1,774 research outputs found

    Canonical interpretation of Y(10750)Y(10750) and Υ(10860)\Upsilon(10860) in the Υ\Upsilon family

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    Inspired by the new resonance Y(10750)Y(10750), we calculate the masses and two-body OZI-allowed strong decays of the higher vector bottomonium sates within both screened and linear potential models. We discuss the possibilities of Υ(10860)\Upsilon(10860) and Y(10750)Y(10750) as mixed states via the SDS-D mixing. Our results suggest that Y(10750)Y(10750) and Υ(10860)\Upsilon(10860) might be explained as mixed states between 5S5S- and 4D4D-wave vector bbˉb\bar{b} states. The Y(10750)Y(10750) and Υ(10860)\Upsilon(10860) resonances may correspond to the mixed states dominated by the 4D4D- and 5S5S-wave components, respectively. The mass and the strong decay behaviors of the Υ(11020)\Upsilon(11020) resonance are consistent with the assignment of the Υ(6S)\Upsilon(6S) state in the potential models.Comment: 9 pages, 4 figures. More discussions are adde

    Planning for Eco-City in China: Policy Mobility in Path Creation of Eco-Zhuhai

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    Idea of eco-city booms in China’s planning practices under central state’s envisioned transition towards “ecological civilization” wherein Zhuhai stands out as an example well fitted the eco-livable paradigm. To disentangle how Zhuhai has achieved such fame, this article identifies two interlocked and nested forms of policy mobility: policy reformulation towards pro-environment and policy circulation of advanced eco-experiences, and reviews key process of eco-city planning in the city since 1980s. Rather than an explicit, long-term vision, the review suggests that Zhuhai’s reputation as an eco-city model results from cumulative effects of early policy formulation towards environmental protection upon its geographical location, its natural assets, and essentially early hysteresis in the growth race. Though subsequent development has been path-dependently locked in, it is benefitted from the planning regime wherein knowledge and experiences related to eco-city are instantly shared

    Role of Λ(1670)\Lambda(1670) in the γpK+ηΛ\gamma p \to K^+ \eta \Lambda reaction near threshold

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    The role of the Λ(1670)\Lambda(1670) resonance in the γpK+ηΛ\gamma p \to K^+ \eta \Lambda reaction near threshold is studied within an effective Lagrangian approach. We perform a calculation for the total and differential cross section of the γpK+ηΛ\gamma p \to K^+ \eta \Lambda reaction by including the contributions from the Λ(1670)\Lambda(1670) intermediate state decaying into ηΛ\eta \Lambda dominated by KK^- and KK^{*-} mesons exchanges, the nucleon pole and N(1535)N^*(1535) resonance decaying into K+ΛK^+ \Lambda dominated by exchanges of ω\omega and KK^- mesons. Besides, the non-resonance process and contact terms to keep the total scattering amplitude gauge invariant are also considered. With our model parameters, the total cross section of this reaction is of the order of 11 nanobarn at photon beam energy Eγ2.5E_{\gamma} \sim 2.5 GeV. It is expected that our model predictions could be tested by future experiments.Comment: Published versio

    Development of small interfering RNA delivery system using PEI-PEG-APRPG polymer for antiangiogenic vascular endothelial growth factor tumor-targeted therapy

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    Zong-Xia Lu1, Li-Ting Liu1,2, Xian-Rong Qi11Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China; 2Department of Pharmacy, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of ChinaBackground: Small interfering RNA (siRNA) can silence target genes in the cytoplasm and be a major tool in gene therapy. Vascular endothelial growth factor (VEGF), a potent regulator of angiogenesis, is overexpressed in most tumors and is closely associated with tumor growth and metastasis. It has been shown that inhibition of VEGF expression by siRNA is an effective and useful method for antiangiogenic tumor therapy.Methods: In the present study, we synthesized a targeted delivery system of PEI-PEG-APRPG incorporating angiogenic vessel-homing Ala-Pro-Arg-Pro-Gly (APRPG) peptide into cationic polyethylenimine (PEI) via a hydrophilic poly(ethylene glycol) (PEG) spacer.Results: PEI-PEG-APRPG effectively condensed siRNA into 20–50 nm nanoparticles with a positive surface charge using a suitable N/P ratio. The siRNA/PEI-PEG-APRPG complex effectively enhanced the stability of siRNA in RNase A, and improved the proliferation-inhibiting ability and transfection efficiency of siRNA in vitro and tumor accumulation in vivo. In addition, the siRNA/PEI-PEG-APRPG complex exhibited high efficiency as antitumor therapy with regard to tumor growth, microvessel density, and VEGF protein and mRNA levels.Conclusion: These findings suggest that PEI-PEG-APRPG effectively delivers siRNA to tumors overexpressing VEGF and thereby inhibits tumor growth.Keywords: PEI-PEG-APRPG, VEGF siRNA, gene delivery, tumor-targeted, antiangiogenic therap
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