Iglesia de San Ignacio de Loyola - Ciudad de Buenos Aires Evaluación Estructural y Propuesta de Refuerzo

In 2003 the “San Ignacio de Loyola” church evidenced a concerning picture of cracking and fracturing that led to their preventive underpinning during five years. A summary of the Church structural behavior that enabled the design of proper reinforcements based on sound technical arguments is included. The background, field studies, features and purposes of several finite element models and the findings on the causes of cracking are detailed. Results could demonstrate that the observed damages were originated by the deterioration of the soil under Alsina street, in turns caused by the rupture of a pipeline transporting clean water. Some interesting details of the structural reinforcements made of reinforced concrete and special consideration of the issues that must be addressed to achieve the goals of structural and architectural compatibility, efficiency and durability are finally described.En el año 2003 la iglesia de San Ignacio de Loyola comenzó a mostrar un cuadro de fisuras y grietas importantes que motivaron su apuntalamiento preventivo durante cinco años. Se resumen los conceptos sobre el comportamiento estructural que permitieron el desarrollo y la ejecución de un proyecto de reparación sustentado en bases firmes y objetivas. También se incluye la investigación de los antecedentes, estudios de campo, características y propósitos de los modelos de elementos finitos y un análisis de las causas de la fisuración. Los resultados obtenidos permiten demostrar que el origen de los daños es compatible con un deterioro del suelo producido por la rotura de una cañería de agua a presión, bajo la calle Alsina. También se presentan los criterios y características de los refuerzos de hormigón armado propuestos, destacando los conceptos puestos en juego para lograr refuerzos estructurales arquitectónica y estructuralmente compatibles, eficientes y durables

Laser-induced fluorescence integrated in a microfluidic immunosensor for quantification of human serum IgG antibodies to Helicobacter pylori

A portable immunosensor coupled to laser-induced fluorescence (LIF) detection system has been successfully developed. It was applied to the quantitative determination of specific IgG antibodies against Helicobacter pylori present in human serum samples. This system is a relevant alternative tool for the diagnostic of peptic ulcer and gastritis diseases produced by H. pylori, which are recognized risk factors for the development of gastric mucosa associated lymphoid tissue lymphoma and gastric adenocarcinoma. More than 50% of the population has been affected by H. pylori, one of the most widespread infections around the world. Our proposed system combines the LIF detection, which offers great sensibility with the specificity of the immunological reactions and the microfluidic technology. The device has a central channel (CC) with packed H. pylori antigen immobilized on 3-aminopropyl-modified controlled pore glass (AP-CPG). Antibodies in serum samples reacted immunologically with the immobilized antigen and then, they were determined using alkaline phosphatase (AP) enzyme-labeled second antibodies specific to human IgG. The 4-methylumbelliferyl phosphate (4-MUP), employed as enzymatic substrate, was converted to soluble fluorescent methylumbelliferone by AP, and this fluorescent product was finally quantified by LIF detection system. The calculated detection limits for LIF detection and the ELISA procedure were 0.17 and 2.1 U mL -1, respectively, and the within- and between-assay coefficients of variation were below 5.1%.Fil: Seia, Marco Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Pereira, Sirley Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Carlos A. Fontán. Universidad Nacional de San Luis; ArgentinaFil: de Vito, Irma Esther. Universidad Nacional de San Luis; ArgentinaFil: Messina, Germán Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Raba, Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin