The goal of this study was to examine morpho-physiological changes in the dorsal subiculum network in the mouse model of temporal lobe epilepsy using extracellular recording, juxtacellular and immunofluorescence double labeling, and anterograde tracing methods. A significant loss of total dorsal subicular neurons, particularly calbindin, parvalbumin (PV), and immunopositive interneurons, was found at 2 months after pilocarpine-induced status epilepticus (SE). However, the sprouting of axons from lateral entorhinal cortex (LEnt) was observed to contact with surviving subicular neurons. These neurons had two predominant discharge patterns: bursting and fast irregular discharges. The bursting neurons were mainly pyramidal cells, and their dendritic spine density and bursting discharge rates were increased significantly in SE mice compared to the control group. Fast irregular discharge neurons were PV-immunopositive interneurons, and had less dendritic spines in SE mice when compared to control mice. When LEnt was stimulated, bursting and fast irregular discharge neurons had much shorter latency and stronger excitatory response in SE mice compared to the control group. Our results illustrate that morpho-physiological changes in the dorsal subiculum could be part of a multilevel pathological network that occurs simultaneously in many brain areas to contribute to the generation of epileptiform activity.

Arch springing is an important critical joint in a steel truss arch bridge, and it has a great influence on the mechanical behavior of the global structure. The adoption of a reasonable structure of the springing joint is of important significance in the design of an arch bridge. In this paper, with regard to the structure of Xinshiji Bridge, two types of arch springing were put forward. In Scheme-1, the lower chords of steel truss arch ribs are connected to the concrete piers with shear studs on the ribs and cap plates welded on the ribs at the top of concrete piers., while Scheme-2 is a integrated spring joint with a base plate on the bottom of the steel arch ribs and with reinforcing bars through the holes on the joints steel arch ribs. 3D finite element models of the two types of springing joint were established and the relative slips between the concrete and steel were taken into account in the analyses. The mechanical behavior of the concrete and the steel structure of the joints under applied loads was investigated and the analysis result showed that Scheme-2 is a relative better structure of springing joint, with less principle tensile stress in concrete and less Mises stress in steel plates.

Steel and concrete composite structures are widely used in bridge engineering, for it can fully utilize the compression property of concrete and tensile behavior of the steel. However, the coupled behavior of shrinkage and creep exist in concrete. The creep behavior is dependent on the initial stress, while shrinkage is not. The shrinkage and creep of the concrete have a significant influence on the internal force and deformation and it may cause the cracking or even the failure of the structure. Nowadays, precast concrete slab is widely adopted in the composite bridges to reduce the effect of shrinkage and creep. Storage time is a critical parameter for the precast concrete slab to reach the best economic benefit and mechanical behavior of the structure. Therefore, in this paper, the finite element model of Xinshiji Bridge with the consideration of the relative slip between the steel and concrete was established to investigate the influence of loading age of the concrete on the mechanical behavior of the composite bridge, and the optimal storage time was determined.