Despite the fact that high-valent nickel-based oxides exhibit promising catalytic activity for the urea oxidation reaction (UOR), the fundamental questions concerning the origin of the high performance and the structure-activity correlations remain to be elucidated. Here, we unveil the underlying enhanced mechanism of UOR by employing a series of prepared cation-vacancy controllable LiNiO 2 (LNO) model catalysts. Impressively, the optimized layered LNO-2 exhibits an extremely low overpotential at 10 mA cm À 2 along with excellent stability after the 160 h test. Operando characterisations combined with the theoretical analysis reveal the activated lattice oxygen in layered LiNiO 2 with moderate cation vacancies triggers charge disproportion of the Ni site to form Ni 4 + species, facilitating deprotonation in a lattice oxygen involved catalytic process.

Although the synthesis of single atom catalyst (SAC) has attracted intensive attention for hydrogen evolution reaction (HER), realizing the precise control in the structure of atomic catalysts and the electronic...

Background: Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is a highly vascularized solid tumor. Angiopoietin-2 (ANGPT2) has been described as an attractive target for antiangiogenic therapy. Exosomes are small extracellular vesicles secreted by most cell types and contribute to cell-to-cell communication by delivering functional cargo to recipient cells. The expression of ANGPT2 in tumor-derived exosomes remains unknown. Methods: We detected the ANGPT2 expression in HCC-derived exosomes by immunoblotting, enzyme-linked immunosorbent assay and immunogold labeling, then observed exosomal ANGPT2 internalization and recycling by confocal laser scanning microscopy, co-immunoprecipitation and immunoblotting. We used two HCC cell lines (Hep3B and MHCC97H) to overexpress ANGPT2 by lentivirus infection or knockdown ANGPT2 by the CRISPR/Cas system, then isolated exosomes to coculture with human umbilical vein endothelial cells (HUVECs) and observed the angiogenesis by Matrigel microtubule formation assay, transwell migration assay, wound healing assay, cell counting kit-8 assay, immunoblotting and in vivo tumorigenesis assay. Results: We found that HCC-derived exosomes carried ANGPT2 and delivered it into HUVECs by exosome endocytosis, this delivery led to a notable increase in angiogenesis by a Tie2-independent pathway. Concomitantly, we observed that HCC cell-secreted exosomal ANGPT2 was recycled by recipient HUVECs and might be reused. In addition, the CRISPR-Cas systems to knock down ANGPT2 significantly inhibited the angiogenesis induced by HCC cell-secreted exosomal ANGPT2, and obviously suppressed the epithelial-mesenchymal transition activation in HCC. Conclusions: Taken together, these results reveal a novel pathway of tumor angiogenesis induced by HCC cellsecreted exosomal ANGPT2 that is different from the classic ANGPT2/Tie2 pathway. This way may be a potential therapeutic target for antiangiogenic therapy.

Combining periprostatic nerve block and intraprostatic local anesthesia provided significantly better pain control than periprostatic nerve block alone. The combination may be of maximum benefit in patients with a smaller prostate volume or younger patients.

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Ion modulation aids the one-pot synthesis of core–shell PBA@PBA nanocrystals with tunable shapes, serving as templates for creating intricate PBA nanocages with uncommon configurations.

Rational synthesis of highly dispersed electrocatalyst with excellent electrocatalytic performance is critical for energy and environment applications. However, metal cluster with high surface free energy remains a challenge for the synthesis of stable and highly active catalysts. Herein, a highly dispersed platinum cluster anchored on the Mn vacancy of MnO2 nanosheets (PtAC‐MnO2) via in situ electrochemical methods is reported. The strongly binding energy between Pt clusters and supports can effectively suppress the migration of active Pt atoms and optimize their electronic structure for excellent electrocatalytic properties. Impressively, the PtAC‐MnO2 demonstrates a considerably low overpotential (η100) of 47 mV at 100 mA cm−2 and can be catalyzed continuously at 10 mA cm−2 for 80 h, showing better catalytic stability than the state‐of‐the‐art commercial Pt/C catalysts. A cationic vacancy defect strategy for the design and preparation of metal cluster catalysts is provided.

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