DNA Facilitates the Sorption of Polycyclic Aromatic Hydrocarbons on Montmorillonites

The sorption of polycyclic aromatic hydrocarbons (PAHs) to montmorillonites is largely influenced by their interactions with dissolved organic matter (DOM). However, the role of DOM rather than humic and fulvic acids (e.g., extracellular DNA) in the PAH sorption to soil clays is little known. Here, we demonstrate that extracellular double-stranded salmon testes DNA substantially increased the sorption of phenanthrene and pyrene to Na-, Ca-, and Fe-modified montmorillonites. All PAH sorption isotherms fitted the linear and Freundlich models reasonably well (<i>R</i>² = 0.918–0.999). Distribution coefficients were increased from 0.0458–0.103 and 0.0493–0.141 L/g at 0 mg/L DNA to 0.413–0.589 and 0.385–0.560 L/g at 10 mg/L DNA for phenanthrene and pyrene, respectively. Spectroscopic and computational chemistry analyses confirmed that PAHs were first inserted into DNA by binding with the nucleobases via van der Waals and π–π electron donor–acceptor interactions. Compared to PAHs, the DNA–PAH complex can be more easily sorbed to cation-modified montmorillonites by complexation between DNA phosphate and exchangeable cations in addition to intercalation into clay interlayers. This work highlights the importance of understanding the control on contaminant sorption by many organic compounds that are ubiquitous in soils but not represented by humic and fulvic acids

Search strategy (PubMed).

IntroductionChronic obstructive pulmonary disease (COPD) is a common, irreversible but preventable disease characterized by persistent respiratory symptoms. The mortality rate of COPD is predicted to reach 5.4 million by the year 2060. Despite its heavy burden on healthcare expenditure worldwide, only 15% of cases are medically identified. The potential benefits of facemask-wearing for COPD patients remain a topic of debate.MethodsWe will conduct a systematic review of all randomized trials and non-randomized controlled trials to evaluate the impact of facemasks on COPD patients. Our review will be based on literature obtained through a comprehensive search strategy across multiple electronic databases, including the Cochrane Library, Embase, PubMed, Web of Science, the Chinese Biomedical Database (SinoMed), and China National Knowledge Infrastructure (CNKI), with no restrictions on language or date of publication. Two independent researchers will extract and assess all relevant data using pre-designed data extraction forms. The included studies will be assessed using the Cochrane RoB2 tool and the suggested risk of bias criteria proposed by the Effective Practice and Organization of Care reviews group of the Cochrane collaboration. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We will use Review Manager 5.4 software for statistical analysis.DiscussionIn the context of COVID-19, it is important for COPD patients to wear facemasks. This study aims to conduct a comprehensive and systematic assessment of the impact of facemasks on the physiology and activity of COPD patients.Trial registrationPROSPERO registration numberCRD42022326265.</div

PRISMA-P 2015 checklist.

IntroductionChronic obstructive pulmonary disease (COPD) is a common, irreversible but preventable disease characterized by persistent respiratory symptoms. The mortality rate of COPD is predicted to reach 5.4 million by the year 2060. Despite its heavy burden on healthcare expenditure worldwide, only 15% of cases are medically identified. The potential benefits of facemask-wearing for COPD patients remain a topic of debate.MethodsWe will conduct a systematic review of all randomized trials and non-randomized controlled trials to evaluate the impact of facemasks on COPD patients. Our review will be based on literature obtained through a comprehensive search strategy across multiple electronic databases, including the Cochrane Library, Embase, PubMed, Web of Science, the Chinese Biomedical Database (SinoMed), and China National Knowledge Infrastructure (CNKI), with no restrictions on language or date of publication. Two independent researchers will extract and assess all relevant data using pre-designed data extraction forms. The included studies will be assessed using the Cochrane RoB2 tool and the suggested risk of bias criteria proposed by the Effective Practice and Organization of Care reviews group of the Cochrane collaboration. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We will use Review Manager 5.4 software for statistical analysis.DiscussionIn the context of COVID-19, it is important for COPD patients to wear facemasks. This study aims to conduct a comprehensive and systematic assessment of the impact of facemasks on the physiology and activity of COPD patients.Trial registrationPROSPERO registration numberCRD42022326265.</div