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| Articles
by
Xi Zhang |
Total Records (
2 ) for
Xi Zhang |
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Pengfei Guan
and
Xi Zhang
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In this paper, we study a geodesic equation in the space of Sasakian metrics H
The equation leads to the Dirichlet problem of a complex Monge–Ampere type equation on the Kähler cone. This equation differs from the standard complex Monge–Ampere equation in a significant way, with gradient terms involved in the (1,1)
symmetric tensor of the operator. We establish appropriate regularity estimates for this complex Monge–Ampere type equation. As geometric application, we show that the space of Sasakian metrics H
is a metric space, and the constant transversal scalar curvature metric realizes the global minimum of K-energy if the first basic Chern class 
. We also prove that the constant transversal scalar curvature metric is unique in each basic Kahler class if the first basic Chern class is either strictly negative or zero. |
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Guo-Dong Li
,
Xi Zhang
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Rong Li
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Yue-Dan Wang
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Yan-Li Wang
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Ke-Jun Han
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Xiao-Ping Qian
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Cheng-Gang Yang
,
Ping Liu
,
Qun Wei
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Wei-Feng Chen
,
Jun Zhang
and
Yu Zhang
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CHP2 (calcineurin B homologous protein 2) was initially identified as a tumor-associated antigen highly expressed in hepatocellular carcinoma. Its biological function remains largely unknown except for a potential role in transmembrane Na+/H+ exchange. In the present study, we observed that ectopic expression of CHP2 promoted the proliferation of HEK293 cells, whereas knockdown of endogenous CHP2 expression in HepG2 inhibited cell proliferation. When inoculated into nude mice, CHP2 transfected HEK293 cells displayed markedly increased oncogenic potential. In analysis of the underlying molecular mechanisms, we found that like calcineurin B, CHP2 was able to bind to and stimulate the phosphatase activity of calcineurin A. In accord with this, CHP2-transfected cells showed increased nuclear presence of NFATc3 (nuclear factor of activated T cells) and enhanced NFAT activity. Finally, both accelerated cell proliferation and NFAT activation following CHP2 transfection could be suppressed by the calcineurin inhibitor cyclosporine A, suggesting an intrinsic connection between these events. Taken together, our results highlighted a potential role of CHP2 in tumorigenesis and revealed a novel function of CHP2 as an activator of the calcineurin/NFAT signaling pathway. |
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