Orbital coupling of hetero-diatomic nickel-iron site for bifunctional electrocatalysis of CO2 reduction and oxygen evolution.

While inheriting the exceptional merits of single atom catalysts, diatomic site catalysts (DASCs) utilize two adjacent atomic metal species for their complementary functionalities and synergistic actions. Herein, a DASC consisting of nickel-iron hetero-diatomic pairs anchored on nitrogen-doped graphene is synthesized. It exhibits extraordinary electrocatalytic activities and stability for both CO2 reduction reaction (CO2RR) and oxygen evolution reaction (OER). Furthermore, the rechargeable Zn-CO2 battery equipped with such bifunctional catalyst shows high Faradaic efficiency and outstanding rechargeability. The in-depth experimental and theoretical analyses reveal the orbital coupling between the catalytic iron center and the adjacent nickel atom, which leads to alteration in orbital energy level, unique electronic states, higher oxidation state of iron, and weakened binding strength to the reaction intermediates, thus boosted CO2RR and OER performance. This work provides critical insights to rational design, working mechanism, and application of hetero-DASCs.

DHA/EPA-Enriched Phosphatidylcholine Suppresses Tumor Growth and Metastasis via Activating Peroxisome Proliferator-Activated Receptor γ in Lewis Lung Cancer Mice.

In the present study, the antitumor effects of docosahexaenoic acid-phosphatidylcholine (DHA-PC) and eicosapentanoic acid-phosphatidylcholine (EPA-PC) in Lewis lung cancer mice were investigated. As observed, DHA-PC and EPA-PC obviously inhibited the transplanted tumor growth and the positive expression of Ki67. The metastatic nodules and hematoxylin and eosin (HE) staining of the lung indicated that DHA-PC and EPA-PC suppressed lung metastasis. PPARγ has a key role in cell survival, which may be a target for cancer therapy. Further mechanism research indicated that DHA-PC and EPA-PC significantly enhanced the levels of PPARγ and subsequently downregulated the NF-κB pathway. DHA-PC and EPA-PC accelerate cancer cell apoptosis by decreasing NF-κB-mediated antiapoptotic factors Bcl-2 and Bcl-XL, thereby inhibiting tumor growth. In addition, DHA-PC and EPA-PC significantly decreased the levels of NF-κB-mediated matrix metallopeptidase 9 (MMP9) and heparanase (HPA), which block the extracellular matrix (ECM) degradation, thereby suppressing lung metastasis. These findings suggested that DHA-PC and EPA-PC could be used as food supplements and/or functional ingredients for cancer patients.