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1. chinaXiv:201703.00592 [pdf]

The Contribution of One-photon Annihilation at ψ(2S) in e+e- Experiment

Wang Ping; Yuan Chang-Zheng; Mo Xiao-Hu
Subjects: Physics >> Condensed Matter: Structural, Mechanical and Thermal Properties

The continuum one-photon annihilation at ψ(2S) in e+e-􀀀experiment is studied. Such contributions to the measured final state ωπ0 and π+π- at ψ(2S) mass are estimated by phenomenological models. It is found that these contributions must be taken into account in the determination of branching ratios of ψ(2S) →ωπ0 and ψ(2S) → π+π- , as well as other electromagnetic decay modes. The study eaches the conclusion that in order for BES to obtain the correct branching ratios on these decay modes, at least 10pb-1 of data below the ψ(2S) peak is needed.

submitted time 2017-03-26 Hits374Downloads226 Comment 0

2. chinaXiv:201605.01529 [pdf]

A Werner syndrome stem cell model unveils heterochromatin alterations as a driver of human aging

Zhang, Weiqi; Wang, Ping; Zhou, Junzhi; Ren, Ruotong; Xu, Xiuling; Yuan, Tingting; Yang, Jiping; Li, Ying; Guan, Dee; Pan, Huize; Duan, Shunlei; Ding, Zhichao; Chen, Chang; Yang, Fuquan; Liu, Guang-Hui; Li, Jingyi; Liu, Xiaomeng; Tang, Fuchou; Suzuki, Keiichiro; Ocampo, Alejandro
Subjects: Biology >> Biophysics

Werner syndrome (WS) is a premature aging disorder caused by WRN protein deficiency. Here, we report on the generation of a human WS model in human embryonic stem cells (ESCs). Differentiation of WRN-null ESCs to mesenchymal stem cells (MSCs) recapitulates features of premature cellular aging, a global loss of H3K9me3, and changes in heterochromatin architecture. We show that WRN associates with heterochromatin proteins SUV39H1 and HP1 alpha and nuclear lamina-heterochromatin anchoring protein LAP2 beta. Targeted knock-in of catalytically inactive SUV39H1 in wild-type MSCs recapitulates accelerated cellular senescence, resembling WRN-deficient MSCs. Moreover, decrease in WRN and heterochromatin marks are detected in MSCs from older individuals. Our observations uncover a role for WRN in maintaining heterochromatin stability and highlight heterochromatin disorganization as a potential determinant of human aging.

submitted time 2016-05-12 Hits798Downloads490 Comment 0

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