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Experiencia en COVID-19 en pacientes hospitalizados en unidades de paciente crítico pediátrico durante el periodo pandémico
(Sociedad Chilena de Perdiatría, 2023) Wegner Araya, Adriana; Céspedes Fernández, Pamela; Astudillo Paredes, Patricio; Diettes González, Adriana; Díaz Rubio, Franco; Scheu Goncalves, Christian Andrés; Chauriye Kuncar, Verónica; Gaete Amenábar, Tomás; Zamora Astudillo, Marta; Acuña Aguirre, Carlos; Drago Thibaut, Michele; Monreal Eloaiza, Víctor; Lapadula Amelina, Michelangelo; Pietroboni Fuster, Pietro; Varela Ortiz, Javier; Gallardo Martínez, Alena; Scheuch Ruiz, Karin; Manen Chinchón, Andrés; Villarroel Carreño, María José; Verscheure Peralta, Felipe; Maldonado Valenzuela, Blanca; Meyer Flores, Matías
Objetivo: Caracterizar el comportamiento de COVID-19 en niños chilenos hospitalizados en unidades de paciente crítico pediátrico (UPCP) y evaluar factores de riesgo para COVID-19 severo. Pacientes y Método: Estudio multicéntrico cohorte prospectivo, pacientes 0-18 años con SARS-CoV-2 confirmado hospitalizados en UPCP. Se registraron variables clínicas, laboratorio, imagenológicas y terapéuticas. Se comparó “COVID-19 leve/moderado” versus “COVID-19 severo” utilizando mediana con rango intercuartil (RIC), test U Mann-Whitney, Test Fisher de dos colas y análisis multivariado binario forward para ajuste de variables para “COVID-19 severo”. Significativo p < 0,05. Resultados: 219 pacientes, 55,3% hombres, mediana edad 86 meses (RIC: 13,5-156). Comorbilidades principales: obesidad, enfermedades respiratorias. Mortalidad global: 3,6%. “COVID-19 severo” (26,5%) mostró más leucopenia, linfopenia, más inflamación y alteración de órganos (p < 0,05). También desarrolló más Sepsis/shock, SDRA y disfunción de órganos, requirió más terapia hemodinámica, antiinflamatoria, anticoagulación, antibioterapia, con mayor estadía en UPCP/hospitalaria (p < 0,05) y mortalidad de 13,8%. Factores de riesgo asociados a “COVID-19 severo”: shock al ingreso (aOR 28,44 [IC95%: 10,45-77,4]), obesidad (aOR 3,55 [IC95%: 1,3-9,6]), condensación (aOR 3,1 [IC95%: 1,1-8,7]), atelectasia (aOR: 8.7 [IC95%: 1,17-64,3]), corticoides dosis de estrés (aOR 7,7 [IC95%: 1,9-30,6]), antibioterapia precoz (aOR: 12,02 [IC95%: 1,11-130,02]), inmunodeficiencia adquirida/ congénita (aOR: 19,2 [IC95%: 1,19-321]) y patología oncológica (aOR: 10,7 [IC95%: 2,14-47,8]). Conclusión: En esta cohorte pediátrica chilena, el perfil de paciente que ingresó a UPCP fue de sexo masculino en edad escolar con comorbilidad asociada. Factores de riesgo asociados a COVID-19 severo fueron: presencia de comorbilidades (inmunodeficiencia adquirida/congénita, patología oncológica y obesidad), shock al ingreso y condensaciones en las imágenes radiológicas.
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Testing of strong multi-layered wood frame shear walls with non-structural layers
(2023) Valdivieso Cascante, Diego Nicolas; López-García González, Diego; Montaño Castañeda, Jairo Alonso; Guindos Bretones, Pablo
In areas of high seismic activity it is important to provide Light Frame Timber Buildings (LFTBs) with enhanced levels of lateral stiffness and strength, as well as to prevent excessive levels of non-structural (NSC) damage. Chilean wood-frame shear walls are usually sheathed at both sides with OSB and covered by one/two-ply type X gypsum wallboard (GWB) fastened to the frame with narrow patterns of nails or screws. The result is a multi-layered strong shear wall (MLSSW), which is not considered as such by design codes and mechanical models. The objective of this paper is to report an experimental evaluation of typical Chilean MLSSWs, with emphasis on the influence of NSCs. Connection-level and assembly-level of 1:1 aspect ratio shear walls were evaluated through experimental tests. Results showed increments of 53% and 160% in elastic stiffness and maximum capacity, respectively, while keeping virtually the same deformation capacity and energy dissipation of equivalent bare (non-GWB finished) shear walls. It is postulated that such increases may arise from the high embedment strength of the GWB, and that the deeply screwed GWB may prevent nails from pulling out during hysteresis cycles. It is concluded that GWBs have a significant structural influence on MLSSWs, and such influence should be taken into account in structural design.
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Interrater Agreement of Physicians Identifying Lung Sliding Artifact on B-Mode And M-Mode Point of Care Ultrasound (POCUS)
(2025) Prager, Ross; Clausdorff Fiedler, Hans Jurgen; Smith, Delaney; Wu, Derek; Arntfield, Robert
Background: Chest point of care ultrasound (POCUS) is a first-line diagnostic test to identify lung sliding, an important artifact to diagnose or rule out pneumothorax. Despite enthusiastic adoption of this modality, the interrater reliability forphysicians to identify lung sliding is unknown. Additionally, the relative diagnostic performance of physicians interpreting B-mode and M-mode ultrasound is unclear. We sought to determine the interrater reliability of physicians to detect lung sliding on B-mode and M-mode POCUS. Methods: We performed a cross-sectional interrater agreement study surveying acute care physicians on their interpretation of 20 B-mode and M-mode POCUS clips. Two experienced clinicians determined the reference standard diagnosis. Respondents reported their interpretation of each POCUS B-mode clip or M-mode image. The primary outcome was the interrater agreement, determined by an intra-class correlation coefficient (ICC). Results: From September to November 2023, there were 20 survey respondents. Fourteen (70%) respondents were resident physicians. Respondents were confident or very confident in their skill performing chest POCUS in 14 (70%) cases, with 19 (90%) performing chest POCUS every week or more frequently. The ICC on B-mode was 0.44 and for M-mode was 0.43, indicating moderate agreement. There were no significant differences in interrater reliability between subgroups of confidence or experience. Conclusion: There is only moderate interrater reliability between clinicians to diagnose lung sliding. Clinicians have superior accuracy on B-mode compared to M-mode clips.
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Construcción de viviendas sociales en áreas de riesgo de tsunami
(2008) Lagos López, Marcelo; Cisternas Vega, Marco; Mardones Flores, María Hinia
Se evalúa el riesgo de viviendas sociales construidas en la costa, expuestas al peligro de tsunami, mediante técnicas de modelación numérica. Para ello se utiliza como escenario el último evento destructivo que afectó el centro–sur de Chile, el tsunami de 1960. Caracterizando y cuantificando parámetros hidrodinámicos de la inundación, tales como la profundidad de esta y la velocidad de la corriente, se estima el potencial daño a las viviendas. Finalmente, se reflexiona sobre la importancia de la localización de viviendas sociales y su relación con la exposición a procesos naturales extremos.
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Testing the influence of 3D coupling effects on the lateral response of non-planar T-shape wood frame shear walls
(2023) Valdivieso Cascante, Diego Nicolas; López-García, González Diego; Almazán Campillay, José Luis; Montaño Castañeda, Jairo Alonso; Guindos Bretones, Pablo
Cumulative shear wall overturning (CSWO) is a common response of structural models of multistory Light-Frame Timber Buildings (LFTBs) under lateral loads. Governed by holdown uplift and shear wall (SW) bending, large CSWO occurs in LFTBs due to the light self-weight of wood and the dominant rocking flexibility of stiff SWs. Even though CSWO is paramount in seismic design because of its effect on the flexibility of LFTBs (making hard to achieve the inter-story drift limits), this phenomenon is not incorporated into the structural models of LFTBs. For instance, in the design of LFTBs for lateral loads it is assumed that SWs behave as planar isolated elements. However, CSWO may be influenced by 3D coupling effects (3D-SWCE) in non-planar SWs such as T or L assemblies. This paper describes a large full-scale experiment of a 7.32 m x 5.1 m assembly, performed to gather insight into 3D-SWCEs through the cyclic evaluation of a non-planar T-shape SW. Results showed an asymmetric behaviour of the T-shape SW with increments of 20% and 98% in elastic stiffness and maximum capacity, respectively, with respect to those of a planar SW. It is concluded that 3D-SWCEs have a significant structural influence on the response of LFTBs.