Adaptive frequency sweep analysis for electromagnetic problems using the Thiele interpolating continued fractions

A direct rational approximation method based on Thiele interpolating continued fractions theory is proposed for fast frequency sweep analysis of electromagnetic problems. And an adaptive algorithm is also formed. Compared with the conventional rational approximation method, the proposed method can get a rational approximation directly without a great number of matrix inverse computations and doesn't need to allocate much memory for high derivatives of the dense impedance matrix. Meanwhile, the computation of surface currents by continued fractions can be sped up as compared with the traditional rational approximation. Numerical simulations for broad band scattering analysis of different shaped objects are discussed to shown the effectiveness of the present method. © 2010 IEEE.published_or_final_versionThe 2nd International Conference on Education Technology and Computer (ICETC 2010), Shanghai, China, 22-24 June 2010. In Proceedings of 2nd ICETC, 2010, v. 5, p. 126-12

Clinical relevance and therapeutic potential of angiopoietin-like protein 4 in hepatocellular carcinoma

published_or_final_versio

Dehydrogenation mechanisms of Ca(NH2BH3)2: The less the charge transfer, the lower the barrier

Our first-principles study of Ca(NHBH) reveals that the gas phase energy barrier for the first H release is 1.90 eV via a Caâ"̄H transition state and 1.71 eV via an N-Hâ"̄B transition state for the second H release. In the dimer, the barrier for H release from the bridging [NH BH] species is 1.60 eV via an N-Hâ"̄B transition state, and 0.94 eV via an N-Hâ"̄B transition state for the non-bridging [NH BH] species. Analysis of the atomic charge distribution shows that the mechanism of dehydrogenation is determined by the charge transfer between the transition state and the initial state: the less the charge transfer, the lower the barrier to dehydrogenation

Suppression of tumorigenesis and metastasis of hepatocellular carcinoma by shRNA interference targeting on homeoprotein Six1

We previously demonstrated that the overexpression of homeoprotein Six1 in hepatocellular carcinoma (HCC) patients is associated with venous infiltration, advanced pathologic tumor metastasis (pTNM) stage and poor overall survival rate (Ng et al. Br J Cancer 2006;95:1050-5). In this study, short hairpin RNA (shRNA) interference approach was used to suppress the expression of Six1 in a metastatic HCC cell line MHCC97L. Stable transfectant MHCC97L-shSix1 carrying Six1-specific shRNA plasmid was established to downregulate Six1 expression to about 40% when compared with MHCC97L-Control. In vitro functional assays demonstrated that the growth rate and proliferation ability of MHCC97L-shSix1 cells were markedly decreased. Moreover, significant decrease of cell motility and invasiveness were observed in MHCC97L-shSix1 cells. Data from in vivo xenograft tumorigenesis model demonstrated that the size of tumor in MHCC97L-shSix1 group was dramatically reduced. Experimental and spontaneous metastasis models indicated that targeting Six1 suppression noticeably reduced the pulmonary metastasis in MHCC97L-shSix1 group. To identify Six1-regulated targets, cDNA microarray was employed to compare the expression profiles of MHCC97L-Control and MHCC97L-shSix1 cells. Twenty-eight downregulated and 24 upregulated genes with known functions were identified in MHCC97L-shSix1. The functions of these target genes are involved in diverse biological activities. Our data suggest that Six1 may be involved in regulation of proliferation and invasiveness of HCC; thus targeting suppression of Six1 is a viable option for treating HCC patients. © 2009 UICC.postprin

PARAMETRIZATION OF HIGH-SPEED TRAIN STREAMLINE SHAPE

In the past decade, the high speed trains (HSTs) in China have experienced a booming development, with the design of CRH380A as a predominant example. A series of brand new HSTs have been developed with high aerodynamic performance, which includes the running resistance, the lift of the trailing car, pressure waves when trains pass by each other, aerodynamic noise in the far field, etc. In order to design HSTs with better aerodynamic performance, it is necessary to perform aerodynamic shape optimization, especially to optimize the streamline shape of HSTs. Parametrization is the basis for the whole optimization process, since good parametrization approach not only affects the optimization strategy, but also determines the design space and optimization efficiency. In the present paper, a series of work related to the streamline shape parametrization performed by the author in recent years have been introduced. Four different parametrization approaches have been exhibited, which are Local Shape Function method (LSF) and Free-Foam Deformation method (FFD), Modified Vehicle Modeling Function method (MVMF), Class function/Shape function Transformation method (CST). These methods could be categorized into two kinds: shape disturbance approach (LSF and FFD) and shape description approach (MVMF and CST). Among these four methods, some are developed by the authors while some are locally modified so as to meet the parametrization of the streamline shape. The detailed process of these four approaches are exhibited in the present paper and the characteristics of these four approaches are compared.</p