Aim: Sca-1+CD31− cells were shown to be endothelial stem/progenitor cells, found in many mammalian tissues, including heart, were able to differentiate into cardiomyocytes in vitro and in vivo. Our previous work indicated that heart derived Sca-1+CD31− cells increased Nr1d1 mRNA level and decreased cells plasticity with aging. However, little is known about how NR1D1 affects Sca-1+CD31− cells plasticity. Methods: Lentiviral vector was used to stably overexpress Nr1d1 in young Sca-1+CD31− cells and to knockdown Nr1d1 in aged Sca-1+CD31− cells. Cell differentiation, proliferation, apoptosis, and cell cycle were evaluated. Results and Conclusions: The overexpression of Nr1d1 in young Sca-1+CD31− cells inhibited cell proliferation and promoted apoptosis. Knockdown of Nr1d1 in aged Sca-1+CD31− cells promoted cell proliferation and inhib-ited apoptosis. Using mouse cardiac myocytes cell line, confirmed the effect of Nr1d1 and indi-cated that Nr1d1 induce Serpina3 expression via Nr1d1 interaction with Nr4a3. Nr1d1 may there-fore be identified as a potent anti-aging receptor and be a therapeutic target for aging relative diseases.

In this paper, we first report that WO_x contained nanoalloys exhibit stable electrocatalytic performance in alkaline media, though bulk WO₃ are easy to be dissolved in NaOH solutions. Carbon supported oxide-rich Pd-W alloy nanoparticles (PdW/C) with different Pd:W atom ratios were prepared by reduction-oxidation method. Among the catalysts, the oxide-rich Pd0.8W0.2/C (Pd/W = 8:2, atom ratio) exhibits the highest catalytic activity for oxygen reduction reaction. The X-ray photoelectron spectroscopy data shows that ~40% of Pd atoms and ~60% of the W atoms are in their oxides form. The Pd 3d_5/2 peaks in oxide-rich Pd-W nanoalloys are positive shift compared with that of Pd/C, which indicates the electronic structure of Pd is affected by the strong interaction between Pd and W/WO₃. Compare to Pd/C, the onset potential of oxygen reduction reaction at the oxide-rich Pd_0.8W_0.2/C is positive shifted. The current density (mA·mg Pd⁻¹) at the oxide-rich Pd_0.8W_0.2/C is ~1.6 times of that at Pd/C. The oxide-rich Pd_0.8W_0.2/C also exhibits higher catalytic stability than Pd/C, which demonstrate that it is a prospective candidate for the cathode of fuel cells operated with alkaline electrolyte.