ABSTRACT We previously revealed the involvement of extracellular regulated protein kinases 1/2 (ERK1/2) in interleukin-6 (IL-6) secretion induced by cyclic compressive force (CCF) in MLO-Y4 cells. In this study, we investigated the contributions of the p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways to IL-6 secretion by stimulating MLO-Y4 cells with CCF. At 80% confluence, different magnitudes (1000μstrain, 2000 μstrain and 4000 μstrain), frequencies (0.5 Hz, 1.0 Hz and 2.0 Hz) and durations (10 min, 30 min, 1 h, 3 h and 6 h) of CCF were loaded onto cells using a four-point bending system. Flow Cytometry (FCM) analysis was used to analyze cell mortality rates after CCF loading. p38 and p65 phosphorylation as well as IκBα degradation in MLO-Y4 cells were detected by Western blotting (WB). Changes in IL-6 secretion after inhibitor treatment were assessed by enzyme-linked immunosorbent assays (ELISAs). Cellular viability was over 90 percent after CCF. p38 and p65 phosphorylation increased under all conditions, whereas IκBα protein levels decreased. However, phosphorylation and degradation were not completely dependent on the loading magnitude, frequency or duration. Furthermore, p38 inhibition using the specific inhibitor SB203580 reduced both p38 phosphorylation and IL-6 secretion. Similarly, NF-κB inhibition using BAY 11-7082 decreased p65 phosphorylation and IL-6 secretion but increased the concentration of IκBα. These findings reveal significant roles for the p38 and NF-κB signaling pathways in IL-6 secretion induced by CCF in MLO-Y4 cells.

El terremoto de Wenchuan, el 12 de mayo de 2008, generó una gran cantidad de material sólido suelto que puede producir flujos de detritos devastadores. En los años posteriores al terremoto han ocurrido deslizamientos a gran escala individuales y simultáneos que han causado daño a los habitantes reubicados y a los esfuerzos de reconstrucción. Las ciudades reconstruidas de Yingxiu, Yinxing y Miansi han sufrido flujos de detritos y otros desastres secundarios desde el terremoto, y no están exentas de eventos futuros. Un evento simultáneo de flujo de detritos afectó a cuatro localidades del condado de Wenchuan, a lo largo de la autopista de Duwen, parte de la carretera nacional 213, en la medianoche del 10 de julio de 2013, después de una lluvia extrema de 176,2 mm 24h-1. Los movimientos de detritos ocurrieron en siete pendientes. Un total de 1500 personas resultaron afectadas debido a la destrucción en áreas de reasentamiento, fábricas, estaciones eléctricas y viviendas. Debido a este devastador hecho, el tráfico de la autopista Duwen estuvo interrumpido durante el período del desastre y mientras se recuperaba la zona. Este estudio se enfoca en el deslizamiento del Puente Lianshan, donde se analizaron las características y las causas del flujo de detritos basados en investigaciones de campo, interpretación de detección remota y experimentos de laboratorio. Se calcularon y analizaron los parámetros dinámicos particulares del flujo de detritos como la densidad, velocidad, descarga, volumen total y fuerza de impacto. También se analizaron los procesos dinámicos y los cambios que ocurrieron en el flujo de detritos, al igual que se estudiaron las características de bloqueo y ruptura del flujo con base en cálculos estadísticos y análisis de los parámetros dinámicos característicos. Finalmente, se propone un programa para prevenir mayores movimientos de detritos de acuerdo con la investigación de campo y basado en los análisis de las características y procesos dinámicos del flujo de material sólido suelto.

The Wenchuan earthquake of May 12, 2008, generated a significant amount of loose solid material that can produce devastating debris flows. In the five years since the earthquake, there have been many large-scale individual and group catastrophic debris flows that have caused lots of damage to the resettled population and the reconstruction efforts. The reconstructed towns of Yingxiu, Yinxing and Miansi have suffered debris flows and other secondary disasters in the past five years and are still not out of danger in the future. A debris-flow catastrophic event hit four towns of Wenchuan County along the Duwen Highway, part of China's National Highway 213, at midnight on July 10, 2013, following a local extreme rainfall of 176.2mm 24h-1. The debris flows occurred simultaneously along seven gullies. A total of 15000 people were affected due to the destruction of resettlement areas, factories, power stations, and houses. Because of this devastating event, traffic along the Duwen highway was completely disrupted during the disaster and recovery period. The present study focuses on the Lianshan Bridge debris flow gully; the disaster characteristics and cause of the debris flow were analyzed based on field investigations, remote sensing interpretation, and laboratory experiments. The particular dynamic parameters of the debris flow were calculated and analyzed including density, velocity, discharge, total volume and impact force. Also, the dynamic processes and changes that occurred in the debris flow were examined, and the block and burst characteristics of debris flow were studied based on statistical calculation and analysis dynamic characteristic parameters of debris flow. Finally, a program to prevent further debris flow was proposed according to the on-site investigation and based on the analysis of the features and dynamic processes of the debris flow.

The absolute fault displacement in co-seismic deformation is derived assuming that location, depth, faulting mechanism and magnitude of the earthquake are known. The 2008 Wenchuan earthquake (M8.0) is used as an example to determine the distribution of seismic intensities using absolute displacement and a crustal model. We fnd that an early prediction of the distribution of seismic intensities after a large earthquake may be performed from the estimated absolute co-seismic displacements using known information from distant stations. Early information on intensities may be vital in disaster evaluation and emergency response after a disastrous event, such as the 2008 Wenchuan earthquake in China.

Para un sismo, el desplazamiento cosísmico absoluto de la falla puede calcularse con base de la localización, la profundidad focal, el mecanismo focal y la magnitud. Así, en base a informaciones provenientes de estaciones remotas, es posible estimar el desplazamiento cosísmico e inferir la correspondiente distribución de intensidades sísmicas. Se presenta el ejemplo del sismo de Wenchuan de 2008, M8.0, y se determina exitosamente la distribución de intensidades utilizando los desplazamientos cosísmicos más un modelo de velocidades. Una evaluación preliminar de intensidades es indispensable para efectos de un diagnóstico temprano del desastre y de una respuesta emergente efectiva en caso de un sismo destructor como el de 2008 en Wenchuan, China.