Elastic Spin Hall effect in Mechanical Graphene

We show that spin-orbit interaction and elastic spin-Hall effect can exist in a classical mechanical system consisting of a two-dimensional honeycomb lattice of masses and springs. The band structure shows the presence of splitting at K point induced by the difference of longitudinal and transverse elastic constant, and this splitting can be regarded as an effective Dresselhaus-type spin-orbit coupling. Interestingly, as an initial displacement away from the equilibrium is applied, the time evolution simulation shows that waves of different spin polarization propagates along different directions at the Gamma and K point, which is characteristic of spin-Hall effect. Several cases for spin-Hall effect are also discussed.Comment: 15 pages, 5 figures, and 3395 word

Novel wave phenomena in classical vibrations

In this thesis, from discrete spring-mass systems to continuous elastic solids, the possibility of achieving topological phases and elastic spin-Hall effect are analytically and numerically discussed. Originating from time-reversal symmetry breaking via applying external fields, a unidirectional and backscattering-immune edge state arises owing to the topological protection. Caused by the effective spin-orbit coupling, the elastic counterpart of spin-Hall effect arises at certain area of the momentum space. Also, the proposed arguments are verified by numerical calculation of practical mechanical crystals and elastic composites. We believe these studies pave the way for the future researches in topological elasticity. On the other hand, PT symmetry, which is a weaker restriction than Hermicity, allows real eigenvalues in a non-Hermitian Hamiltonian. However, it is challenging to introduce the PT condition into quantum mechanical systems. In this thesis, we consider an acoustic metamaterial made of periodically arranged spinning cylinders. By virtue of the rotational Doppler effects, the dispersion relation around the rotating speed of rods is significantly influenced by the rotation. The frequency shifts cause a PT symmetric Hamiltonian so that, at specific points, the spontaneous PT symmetry breaking emerges and exceptional points arise. Lastly a possible setup is discussed for the future experimental realisation

Governance Mechanism of E-health in Chinese Urban Communities: The Case of Zhabei District in Shanghai

E-health governance can be divided into four kinds of models: government-oriented, market-oriented, government-market cooperation, and multi-collaborative governance. With the development of market economy, democratic consciousness and management philosophy, traditional e-health management faces many challenges. And multi-collaborative governance model is becoming a good choice for the community e-health. In order to further analyze the characteristics and applicability of this model and explore the sustainable development path, this paper selects Zhabei District as a typical case and distinguishes the roles of different governance bodies in community e-health. By this study, we recognize that the e-health governance of Chinese urban community has some problems, such as, insufficient involvement of non-governmental body, obvious conflict of interest and the lack of collaboration among the various subjects. Therefore, it is supposed to construct an integrated e-health development mechanism. Based on collaborative governance theory, the mechanism has to follow three basic principles. At the same time, effective operation of this mechanism need five mechanisms which include trust, communication and negotiation, cost sharing, supervision and feedback. Key words: community e-health, collaborative governance, medical service, Zhabei Distric

Curcumin suppresses leukemia cell proliferation by downregulation of P13K/AKT/mTOR signalling pathway

Purpose: To investigate the effect of curcumin ester on the proliferation of leukemia cell lines in vitro. Methods: Changes in WEHI-3 and THP 1 cell viabilities were measured using Cell Counting Kit 8 (CCK 8). Analysis of cell cycle and determination of apoptosis were carried out using propidium iodide and Annexin V fluorescein isothiocyanate staining. Transmission electron microscopy was used for observing the presence of apoptotic features in cells. Results: Treatment with curcumin ester for 72 h caused significant reduction in the proliferation of WEHI-3 and THP 1 cells. Curcumin ester, at a dose of 50 µM, decreased the proliferations of WEHI-3 and THP 1 cells to 28 and 32 %, respectively. On exposure to curcumin ester for 72 h, cell cycle in WEHI-3 cells was arrested in G1/G0 phase. Curcumin ester at doses of 25, 30 and 50 µM enhanced apoptosis in WEHI-3 cells to 46, 58 and 64 %, respectively. Curcumin ester suppressed the levels of phosphoinositide 3 kinase (PI3K), protein kinase B (AKT) and mechanistic target of rapamycin (mTOR) protein and mRNA in WEHI-3 cells. In curcumin ester-treated WEHI-3 cells, the presence of apop¬totic bodies increased significantly and concentration-dependently. Conclusion: These results demonstrate that curcumin ester inhibits leukemia cell proliferation by inducing apoptosis and arresting cell cycle in G1/G0 phase, probably via suppression of PI3K, AKT and mTOR, and promotion of PTEN. Thus, curcumin ester has potentials for use in the development of an effective treatment strategy for leukemia

Two-pion interferometry for partially coherent sources in relativistic heavy-ion collisions in a multi-phase transport model

We perform two-pion Hanbury Brown-Twiss (HBT) interferometry for the partially coherent pion-emitting sources in relativistic heavy-ion collisions, using a multi-phase transport (AMPT) model. A longitudinal coherent emission length, as well as a transverse coherent emission length, are introduced to the pion generation coordinates in calculating the HBT correlation functions of the partially coherent sources. We compare the model results with and without coherent emission conditions with experimental data in Au-Au collisions at center-of-mass energy $\sqrt{s_{NN}}=$200 GeV, and in Pb-Pb collisions at center-of-mass energy $\sqrt{s_{NN}}=$2.76 TeV, and find that the HBT results of the partially coherent sources are closer to the experimental data than those of chaotic sources.Comment: 20 pages,8 figure