Free-radical triggered formation of dioxins from 2-chlorophenol pyrolysis investigated by synchrotron radiation photoionization mass spectrometry.

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated naphthalenes (PCNs) are a category of highly toxic and environmentally persistent pollutants released particularly via thermal processes of chlorine-containing materials. However, the detailed reaction mechanism, especially the evolution of related radicals remains elusive for decades. Herein we have for the first time characterized the radicals and intermediates during pyrolysis of 2-chlorophenol resulting in PCDD/Fs and PCNs, using a flow tube reactor coupled with in-situ synchrotron radiation photoionization mass spectrometry (SR-PIMS).

Relationship of programmed death ligand-1 expression with clinicopathological features and prognosis in patients with oral squamous cell carcinoma: A meta-analysis.

Background: Programmed death ligand-1 (PD-L1) expression is related to the prognosis of many solid tumors; however, its prognostic value in oral squamous cell carcinoma (OSCC) remains unclear. Here, a meta-analysis was performed to estimate the association of PD-L1 expression with prognosis and clinicopathological features in patients with OSCC.

Methods: PubMed, Web of Science, EMBASE, Cochrane Library, and CNKI databases were searched to find relevant studies for identification of the association of PD-L1 expression with clinicopathological features and overall survival (OS) in patients with OSCC.