Browsing by Author "Orellana, P."

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    Cyclic behavior of wood-frame shear walls with vertical load and bending moment for mid-rise timber buildings
    (2021) Orellana, P.; Santa María, H.; Almazán, J.L.; Estrella, X.
    In light wood-frame buildings, the gravitational and lateral force-resisting systems are composed of floor diaphragms and shear walls. During an earthquake, these walls are subjected to the simultaneous action of in-plane vertical force, shear force, and in-plane bending moment. In a mid-rise building, these internal forces can reach large magnitudes, especially on the lower stories, and could have an important influence on the lateral behavior of the walls. The historical use of light wood-frame construction has been in low-rise buildings. Consequently, few investigations have analyzed the effects of high gravitational forces or in-plane bending moment on the lateral behavior of wood shear walls designed for multi-story buildings. This paper presents an investigation of the cyclic lateral behavior of light wood-frame shear walls, designed for mid-rise buildings, subjected to large axial compressive load and in-plane bending moment. Eight wall specimens were experimentally tested with a cyclic lateral displacement protocol, a constant compressive load, and a cyclic in-plane bending moment. The effects of axial compressive load and in-plane bending moment were analyzed. Also, the wall length and the spacing of sheathing nails were varied to study the effects of these variables on the response. A numerical study was performed to show how these effects could influence the response of mid-rise timber buildings. An improvement in the lateral performance of the walls was observed compared to walls tested without compressive force nor bending moment, showing an increase in stiffness, load-carrying capacity, and dissipated energy.
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    Hiperinsulinismo congénito del recién nacido: A propósito de un caso clínico
    (2017) Sáez, Juan Carlos; Pattillo Silva, Juan Carlos; Orellana, P.; Godoy, C.
    El hiperinsulinismo congénito (HC) es la causa más frecuente de hipoglicemia persistente del recién nacido (RN), y se caracteriza por secreción no regulada de insulina frente a hipoglicemia. El manejo inicial es médico, pero en caso de fracaso, la pancreatectomía parcial es el tratamiento quirúrgico de elección. Objetivo: Comunicar el caso de un RN con HC con énfasis en el estudio genético, de imágenes y manejo quirúrgico, incluyendo la cirugía laparoscópica. Caso clínico: RN de término, con hipoglicemia prolongada por HC que no respondió al tratamiento médico. La ultrasonografía y resonancia nuclear magnética abdominal fueron normales. PET/CT Galio 68 evidenció aumento de metabolismo glucídico focalizado en el cuerpo pancreático. Se realizó pancreatectomía córporo-caudal laparoscópica sin incidentes, con mejoría de la hipoglicemia. El estudio genético fue compatible con HC focal, confirmado luego por biopsia. Conclusión: Se expone acerca de las características clínicas y diagnóstico del HC, en particular el rol de la cirugía y ventajas del abordaje laparoscópico.
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    Impact of International Atomic Energy Agency support to the development of nuclear cardiology in low-and-middle-income countries: Case of Latin America and the Caribbean
    (2019) Gutierrez-Villamil, C.; Peix, A.; Orellana, P.; Berrocal, I; Ramirez, R.; Estrada-Lobato, E.; Paez, D.
    Cardiovascular diseases (CVDs) are the leading cause of death in Latin America and the Caribbean (LAC) region as well as worldwide. Lifestyle, nutritional habits and the upsurge of obesity have contributed to the increase in the prevalence of CVDs in the region. The role of nuclear cardiology in the management of patients with CVDs is well established. Particularly, myocardial perfusion imaging is widely used in LAC countries and has been increasingly integrated into the healthcare systems in the region for the diagnosis of coronary artery disease, risk stratification and to guide patient management. In its role to support countries around the world to address their health needs through the peaceful applications of nuclear techniques, the International Atomic Energy Agency (IAEA) has provided assistance to the LAC region for the establishment and strengthening of the nuclear cardiology practice. To that extent, the IAEA provides support in building capacities of multidisciplinary teams of professionals, the provision of medical equipment and the promotion of communication and exchange of knowledge among the different stakeholders. In addition, the IAEA encourages the participation of nuclear medicine centers in international multi-center research studies. In this paper, we present some of the projects through which the IAEA has supported the LAC region, including regional technical cooperation projects and coordinated research projects related to cardiology within the current multimodality approach to cardiac imaging.
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    Large deletions and splicing-site mutations inthe STK11 gene in Peutz-Jeghers Chilean families
    (2013) Orellana, P.; Carvallo de Saint Quentin, Pilar
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    The relationship between motivation to read and reading comprehension in chilean elementary students
    (2020) Orellana, P.; Melo, C.; Baldwin, P.; De Julio, S.; Pezoa Sandoval, José Pablo