Impaired Blood Neutrophil Function in the Frequent Exacerbator of Chronic Obstructive Pulmonary Disease: A Proof-of-Concept Study.

PURPOSE: The underlying biological mechanisms of the frequent exacerbator phenotype of COPD remain unclear. We compared systemic neutrophil function in COPD patients with or without frequent exacerbations. METHODS: Whole blood from COPD frequent exacerbators (defined as ≥2 moderate-severe exacerbations in the previous 2 years) and non-exacerbators (no exacerbations in the preceding 2 years) was assayed for neutrophil function. Neutrophil function in healthy ex-smoking volunteers was also measured as a control (reference) group. RESULTS: A total of 52 subjects were included in this study: 26 frequent exacerbators, 18 non-exacerbators and 8 healthy controls. COPD frequent exacerbators had blunted blood neutrophil fMLP-stimulated oxidative burst compared to both non-exacerbators (p < 0.01) and healthy controls (p < 0.001). There were no differences between COPD frequent exacerbators and non-exacerbators in blood neutrophil PMA-stimulated oxidative burst, but both COPD groups had reduced responses compared to healthy controls (p < 0.001). Bacterial-stimulated neutrophil degranulation was greater in frequent exacerbators than non-exacerbators (p < 0.05). CONCLUSION: This study is the first to report aberrant receptor-mediated blood neutrophil function in the frequent exacerbator of COPD.

Solar photocatalysts: non-metal (C, N, and S)-doped ZnO synthesized through an industrially sustainable in situ approach for environmental remediation applications.

One of the biggest issues the world is currently experiencing is the scarcity of pure water due to the contamination of pure water by human activities. Highly efficient, semiconducting photocatalytic materials have great potential as future catalytic materials for facilitating the clean-up process of contaminated water. Among the many semiconductor photocatalysts, non-metal-doped zinc oxide (ZnO) nanoparticles have attracted special attention in the scientific field for environmental remediation applications. The present paper reports an easy and viable synthesis of C-, N-, and S-based ZnO semiconductor photocatalysts through a simple heating method. The structural changes in the obtained samples were studied using XRD, TG/DTA, and FT-IR analyses, and morphological examinations were performed using TEM and SEM. The quantification of non-metal dopants was carried out using CNS and XPS analyses. The surface areas of the samples were analyzed using the BET method and the band energies of the samples were measured using UV-vis-diffuse reflectance Kubelka-Munk plots. Photoactivity studies were performed and revealed that the utilized in situ method resulted in the development of high-performance sulphur - (81.4%, k = 1.951 × 10-2 min-1), nitrogen - (78.5%, k = 2.271 × 10-2 min-1), and carbon - (67.2%, k = 1.392 × 10-2 min-1) doped ZnO photocatalysts. As revealed through XPS and UV analyses, a possible electron-transfer mechanism is suggested, wherein electronic transition occurred from different sub-bands when non-metal elements were introduced into the ZnO lattice. The study paves the way for the bulk-scale fabrication of doped nanoparticles through a simple heating method, whereby the unique combination of the present method with bandgap engineering will ultimately produce advanced non-metal-based ZnO photocatalysts that could find useful applications in sustainable industrial sectors.