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The bifurcations and chaotic dynamics of a simply supported symmetric cross-ply composite laminated piezoelectric rectangular plate are studied for the first time, which are simultaneously forced by the transverse, in-plane excitations and the excitation loaded by piezoelectric layers. Based on the Reddy's third-order shear deformation plate theory, the nonlinear governing equations of motion for the composite laminated piezoelectric rectangular plate are derived by using the Hamilton's principle. The Galerkin's approach is used to discretize partial differential governing equations to a two-degreeof-freedom nonlinear system under combined the parametric and external excitations. The method of multiple scales is employed to obtain the four-dimensional averaged equation. Numerical method is utilized to find the periodic and chaotic responses of the composite laminated piezoelectric rectangular plate. The numerical results indicate the existence of the periodic and chaotic responses in the averaged equation. The influence of the transverse, in-plane and piezoelectric excitations on the bifurcations and chaotic behaviors of the composite laminated piezoelectric rectangular plate is investigated numerically.composite laminated piezoelectric rectangular plate, third-order shear deformation, parametric excitation, bifurcation, chaos

In this report, the mechanism of the antitumor activities of Kushen flavonoids (KS-Fs) were explored. KS-Fs and kurarinone (Kur), a single flavonoid compound, were able to induce apoptosis of H460 and Eca-109 cells in vitro and H460 cells in vivo. The apoptosis inducing effect was enhanced in the presence of Taxol. In H460 xenograft mice treated with Kur, down-regulation of Bcl-2 and up-regulation of caspase 8 and caspase 3 in tumors were observed by immunohistochemical staining. In addition, KS-Fs and Kur were able to inhibit TNFalpha-induced NF-kappaB activation in 293 cells mediated by the decreased IkappaBalpha phosphorylation. Further the effects of KS-Fs and Kur on multiple receptor tyrosine kinase activities were explored. In cell-based assays, KS-Fs and Kur inhibited the EGF-induced EGF receptor phosphorylation in A431 cells and a constitutively activated Her-2 in MDA-MB-453s cells. In enzymatic assays, KS-Fs and Kur inhibited KDR, but not PDGF BR activities. In A431 xenograft mice treated with Kur, an inhibition of EGF receptor phosphorylation in tumors was observed. These results reveal a novel mechanism by which KS-Fs induces apoptosis in tumors by acting on multiple cellular targets including the inhibition of NF-kappaB activation and multiple receptor tyrosine kinase activities.

Kushen (KS), the dried roots of Sophora flavescens Aiton, has a long history of use in traditional Chinese medicine to treat inflammatory diseases and cancer. Kushen alkaloids (KS-As) and Kushen flavonoids (KS-Fs) are the well characterized components in KS. KS-As have been considered biologically active and developed in China as anticancer drugs. In an effort to screen novel antitumor agents from botanicals, more potent antitumor activities were identified in KS-Fs than in KS-As. KS-Fs were able to inhibit the growth of a panel of tumor cell lines and enhanced the antitumor activities of Taxol in vitro. The antitumor activities of KS-Fs and Kur, a single KS-Fs compound, were demonstrated in murine and xenograft human tumor models. Further, it was shown that KS-Fs and Kur were able to enhance the effect of Taxol to inhibit the growth of H460 and Eca-109 xenograft tumors. In addition, peripheral blood cell counts were not significantly affected in normal mice treated with KS-Fs at 200 mg/kg/day for 2 weeks. These results suggest that KS-Fs may be developed as novel antitumor agents and that the currently marketed KS-As drugs in China may have missed the major antitumor activities in Kushen.

This paper presents the analysis of the global bifurcations and chaotic dynamics for the nonlinear nonplanar oscillations of a cantilever beam subjected to a harmonic axial excitation and transverse excitations at the free end. The governing nonlinear equations of nonplanar motion with parametric and external excitations are obtained. The Galerkin procedure is applied to the partial differential governing equation to obtain a two-degree-of-freedom nonlinear system with parametric and forcing excitations. The resonant case considered here is 2:1 internal resonance, principal parametric resonance-1/2 subharmonic resonance for the in-plane mode and fundamental parametric resonance-primary resonance for the out-of-plane mode. The parametrically and externally excited system is transformed to the averaged equations by using the method of multiple scales. From the averaged equation obtained here, the theory of normal form is applied to find the explicit formulas of normal forms associated with a double zero and a pair of pure imaginary eigenvalues. Based on the normal form obtained above, a global perturbation method is utilized to analyze the global bifurcations and chaotic dynamics in the nonlinear nonplanar oscillations of the cantilever beam. The global bifurcation analysis indicates that there exist the heteroclinic bifurcations and the Silnikov type single-pulse homoclinic orbit in the averaged equation for the nonlinear nonplanar oscillations of the cantilever beam. These results show that the chaotic motions can occur in the nonlinear nonplanar oscillations of the cantilever beam. Numerical simulations verify the analytical predictions.

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In this paper, an extended Rikitake system is studied. Several issues, such as Hopf bifurcation, coexistence of stable equilibria and hidden attractor, and dynamics analysis at infinity are investigated either analytically or numerically. Especially, by a simple linear transformation, the wide range of hidden attractors is noticed, and the Lyapunov exponents diagram is given. The obtained results show that the unstable periodic solution generated by Hopf bifurcation leads to the hidden attractor. The existence of hidden attractors that may render the system's behavior unpredictable not only depends on the value of system parameters but also on the value of initial conditions. The phenomena are important and potentially problematic in engineering applications.