Experimental and Numerical Study of Static Behavior of Precast Segmental Hollow Bridge Piers.

To investigate the static performance of precast segmental hollow piers, two precast segmental hollow pier specimens were designed for static loading tests on the top of piers. The finite element model of precast segmental hollow piers was established by the finite element software Abaqus and verified based on the test results. Based on the experimental and finite element models, three optimal design solutions were proposed, and the calculation results of each solution were analyzed. The results show that precast segmental hollow pier mechanical behavior is similar to that of cantilevered bending members. The specimens present brittle damage characteristics after the destruction of the structure at the bottom of the pier pressure edge as the axis of the rigid body rotation. Following the test loading process, the bonding between the segments is good, except for the pier bottom damage surface of the rest of the bonding surface, which has no relative displacement. The calculation results of the finite element model are in good agreement with the test results and can effectively predict the load-displacement response of precast piers. Three optimized design solutions are proposed. The finite element simulation proves all three optimized design solutions show better overall ductility than the original solution and can effectively improve the performance of segmental precast hollow piers.

[Impact of Size on Environmental Behavior of Metal Oxide Nanoparticles].

With the rapid development of nanotechnology, the environmental behavior and ecological effect of nanoparticles (NPs) are receiving more and more attention. As an important environmental component, metal oxide NPs occur widely in nature, such as in water bodies, air, soils, and sediments. They have a large surface area and high surface activity, allowing them to control and affect the speciation, migration, transformation, and bioavailability of some contaminants and nutrients in the environment. The nano-size is a unique property of nanoparticles. The size of particles regulates and determines the structure and physicochemical properties of nano-oxides, which greatly affects interfacial reactions with the relevant elements and environmental geochemical behaviors. The effects of NPs size on the environmental geochemical behaviors, such as adsorption, (reductive) dissolution, (catalytic) oxidation, aggregation and transport, are briefly summarized, and the mechanism of the size effect is discussed. Finally, hot spots for future research of metal oxide nanoparticles related to size effects in the environment are proposed.

Aromatic-turmerone ameliorates imiquimod-induced psoriasis-like inflammation of BALB/c mice.

Psoriasis is a usual immune-mediated inflammatory skin disease with undefined pathogenesis. Aromatic-turmerone (ATM) is a mainly constituent of essential oil from Curcuma longa L. It has been shown to exhibit strong anti-oxidant, anti-tumor activities and anti-inflammatory effects. In this study, we investigated the effects of ATM on imiquimod (IMQ)-induced psoriasis-like BALB/c mice and its molecular mechanisms for anti-inflammatory effect. ATM showed inhibition of the transfer of CD8+ T cells in epidermis, and reduced expression of NF-κB and COX-2 as well as phosphorylation of p38 MAPK. It also decreased the level of TNF-α and IL-6, and down-regulates IL-17 IL-22 and IL-23 mRNA synthesis. Notably, we demonstrated that topically applied ATM alleviated skin inflammation in IMQ-induced mice. These results indicate that ATM, a natural active compound exhibits anti-inflammatory activity and is a promising candidate molecule to treat inflammatory skin diseases, such as psoriasis.

Synthesis of carbazole derivatives containing chalcone analogs as non-intercalative topoisomerase II catalytic inhibitors and apoptosis inducers.

Novel topoisomerase II (Topo II) inhibitors have gained considerable interest for the development of anticancer agents. In this study, a series of carbazole derivatives containing chalcone analogs (CDCAs) were synthesized and investigated for their Topo II inhibition and cytotoxic activities. The results from Topo II mediated DNA relaxation assay showed that CDCAs could significantly inhibit the activity of Topo II, and the structure-activity relationship indicated the halogen substituent in phenyl ring play an important role in the activity. Further mechanism studies revealed that CDCAs function as non-intercalative Topo II catalytic inhibitors. Moreover, some CDCAs showed micromolar cytotoxic activities. The most potent compound 3h exhibited notable growth inhibition against four human cancer cell lines. Flow cytometric analysis revealed that compounds 3d and 3h arrested the HL-60 cells in sub G1 phase by induction of apoptosis. It was further confirmed by Annexin-V-FITC binding assay. Western blot analysis revealed that compound 3h induces apoptosis likely through the activation of caspase proteins.