831 research outputs found
Refined analysis of polarization in electron-positron annihilation process
We investigate the production of spin-3/2 hyperon pairs, , in electron-positron annihilation within the helicity
amplitude formalism. A refined selection of helicity basis matrices is proposed
to relate polarization expansion coefficients and spin density matrix elements
and to illuminate their inherent physical interpretations and symmetrical
properties. With a novel parametrization scheme of helicity amplitudes, we
perform an analysis of polarization correlation coefficients for double-tag
pairs. We present three sets of expressions to
describe the decay of hyperons, and further address the existing
tension in the measurements of its decay parameters, particularly
. The method and the framework developed in this paper can also
be applied to studies of the production and decay mechanisms of other spin-3/2
particles.Comment: 43 pages, 4 figure
Delisheng, a Chinese medicinal compound, exerts anti-proliferative and pro-apoptotic effects on HepG2 cells through extrinsic and intrinsic pathways
The anti-proliferative, cytotoxic and apoptogenic activities of delisheng, a Chinese medicinal compound, has been investigated. In this study, the hepatocarcinoma cell line (HepG2) and the liver cell line (L-02) were exposed to delisheng (6.25, 50 and 100 μl/ml). Delisheng suppressed the proliferation and viability of normal liver L-02 cells slightly, but strongly inhibited the proliferation and viability of hepatocarcinoma HepG2 cells. The flow cytometric analysis of HepG2 cells demonstrated that delisheng primarily arrested the HepG2 cells at the G1 phase of the cell cycle. Annexin V-FITC/PI staining corroborates the apoptogenic nature of delisheng on HepG2 cells. The anti-proliferative and pro-apoptotic effect of delisheng in HepG2 cells was associated with changes in the Bcl-2/Bax ratio and the induction of caspase-mediated apoptosis. Upregulation of DR5 expression was observed in HepG2 cells after treatment with delisheng. The findings from the present study suggest that delisheng has selective cytotoxic activities against HepG2 cells. Delisheng triggered time- and dose-dependent apoptosis in HepG2 cells by activating the mitochondria-mediated and death receptor-mediated apoptotic pathways
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