han realizado de acuerdo a los estudios publicados extraídos de Pubmed. La calidad de la evidencia y la intensidad de las recomendaciones fueron graduadas de acuerdo al sistema Grading of Recommendations Assessment Development and Evaluation (GRADE). Cuando no existían evidencias suficientes, las recomendaciones se basaron en la opinión del comité que redactó la guía

    Absence of antibodies against KIR4.1 in multiple sclerosis: A three-technique approach and systematic review

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    <div><p>Introduction</p><p>Antibodies targeting the inward-rectifying potassium channel KIR4.1 have been associated with multiple sclerosis (MS) but studies using diverse techniques have failed to replicate this association. The detection of these antibodies is challenging; KIR4.1 glycosylation patterns and the use of diverse technical approaches may account for the disparity of results. We aimed to replicate the association using three different approaches to overcome the technical limitations of a single technique. We also performed a systematic review to examine the association of anti-KIR4.1 antibodies with MS.</p><p>Methods</p><p>Serum samples from patients with MS (n = 108) and controls (n = 77) were tested for the presence of anti-KIR4.1 antibodies using three methods: 1) by ELISA with the low-glycosylated fraction of recombinant KIR4.1 purified from transfected HEK293 cells according to original protocols; 2) by immunocytochemistry using KIR4.1-transfected HEK293 cells; and 3) by immunocytochemistry using the KIR4.1.-transfected MO3.13 oligodendrocyte cell line. We developed a systematic review and meta-analysis of the association of anti-KIR4.1 antibodies with MS according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.</p><p>Results</p><p>We did not detect anti-KIR4.1 antibodies in the MS patients or in controls using ELISA. Neither did we detect any significant reactivity against the antigen on the cell surface using the KIR4.1-transfected HEK293 cells or the KIR4.1-transfected MO3.13 cells. We included 13 prospective controlled studies in the systematic review. Only three studies showed a positive association between anti-KIR4.1 and MS. Clinical and statistical heterogeneity between studies precluded meta-analysis of their results.</p><p>Conclusion</p><p>We found no association between anti-KIR4.1 antibody positivity and MS. Although this lack of replication may be due to technical limitations, evidence from our study and others is mounting against the role of KIR4.1 as a relevant MS autoantigen.</p></div
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