Fe-Based Metal Organic Framework-Derived FeNiP/N-Doped Carbon Heterogeneous Core-Shell Structures for Oxygen Evolution.

It is of great significance to explore high activity, low overpotential, and outstanding durability electrocatalysts without precious metals for oxygen evolution reaction to reduce the energy consumption in the electrolysis of water to product hydrogen. Metal organic frameworks (MOFs) with periodic structure and uniform pore distribution have been widely used as precursors for the synthesis of transition metal electrocatalysts. Herein, we first synthesized nanoscale Fe-soc-MOFs with relatively high specific surface area and in situ converted it into nickel-iron double layer hydroxide/MOF (FeNi LDH/MOF) by Ni2+ etching. Finally, a nickel-iron phosphide/nitrogen-doped carbon cubic nanocage (FeNiP/NC) was obtained by calcination and phosphating. FeNiP/NC with its unique core-shell structure has an overpotential of only 240 mV at a current density of 10 mA/cm2 and can be continuously electrolyzed for 45 h. High catalytic activity of FeNiP/NC is mainly attributed to the action of Fe and Ni bimetals and the synergistic effect between FeNiP and N-doped porous carbon, which was confirmed by the calculation of density functional theory (i.e., Gibbs free energy). After a long period of electrolysis, FeNiP was converted to MOOH (M = Fe and Ni) and became the new active site. This study provides a feasible optimization strategy for the development of high-efficiency three-dimensional electrode materials without precious metals.

Regulation of uric acid and glyoxylate metabolism by UgmR protein in Pseudomonas aeruginosa.

The opportunistic pathogen Pseudomonas aeruginosa has evolved several systems to adapt to complex environments. The GntR family proteins play important roles in the regulation of metabolic processes and bacterial pathogenesis. In this study, we uncovered that the gene clusters of PA1513-PA1518 and PA1498-PA1502 in P. aeruginosa are required for uric acid and glyoxylate metabolism respectively. We also identified a GntR family regulator UgmR that is involved in regulation of uric acid and glyoxylate metabolism. Promoter activity measurement and biochemical assays revealed that the UgmR directly represses the transcriptional activity of PA1513-PA1518 and PA1498-PA1502, and this inhibition was relieved by the addition of uric acid. Importantly, further experiments showed that UgmR also participates in the glyoxylate shunt. Collectively, these findings contribute to a better understanding of the UgmR factor involved in uric acid and glyoxylate metabolism, which provide insights into the complex metabolic pathways in P. aeruginosa.

Prognostic and Clinicopathological Value of PD-L1 in Melanoma: A Meta-Analysis.

BACKGROUND: There is a growing interest in using programmed death ligand-1 (PD-L1) as a prognostic marker for melanoma. We conducted this meta-analysis to explore the prognostic and clinicopathological value of PD-L1 in melanoma. MATERIALS AND METHODS: The electronic databases PubMed, Web of Science and the Cochrane Library were searched for relevant studies. The major investigated parameters were PD-L1 expression levels in relation to patient gender, tumor-infiltrating lymphocytes (TILs), tumor stage, lymph node (LN) metastasis, histological type, progression-free survival (PFS) and overall survival (OS). Odds ratios (ORs) and hazard ratios (HRs) were computed using the fixed-effect or random-effects model according to data heterogeneity. RESULTS: Positive PD-L1 expression was significantly associated with high levels of TILs (OR = 7.56, 95% CI 2.04-28.02), metastatic melanoma (OR = 0.45, 95% CI 0.30-0.67) and LN-positive melanoma (OR = 2.56, 95% CI 1.31-4.99) but not gender or histological type. In addition, the pooled HRs showed no relation between PD-L1 expression and PFS (HR = 1.18, 95% CI 0.83-1.69) or OS (HR = 0.77, 95% CI 0.47-1.25). When restricted to metastatic melanoma, positive PD-L1 expression was significantly related to prolonged OS (HR = 0.57, 95% CI 0.46-0.70). CONCLUSIONS: Positive PD-L1 expression may be an important prognostic factor for longer OS in patients with metastatic melanoma.